Advise on Trail Braking

[pdy]

.... Completing my thought for you;

Simply jamming on the brakes will unsettle the car, and ABS will keep you from looking too stupid. But it will make the braking time/distance more than
judicious and smooth application of the brakes, with or without ABS.

ABS just MIGHT allow the good driver to brake better, but unless it works right at the limits, it won't be an improvement over the REALLY GOOD driver.

[Jad]

Paul,

I think you make a very good point about have to brake properly to settle the car and let the ABS work at its best. However, I disagree with your comment that it won't help a really good driver as it does allow each of the four wheels to brake independently at their limit, which can not be done with one brake pedal and is required for maximum braking with surface variations, let alone turning and trail braking techniques.

Basically, I think ABS makes every level of driver better than they are, but that does not mean a bad driver with ABS can outbrake a good driver without.

[Bob Gagnon]

In the 964 Carrera Cup series, the cars were set up by Porsche with an ABS switch so the drivers could turn off the ABS if they chose.

My understanding is that most driver's left it switched "ON".

Also, in developing the 3.8 RSR Porsche had the option of developing the car without ABS at all, and used ABS with an ABS controller of different design than the normal 964's controller. I think that it merely incorporates the faster sampling rate of what is now in 993 and later ABS 5 equipped cars.

So in these circumstances, since the drivers and Porsche chose ABS, it must have had some advantage.

BTW, I wanted to buy the RSR's ABS controller which has the same part number as my stock 964 controller but with a "G" after it. That "G" would have cost $11,600 more ($12,400 vs $800) than my stock controller; yes, I did not buy it.

[kurquhart]

In the 964 Carrera Cup series, the cars were set up by Porsche with an ABS switch so the drivers could turn off the ABS if they chose.

My understanding is that most driver's left it switched "ON".

Also, in developing the 3.8 RSR Porsche had the option of developing the car without ABS at all, and used ABS with an ABS controller of different design than the normal 964's controller. I think that it merely incorporates the faster sampling rate of what is now in 993 and later ABS 5 equipped cars.

So in these circumstances, since the drivers and Porsche chose ABS, it must have had some advantage.

BTW, I wanted to buy the RSR's ABS controller which has the same part number as my stock 964 controller but with a "G" after it. That "G" would have cost $11,600 more ($12,400 vs $800) than my stock controller; yes, I did not buy it.

I never said that it was a disadvantage, so I don't feel a need to remove it (or turn it off). However, it does not stop my car (90 C2) faster, so it is not a performance advantage for me. It does save flat-spotting tires, so it does have an economic advantage.

The Cup cars have the same high pressure brake system as used on C4 and Turbo. Do all of these variants use the same ABS system?

[Bob Gagnon]

It does save flat-spotting tires, so it does have an economic advantage.

The Cup cars have the same high pressure brake system as used on C4 and Turbo. Do all of these variants use the same ABS system?

I think you are "right on" with the flat-spotting, which in a race could be more than an economic problem.

The C2, Turbo, RS and Cup all use the same system, the pressure source doesn't affect it significantly.

The C4 uses a slightly different system since it has to adjust for the 4 wheel drive.