333pg333

Hi,

I'm looking at possibly using a Boxster ABS unit for a project. I'm wondering if these work in sync with the PASM etc ? If so, do some of the early model Boxsters come without the PASM and therefore the ABS works entirely on it's own? Or can the more recent models be split off from the PASM etc?

Thanks

Patrick

amondc

There is a 3 channel ABS system and a 4 channel one. The 3 channel is for the early cars without Traction control.

Mike Murphy

My 2000 Boxster S came neither with PASM nor traction control. It only has ABS.

333pg333

Thanks guys. So on another note, for this project I am also looking at implementing Traction Control via a standalone ems.
I wonder if I can't use some of the existing electronics for my T/C? Probably not. How is it activated in the Boxster? Does it
pull ignition from the motor or does it activate brakes?

Mike Murphy

I think it's mostly brakes. From what I've read, the native TC on these early cars were really no good on the track or for performance driving. Best TC device is an aftermarket LSD option (mechanical). Otherwise, the innate Porsche option was just good for getting unstuck in the snow/ice/mud and that was about it.

333pg333

I wouldn't be looking at using the actual mechanical side of the t/c or PASM, more just to use the signal and sensors. I will be pulling timing from the motor rather than activating brakes. Don't like the idea of the brakes coming on when I'm not pushing that pedal. As I get closer I will need to get more in depth with the workings. Is there a resident expert on these matters in here?

amondc

The boxster t/c works by engaging the ABD (Automatic brake differential) then if that does not stop the wheels from spining it will cut spark to the motor. It is a very crude system compared to what they have today but it works.

Mike Murphy

Try searching Rennlist across all other sections.

00r101

Are you confusing PSM and PASM? Lots of people make this common mistake. They are two different things. PSM is Porsche Stability Managment and it does work with ABS in a manner of speaking. PASM is Porsche Active Suspension Management and does not interact with ABS.

333pg333

Well you're absolutely right and I do confuse these from time to time. The ABS I am replacing is basically the earliest series from Porsche. My project is a highly modified 951 with all sorts of custom product on it. I'm not a college kid who is tyre kicking his fantasy. This will have a highly developed 3L turbo motor which is already built. I have a GT2 tranny awaiting and a bunch of other stuff, so basically any upgrade from the old 1980's ABS will be an improvement. It may not be the Boxster's but this is where I was directed by someone else with another modified 951 racecar who was thinking of doing the same. I think the concept was that even though the engines are in different places the overall weight and balance of the cars are quite similar. Not sure what effect me lightening my car by several hundred pounds may have though?
In reality all I 'think' I need for the Traction control are the sensors/signals to send to the LINK standalone to process and pull ignition.

Mike Murphy

Patrick, do you have access to the Bentley Porsche Boxster Service Manual? It may describe the components and systems that you're interested in. In the meantime, I'll see if I can find a PDF version somewhere. I, too, am interested in the specific workings of these systems.

333pg333

Thanks a bunch Murph.

onefastviking

BMW system works better, I hate having to say that !
Also Porsche (Bosch)Motorsports system works even better although very costly.

333pg333

Thanks OFV. I have wondered on why or if I need to use a Porsche version? Yes I'd love the Bosch Msports model and even moreso the bucks to be able to afford it!

onefastviking

There are a few companies working on software for the Porsches ABS but the BMW ABS is more developed for racing. You will need (want) a 4 channel system if you do not have one currently in your car, although you can make your car a 4 channel system without too much hassle. You can also sometimes find deals on people that have upgraded to the top of the line Bosch Motorsports units.
The BMW system works great although it's not a straight street system, it is a different setup and programming. The Bosch Motorsports works even better, the Motorsports has preprogrammed maps for different braking situations, wet,cold, hot & sticky, etc. these can be changed on the fly by the driver. The BMW has no dial but has full diagnostics and works pretty flawlessly. Figure $8k +/- for the BMW, more for the Motorsports.