R32 ABS on track - tunable?

[David Owens]

Running an R32GTS track only car (on groved slicks) I am interested in running ABS. Ideally it will be switchable, and potentially only used in the wet. While I have done plenty of web surfing looking for info I can come up with very little useful info.

Has anyone done any track development of ABS?

As far as I can determine I want to run the fastest cycle time possible, with a four sensor, three channel system. Maximising front braking, but running the rears to the lowest grip of each (for stability). The pressure relief and recovery is triggered from acceleration rates which are "improbable", (i.e. too quick to be not skidding) which might need some tuning given the stiffness of the chassis and the grip of the tyres.

I can find one after market ABS system for heavy equipment, not sure the budget and style is really likely to be what I need. And I have a belief/idea that some people have used the Mitsubishi Magna controller. It would seem that a programmable controller would not be too difficult (given data loggers and ECMs now available) but may be the liability/litigation means no one wants to supply?

Anyone prepared to share some development insights, or knowledge of a supplier of a tunable controller?

[Sydneykid]

Have tried many ABS systems on numerous race cars, they are simply not as effective as the driver. Plus they are down right dangerous when you leave the track, particularly on the grass in the wet.

[David Owens]

Sydneykid, I hear your comment on the off tarmac stuff (I'm deluding myself that a thumb push button on the wheel to knock out the ABS is going to help ). With the various ABSs you have used have you just run a "street" ABS or been able to play a little more? I am persuaded its worth a look because where its allowed by the rules the factories tend to have used them with some success - and seriously talented drivers. BMW M3s were pretty impressive under brakes and even had an "overtake" program where it ran 4 channel low and the car steered itself all over the track with the rear brake bias L/R.

Tassie is plenty wet and there is also the prospect of tarmac rallies, which makes me think I would at least try to have a go. I think the wet may well end up being the only time its used - as you say, a well practiced human can actually get fairly impressive at stopping a race car.

[Sydneykid]

Sydneykid, I hear your comment on the off tarmac stuff (I'm deluding myself that a thumb push button on the wheel to knock out the ABS is going to help   ).  With the various ABSs you have used have you just run a "street" ABS or been able to play a little more?  I am persuaded its worth a look because where its allowed by the rules the factories tend to have used them with some success - and seriously talented drivers.  BMW M3s were pretty impressive under brakes and even had an "overtake" program where it ran 4 channel low and the car steered itself all over the track with the rear brake bias L/R.

Tassie is plenty wet and there is also the prospect of tarmac rallies, which makes me think I would at least try to have a go.  I think the wet may well end up being the only time its used - as you say, a well practiced human can actually get fairly impressive at stopping a race car.

With the Porsches there are a number of programs and different hardware available for the ABS. We have yet to find one that stops as well as the driver can manage. Plus the competition software/controller upgrades cost ~$2K each and the hardware (actuators) start at $3K. They are not the same as or are they modified road car actuators, they are unique. We spend the money elsewhere.

PS; we find the 1.5 way diffs on the GTRs' work better at limiting the inside wheel locking.