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).
Wilwood adjustable proportioning valve discretely mounted underneath ABS unit.
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!
Hubs were 3D scanned to aid with development of wheel speed sensor mounts - 3D printed prototype seen here.
In-house machining of wheel speed mounts - ensuring extreme accuracy.
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.
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).
Wilwood adjustable proportioning valve discretely mounted underneath ABS unit.
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!
Hubs were 3D scanned to aid with development of wheel speed sensor mounts - 3D printed prototype seen here.
In-house machining of wheel speed mounts - ensuring extreme accuracy.
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.
