The Ultimate ABS Solution for the NSX

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17 July 2017
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31
Location
Tokyo
NSX ABS - Some Background

As any early NSX owner knows, the ABS system the NSX was originally launched with is rather old fashioned and, by today’s standards, unusual. Someone referred to it as ‘steampunk style’ ABS and that’s a fairly apt description compared to the compact and clean ‘Bosch-style’ ABS units we are used to seeing in modern road cars and indeed the latest versions of NSX (from 2000 onwards).

Even that steampunk system was rather advanced in many ways, being Honda’s first true four-channel ABS system - the Skyline GT-R for example had only 3-channel ABS as standard until the R34 came along in 1999! Our steampunk system was effective at preventing lockups in emergency braking situation but was limited by the technology of the time - it was too slow to be useful on track and was prone to performance degradation without maintenance.

Why Upgrade at all?

The steampunk units are hard to service and perform poorly by modern standards - and thanks to Honda themselves updating the system within the model life we had a great option to upgrade our early cars with some help from the aftermarket - the 2000+ ABS system.

Installing 2000+ ABS into an earlier NSX has been a popular upgrade for some time, one I’ve performed to my own car. However these units are seemingly discontinued from Honda, and even if you are able to buy one the technology is almost 25 years old - think of what computers & mobile phones looked like in the year 2000 (those that survived the millennium bug, anyway!) - they are vintage collectors items. It seemed an ideal time to develop a no-compromise solution.

What is the State of The Art for ABS?

The obvious place to look for cutting edge vehicle technology is contemporary professional motorsport. In any category where the rules permit it, Bosch Motorsport ABS has been adopted. Factory GT3 and GT4 cars from Porsche, AMG, McLaren etc. use the system, and recently it is being adopted by some low volume road car manufacturers: Singer for their DLS, Ariel Atom 4R, and so on.

The Bosch M5 system uses wheel speed sensors in conjunction with hydraulic pressure sensors for the front and rear brake circuit and a 6-axis accelerometer. Each unit is calibrated for the individual vehicle it is installed into - vehicle weight, vehicle track, wheel weights, wheel circumferences, wheelbase etc. and the driver can select one of 11 ABS maps on the fly. Data logging and CAN integration into standard or aftermarket engine/dynamic control systems to share wheelspeed signals etc. is possible, unlike a locked road car ABS. Just like you wouldn’t upgrade engine components (cams, injectors, etc.) without retuning the ECU, ‘upgrading’ a vehicle's braking system should be considered in conjunction with the ABS system. A factory ABS control unit has no idea if, for example, the vehicle now has double the deceleration potential due to a big brake kit and race tyres, nor can it adapt to multi-piston calipers with a greater volume of hydraulic fluid to move. In some circumstances this can lead to dangerous ABS interventions often referred to as ‘ice mode’ - a wheel speed deceleration rate outside the factory calibration. This poor performance leads people to either drive around the crappy ABS, delete it completely or, ideally, look for a solution that is calibrated to their vehicle.

A very relevant example of the need for ABS calibration is the NSX itself - the NA2 Type R had a unique ABS module and calibration to suit the different dynamics of the R, and indeed the expected driving style of the owner, compared to the non-R versions. ABS calibrations are as unique and purpose-specific just like engine calibrations!

A Motorsport ABS system is fundamentally designed for performance first, safety and stability second and NVH etc. a distant third, which is an inversion of the priorities of a road car system. For an unmodified road car being driven on the road, the original ABS will usually be extremely good - OEM development programs dedicate significant resources to ensuring the system is safe and effective at maintaining controllability even on split surfaces (half dirt/half tarmac) etc. If your standard ABS is functional, your car is unmodified and you do not drive your car on the track, Motorsport ABS is not for you. However for those of us with modified cars (especially wheels/tyres, brakes and suspension) and/or do drive on the circuit, this sort of system can be a very worthwhile upgrade, and if you are a pure racer I would say that this technology is a must-have.

