Correct cable to make battery-cables from. Why crimping is the correct method. Not solder. (With real world examples) How crimping works.
Tools necessary. How to use them.
Where to source the terminal posts from.
How tight to do battery terminals
Why battery-post terminals are the BEST terminals method. Compared to other shite.
How to find a suitable chassis ground in a relocated battery instance.
Expandable-braid vs DR-25.
Terminal covers and why you should use them.
Why would you even need to make some?
What’s wrong with the oem battery cables? For majority of people absolutely nothing. They work and are on vehicles that have over 300,000miles and continue to work fine from a design stand-point. So what gives? Why fix what’s not broken? Like most things there is no one definitive answer to the question. So let’s briefly discuss it.
Okay, so number one. Just talking battery-terminals with the existing cables. Your terminals are damaged/broken and you are left with a defective part. Visually strands of wire are hanging out the battery-terminal where the conductor is stripped bare and is attached to the battery-terminal. For those unaware, this is a very serious issue and will, not could. Definitely create a servre problem. Such as the remaining strands effectively acting as a smaller gauge wire and not up to the current demand that the oem gauge wire is designed for. So the wire would then becomes a fuse and it would melt and you could have a fire and to top it off you’d be stranded on the side of the road! Absolutely knackered. So you’re looking to put new terminals on the oem cables. Quite a common job for vehicles that are prone for poor battery terminals from the factory. Poor wiring is a common issue on French vehicles, typically older French vehicles. So you’re looking to put new terminals that are a upgrade from the poor oem part.
Onto number two. You’ve got a project vehicle or the vehicles wiring is none existent or has been in a fire. You’re trying to mimic the factory wiring but upgrade the battery cables at the same time. You’re replacing end to cables. So from starter motor to the battery and depending on the vehicles wiring configuration. The wiring from the alternator to the battery or most likely the link between the alternator and the starter motor. Then from the battery to the fusebox. Replacing every leg in the system.
Thirdly, you’ve started a battery relocation and need new cables that never existed before in your vehicle. If you’re looking at doing a battery-relocation on a NC MX-5 or want to see my simple relocation setup. Please check out my NC battery-relocation article found here. In this articles tutorial I will be creating the cables from the new MTA power-distribution box to the positive battery terminal. In addition the necessary ground cable from the chassis to the negative battery terminal.
Okay no we have a reason. What’s the correct materials for success?
So let’s talk about the tools you’ll need for this job. You’ll need a crimper (either hydraulic-operated or manual/hand operated) that will crimp the crimp-lug that’s sized to slide on the end of your cable. A heat-gun, you can get away with using a hair-dryer or blow-troch. Worth mentioning if you’re using a naked flame to recover heatshrink pay attention to keep the heatshrink far away from the tip of the flame and keep moving the heatshrink (the crimped end of the cable) around 360 degrees and up and down. You DO NOT want to focus on one particular spot when recovering heatshrink regardless of the heat source used. But due to the immense heat of a naked-flame from a blow-torch the time and ultimately room for error before you begin to melt the heatshrink and highly likely the cables insulation, is reduced. You’ll need some scissors to cut the heatshrink to the correct length. Some means of cutting the cable end as square as possible. You can use some ratchet-cable shears or hand croppers. Or depending on the size of the cable a junior hacksaw or a regular hacksaw. Worth mentioning a hacksaw will squish the end of the cable considerably more than the alternate methods mentioned.
Why crimp?
You may have heard of crimping when it comes to large battery cables. You might not. You may have heard of soldering battery cables. I’m going to tackle this question head on. Why crimp over soldering or using those horrific set-screw terminals. Soldering repetively while being consistent is a serious skill. Soldering requires more tools and equipment such as lead-solder, rosin-flux, soldering-iron or gun, heatshrink. Where as crimping is a far simpler method of securing crimp-lugs to the end of cables. They are actually used in industrial electrical infrastructure to connect sub-main cables from their respective supply. So it is a common practice for small to large cables.
To carry out a successful crimping operation the user only needs. A crimper either manual or hydraulic, 3:1 glue lined heatshrink and a crimp-lug with the correct size for the cable and diameter hole you have determined you require. That’s it. Meaning with the very basic technique required to perform a successful crimping operation if I completed one end of the cable. You’d be able to complete the other end and it would be to the same standard as the my end. Crimping essentially is performing a cold-weld as you crush the tinned copper tube-terminals (crimp-lugs) to the copper strands of the stranded cable. Crimping is preferred to soldering, as soldering creates a more brittle (hard) connection. Good practice for soldering is usually incorporating a mechanical strain-relief method to take the strain off the solder-joint. Where as with a cold-crimp joint there’s no need. Crimping will allow a more flexible bend radius from the crimp-lug as you don’t have solder (especially if you have used rosin-flux) that has wicked up the strands and made the joint longer. That’s why when soldering is required say in a oem connector, the user will submerge the multiple solder joints in potting compound. This is a specific type of epoxy made for this purpose. Proving the requirement for solder joints to need mechanical strain-relief. Crimping of course is also a cold process and does not require ire safety equipment such as the correct type of fire-extinguisher nearby when soldering (hot works).
Tooling.
I touched upon the tools and parts needed to perform a successful crimp above but less dive deeper.
Let’s start with the crimp-lugs themselves. Often referred to as tinned-copper tube terminals. They come in slightly different designs, they can come flat or as a 90degree, with a bell-mouth or straight cable entry, different size holes to secure the crimp-lug down via the respective bolt. The bell-mouth cable entry is the better style and far easier to slip over the end of your stripped conductor (strands). Don’t be fooled thinking that 90degree crimp-lugs are just bent straight crimp-lugs. They are indeed longer to account for the length loss of the bend. The amount is critical for the crimp-lug to clear say the fusebox or whatever it is fouling against below. You’ll probably never use 90degree crimp-lugs but it’s best to know the difference and that they exist. Some crimp-lugs come with a shorter or longer stepped-down flat section where the hole is drilled and positioned to secure the crimp-lug down. Generally speaking this isn’t going to cause in an incapability issue however it is worth noting.
The heatshrink you need to use is labelled 3:1 shrink ratio. This 3:1 ratio heathsrink has a inner glue lining that melts and forms a water-resistant seal around the cable and the heatshrink. Regular run of the mill heathsrink is not suitable for this use. Remember to size your heatshrink accordingly to the size of crimp-lugs you are going to be using outside cable diameter. You want heatshrink that fits over with no hassle yet is a close size to the recovered size it’s going to be after the heat exposure.
Moving onto the main tool itself. The crimper! There are two different types of crimpers that are commonly used or electrical purpose. That is hydraulic and hand (manual) crimpers. Hydraulic crimpers are more expensive however the dies they take depending on the size the crimper will go up to. Are a wider crimp zone. Eliminating the preference to double-crimp when using a hand operated crimper where the crimping zone is narrower. As seen on my MX5’s cables in this article. That was performed by a hydraulic crimper. Not my own personal hand crimpers. When purchasing a crimper it is absolutely necessary to know the maximum size battery-cable you intend to ever crimp in the future to ensure you have a crimper that is able to successfully perform the operation by having the correct dies and force required. The crimper will come as a complete set with the dies.
General electrical tools are needed too such as scissors or electricians-scissors, stanley-knife, cable-croppers or ratchet-cable-cutters or a junior hacksaw or hacksaw. But be warned about using a hack-saw as mentioned above in regard to the cable end becoming more square which may lead to difficulties fitting into the crimp-lug once stripped to bare conductor. A heat-gun or hair-dryer are the most appropriate sources of heat that reduce the risk of burning the heat-shrink and the cables insulation. However a naked flame such as blow-torch or lighter will do just be so careful not to allow the naked-flame to touch the cable and heatshrink and to work very quickly and keep the cable and/or heat-source moving around fast to avoid melting either the cable or heathsrink.
Tightening down terminals.
Why is this method the better method out there?
For a battery relocation, where do I find a suitable ground?
Let’s dive into the first question. Why upgrade over the stock brakes? How good are the stock brakes? This is a fairly common question in the groups. To answer that short and fast, the answer is for stock or 200bhp cars they are plenty adequate. Let alone with upgraded pads such as Carbotech XP8’s, Roddisons, PBS Pro-Race just to name a handful. Just make sure whatever pads you choose can work from cold if it is your daily or commuting vehicle to the track. However, once we get into engine setups that can produce easily over 200bhp we need to start to consider upgrading the callipers and going to a slightly larger disc. Again mentioning the pads compound needing to work from cold isn’t only for performance and safety concerns but, because a race compound does not have enough heat into the compound will run cold and will eat away at your new discs very quickly. Make sure you do your due diligence when you’re considering different pads.
What choices are there beside standard brakes?
