Chris C.

Strangely enough they teach trail braking in 911s to all newbies at PDE. I guess it shows how good the new cars and PSM are that they don't worry about Trailing Throttle Oversteer.

1AS

Bob,
I truly can't help myself sometimes.
Perhaps I should have mentioned that trying this in an earlier series 911, such as a 964 will immediately result in excellent oversteer, control of which separates "Porsche driver" from "driver". That is a definite "don't try this with your wife in the car" tidbit. AS

MJones

The major reason: at the end of the brake zones the track falls away into the corners on T1, 5, 7, 11. your just keeping some weight on the nose to aid turn-in.

Bob Rouleau

Alex - you are too good at this and no longer remember how it was in the beginning

The most common cause of understeer is accelerating before the apex.

I prefer not to teach trail braking to anyone unless they can show that they:

Can apply and especially release the brakes very smoothly;
Have adequate feel for the car to detect incipient oversteer.

In a 911 the safest way to enter a corner is the brake in a straight line and drive into the corner at a constant speed, i.e. just enough throttle to neither accelerate nor coast into the corner.

Best,

mdonline

I took the autocross school today in San Francisco. I had a really bad case of understeer in the oval exercise. The car had so much power that when I exited the apex, I just couln't keep the car in the course. Didn't feel like I was going that fast, but I must have. I was expecting that the 997 should stick like glue. I was surprised how little it takes to get out of the control.

So I take it from this forum that understeer is not a problem with the 997. This must be MINE.

Well with all the understeer I was doing, I scrubbed off at least 75% of the rubber in my front right tire, OUCH!!!!!

Bullet

Read the post just aboe yours and you'll surely find the answer to your problem there. You were likely acelerating during the turn. Acceleration shifts weight to the already huge and grippy rear wheels, so your front wheels have ess turning influence - hence, understeer. A VERY common error, and a nice way to practice inducing understeer. The key, as has been described is to brake in a straight line (putting weight on front wheels) then turn in and keep a neutral throttle through the turn. It takes practice, but it is the first step. Once you can manage braking well and neutral throttle, there are other tricks to learn, but you have to walk before you run. Well, you don't really, b/c the car is so great and PSM will save you usually, but if you wan to improve and not plateau, you must first walk.

yemenmocha

Two things...

1. I agree with the others that the driving school option is something you really ought to do. I've only had a one day event (well two events). I learned the limits of the M3 on the skidpad, what it is like to go beyond those limits, what it is like to catch the car from going further, etc. Now I can easily sense when I'm getting close to that point and given that I'm on public roads this rarely happens. I "know" my car much better because of the school, I'm safer, and have a lot more confidence in my abilities when in that car. I can't wait to do the same at as school using 997's, probably Barber or PDE this next year. I'm mostly concerned about the rear weight issue of course. Until I get more comfortable with that I can't see myself taking the same turns as I do in the M3. Gotta respect the car's limits and your limits.

2. Can anyone recommend further books or even better, DVD's that are worth seeing/reading? I know it's no substitute for driving school but it might make a good supplement.


Aaron

Crazy Canuck

Going Faster! Mastering the Art of Race Driving (Skip Barber)

Speed Secrets (Ross Bentley)
Speed Secrets 2 (Ross Bentley)

They are the best of the bunch that I have purchased.

1AS

Believe me, the 996 tt has the problem. If you didn't feel the problem, the ASC was making it invisible to you, and you weren't sensing the ASC intervention. Or, you weren't going fast enough.
You won't feel it unless you are past the point where the tires squeal (that starts when you're reaching about 90% of available grip)
If you go past that point, the car will push, particularly if you are on the throttle. To avoid it, you need to manage the weight distribution.
It is intentionally designed-in. You have to learn to drive to work around it. AS

Tbred911

ditto on the alignment.... HUGE difference.

mdonline

This is what I learned after two days of autocross school. BTW, Golden Gate Region, Bay Area, Zone 7, put on a fantastic event this weekend. Lots of seat time. Highly recommend it.

1. 997S is like a rocket ship in second gear. Throttle response is amazing. Throttle too early before the car is pointing at the apex will cause severe understeering. Too much power for an amateur like me.

2. The rear tires are like glue. It is very hard to induce oversteer. With all the power and weight in the rear, I was fighting understeer the whole two days.

3. Braking is amazing in 997S. Trust the brakes. Stomp on it and ABS will save you (not good driving techniques but works well for an amateur like me). Toward the end of the class, I was braking very hard, turned the nose, and accelerated through the apex. With hard braking, I was able to shaved 2 seconds off the clock. My instructor was screaming brake brake brake, and I waited for another split a second before braking. Even the instructor was amazed of how well the brakes worked. Yup, thank you large calibers and ABS!

krC2S

very true..in lower speeds the car is pretty stable..very little oversteer with just throttle

but don't be fooled...with some momentum and not much throttle.. a bit agressive with the steering wheel can easily induce oversteer..it's the pendulum effect of the 911!!

i second the alignment is HUGE + if you have ps2's they understeer less then pirelli's it seemed

just track it !!