Fitting Bosch Motorsport M5 ABS to an NSX

My day job is marketing at Bosch Motorsport Australia. In my role I’ve had the opportunity to experience the Motorsport ABS and hear the strong testimony from customers who have installed the system in their own vehicles. As an NSX owner, naturally it didn’t take long for me to consider installing a system into my personal car. After some discussions with Ashley Field, owner at 909 Motorsport, we decided to develop a kit for the NSX which he could then make available to other owners. Frankly the NSX market is quite small in Australia, so our goal is to support adoption in the US, Japan and Europe as well.

909 Motorsport is one of the leading authorities when it comes to integration of Motorsport ABS into vintage & performance vehicles. Time attack fans are probably familiar with WTAC here in Australia - well Ash has supplied/supported most of those vehicles including the outright champion RP968.

Ash’s approach for developing this NSX kit has been extremely thorough, and has exceeded even my high expectations of the work coming into this project. Where possible existing wiring, connectors, and brake lines are reused. As a result, no wires need cutting, nor holes need to be drilled. All brackets and hardware are precision machined in-house and will be supplied with the kit. Even the integration of the position selection switch and ABS light is thoughtfully ‘OEM+’. I am comfortable saying that this will be the ultimate ABS upgrade for the NSX, and I'm sure the pursuit of perfection will resonate with many of you here.

At the time of writing this post the installation is almost complete, and I’m planning to do some dynamic testing of the system by the end of this month, at which time I’ll provide some more updates.

Let me know any questions you guys might have and I’ll do my best to answer them!

- Blake

Some progress photos from the development:

M5 modulator unit test mounted on custom aluminium bracket with vibration dampening mounts (final version will be powdercoated).
Bosch Motorsport ABS - Honda NSX - 909 Kit--2.jpg

Wilwood adjustable proportioning valve discretely mounted underneath ABS unit.
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A bulkhead has been incorporated into the brake lines for ease of install and servicability. Anyone who has installed the 2000+ system with factory brake lines will appreciate this touch!
Bosch Motorsport ABS - Honda NSX - 909 Kit--3.jpg

Hubs were 3D scanned to aid with development of wheel speed sensor mounts - 3D printed prototype seen here.
Bosch Motorsport ABS - Honda NSX - 909 Kit--6.jpg

In-house machining of wheel speed mounts - ensuring extreme accuracy.
Bosch Motorsport ABS - Honda NSX - 909 Kit--10.jpg

Care has been taken to integrate where possible with existing vehicle electronics. For those who have removed factory wiring, a standard Bosch Motorsport loom can be supplied.
Bosch Motorsport ABS - Honda NSX - 909 Kit-.jpg
 

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@blaketjones, I’m very intrigued to know more and interested in the upgrade. My questions:

From the pictures, it appears to be a right hand drive. How long until a left hand drive version is prototyped?

Does this system integrate with the OEM warning indicators? Or maybe a better question, what user visible or OEM functionality is not supported?

What testing has been done or will be done to validate the upgrade’s functionality/capability?

Is there an estimated or final price point available yet?

Do you have any data showing the improvement over the OEM system or expected improvement?

When is is the planned production schedule? Do you need a group commitment to initiate production?

Will all years/versions be supported?

Thanks
Lance
 
@blaketjones, I’m very intrigued to know more and interested in the upgrade. My questions:

From the pictures, it appears to be a right hand drive. How long until a left hand drive version is prototyped?
Thanks for the questions Lance. Yes, being in Australia, my car is RHD. Brackets have been designed in consideration for LHD (the mounting points are present regardless of RHD/LHD), some experimentation and development will be required for brake lines - otherwise the system is the same. We may need some help from LHD owners to button down the final details.
Does this system integrate with the OEM warning indicators? Or maybe a better question, what user visible or OEM functionality is not supported?
Our intention is to use the Bosch ABS warning light output to drive the factory ABS light, I will confirm if this is successful.
What testing has been done or will be done to validate the upgrade’s functionality/capability?
The performance functionality of the Bosch ABS system is well proven, but we will be data logging the track tests with ABS switched on and off. Capability is dependent on the overall brake system and car, but in highly developed time attack cars at Sydney Motorsport Park, track time improvement is quoted in the 1-3 second range (1:18s lap record).
Is there an estimated or final price point available yet?
909 will release the pricing once the kit is finalised and all costs are fully understood. For reference, the bare clubsport kit retails for $7.8K USD, so it is not a cheap option.
Do you have any data showing the improvement over the OEM system or expected improvement?
Not yet, we will attempt to do some demonstrative comparisons between different NSX systems, but it's unlikely to be a true control test.
When is is the planned production schedule? Do you need a group commitment to initiate production?
909 will confirm shortly - group commitment will certainly make things easier :)
Will all years/versions be supported?

Thanks
Lance
Yes, that is the plan, to be confirmed in time.
 
Wow, this is amazing work considering that NISSIN has stopped producing the NSX ABS Modulators now. Great alternative option. I'm looking forward to the end result Blake!

If you have any data on the comparisons vs the OEM 2000+ ABS and the S2000 AP1 ABS units, I think it would be beneficial to show potential customers on the pros of Bosch system.
 
Sadly, sign me up. As with all 91-99 cars, not a matter of "if" but "when." Stinks
 
That's awesome. I'm subscribing to stay updated. I just installed an NSX-R modulator to my car and will be testing that shortly, but having worked on programming of the M5 on the GT4 Mustang racecars, I'm a big fan of Bosch ABS modules and depending on the cost, might be interested in going this route at some point.

It's great to see NSX enthusiasts from around the world with different backgrounds bringing modern technology to this iconic and world-class platform.
 
@blaketjones it's great to see you contributing here! I've followed your Project NSX in Speedhunters for years.

Dumb question, but the Bosch unit looks just like the Nissin OEM one. Are the internals different or it is just programming logic?
 
Very cool project! I love that you're using custom hard lines instead of taking the lazy way out and using SS hoses like some of the delete kits I've seen floating around.

The price tag is a little scary but if it saves a few seconds on track I imagine the hardcore guys will be all over it. I'm looking forward to comparisons vs the NSX and S2K modulators.

@Honcho the Bosch unit uses completely different hardware and software.
 
Wow, this is amazing work considering that NISSIN has stopped producing the NSX ABS Modulators now. Great alternative option. I'm looking forward to the end result Blake!

If you have any data on the comparisons vs the OEM 2000+ ABS and the S2000 AP1 ABS units, I think it would be beneficial to show potential customers on the pros of Bosch system.
Thanks Marc. We will try to do some demonstrative tests, but was there any particular data you were interested in?
 
@blaketjones it's great to see you contributing here! I've followed your Project NSX in Speedhunters for years.

Dumb question, but the Bosch unit looks just like the Nissin OEM one. Are the internals different or it is just programming logic?
Thanks @Honcho - I have gleaned plenty from your valuable posts here over the years, so there's a little bit of you in those Speedhunters stories!

As @MotorMouth93 said, these units are dissimilar despite similar external appearances.
 
That's awesome. I'm subscribing to stay updated. I just installed an NSX-R modulator to my car and will be testing that shortly, but having worked on programming of the M5 on the GT4 Mustang racecars, I'm a big fan of Bosch ABS modules and depending on the cost, might be interested in going this route at some point.

It's great to see NSX enthusiasts from around the world with different backgrounds bringing modern technology to this iconic and world-class platform.
Thanks for the kind words @stuntman - interested to hear your experience with the NSX-R modulator!
 
As a fellow Australian NSX owner and having followed your NSX journey on Speedhunters, I can't wait to see the end results of this project.
 