So this then opens the door to the aftermarket scene. What big brake kits (BBK) are there for the NC as of writing this article then? So depending on how you intend to operate the vehicle you have many options. I’ll start with a strongly recommended BBK for most 200-400bhp area cars which is the BBK from Stewart at FreakyParts. He sells a very strongly suggested Brembo BBK that uses his custom calliper brackets to fit Brembo OEM Renault Megane callipers. Many people go this route as the overall cost of this kit is about £1000. Very good value for money. The discs or rotors depending on where you are from in the world are a one-piece design as opposed to a two-piece rotor-hat and rotor-ring design. I’ve heard this kit works well with the standard rear callipers too.
Which in itself is a massive pain to upgrade due to the parking brake feature and doing so at a very low cost is nearly impossible. Some kits come with four-piston rear callipers that also come with a separate calliper for the parking brake. Which in itself begins to overcomplicate the setup. But is necessary on extremely competitive track cars running over 600bhp. Don’t think you need that type of setup on a fast road or light-use track car with the same power as your better upgrading the rear discs and pads. Some even do RX8 oem rear brakes. A far more cost-effective solution.
I’ll move on to my personal choice for my vehicle. The V8Roadsters Wilwood four-piston BBK. This kit includes a two-piece rotor design. This is nice so you only have to replace the rotor-ring instead of the whole disc assembly. This allows V8Roadsters to make the disc assembly extremely light even with the larger 12.19″ rotor option that I chose. This essentially means less un-sprung weight which is great for road or track cars. For those not familiar with the term. It refers to the total weight of every component that is not supported by the vehicle’s suspension system such as the chassis, engine, drivetrain etc. This kit also includes two stainless-steel braided front brake lines. Most kits will include the same. It’s worth mentioning here if you haven’t already swapped out your rear brake lines to braided ones, the pedal feel is more consistent. What I like about this kit is the use of AN4 style fittings instead of the traditional banjo bolt and copper crush-washer affair. The callipers this kit uses are Wilwood Dynapro four universal callipers. Hence the four brake-bleed nipples.
The kit comes with Wilwood BP10 compound pads. Great for use from cold but not a true track/race pad. Meaning if you wish to use this kit for track and commuting your best bet is to carry two different pad sets. For the different operating temperature ranges. As suggested by Dave Moore. This kit including import tax duty cost me about £1500 and works well with the OEM rear brake setup.
Lastly, let’s look at the most overkill option for most of us. Goodwin-Racing NC Monster big-brake superlite kit. This setup is the bee’s knees for those seriously competitive on track. You will never need this kind of setup for street use. But if you’re running around 600bhp and are a dedicated track-build this is exactly what you need. The cost is steep but these are using Wilwood callipers and these would typically be used without ABS and/or a brake-bias valve so the setup can be optimised depending on track conditions etc. This kit is about £5500.
Why I went with my choice
I’ve always wanted a two-piece rotor design since I got into modifying cars. They just look nuts. Just like the over 1000cc injector bragging right lol. So truthfully, that was my main reason. Second was the weight savings over using a two-piece design and the economical point of view of just replacing the pads and rotor-ring. Instead of the hat section of a single-piece design. Thirdly was the ease of access to the replacement parts worldwide. I can get these replacement parts for a fair price pretty quickly. I went with the V8Roadsters kit over the Goodwin-Racing (GWR) kit as many forum members of Miata.net suggested them because the rotor-hat powder-coating is far better than the GWR kit. I can confirm that once fitted the kit looks the nuts. The last reason is this kit is a radially mounted calliper setup. Which is better than an axial setup. The short explanation is, that the positioning of radially mounted callipers allows for more rigidity or less torsional flex (lateral movement) which translates to a firmer and more consistent brake pedal.
What’s involved?
This is not an installation guide but a glimpse of what’s involved. Once you have removed all the OEM parts you should start by fitting the stainless-steel (SS) braided hoses to the hardline union fitting in the inner wheel-arch. Then clean up the OEM carrier bracket bolts up with a brass wire wheel, clean with brake-clean and install. Torque them to 100Nm. I also use a yellow Edding paint pen to mark two lines on the bolt and calliper bracket. So should they move I can visually see and catch the problem before it turns into a fatality. Then assemble the disc assembly. Torque the serrated flange nuts and countersunk bolts to spec using a minimum of a two-step process gradually increasing torque to the final figure mentioned in a star-cross pattern. That is mission-critical. Starting at 18ft-lbs (25Nm) and then final torque at 28ft-lbs (38Nm). I suggest using a paint pen to make a small mark on each nut after you’ve done the final torque value. Then proceed to check them in a ring until you come back to the first one. This will ensure they are 100% the same torque and ultimately the same clamping force.
Then install it on the vehicle using your lug nuts to hold the disc on until the calliper is fixed. This kit does not use the countersunk screws to retain the disc while the wheel is off. Once driven the calliper will hold the disc on when lug nuts are removed. As the lug nuts provide the clamping force for your discs, not the countersunk screws. That’s why it’s important to torque your wheels to spec. Which is 114Nm in a star-cross pattern. Fit the calliper using the supplied spacers and cap bolts and work back and forth until the calliper is snug and no gaps can be found between the calliper and spacer and spacer and bracket. This can be done with a 3/8″ ratchet. Then torque those radially mounted bolts to 50ft-lbs (68Nm). I then paint-pen inside the cap-head.
Install the 1/8NPT male to 90 AN4 steel fitting using your PTFE tape as shown on the Wilwood website. Link here. This is not an installation guide. This is just to show you how easy they are for a competent car guy or girl to install themselves. Follow the Wilwood datasheet for the correct brake line fitting installation. If you have any doubts about bolting the bracket and callipers together speak to a professional mechanic. DO NOT chance it. Your life is worth more than the cost of a mechanic’s guidance or installation fee.
It’s worth noting you will need Teflon (PTFE) tape for the brake-line fittings. That is not included but is extremely cheap and can be found almost anywhere.
Do I recommend these to other owners?
So I was recommended these by Lawrence Lindsey-Dean as that is what his Honda K24 NC runs and I will agree they are worth their cost. I purchased the whole package from V8Roadsters but you can go the cheaper route like Lawrence and just buy the rotor-hats and calliper brackets and nuts/bolts and brake hoses then source the rotor-rings, callipers and brake pads within Europe to save a couple of hundred quid.
Brake pads
I will be using the Wilwood BP10 brake pads for street use and if I need better pads for track I will swap for track-only race pads at the track. I am using the tried and tested Motul RBF660 racing brake fluid. That is recommended for any spirited driving. It’s worth noting if you haven’t already before you bleed the brakes, fit a Hel SS braided clutch hose for a more consistent clutch pedal feel. Since the clutch and brake masters share the same reservoir do it at the same time. Thank me later lol.
Bleeding hydraulic systems on a NC
To bleed the brake and clutch lines on a NC you can use a Gunsons Ezeebleed or Motive Power-bleeder.
Before we start, we need to clarify a few basic facts. Firstly, the stock ECU can run the stock 1.8/2.0 litre MZR/LF engine when the engine is turbocharged or supercharged. In fact, the leading UK tuner BBR has been tuning NC’s while utilizing the stock ecu. They and many others reflash the ecu with software such as VersaTuner or ECUTek. This works quite well as it goes without saying the stock ecu does not have to come out of the vehicle. Reducing work, thus labour costs.
So, if the stock computer can be remapped and BBR have successfully utilised a remapped stock-ecu for their higher-tier turbo and supercharger packages, then why even look further?
A few important reasons to start with. The stock-ecu cannot be tuned on-the-fly. What does this mean? On-the-fly tuning is, as the name may suggest. Changes made almost immediately. A real world example is: a cell’s value in a table. Which could be your base-fuel-map that can easily be modified to another value and a few seconds later the ecu would automatically apply that change. So the engines behaviour would change almost immediately based on the tuners inputs. Speeding up the tuning-process and thus labour-costs. That is particularly important, and we’ll come back to that later in this article.
The next con of utilising the stock-ecu for your engine-management is that even with remapping software you do not have anywhere near the same level of functionality of an aftermarket-ecu. Let’s imagine you want to connect a boost-control-knob to change boost-pressure values on-the-fly. Now, although a remapped stock-ecu can operate a boost-control-solenoid, it has no means of the driver adjusting the pressure setting. This is because of the limited I/O available. Which, on a turbocharged vehicle. It is ultimately a power setting that would be ideal to operate on-the-fly as the driving conditions change. Especially in a competitive car.
