The ultimate ABS system for these cars is the BMW RSR system. It is about 12k installed.

 

PSM pre-charge pump disconnect is all you need.
Verified and true tested over and over again.

ABS and electronic brake balance will work excellent.
No PSM activity going on whatsoever, even under braking with the car sideways and opposite lock, the PSM will leave you alone to sort it out yourself.

All warning lights will go away when you plug the pump back in (and restart the car).

Doing this also significantly reduces the risk for any brake overheating (as long as pads and fluid are fresh) since the PSM doesn't constatly jab the brakes for everything you do.

 

^^ Amen to that ^^

I've gotten more laps out of my brakes now than ever before!!!

 

How do you disconnect the PSM pre-charge pump?

 

Conclusions = After my second WG day & this forum's feedback, i have concluded that the stock psm parameters cannot take into account g-forces the Hoosiers provide. I had my 2nd day at WGlenn work out very well with no interruptions running in the 'off position' (asides from a weird over-abs'ed braking episode). Drivers I have spoken to with Corvettes, Porsche's, BMW, all run stability off with Hoosiers due to similar complaints. I admire the ability of Hoosiers to grip so well but also realize their grip points need to be respected.

I wonder if posche tests cars with hoosiers or is it only the M-Sport Cup tires? Also I am surprised there is no tuners of the psm system to move up parameters for track use.

sechsgang = i have seen your efforts to build the ultimate turbo race car, there were alot of odd tasks you had to deal with along the way including abs and psm issues. I would consider another car to experiment with, perhaps a 996 or 997 gt3 to continue the driving experience...

 

Open the front trunk.

On driver's side you have a plastic cowl/cover with a hole for brake fluid and this same plastic cover holds the interior light.

Remove this cover.

Now you see the brake master cylinder and the ABS unit. Next to the ABS unit, kind of under the master cylinder if I recall the stuff there right, there's a cylindrical pump, this is the pre-charge pump. Unplug the power connector (fairly thick black and red cables supply power to this one).

I was about to place a switch inside the car for this cable, just to be able to quickly have some fun with the car and no PSM interference doing so.

There's a photo somewhere around, maybe it was in the "Dangerous brake problem at Nurburgring" thread.

 

Thanks MrWhite, I'll check this out. My driving is finally starting to cause the PSM intrusion and I want to be free of it.

 

Here are the pictures

 

Of course no manufacturer is going to test their car on hoosiers. There is no reason too, however the characteristics of an MPSC and a Hoosier are not that much different so the cars should handle them better. However many cars throw fits with race tires on them. The problem with the 996's is that Porsche tried to make the PSM unpreventable which is terrible.


You can still go fast with PSM on with hoosiers. That is a fact. But you have to be very gentle with turning inputs. There is no tossing the car around and the car is less safe IMO. But PSM off interruption might be worse with the "brake checks" because it just taps the brakes and doesn't cut throttle so you could have no idea that the brakes are being applied. That is just plain hazardous, but as long as you let the car catch itself and not try to drive through any sliding once it thinks you're in danger, you'll be ok. Trail braking is also not a great idea.

 

It's hard to go medium fast without some fairly dramatic steering inputs here and there. It's impossible to go VERY fast without trailbraking, but we are talking 9 to 10 tenths increment here.

Also, the most fun thing about a 911 is to use throttle steer to adjust lines at certain points (ie T5b at VIR), and PSM doesn't like that at all.

I think it comes down to the fact that hoosiers require a certain level of skill/experience. That skill/experience envelope is WIDER than PSM's is, so if you've gotten to the hoosier point with PSM on, you haven't really experienced what you should have (ie catching a slide with the right amount of throttle and getting ready for the swing around...).

 

To an extent you're right, but I'm talking about hardcore trail braking, not barely doing it. PSM will give you fits (on or off) if you are really trailing to get rotation into a corner.

My point I guess is that when you trail brake into a corner (with PSM off), the PSM thinks you need it and continues applying the brakes even after you let off so when you transition to hit the throttle, it's still pressing brkes. It's design promotes making you go off the track forwards instead of the backwards tendency of Porsche's. This is not a good thing for drivers pushing the limit of their car. Trail braking is controlling your slip angles. PSM doesn't like slip angles when you're heavily loaded.

 

I think I'm going to disagree: driving with PSM on is no problem, even with R-compound, however... you need to have a clean driving style (which is the quickest driving style for a 996 turbo). PSM even allows for oversteer out of a corner. Not like the drift-freaks... but a normal amount is no problem.

But you do need to run a perfectly set-up car. If the set-up is off, PSM will bother you. Big time. But then, try running without PSM... you will experience a car that had to much under- or (less likely) oversteer.

I recall reading a test in which a racecar driver tried a 996 C4 with PSM on and PSM off. He was quicker with PSM on.

So first: make sure you are running with a perfect set-up. Then decide whether you want to run with PSM on of off.

 

I'm going to have to disagree with your disagreement. Most driver ed programs and other driver training programs, for very good reasons, teach a *smooth, gentle* driving style with very little mid-corner correction. This is a great way to learn, but like anything, it becomes completely wrong at a certain experience level.

The way to go faster is to keep the car right at the edge of grip in a constant dance with the front and rear contact patches fighting between how much grip you need at the front to turn versus how much you need at the rear to accelerate. This dance requires lots of constant throttle and steering adjustment to maximize because the equation of braking vs turning vs accelerating is VERY dynamic.

"Clean" driving is safe and is a good way to learn the smooth transitions you need in order to get to the next level, but it's NOT the way to drive really fast. If you have hoosiers and pagids in the black group, I would assume you can trail brake very well, catch a tank slapper, barely touch the ABS in most braking zones and make thousands of little throttle and steering corrections per lap. If you can't do all that, you should learn how on street tires with PSM off, then move to hoosiers.

 

Thousands? That's a bit much, you do not need thousands of corrections unless it's the nurburgring, and even then, not that many. On a 12 turn track like Road Atlanta or even tracks with 20 turns you'd need almost 100 corrections per turn just to break 1000. That's way over the top.

I see your point, but I think it is over the top for a DE. Even guys who race are not 10/10ths in a DE. The problem with modern cars is that they are still capable of very high speeds with or without traction control.

 

Thanks for the pics SpeedFreak