Yes, it's really cool to see someone working on a more modern ABS upgrade for the early NSX's!
 
When the time comes for a LHD "beta tester", Charlotte with her 666 RWHP is volunteering her services. She is running StopTech ST-40s on all 4 corners btw.
 
So, an update on the Bosch Motorsport ABS project. Thanks to everyone who has shown interest and asked questions so far.

The kit development & installation has been functionally completed at 909 Motorsport allowing us to execute an initial shakedown at the track.

Installation Details

As I expressed in the first post, Ash’s attention to detail has really impressed during the development of the kit. A few more examples of this comprehensive approach:

Master switch and diagnostic port mounted under the glovebox, quickly accessible yet out of the way. The bracket features a return at the base to prevent the on/off switch being inadvertently knocked by a passenger playing footsies.
1D2A9260.jpg

The factory ALB light works as standard with the kit. That is to say, if the system is switched off or an error is detected, the ALB dash light will illuminate. Great job Ash!
1D2A9312.jpg

We chose to place the ABS map selection switch in the factory cigar lighter location. Sorry smokers, but you can see that it really was made to be there! Cover opening/closing is unimpeded. The small screen is unrelated to the ABS (that is a CAN readout for some ECU data). There will be further aesthetic developments to this switch which I think you guys will like…
1D2A9265.jpg

Some shots of the machined wheel speed sensor mounts.1D2A9224.jpg
1D2A9236.jpg

ABS module bracket completed with black powder coating. If plastic-coated brake lines were selected and the Bosch Motorsport sticker removed, I think the install would pass as factory to unfamiliar eyes.
1D2A9187.jpg


Driving Impressions

I completed 4 warm up/familiarity laps and then about 15 laps with the Motorsport ABS. At our test track, SMSP south circuit, there are three heavy braking zones where activating the Motorsport ABS is desirable. This was a pure shakedown, so the proportioning was set at 50/50 and ABS map left on setting 7 for the evening, so effectively this is a ‘straight out of the box’ review. My basic driving style (suited to factory ABS/ no ABS) was a quick but progressive ramp of brake pressure, holding that peak pressure then bleeding off toward corner entry as per the racing textbook. Typically I would try to avoid factory ABS intervention, or use it as an indication that I was at the braking system’s threshold (which may or may not be the case). The Motorsport ABS prefers a hard and instant application of maximum brake pressure, and the higher your speed, the more pronounced the benefit of the ABS is. Where I would usually brake just after the 100m marker for one corner, by the end of the test I was confident to accelerate all the way to the 50m marker - effectively halving my braking distance. The deceleration in my car was violent but completely controlled, the drumming feedback in the brake pedal providing confirmation that ABS was working its magic.

93d69078-a0f8-4068-a8db-44a21071ef55.JPG

Unlike fellow countryman Daniel Ricciardo, I would never have been called the “last of the late brakers”. Indeed I think for most amateurs, braking and corner entry is probably the element of our driving with the most significant gap to a professional level driver. It takes significant confidence and precision to nail a late braking point lap after lap (especially with changing grip levels), and the consequences of getting it wrong can obviously be very costly.

For me, this boost in confidence in the heavy braking zones quickly grew into confidence everywhere else. As you can hopefully tell from my writing I had an absolute ball!

What’s Next?

CAN integration into the ECU (Haltech in my case) allows data logging of ABS data (wheel speeds, hydraulic pressures, etc.) and the M5 ABS software makes a suggestion on Front/Rear brake proportioning once it has logged some actual ABS intervention events. After reviewing that data, more rear brake is required in my car which can hopefully be addressed with a grippier pad compound. This wasn’t a surprising finding - my front brakes are Brembo calipers and bigger rotors, while the rear is a larger rotor but standard caliper. I’ll also experiment with different map settings, and Ash observed that I can still yet brake later and start to initiate turn in with ABS active to find more time.