The next and relatively simple issue with the stock-ecu is the vehicle does not actually have an oil-pressure-sensor but, alternatively, an oil-pressure-switch that is mechanically designed so that once the engine reaches a pre-determined minimum pressure level, the ecu would shut-down the engine to potentially save the engine’s lifespan. This is foolish for a handful of reasons. So why did Mazda not use a true oil-pressure-sensor instead of an oil-pressure-switch? Simple, cost. So why is it of great value that an aftermarket-ecu knows the engines in-real-time oil-pressure value? Modern ECU’s such as the Haltech Elite series in particular the Elite 1500 has three-stage-engine-protection. We’ll explore this incredibly powerful feature later. But to conclude this point now. If the user-configured engine-oil-pressure falls below the minimum value set, then the Elite 1500 would immediately shut-down the engine regardless of its running-state. So, the minimum engine-oil-pressure is user definable. Most aftermarket-ecu’s all have at least one-stage-engine-protection in today’s market. Haltech just goes further.
These features are merely a handful of reasons why to opt for the Haltech Elite 1500 for your NC build. I haven’t even scratched the ice on its functionality yet. It is truly that powerful.
How much is a basic Haltech system going to cost me?
It is not unheard of for a standalone ecu to cost over £1000 in todays market. As of writing this article. The Elite 1500 costs £1350 just for the unit on its own. The patch-harness, purchased through a gentleman named Chris from RoadsterWireWorks ended up costing me about £500 for the RHD variant. This makes are running total £1850 before we even factor in the necessary Haltech WB1 wideband NTK o2 controller. The wideband o2 controller costs £396 raising our running-total to £2246. As you will be able to quickly learn. This serious kit costs serious money. Whether its worth the investment, is what this article is aimed to help you make an informed decision. It is worth noting I also have purchased Haltech’s 2×4 CAN keypad and 52mm CAN gauge. These are purely optional and not necessary for installation. Raising my total figure to £2630. If it isn’t obvious yet, I believe in Haltech. So much so to me, the price is justified given the world of features and functionality I have at my fingertips.
I should mention a few disclaimers at this point. I am in no way or shape sponsored by Haltech or RoadsterWireWorks. I have purchased my products just as any of you would, with your hard-earned cash. The products speak for themselves and that’s why I stand behind them as being the best on the planet.
More on RoadsterWireWorks later.
Tell me more about these features
Above all, my personal favourite is the self-learning feature. This feature as the name might suggest uses information the ecu already knows to make corrections and overall create a more responsive and driver friendly engine. Quickly how does it work? Well you remember the WB1 wideband NTK controller I spoke about above? The A/FR from the wideband o2 sensor is sent to the ecu via CANBUS and the ecu can then compare with the target A/FR and if they are different a immediate correction is made. This is the “Short-term fuel-trim”. The “Long-term fuel-trim” takes those corrections in the short-term fuel-trim table and applies them into the long-term fuel-trim table. This is the basic explanation of how the system works. Essentially its just o2 control.
Moving on to my penultimate favourite. The three-stage engine-protection. If you’re a quick learning you’d be correct to think this feature has three stages. But what are the stages? Think of the stages as different levels of a problem. Let’s think about your engine-oil-pressure falling below 15psi. Not good. The third-stage of the three-stage engine-protection would be configured in most instances to immediately shut-down the engine without any interaction from the driver. Potentially saving and preventing expensive engine damage. The first stage could be used let’s say if the A/FR goes a little too lean. The feature could be configured so that during this condition a warning-light on the dash is illuminated and the A/FR is richend by 20% during the time this state is active. This would in turn allow the driver to safely back out of it and then pull over or speak to crew-members and resolve the problem. The second stage you could think of being somewhere in the middle of our examples. Let’s say your at full-tilt. Your engine-oil-pressure drops below 50psi, the second-stage could impose a new rev-limiter to 3,000rpm and illuminate a check-engine light on the dash. While also storing the fault as an error code. Meaning the driver or tuner would have to clear the code to clear the new condition. Thus they could find potential engine damage, that if this feature were not implemented could of cost a lot more in parts and labour to fix.
The stock ecu is limited by its pre-determined inputs and outputs (I/O). While the Elite 1500 may be limited by the amount of wires the physical ecu itself can handle. You have a lot more spare-ways especially with the RoadsterWireWorks patch-harness using the 12-pin auxiliary Deutsch connector. But if your like me and have added a fuel-pressure-sensor, oil-pressure and temperature (combi) sensor and a 3-port MAC valve for boost control duties. Then guess what? You can still add more I/O. With the CAN I/O expander boxes. You can add two CAN I/O expander boxes (A and B) dramatically increasing your available I/O. Leading to endless opportunities for collecting and acting on data from the vehicle.
Speaking of CANBUS. With the RoadsterWireWorks patch-loom the Mazda CAN network is utilised. This means your stock dash-cluster will function as it did before. But just as important the Elite 1500 can communicate with the stock MX5 ABS unit via CANBUS to transmit the individual wheel-speed-sensor data just as it interfaced with the stock-ecu. This frees up I/O since it uses the stock CAN network through the main ecu connectors. Allowing you to setup traction-control and cruise-control. Neat right?
You may have recalled from earlier. I have a Haltech 2×4 CAN keypad and 52mm CAN gauge installed within my personal vehicle as well. This utilises the secondary CAN-port under the waterproof dust cover. Which means I can have two CANBUS networks running simultaneously. Thus, I can transmit operations from the CAN keypad to the ecu for instance for boost control. I can control the boost-level on-the-fly without a need for a laptop and the NSP software. Great. But I can also view the engine instrumentation via the CAN gauge as well. So I can monitor critical values such as engine-oil-pressure and temperature. Absolute manifold pressure and AF/R. If I want to show more I have multiple pages I can change to to display different information. This allows far superior control and monitoring the engine meaning your engine will be safe and have the ensured longevity.
Last feature I’d like to touch upon is “Traction control”. I know a lot of you are probably sighing or confused to why you’d want traction-control. Well it’s as simple as if you at a loss of traction (fun for drifting) then your no longer accelerating. Awful for competitive vehicles. So with the NSP software you can configure a traction-control strategy using the data from the MX5 ABS-module. You can allow a percentage of slip before the system acts. Basically without getting too specific can be setup to aid the driver and not hinder their driving-abilities.
I’d like to briefly mention that their are many ways to wire in a Elite 1500 ecu. From a custom-harness, to modification of a pre-terminated engine-harness from Haltech themselves. But these cost a drastic amount more and if the stock wiring is in good condition no reason to not utilise parts of it. Remove the redundant wiring or leave as is. Your wish. Everything’s sounded pretty good so far right? What’s the catch? So two catches. The stock MX5 alternator is required to be disassembled and converted to a self-regulating alternator with the included new regulator/rectifier-brush-module that Chris supplies in his patch-harness kit amongst with a wiring-diagram etc. This process is actually straightforward and apart from carefully splitting the cases on an older alternator it’s a walk in the part and I recommend you do it the job within a day to not loose track of how it is assembled.
#UPDATE 23/02/2023: I will now mention that Chris offers two variants of his patch-harness. One that doesn’t require the need to change the alternator to a self-regulating unit. He actually now suggests using this variant. However the option is still there.
However if you do forget where a component went I’ll be sure to help if you reach out via email or social-media. The last catch of course as I’m sure you’ve seen this coming is you will need to drill a 2″ hole through your firewall and install the ecu behind the glovebox. More on that process and how I’ve achieved that now.
The install
Let’s start by talking about the first job you’ll find yourself doing. Drilling through the firewall. Which even for me at first was very daunting. However since I’ve now done the job myself I am very happy to guide you through this process from start to finish. So again my NC is RHD. Meaning I have the LHD clutch-master-cylinder flat stamped section over on my passenger side of the firewall. This is the perfect spot to drill and install the 2″ already slid over the loom Haltech grommet. Here’s the critical information. The Haltech grommet fits perfect if your smack centre of stamped section. You’ll be able to see what I mean in the photos below. Now if your thinking ahead you may be thinking shoot, there might be factory wiring running behind there right?? To your response no. Actually if you drill straight through and stop as soon as you punch through with your hole-saw then you will not contact or come close to touching any of the wiring behind that void. Now I’d suggest you use a spring-loaded-centre-punch to guide your pilot drill-bit prior to using the hole-saw. Getting the hole-saw in there is not an easy task. You may have to slightly angle the hole-saw to get it to start. Please take your time and do your best. Once you’ve drilled through successfully I suggest before you cut open your fingers from the burs around the hole. Use a deburring-tool or needle-file to clear both sides of the hole where the burs are. Once it’s safe to gain access you need to pick and pull apart the sound-deadening material away from the hole. Remove as much as you can so the other side of the hole behind the dash hasn’t got anywhere as near much sound-deadening material touching the hole’s perimeter. This is because once you’ve pick and pulled the material out of the way by means of fingers and/or needle-nose-pliers you’ll need to finish the hole with a round needle-file and once done you shouldn’t be able to feel any burs or sharp-edges around the perimeter on both sides. Great. Now using either a touch-up primer-pencil the kind used for car-bodywork repairs or using some primer sprayed into the cap and a small sponge you’ll want to be sure to cover all bare metal with the primer to ensure you never have rust issues in the future. It’s preferred to have some overlap onto your original paint either side just a bit though nothing crazy. The grommet has a thick-lip and will cover the primer and the interior finish around the hole isn’t that critical because you will never see it. But you don’t want rust forming so do a good job and take your time.
