Autosport Labs

I have thought about this for some time and what I would like to see is an aftermarket stand-alone abs controller.

My idea is that the end user would need to source a common abs HCU (hydraulic control unit) and do the install and plumbing. Then it would be a case of figuring out how to mount the wheel speed sensor wheels and vr sensors. (newer cars use active sensors which would be tooo complicated).

Then the controller would simply process the wheel speeds and activate the inlet and outlet/dump valves and pump.

I would love to have this in my old tin can but also the ability to switch it off when I don't want it.

That being said I think I may just work on retrofitting an early 2000s style system just for fun if this seems too ambitious. What do you guys think?

Sunray,

I think some systems could well be retro fitted. I can't say I personally have had any experience with abs, but fundamentally they work by detecting movement on a wheel via a triggerwheel. If the trigger wheel stops then the system will not detect any wheel movement (hence skidding) and so releases pressure to that wheel via a solenoid in the abs unit. I'm not sure if a road speed input would be required such as a speed sensor in the gearbox, or uses a sum of the other triggerwheel sensors.

To disconnect the abs all you would have to do is disconnect the connector to the abs unit.

Would be a nice learning project into brake systems. I'll have a google search into it.

The hardest bit, I guess, would be mounting the triggerwheel and VR sensor.

The nice thing for me here is that I do have a lot of experience with abs thanks to my training. I understand the systems very very well. The trouble is finding an hcu from a system that is not integrated with other systems like integrated vehicle dynamics. Basically need to find one that does not rely on being part of an HSCAN or MSCAN with gateway modules. Maybe one of the older gm setups might work. For a rear drive car even a simple 3 channel system would be like magic on a wet track.

I'm particularly interested in the test harness / simulation rig on this one

I think I may have found a potential donor for the set-up. 1991 chevy s10 pick-ups have a nice almost stand-alone abs where the module, HCU, and prop valve are all mounted to the master cylinder on a bracket.

Lots more tinkering before anything real materializes.

sunray wrote:I think I may have found a potential donor for the set-up. 1991 chevy s10 pick-ups have a nice almost stand-alone abs where the module, HCU, and prop valve are all mounted to the master cylinder on a bracket.

Lots more tinkering before anything real materializes.

Anyone get anywhere on this standalone= Pretty sure ABS is made redundant when installing megajolt.

But if you leave standard ECU is aswell , should it work?

ABS is considered a safety system, hence in most cars its stand-alone anyway.. there are some exceptions (more normally in newer cars) where there are interactions with the engine for things like stability control, where the ABS system interacts with steering and the engine ECU for traction control

If you pick an older car then the ABS system can be made stand-alone and transferrable - the simplest version I've come across would be either the 3-line (1991-1995) Bosch system (which can be remapped with GpN / GpA software to cope with things like slick tyres and adjustable bias) from the BMW E36 or similar, or the later 4-line Bosch system which replaced it (I don't believe this can be remapped) from 1995-1999. These parts are available really cheaply (like $100 for ECU and Pump) and use standard M12x1.0 and M10x1.0 hydraulic fittings. They also use simple and readily available wheel speed sensors, however if you're starting with a car with no wheel speed sensors you will need to do something to fit rings or pick-ups at each wheel (or on the driveshafts)

Its possible to fit the later Mk60 ABS system as a standalone from the E46 M3, which is a significantly improved ABS system, however also more involved, requiring things like line pressure sensors (f/r) handbrake, brake pedal, and some other switches.. Its possible to purchase standalone harnesses for these systems, however they're NOT CHEAP

If you're not building an outright race car then the 4-line e36 system is probably a good bet, if you want something simple (ish) to install with the ability to expand the functionality to a more racy set-up then the earlier 3-line system is a good bet

Drop me a PM or something if you want some additional information - I have a 3-line and 4-line kit of parts sitting in my shop that I'd happily sell as I've recently upgraded to a Mk60 system

Consider the liability issues around making a safety critical system. So, finding a way to adapt an OEM system is very appealing!