There are some minor, mainly aesthetic, refinements Ash will be making to the kit and we will be working on installation documentation and making a plan for LHD development next.

Let me know if you guys have any questions about the kit or testing so far and I’ll do my best to answer them.
 
You're looking a bit scruffy! But all is worth it for the big developments.
Looking forward to the final product.
 
Are you using a Brembo "Lotus" front caliper on a 13" rotor? Which year rear caliper are you using and what's the rotor diameter, so I can calculate your brake bias.

What are your wheel width and tire sizes, spring rates and sway bar settings? NSXs often have a lot of trail-brake rotation and oversteer. The Bosch unit can be programmed to affect and reduce this rotation, which will vary depending on your brake and suspension setup. Are there plans to do any custom mapping or just play around with the factory 1-9 maps?

It would be good to hear your feedback from more trail braking and carrying ABS intervention down to the apex of low speed corners and the effects on this entry rotation.
 
Are you using a Brembo "Lotus" front caliper on a 13" rotor? Which year rear caliper are you using and what's the rotor diameter, so I can calculate your brake bias.

What are your wheel width and tire sizes, spring rates and sway bar settings? NSXs often have a lot of trail-brake rotation and oversteer. The Bosch unit can be programmed to affect and reduce this rotation, which will vary depending on your brake and suspension setup. Are there plans to do any custom mapping or just play around with the factory 1-9 maps?

It would be good to hear your feedback from more trail braking and carrying ABS intervention down to the apex of low speed corners and the effects on this entry rotation.
@stuntman, current setup is:

Front Brake: Brembo Modena caliper, 320mm rotor
Rear Brake: Standard '92 caliper, 330mm rotor
Front tyre: 215/40R17 (AD09)
Rear tyre: 265/35R18 (AD09)
Front spring rate: 8kg/cm (KW V3 Clubsport)
Rear spring rate: 8kg/cm (KW V3 Clubsport)
Front Sway: NSX-R
Rear Sway: Standard

My install is based on a Clubsport kit, which uses the 11 factory maps. The 'Standard' kit has the option to do custom maps but it's out of scope for my (relatively tame street/track) project. Absolutely worthwhile for more serious racers and especially when big aero is involved.
 
@stuntman, current setup is:

Front Brake: Brembo Modena caliper, 320mm rotor
Rear Brake: Standard '92 caliper, 330mm rotor
Front tyre: 215/40R17 (AD09)
Rear tyre: 265/35R18 (AD09)
Front spring rate: 8kg/cm (KW V3 Clubsport)
Rear spring rate: 8kg/cm (KW V3 Clubsport)
Front Sway: NSX-R
Rear Sway: Standard

My install is based on a Clubsport kit, which uses the 11 factory maps. The 'Standard' kit has the option to do custom maps but it's out of scope for my (relatively tame street/track) project. Absolutely worthwhile for more serious racers and especially when big aero is involved.
Thanks for the information. It sounds like your setup is in-line with commonly used setups.

Did you source the caliper from a 360 Modena? I'm 98% sure its what is commonly referred to as a "Lotus" caliper with 40/36mm pistons - the most common caliper used for aftermarket brake systems, including the NSX.

What front rotor are you using? Is it actually 320mm or could it be the standard 328x28mm Brembo 2-pc rotor?

What rear rotor are you using? I'm also struggling to find a 330mm rear rotor that's used on the NSX.
 
Thanks for the information. It sounds like your setup is in-line with commonly used setups.

Did you source the caliper from a 360 Modena? I'm 98% sure its what is commonly referred to as a "Lotus" caliper with 40/36mm pistons - the most common caliper used for aftermarket brake systems, including the NSX.

What front rotor are you using? Is it actually 320mm or could it be the standard 328x28mm Brembo 2-pc rotor?

What rear rotor are you using? I'm also struggling to find a 330mm rear rotor that's used on the NSX.