Now I may be hearing, well what about us LHD NC owners? Where do we drill through? Fortunately I have photos from a gentleman who’s recently done his. You’ll be drilling through to the left area of where your factory A/C and coolant lines go through the firewall. It is a flat section as shown in the photos below. You will have to carry out the exact same procedures as mention above but in that location instead.
@Corey.nc on Instagram’s car
Corey’s firewall hole drilled
Corey’s ecu connections w/ TDR ecu bracket
Corey’s TDR bracket
Corey’s harness routing path
Corey’s loom inside the car
Right, so we’ve drilled out hole and the primer has had about 15-20 minutes to dry. We’ll route the two Haltech ecu connectors through very very carefully. Then we’ll get the length we think we’ll need as we route it down the back of the blower-motor assembly and under-neath the passenger footwell to the outside of the vehicle. Then we can turn up and eventually zip-tie onto the factory-wiring behind the glovebox. Now we can carefully push fit the grommet into place and don’t worry we can move the harness back and forth as we need to later.
We now need to fabricate ourselves an ECU mount and cut the back portion of the glovebox out so that it may still contain the basic safety equipment like a high-visibility-vest, insurance documents, pen and paper etc but will allow the ecu and glovebox to clear each other and the glovebox door shut properly. Here comes the next catch. We do have to remove the passenger-side dash-airbag. To create enough room to fit the ecu and in my instance the CAN hub above the ecu. My bracket for the ecu picks up the two airbag M6 mounting-studs on the dash-frame-structure. It is made from 2mm thick aluminium as is plenty rigid while being lightweight and I have secured the ecu four corners via four M5 stainless-steel rivnuts into the bracket and the ecu is installed onto the bracket prior to installation into the vehicle. I used medium-strength loctite to reduce the likelihood of the ecu vibrating itself free. The CAN hub is just mounted to a flat piece of 2mm thick aluminium which is cut to follow the shape of the original airbag rear plastic. It actually picks up the factory two screws in either corner. The flat bracket actually overhangs down slightly onto the top of the ecu and that void allows two M5 stainless-steel rivnuts again for securing the CAN hub to the bracket itself and once again I used medium-strength threadlocker.
But what about the WB1 wideband NTK controller? Where does that go? In my instance since the exhaust manifold is on the drivers side since my car is again RHD. I have actually installed it onto the transmission tunnel sitting directly under where the plastic-coin-holder trim rests. Giving me plenty of length to drill a hole into the transmission tunnel to reach my exhaust where the NTK o2 sensor will be fitted. However, if your a LHD owner. Then you can also fit the Haltech wideband NTK O2 sensor controller somewhere local behind the glovebox area.
Now we have the ecu and wideband controller installed. We need to speak about the wiring and don’t worry I’ve made it super simple for you to copy my setup.
My NC’s basic wiring alternations
Before we dive head first into my modifications in my personal NC. I’d like to mention that you do not have to follow exactly what I’ve done. That said. I believe 100% that my setup is the best design and I’ve reworked it four times over the years to get to this stage where I’m satisfied.
That said. Let’s dive in. The first big and hilariously easy job I’ve done was a battery-relocation. Why? Because there is little to no room under the bonnet in the NC. So freeing up space and creating better airflow are the prime reasons. However it makes maintenance and work far quicker such as installing a new serpentine-belt. It is also changing the weight distribution of the car some. In my case with the turbo this should work to attempt to counter-balance the vehicle. Now we know why, we need to understand what I’ve done and briefly why everything is as it is. I’d highly suggest you check out my battery-relocation article then once you’ve got you head in the game come back here for more info.
Now you’ve seen what I’ve done and why. We need to explain my hidden little third-fusebox. This little guy sits directly above the second (interior) fusebox. It is only live when the ignition is on. It has six ways (available circuits). If we look below you’ll find a diagram that shows the setup. First we start at the power-distribution-box mentioned in the previous battery-relocation article. Then we go through one of the 30amp Midi fuses and through some 6mm2/10AWG wire that runs through the vehicle following the battery-relocation main power-wire route. But as we get just past the factory interior fusebox we turn up and find ourselves connection to pin-30 on a 40amp normally-open four-pin diode-protected relay. Ground is spoken for by connecting to the chassis and pin-86. In my instance from the back of the seat-warming circuit (that I have entirely removed) I use a heatshrink-lined through-connector and some 1.5mm (same as the original circuit) and find ourselves going to pin-85 completing the coil-side of the relay. Now this could be completed by using the correct-size fuse-tap instead if you wish to retain all your factory interior circuits. Then from pin-87 (the output) we go through a short fly-lead of 6mm2/10AWG to the common-terminal on the BlueSea-Systems 6-way fusebox. This is the variant without the common ground connections. That’s not necessary. Then from the new third fusebox we have a four circuits to date. Nearly all of which use a Deutsch DT 2pin connector a couple of inches from the fusebox to their opposed Deutsch connector that then run off into the field so to speak. The first circuit is the dashcam its a 5amp fuse. The second circuit is the interior-lighting-circuit which is a 3amp fuse. The third circuit is a spare circuit that is connected but not currently used intended for future use. The forth circuit is the power supply to the Haltech wideband o2 controller. This is because the single-channel wideband o2 controller can draw up to a maximum of 3amps during start-up as the sensor is in the heating-phase. As soon as you start the engine. Which means it cannot use the power from the front CANBUS connector under the dust-cover of the ecu for its power demands. Because the CAN keypad is also interlinked with the wideband 02 controller this circuit also powers that but the load of the CAN keypad is minuscule so no trouble there.
Now the main reason I haven’t decided to do a sperate article for the third-fusebox is I’ve added far too many devices to continue to use fuse-taps. More than one fuse-tap in a fusebox of that many ways looks amateur. Not to mention your leaching power from other circuits and its not a good idea. Now I mention the use of a fuse-tap for the power to the coil-side of the 40amp relay. Why am I okay with this? Because the coil of a modern 12/24V relay uses approximately 200mA or 0.2amp. Which is nothing and will not be enough to effect any circuits you have available.
Important checks before start-up
Before you attempt to start the engine you must certainly check out my “Haltech first start-up procedure” article. Failure to do so may result in catastrophic engine damage. Save yourself a head-ache and check it out. The article will be more laptop based.
RoadsterWireWorks
Before we start to conclude this article I need to mention some information about Chris from RoadsterWireWorks. Firstly, the cost of your harness may differ between LHD and RHD variants. This is because LHD owners will have a longer path to take to end up at the factory two ecu connectors. Secondly, is if you’ve made the decision after all you’ve read then you can contact Chris at roadsterwireworks@gmail.com to place an order. To save both you and Chris time. He’ll need to know if you have A/C, if your RHD or LHD and you’ll need to mention if you’ll want to convert your alternator to a self-regulating alternator or use his newer patch-harness that does not require you to touch the alternator. As mentioned above under the “Tell me more about these features” heading and penultimate paragraph, update. If you have any questions about your order Chris is a very helpful guy and believe me you can ask him questions that you may think sound silly. He always comes back to clarify for you and his after-purchase-care is top-notch.
Learn a little about VE-tuning
Now I’ve covered everything necessary for you to install a Haltech Elite 1500 and Wideband NTK o2 controller in your own vehicle. I feel it is my duty to provide you the resources straight from Haltech and other valuable sources on how we tune in VE (Volumetric-Efficiency) as you’ll learn it’s actually relatively simple. The ecu does most of the leg-work. Below our some videos I strongly suggest you watch and if you have any questions search the Haltech forum or web to truly understand what’s going on.
The end
If this article has been helpful to you do me a massive favour and share it with your NC pals. That would be extremely helpful to share the knowledge and make the NC platform more common-knowledge. If I have missed something you think is absolutely necessary to mention in this article please reply down below and I’ll consider adding anything I’ve missed that may be of use. If you’ve come this far then thank you. You are the reason this site works by sharing the knowledge.
So, prior to offering the turbo and manifold combination onto the engine. It is comprised of a new Garrett T25 GT2871R 0.64 A/R bolted to a Kraken cast-iron top-mount manifold. I have purchased a Turbosmart IWG75 to use in conjunction with a three-port MAC valve (Part No: 35-AAA-DDBA-1BA). The IWG75 came with a GT2871R specific bracket. Unfortunately, due to the location of the stock braking-system, the ABS hardlines from the ABS-module on the 45-degree section would foul in either position where the supplied rod and clevis could reach the welded wastegate-door-arm. Please see photos later that show the fouling issue.
I ended up settling on using the supplied bracket with the new actuator. Rather than retain the factory Garrett bracket. However, I raised the bracket up one bolthole clockwise. In turn, this rotates the turbine-housing-clamps. This created two new problems. The first issue was that the stainless-steel rod from the actuator was no longer facing straight towards the clevis-attachment-pin. This was a minor issue. The second issue is that the factory Garrett 50mm clevis would come up short.
IMAGE SLIDESHOW HERE OF HITTING BRAKE LINES
So how did I solve those two issues?
I had to bend the stainless rod out more to widen the angle. I did so by completely disassembling the actuator-body. I didn’t have the correct type C-spanner, so instead, I ended up using a cleaner rag and vice-grips to carefully loosen the outer ring. It worked a treat. I then held down the top-hat of the actuator-body while completely removing the outer-ring-clamp. Slowly releasing the compressed parts carefully. Prior to completing the disassembly, I removed the factory Garrett 50mm clevis and 1/4” UNF nut from the rod-arm. To continue further with the disassembly, I went into the garage to use the vice. I held the rod in the vice to make sure to lock both bends in the jaws on their sides. This way, as I removed the piston and spring assembly, the rod would not move. I removed the piston and spring assembly by putting a spanner through the spring windings and picking up the square flats at the base of the piston. With a little bit of elbow-grease, I freed the piston. Then disassembly was the same as removal of all the other compressed parts before. I set the spring and piston assembly aside and made note of the colour-markings on the spring for future reference. This confirmed my suspicion, it was a 7psi spring. If you’re unfamiliar with aftermarket actuators, the main reason I chose this unit is so I can increase the base-boost-pressure value. The factory Garrett unit is non-serviceable, so there is a fixed rate spring. I removed the rod-arm from the vice. I traced its profile on a piece of cardboard. I then drew the increased angle I needed from the original point after the bend. So, I had a target to aim for. I placed the rod back in the vice again but threaded-on the 1/4″ UNF nut and clevis in order to gain more leverage. Using a mapp-gas torch, I pre-heated the bend until it was hot, but not glowing hot once I removed the heat. I found by using a large spanner, I could apply more leverage without having to directly touch the part. This allowed me to carry out the bending action to the desired increased angle on my cardboard template. This process was trial and error, fine tweaking the bend. Finally, achieving the desired angle. Then I reassembled the entire wastegate-actuator-assembly back together and onto the turbo for a trial fit. I had achieved the angle I needed in situ and would pick up the wastegate-door-arm straight and while I waited for my new longer clevis to arrive, I disassembled the whole thing again. This time, applying some red 242 loctite on the end of the male thread that went into the pistons base thread. Offering the rod and piston and spring assembly back into the vice and tightened it using a spanner and getting onto the flats. Once this was done, I reassembled the entire assembly and installed it onto the turbo and waited for the longer clevis to show up.way,
I knew I needed a much longer clevis. Fortunately, Turbosmart sells longer clevises. I ended up buying it through Tegiwa-Imports here in the United Kingdom. The part number I ordered was “TS-0600-3004”. This clevis has a 6.3mm I.D. hole for the wastegate-door-arm. The thread is 1/4″ UNF and the length was 80mm long. I ended up cutting that down to 67mm long (back-of-thread to centre-of-hole). The original Garrett clevis was 53mm long (back-of-thread to centre-of-hole). As shown in the photo below.
To shorten the length of the originally 80mm long clevis, I preceded to use a ring of tape. To get as square and straight of a cut as I could with the tools I had on hand. I put the clevis in the vice and cut it with a regular hacksaw and 34TPI blade. I then began to file up the circumference with one of my Bahco needle files. It cleaned up well. The only negative is that shortening the clevis this way means I have lost the 2mm countersunk clearance hole. Meaning it makes starting the thread harder and, without more attention, you could easily cross-thread onto the rods male thread. I trial fitted the clevis and found out it was too long. So, I ended up extending the thread down the clevis as it was only partially-threaded as it was originally a longer clevis and I had chopped some of the threaded section off. I did this with two taps from my favourite place for taps and dies in the UK. TracyTools. They are not a sponsor but are my go-to source for taps and dies. The two taps of 1/4” UNF thread I ordered were a HSS plug and HSS taper tap. The tap wrench you’ll need to use these taps is a 5/32” – 1/2″ tap-wrench. I started using the taper-tap and cutting-grease, while turning to threads clockwise. Then two threads counter clockwise to clear the tap from chips. I did this procedure twice before removing the tap completely and clearing the chips off of the tap itself and clearing the blind-thread base from all the chips that had fallen down. Then I started the whole process again. I repeated this whole process about three times until the tap had bottomed-out. Then I swapped over the taper-tap to the plug-tap and repeated. After the thread was extended, I used a pick and some water to rinse all the chips out of the female thread. This took about ten attempts till the threads were free of stainless chips. I trial fitted the turbo and found I was about 2-3mm too long still. So the logical procedure was to remove about 2-3 threads off of the rod-arm threaded-section so I still had as much thread engagement as possible. This was because I needed my 3mm pre-load as Turbosmart suggested with the IWG75 instructions. Trial fitted again and it worked perfectly. With about 3-4 threads left on the rods threaded section after the nut.
Awesome. It finally worked out. I then, later the next day, trial fitted on the car since the relocation of the wastegate-actuator, and it fit a treat. I have about 5-6mm of clearance from the ABS lines as they were from the factory. If I ever have any contact with the engine moving on the engine-mounts in the future, I can tweak the lines in situ by a minute amount to give me even more clearance. In the future, I wish to change to harder engine-mounts anyway, so that should eliminate most of the engine twisting under load then releasing back like a spring to its original position.
So lets clarify from a strategic point of view. What components need vacuum-reference to operate in total. First the fuel setup has changed. To an aftermarket fuel-rail by Radium Engineering. This fuel-rail has Radium Engineering’s fuel-pressure-regulator and fuel-pulse-damper mounted directly to the fuel-rail. Both of which need vacuum-reference to operate. Let’s focus on the FPR (fuel-pressure-regulator). The FPR is a “rising-rate” regulator.
To do this we need to clarify some common terms relating to the fuel rail setup.
“Base fuel pressure” – This is is set when the FPR’s vacuum-port is open to atmospheric-pressure. During initial first start-up. Typically this is set at 43.5PSI but can vary from vehicle to vehicle.
“Rising rate” This term is used to describe a common type of FPR. The regulator has a vacuum-port. This is so as the vacuum-source-of-origin increases pressure from negative-pressure (vacuum) to positive-pressure (boost) the FPR can compensate by that value. So to conclude if the base-fuel-pressure is set at 43.5PSI and your intake-manifold has 10psi of boost-pressure then the fuel-pressure increases from 43.5PSI to 53.5PSI under boost conditions.
This is why the FPR needs to be connected to vacuum-reference. I should clarify when we use the term “vacuum” when speaking about engines. This can mean the hose, fitting, part etc can be under vacuum and also under certain conditions be under boost-pressure. So the term vacuum with engines is a sort of loose term as it also refers to boost-pressure. The fuel-pulse-damper (FPD) is used in fuel injection systems to absorb pressure pulsations generated by the fuel-pump operating and by the injectors opening/closing. In our case the vacuum-port needs to be hooked up preferably to the same vacuum-line as the FPR. So a Y-fitting is installed above the fuel-rail to link the FPR and FPR to one common line.
Before we jump ahead we must first understand how we get vacuum-reference to all our components under the bonnet. We do this with a vacuum manifold. It would be worth noting my vehicle is RHD so placement of the vacuum manifold may need to be altered if your using on a LHD vehicle. So lets start at the vacuum chain. First we originate from the intake-manifold, then using the original brake-booster plastic barb we take a short stab of reinforced airbrake hose to a plastic tee. Continuing through the tee we take another stab and connect to the BOFI Racing branded vacuum-manifold via a 90degree 12mm barb to AN6 female fitting, then attached to a AN6 to M20x1.5mm straight fitting with an O-ring. These generic style manifolds can be picked up cheap and they are ideal. However do not listen to the seller about specifications, the large end ports are not 1/2″NPT. They are once again, M20x1.5mm straight-thread and you’ll need a 20mm I.D. 2mm C.S. O-ring to create the proper seal into the aluminium manifolds chamfer. The smaller nipples are 1/8″NPT. You’ll need to use something like Permatex high-temperature thread-sealant to create the seal. Do not use PTFE-tape. Thread-sealant today is preferred. Working away from tee-fitting we take another short stab of hose to connect to the original 3/8″ brake-booster hardline.