The kit is actually from Biot, who don't seem to have much of a footprint outside of Japan. They have a pretty comprehensive range of NSX brake & suspension parts, these are what are on my car:

Front: https://www.biot.co.jp/products/biot/2013/10/brembo4potmodena-320-honda-nsx-1.php

Rear: https://www.biot.co.jp/products/biot/2013/10/rear-offset2p-94.php

Yep, it's an F360 Modena caliper! From the Biot product page: "The F360Modena caliper is the lightest and most compact 4Pot caliper, and is often installed on car models with a narrow selection of wheel offsets and mid-engine cars. The rotor size can also be selected from up to 355φ compared to the Lotus caliper, and the piston size is also approximately 10% larger in capacity than the Lotus."
 
The kit is actually from Biot, who don't seem to have much of a footprint outside of Japan. They have a pretty comprehensive range of NSX brake & suspension parts, these are what are on my car:

Front: https://www.biot.co.jp/products/biot/2013/10/brembo4potmodena-320-honda-nsx-1.php

Rear: https://www.biot.co.jp/products/biot/2013/10/rear-offset2p-94.php

Yep, it's an F360 Modena caliper! From the Biot product page: "The F360Modena caliper is the lightest and most compact 4Pot caliper, and is often installed on car models with a narrow selection of wheel offsets and mid-engine cars. The rotor size can also be selected from up to 355φ compared to the Lotus caliper, and the piston size is also approximately 10% larger in capacity than the Lotus."
I'm not familiar with that brand. So the Modena's caliper has a 42/38mm pistons in it (vs 40/36mm for the commonly use "Lotus" caliper.

When combined with a 320mm front and 330mm rear rotor, the brake bias of your setup is 62.1% front bias.

By comparison:

91-96 NSX = 60.3%
97+ NSX = 52.2%
2002 NSX-R = 53.4%
91-96 NSX with Brembo "Lotus" Front caliper = 64.7%

That is not inconsequentially more front bias than the stock 91-96' NSX factory brake bias. How do you set your brake bias proportioning?
 
I'm not familiar with that brand. So the Modena's caliper has a 42/38mm pistons in it (vs 40/36mm for the commonly use "Lotus" caliper.

When combined with a 320mm front and 330mm rear rotor, the brake bias of your setup is 62.1% front bias.

By comparison:

91-96 NSX = 60.3%
97+ NSX = 52.2%
2002 NSX-R = 53.4%
91-96 NSX with Brembo "Lotus" Front caliper = 64.7%

That is not inconsequentially more front bias than the stock 91-96' NSX factory brake bias. How do you set your brake bias proportioning?

Thanks for those numbers and the calculation Billy, very helpful context. That calculated bias is not ideal (not terrible either) - but it’s what I have to work with at the moment. There may be larger rear calipers in my future. Can you recommend any cost effective options for something sized appropriately (ideally with an integrated handbrake)?

The kit 909 Motorsport developed incorporates a Wilwood proportioning valve on the rear circuit, but with my ‘big front’ setup that has not corrected bias sufficiently. The rear pads are a Biot street compound, so I’m confident that a pad with a higher CoF will get us closer to the ideal in the short term.

It’s all part of the ongoing development process, and it’s very helpful to have data from the system combined with insights from some experts on the NSX platform like yourself.
 
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If you're running the NA1 rear calipers still with the larger rotors then upgrading to NA2 rear calipers will probably get the bias much closer to ideal, they use a much larger piston and still have an integrated hand brake.

They can be tough to find though, if you keep an eye on rockauto you can occasionally pick up a set for $500ish.
 
If you're running the NA1 rear calipers still with the larger rotors then upgrading to NA2 rear calipers will probably get the bias much closer to ideal, they use a much larger piston and still have an integrated hand brake.

They can be tough to find though, if you keep an eye on rockauto you can occasionally pick up a set for $500ish.
OEM and reasonably priced? Lovely. I will keep my eyes peeled.
 
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