So, I’ve been wanting a high quality, stable phone mount in my NC1 for a while now. Until then I’ve been placing my iPhone 12 in my I.L. Motorsport centre storage compartment (cupholder delete). This was fine for about three years. But now I’ve been keen on using my Draggy and other vehicle statistic apps to benchmark my times.
The details.
What is my setup then? Well, it’s relatively straightforward. I am using a Brodit P-clip that attaches to the NC1 passenger side (RHD, so left triangle panel by the radio) piece. It simply clips over and attaches strong. Very snug fit. Especially with Stuart’s (COO Creations) Alcantara wrapped triangles. Then it attaches to a RAM 1″ ball base mount. Part number: “RAM Mounts RAM-B-347U”. Due to the position on the Brodit mount I only use the three out of four M5 holes. For hardware I use these chemically coated black stainless hardware from “jac.bolts” on eBay. I use their black stainless (M5 x 20mm) button-head allen bolts, their black stainless M5 nylocks and finally their black stainless (M5 I.D. x 10mm O.D.) flat penny washers on front and back. Why did I use this black stainless stuff? I’ve seen it lurking about on eBay for a while now. Liked the idea of black nuts, bolts and washers on the interior and the added fact their stainless if the coating does get nicked would be very unlikely to rust. After all its “stain-less” not “stain-proof”. So was a good excuse to use fancy hardware.
Sideshot
From that 1″ RAM mount ball I use the shortest RAM female to female straight arm you can get. I believe it’s approximately 2.5″ total length including both ball joints. Part number: “RAM Mounts RAM-B-201U-A”. From the end of that I use the ever so popular RAM X-grip phone mount. This mount applies plenty of spring pressure to retain your phone even in some bumpy and vibration prone environments. In RAM’s example superbikes! Part number: “RAM Mounts Ram-Hol-UN10BU”.
Front shot
This setup even works well with me seeing my phone with very little amount being blocked by my G-Racing short-shifter from my seating position. I have a Pioneer SPH250DAB Apple Carplay radio that I use in conjunction with this phone. So, I have a 0.8Metre USB type-a to lightning connector Anker cable that I run under the radio-surround just under the climate controls.
My view
But that is my phone mount. Short and simple little article about my setup. If you’re looking to get a Brodit mount, don’t make the same mistake as my mate Stuart by purchasing the NC1 version if you have the later NC2/NC3 style radio-surrounds. They are totally different mounts, due to the Mazda interior changes. Hope this has been helpful to some.
For those that have been following me on the socials you’d probably know all I’ve had with these lights is trouble. For those that are unaware or newcomers and have come to my website interested in these lights. Welcome. This article will be a hybrid of a review and solution to how I and many other CarbonMiata customers went about installing these from start to finish and the drama along the way. Hopefully once you’ve read this article you’ll be able to make an informed decision if these are worth your time.
First impressions out of the box.
Upon receiving them and opening the box up, they appeared to be in good condition. Before I purchased these, I heard a lot of bad and mixed reviews in both the MX-5 Europe and NC Miata Facebook groups. So, I had a little insight prior to purchase. So, what did I notice? Well, the lights came as complete units with the LED round assemblies installed into their respective side fiberglass housings. Problem is the hole that had been drilled centre between the two M6 studs that are integral to the LED assemblies was too small. Because of this the slight misalignment of the LED assemblies meant the installer had slightly pinched the cables that came out the back of these LED assemblies. Not ideal at all.
The next critical issue I quickly identified was the fixing method for these lights. They come with one M6 gutter-bolt that is cured with resin inside a tab that replaces a factory locating pin. (You must remove that white plastic seal to install these). I was very confused at first as I was not sure how the Mazda brake lights were attached at the time. But I was worried. I thought surely these lights were made specifically for a Mk3/NC MX-5 so they’d provide a proper mounting solution to secure these to the vehicle. No. They don’t.
The final critical issue I came across was the damn right amateur wiring. The harnesses that adapt your Mazda light holder connectors to the new CarbonMiata was a twist and tape connection. No crimping, not even any soldering. Just twist and tape. That was it. They came taped up in this horrendous 3M electrical tap. I was even more shocked when I found this out and was flabbergasted considering the cost of these were $365 excluding taxes and shipping to my country. I paid a lot of money for what these are for them to complete the terminations by twist and tape. I was shocked quite frankly…
If you think that was where the wiring issues ended boy, you are dead wrong. To fully disassemble the respective side brake lights, I had to undo all the installers wiring to be able to easily separate the two LED assemblies (per respective side) so that the housings could be given to my body and paint gentleman to do his work. It would be impossible to do a thorough paint job on these housings with the LED assemblies remaining installed. Since they are such a snug fit. Again, not ideal.
More details…
Now for the technical details. I will keep this straight to the point.
The brake light housings unlike the Mazda brake lights do not come with a foam gasket that seals up to the stamped-out section in your boot where your factory lamp connections are. In fact, they don’t provide absolutely any seal whatsoever. You can see the lack of detail and thought being a common occurrence, can’t you? They do not recess back like the Mazda ones do which of course leads to the boot compartment not having the same sealing as it did out of the factory. Which leads to moisture issues and could potentially lead to water ingress. A serious problem!
OEM Mazda NC1 boot seals
As mentioned earlier these brake light housings only come with the one M6 stud fixing. You absolutely cannot just secure these using that one fixing. They’d never sit back snug without a second fixing point. So not only for $365 they come with a twist and tape wiring method. But they also come with half the fixings included needed to install these. Nice job CarbonMiata. It’s bad enough that you’ll have to rewire these to begin with due to poor foresight. But you’ll also have to fabricate yourself a fixing bracket. One that should come with the light integral or be supplied with the pair of brake lights from CarbonMiata themselves as a separate item. You will be amused when you see what sort of bracket is required to fix the poor design of these later. But the cost for the material of these brackets is minuscule.
Another users CM brake lights with essentially same bracket I had to make.Note no foam seal or any seal at all…
Wiring.
As mentioned at the start of the article. The twist and tape termination method took me about an hour for a semi-professional like myself to carefully unwrap and unpick the awful wiring. While creating a rough wiring diagram to transpose the lamp connectors to the LED assembly tails. Not forgetting the included 50Watt resistor. If you’re someone who indulges into vehicle wiring or any 12V/24VDC system, you’ll be confused when you see the wiring colour choices for wire designation. For those unfamiliar, solid red is usually 12VDC while black is GROUND. Then you use other colours for different switch-lines. However, on these they have used blue as your GROUND path. Which makes for an annoyance when the harness is nearly complete and either sleeved up, heat shrunk or fleece tapped up and your confirming final terminations for correct pinout.
After I had fully dissembled and created myself a wiring diagram to understand how they were intended to be connected for correct light operation. I realised it would be ideal given the current draw of these lights compared to the Mazda incandescent lamps, to provide each LED assembly with only one ground. This is fine and how each LED assembly was designed to be connected. After I had decided the correct way to terminate these. I went and purchased the best connectors you can readily buy to make these a modular setup. I am of course talking about the awesome Deutsch connectors. Specifically, the DT series. This would mean I could create each respective sides (Left and Right) brake light harnesses on the bench. While importantly being able to swiftly de-pin and re-pin the tails from the LED assemblies to make install after they came back from paint a walk in the park. I will mention now, I did use a round-file to open the centre hole for the cables by about 5mm to avoid that misalignment pinching issue. Where it left an impression on the cable. No issue anymore.
I wanted a one plug connection method to remove the light from the body-side wiring. I opted for a Deutsch DT 8pin connector kit (Male and female with corresponding pins to crimp). These 8pin DT kits came to approximately £10 each. I of course needed 2 kits (2 male, 2 female) for both sides. Why 8pin not say 6pin? At the time I wasn’t 100% sure on some final details. I ended up simplifying the wiring further and needed less ways. So as someone who wishes to mimic my setup. You’ll be perfectly fine 6pin DT connector kits.
It goes without saying, I have cut the lamp holder connector ends off and have put them all in the Deutsch DT 8pin connector. Minus (spoiler alert) the right brake light fog light connections. These were put into a separate Deutsch DT 2pin connector. More on the rear fog light later.
The harness section itself is wrapped up in tessa fleece tape. This product is designed for interior use and works very well. I have used regular tessa auto electrical tape to bunch the wires together underneath the fleece tape. While also using it to tape the section where the silver heat sleeve is installed underneath two complete windings. To create a layer to avoid the stray glass fibres potentially cutting though the wiring over time and vibration. Then used to secure the very ends of the silver heat sleeve down before finally going over the heat sleeve ends by going over the whole harness again with tessa fleece tape to make it look discrete and professional. I’d recommend you use some silver or gold fiberglass backed heat sleeving around the area the resistor will sit back against. Because if you sit with your indicators or hazards on for a prolonged period then these do get too hot to touch with bare hands.
Which leads me onto why we even need the 50Watt resistor first anyways?! Well. Your cars oem flasher module has a function whereby it will flash twice as fast on a lamp that the system feels is about to blow the light element soon. This is done because the flasher module will sense that lamp is drawing far less current than it usually is. This feature is called “hyper-flash”. If your familiar with LED’s. They consume less than a 1/10th of the current of an incandescent lamp. Which is why they last longer since they don’t draw a lot of current, so they do not get that hot. So, they won’t burn out as fast. While also taking less drain off your vehicles electrical system due to the less current draw. But in this instance on our indicator and hazards circuit this will cause the hyper-flash feature. Meaning your LED indicator will be flashing twice as fast. We solve this problem by using a 50Watt (5 amps @ 12VDC) resistor wired in parallel across the load (indicator switch-line and ground). So once the circuit is energised the resistor is fooling the Mazda flasher module to think the vehicle still has incandescent lamps fitted on the indicator and hazards circuit. It simply turns that current into heat. Thus, my effort to protect the harness and anything in the boot from them. Including plastics, other wiring and metallic surfaces.
That’s it for the electrical point of view.
Making them ACTUALLY fit as advertised.
For those that are in the know. Yes, these are indeed advertised for the NC3.5 and NC3.75 face-lift models. But that is immaterial to the fact they only come with one fixing point. This point only justifies the ever so small and different shape Mk3/NC1 bumper gap with these brake lights. Which CarbonMiata do mention somewhere.
So, what’s my solution? Well, it’s a simple bracket made from 1.5mm 304 stainless sheet metal. Bent like the diagram below. Two 45-degree bends and that’s it. I pick up the inner (from centre of bumper) stud from the LED light assemblies sticking out the back. Then I used the existing fixing hole and used a M8 A2 stainless riv-nut and bolt (what best fit the existing hole). to attach the other end and bolted it through with a A2 stainless penny washer on the car attachment point. This solution is solid and is plenty rigid.
The oval shape opening has some metal-spined rubber weather-strip around the edge with the wiring passing through for both LED light assemblies. I have not yet found a suitable way to seal these openings up to combat moisture in the boot compartment without making brake light removal for when you need to remove the bumper for instance a pain and troublesome.
What you thought I forgot?
Disclaimer: I’m no legal professional, contact a legal expert or mechanic if you are unsure. To solve the fact both passenger and driver side lights are now both reverse lights. We relocate the rear fog-light *(UK MOT required)* to the centre of the rear diffuser. This is compliant with MOT regulations. The LED fog light I purchased can be found here.
For this I took a ground (black) on car body-side and the rear-fog light wire and put it into a 2pin Deutsch DT connector kit. Then run the wiring through the back void that has now been created behind the stamped chassis section where the foam seal used to be down under the bumper. Then it goes to another identical 2pin Deutsch DT 2pin connector kit (male + female) under the car and sits in a mount for the connector to keep the wiring tucked out of the way. Reasoning for two connectors is both servicing and maintenance.
Conclusion
So if you’re in the market for aftermarket brake-lights should you consider these as an option? Well if you’re wanting a plug and play wiring solution and bolt-in design with no extra work needed to fit them then I’d have to say these are not for you. However if you’re okay with having to re-wire and create your own mounting brackets to fit these at the cost of, in my opinion a slightly better looking rear-end then these are worth it. My final thought is these should not cost nowhere near as much as they do and CarbonMiata should offer these with the mounting bracket supplied and the option to for the customer to wire them up for a slightly less cost of the units pre-wired to work with oem lamp connectors.
I hope this article has been highly useful for you to make an educated decision on whether these are worth your hand earned cash. Or if you should look elsewhere for a more honest solution. As always, any questions don’t hesitate to ask in the comments to this article. Thank you for reading this far and have a good day.
Interested in relocating your NC’s battery into your boot? I’ve made this guide super simple, without missing out any details. Now relocating your battery as an overall idea sounds incredibly simple right? There’s quite a few things you’ll need to do and take into account when relocating your battery from under the bonnet to the boot. Before we start, I’d like to mention there is only one downside when doing this. That’s, your chosen battery will now be taking up space in your boot. If you’re happy that you can live with that, then let’s get started.
The structure of this article will be as follows. Shortly we’ll dive into what your going to need and why. That’ll be the first page. The next page can be located down at the end of this page, where I’ll go over a step-by-step installation guide. By the end of this article you should be well equipped to tackle this on your own vehicle.
Choosing your battery and mounting hardware
Let’s start at the heart of your car’s electrical system, the battery. Whenever mounting a battery outside the engine compartment, it should always be a sealed AGM type battery. Period. Why’s this incredibly important? Two reasons, first let’s say the worst thing happens… Your in a wreck, the vehicle’s upside down. If you were to re-use the original battery you’ll find mounted under the bonnet, you’re quite likely to have hydrochloric acid leaking out everywhere. Terrible situation. The second reason is an AGM dry-cell battery does not need any venting. A regular car battery will have a tube that is used to vent away hydrogen gas as your battery charges. So to avoid both of them issues we use a dry-cell sealed AGM type battery that can be mounted in the passenger compartment and can also be mounted any orientation, no problem.
What options are on the market then for this? There are an infinite amount of options, entirely dependant how you intend to use the car and your preference over AGM and lithium technology. I’ll briefly discuss AGM (Absorbed Glass Mat) vs conventional flooded batteries then we’ll compare against newer lithium designs.
AGM batteries are common-place in new cars such as BMW, Mercedes, Audi, Mini, Volvo. A few pros of AGM vs a conventional flooded battery are. Maintenance free (no longer topping up with deionised water), higher cold-start figures and most importantly to us. They are totally sealed and are leak and vapour free. Whereas a traditional flooded car battery will need to be kept behind a firewall and have a vent tube for the hydrogen gas that is released when charging and discharging. An AGM battery does not need to be vented and can be safely placed in the passenger compartment. Which the boot is classified as their is no sealed firewall between the boot and the interior. Only a removable bulkhead that is not a firewall. Some AGM battery manufactures are: Yuasa, Oddessey and Optima.
Newer lithium batteries have the obvious advantage that due to using lithium in replacement of lead, their weight is significantly reduced. However they may cost three to four times more. LifePo4 is the latest lithium design, which stands for “lithium Iron phosphate”. Generally speaking lithium batteries don’t work well in really cold climates. Though that doesn’t apply to the vast majority of NC MX-5 owners. They can be discharged to 0% and this will not reduce the lifespan of the battery due to the effect of charging an AGM battery below 50% its capacity (Ah) will heat up the plates and shorten the lifespan prematurely. Something you may be aware of is that lithium batteries can experience a thermal runaway event that are very difficult to extinguish. Due to this safety concern most high-quality lithium batteries have a fire-proof casing to contain the worst case scenario but it is defently worth being aware of. Some LifePo4 battery manufactures are: DeadWeightIndustries and AntiGravity.
When choosing a suitable battery for the NC it is imperative that you select one that has a minimum of 400CCA (Cold cranking amps). Ideally more is better and will not have any negative effect going larger. The starter motor and the small load of the ecu and fuel-injectors, ignition system pull the necessary amount of current (Amps) they require. Going with a larger CCA battery will not mean the starter will spin faster. However as the battery prematurely deteriates you’ll still have more than the minimum amount required to start the engine and you will not be working the battery as hard with some headroom.
Now you’ve chosen your ideal battery. You’ll need to find the appropriate hardware to mount it securely in the boot of your vehicle. You will find all sorts of enclosures. My personal vehicle has a Motamec standard battery enclosure. If you intend to use common batteries such as an Oddessy PC680 you’ll find many enclosures suited specifically for that battery only. This goes for most batteries. However don’t stress if you can’t find a battery specific enclosure. You will either have to use a standard dimension battery enclosure like my Motamec or you may find other universal dimension enclosures like the two other sizes Motamec offer. The hardware you’ll need to fix your enclosure down to the boot floor must be a minimum of four x M8 8.8 (grade 8) BZP (bright zinc plated steel) hex-bolts with M8 8.8 Nuts and BZP washers. Regardless if you use an AGM or lithium battery they are still heavy items that can easily turn into projectiles if not secured down properly. So stick to that as a baseline.
What parts will I need?
Below will be a list of parts that will have a cost and link where to buy them in UK.
A suitable AGM or lithium battery. (£100-£400)
A suitable battery enclosure. (£40-£100)
Six metres of black 40mm2 OFC welding cable. (£60)
Five metres of 16.9mm I.D. non-split plastic-conduit (£10)
MTA power-distribution box (£25)
Four 200A Megafuse (Three for spares in emergency) (£10)
Littlefuse midi inline fuse-holder (£8)
Four 125A midifuse (Three for spares in emergency) (£5)
A suitable crimper with 50mm2 dies.
3:1 ratio glue-lined heatshrink
HPDE sheet
M8 positive battery terminal post
Dis-car-nect negative terminal battery isolator
Expandable braid
Battery terminal covers
Are you ready?
If so, then lets get started with the install guide. Please navigate to the second page and lets get it.
Interested in installing a aftermarket steering-wheel into your car? But not sure what’s involved and what you’ll need? Hopefully this guide should clear that up for NC/MK3 owners.
What you’ll need?
Let’s keep this article real nice and simple and straight to the point. I will now cover all of the parts you’ll need in a logical order and explain them.
Boss Kit
Essentially all vehicles will have a unique spline on the steering shaft. A boss’s job is to translate that spline to a universal and standard PCD (bolt pattern) for installation of aftermarket steering-wheel.
Boss’s also come in different lengths, the most common is the short (55mm) style boss. However they do sell longer boss’s that will essentially place the wheel closer to your body. If your looking into a snap-off quick-release such as a NRG or WorksBell unit then I strongly suggest you choose the short (55mm) boss so you don’t end up with the steering-wheel too close to you.
SRS Resistors
To counteract the fact your airbag is now out of the vehicle, we will now use resistors and an inline-fuse-holder assembly to fool the SRS-Module (Airbag system) to believe the airbag is still in its original location and if the vehicle is in an impact the inline fuse (2amp fuse) will blow and create an open-circuit. Acting as a airbag would, this is the best way to replicate the factory airbag. The SRS-Module will be non-wiser.
The NC1/MK3.0 chassis will require just one of these SRS-Resistor-assemblies. The NC2/MK3.5 and later NC3/MK3.75 will require two of these assemblies. Most high-quality boss manufactures like WorksBell will supply these assemblies in their kit and will work with any year vehicle.
Your boss-kit will explain how to install these resistor-assemblies.
Steering-wheel
Everyone knows what a steering-wheel is, so let’s skip the explanation and jump head first into the different types, styles and sizes of steering wheels you need to know about before spending your hard-earned money.
The most common size of steering-wheel is a 350mm wheel. This size is most likely very close to your stock steering-wheel from the factory. It is quite a good size and will enable you to still read your gauge-cluster with no obstruction. You can however go to a smaller size steering-wheel, a few people do this in really small cars where interior space is limited and the benefit is a little more leg-room. However speaking of the NC/MK3 chassis I personally would recommend you stick to a 350mm wheel.
That’s great now I know the size, what else is their? Well secondly you’ll need to choose the style of steering-wheel you’ll want to use. Aftermarket steering-wheels come in mainly two different categories. That is “deep dish” (like the name suggests the wheel has depth and will ultimately sit closer to your body) and the second is “flat” this is also straight-forward to understand.
The third thing is the material you’ll want. Speaking from experience leather steering-wheels are the most durable and can be driven daily with no need for any gloves. They are also nice if you don’t wish to wear gloves at the track-day. Personal experience right? The other main option is suede. Now suede steering-wheels may look awesome to some, they have a massive drawback for driver’s who wish to keep their car for some time.. That is without wearing driving-gloves the oils in your skin will deteriorate the suede material and can change the feel. Not good. However if you are going to be mainly driving your car predominately around the track then a suede steering-wheel with proper gloves will be a good choice! In fact some claim that suede wheels will have a slightly better grip with gloves, perfect for a true racecar. Now if your like my friend Olly you may also like to have a wooden steering-wheel. A massive throwback to classic cars, a wooden steering wheel will look great in a vintage style car. To get the best feel of a wooden-steering wheel it is recommend to use a pair of leather driving-gloves. This is also where the term “glovebox originates from”. The last real material you’ll see is neoprene. This material will feel similar to your stock-wheel and is cheaper to produce than a leather wheel but is not as durable as a leather-wheel.
I’d just like to add that you should check what style PCD (bolt pattern) the steering-wheel you like has. As their are two types of PCD for a steering-wheel. The “Sparco” style, with the single countersunk-screw being at the top of the wheel. The second is the “Nardi” style, which has the two countersunk-screws at the top of the wheel. I have attached a photo above, the first is the “Sparco” PCD and the second is the “Nardi” style for clarity. This is important as if you do not run a quick-release and just the boss you may need a adapter to change the PCD of the wheel.
Optional – Quick-release
You’ve probably seen these used in many racecars. There’s a good reason for that. With a full bucket-seat and 6-point harness setup it may be difficult to get in and out of the vehicle with the wheel in the way. This way the steering-wheel can be detached and re-attached once the driver is in. This is not essential however if you intend to fit aftermarket bucket-seat’s this could be worth it.
Having trouble or just straight-up confused about fitting aftermarket bucket seats into your NC/MK3? Stress no more. This post should hopefully clear-up most of and hopefully all of your concerns and questions!
Finding the perfect seat for you!
The first part your going to have to consider is what seat you wish to fit. Now of course not just any seat will fit the profile of the NC/MK3. So I have compiled a few links below to articles and forum posts that show what seats WILL fit in your car. But first just naming a few popular seats off the bat for the NC/MK3, Sparco Evo QRT, Cobra Monaco Pro, Sabelt GT-090 Racer Duo, Sparco Sprint.
Now what’s more important than the seat fitting in your car is it fitting you! Yes, bucket-seats won’t fit everyone. A properly chosen seat should fit you snug but not too tight that your uncomfortable. That last part is very important. The second most important thing for anyone wanting to take their car to the track is the upper two harness pass-through holes are at the appropriate level in relation to your shoulders. Too high and when the harness is tightened up it could potentially crush your spinal-cord and that is not something to joke about.
Sounds a little intimdating for a newbie buying their first bucket seats right? Well maybe a little bit but if you have a supportive bucket-seat retailer nearby you should be able to find the seats that you have been told will fit your NC/MK3 and try them out both for your butt and also your car! That way you will know they will fit before you spend the cash.
However if for whatever reason you cannot test fit a seat because you have no local bucket-seat retailer then you can still make sure your seat fit’s by using a few simple measurements and questions back and forth with a reputable online-retailer. So what measurements do I need to take and how?? Let’s first start with your butt-to-shoulder measurement. To take this I recommend you sit on a flat floor with your back straight up square with another straight object such as a wardrobe, wall (if possible), basically any object taller than you and straight/square. This does help if you have another person double check your doing this correct but now you measure from the ground (bottom of your butt) to the highest point of your shoulders (this will be closer in near your neck). This will give you the measurement to confirm if your harness pass-through’s will be safe for harness use. The second measurement is your waist. Pretty straight forward right? Like buying a new pair of trackies lol. The third is the width of your shoulders. You do not want a seat where the upper side-supports are too small. For correct fitment your shoulders and body should sit back into them. Don’t be too worried if you think your shoulders are too wide for the seat you think will fit you. They will not wrap around your shoulders but simply you just sit back into them. (I am not referring to high-spec halo seats here but the classic bucket seat style). The main target here is to find a seat that is comfortable for you.
Mounting your new seat!
Once you’ve got the right seat that will both you and your car, you need to think about how you wish to mount your seat to your car’s floor. Now their are two options here. Sliders or a fixed position mount. Sliders are good for street use where a harness won’t be used. HOWEVER, if you want to run a six-point harness the lower two crotch belt’s will need to be fixed in a permanent position making the slider not an option. Most bucket-seat retailers and motorsport shops/websites that you are getting your seat from will also sell the mounting hardware. Speaking of before I forget to mention you will need four M8 bolts to fix the seat via the side-mounts. Some seats do have bottom mount mounts but MOST bucket-seats will only use side-mount’s which allow the seat to be lowered more than a bottom-mount.
Now you’ve made the decision on sliders or a fixed position, you will need to know what you actually need to do either option. Both setups will require the four M8 bolts to attach the seat to your mounting solution. Both setups will require what we call a “vehicle-specific base mount” as referred to as “VSBM” from this point on . This hence the name is unique to the floor of your vehicle in our case the NC/MK3. Now the difference between sliders and a fixed setup is here. If you want sliders you will now of course need a pair of sliding-rails that will attach to your VSBM and then to the seat. So to run a sliding-seat setup you will need a VSBM, four M8 seat bolts and a sliding seat rail. If you wish to permanently fix the seat in one position you will need a VSBM, four M8 seat bolts, side mounts (that will go between the VSBM and the seat itself). When looking at purchasing a fixed setup you will find a few VSBM’s come as a kit with side mounts. These are usually just called bucket-seat mounts. Some even come with holes for the two lower crotch belts for a 6 point harness.
Electroni.. what..?
Here’s the tricky part coming up. Electronics! Hate them or love them they are tricky at times. With some help from awesome forum users I have supplied the info you will need to get your new bucket-seats in without any irritating SRS-Airbag and OEM seat-belt light flashing and beeping in your Mazda. Trust me that beeping would drive you insane in a matter of minutes lol.
