ivangene

thanks for replys

just for my own knowledge, what class did you put yourself in (beginner / intermediate ? )
the tire presure seems a bit high - anyone else care to comment on that one ? This is on PS2's and hot day out (track temps over 100 my guess)

the camber in front is basically zero...with the US standard I ran those numbers and had some great straight runs (although I was trying to turn - bit of push!!) and I could get the back upset and have it come around quite easy if I wasnt very smooth (which I wasnt a couple times) because of the imput + body roll + lack of slowing down in the head = spin rule (autocross is a bit more forgiving in this event than PR would be)

my last run, last month was by far my best ever. I have to say, I really slowed down...I know it seems backwards, but I was overdriving and over compensating and trying way to hard...I really wanted to be fast.... but when I slowed down, I actually was fast....this is no substitue for more seat time and I hope your next run out will give you a better return on your money/time investment - for me, I hope I remember that last run this weekend and build on that not spread my legs and WEEE all over what little i have learned

BimmFiniti

Good list. I need to work on my smoothness and these points.

I don't think I was pushing it too much, actually. Nothing stupid; never got into any trouble. I just wasn't happy with the result.

BimmFiniti

I was classified last year as intermediate based on last year's track day. I was in "C" group and held my own OK.

Just the stock numbers. You're right, it was a warm day.

Sounds familiar. I can see how it would be much easier to be smooth and not rush with more seat time.

mglobe

Getting some more negative camber in the front will help with the push. But as many have commented here, seat time will also. You've come from a car that has a dramatically different weight distribution. I've watched a number of drivers who are much more experienced and talented than I am jump in my car from their front and mid-engined cars, and have to adjust. They adjust quickly because of their level of talent, but the first lap or two gives them a challenge. Give yourself time.

DCP

I go to track days with my brother, who just happens to have a 01 330 with the sports suspension. We trade cars of course.

I know what you mean on the understeer and the overdriving. In comparison, the BMW is far easier to drive to its limits. As you will soon learn, that is part of the 911 addiction. Learning the right speed and right technique to get the car to turn in and then, when you are able to get to the apex with the right speed and car attitude, the ability to get on the throttle with a heroic application of throttle to the end of turn, well, it's truly great stuff.

himself

Yikes! 36/44 cold will make those PS2s sing like a banshee when warm! They don't really like over 40 HOT when on the track. You can expect ~10 lbs increase in tire pressure with the PS2 from cold to hot. Running them at 46/54 isn't necessarily unsafe, but very far from optimal. You will find it more enjoyable if you start them at 32/32 next time, and then bleed them down to 40/40 [or even 38/38] after your first session. **be sure you fill the tires back to factory specs when you leave the track!**

Next alignment, you should try to get another -.75 to -1 degree all the way around. It will make the car a lot better. It might eat tires faster though.

On my car my alignment specs were:
Camber Front (R/L) -1.99 / -1.99
Caster Front (R/L) 8.0 / 8.0
Toe Front (R/L) .05 / .05

Camber Rear (R/L) -2.48 / -2.52
Toe Rear (R/L) .17 / .17

ivangene

My first run in my car I had the tires pumped up too... I figured that was pretty high and would get some feedback....

so the tread rating on the PS2's is 220, and the Sumi ZIII's is 300... I need a little more air in the sumis than a PS2 (RIGHT?) higher number = harder tire = softer sidewall from what I have been told - will will check them and try for about 40/42 hot

do you take a pump to the track or just fill up at the gas station on the way home or at home once you arrive? -

himself

You don't want any tire to get too hot and have them eat the middle of the tire away. You want pressures that give the most even contact patch. The easiest way to tell is with a pyrometer.

FWIW, I ran my Sumis on the track a few times in the wet and then when it got dry. I ran them at just under 40. They were fine at those pressures. But in the rain, they were actually quite crappy

Also, at our track, we have trackside support with compressors. I'm sure someone at your DEs will have a tank.

-td

JimB

I guess I'll throw my 2 cents worth in although I agree completely that getting a good instructor to help at the track is much more valuable.

To those I contradict, sorry. I could be wrong.

1) Do not brake in a straight line. I teach students on their first day on the track to brake (at least lightly) through turn in. It is very important to keep a little weight on the front. This will really help rotate the car before the apex.

2) Each corner is different but think in terms of a geometric apex. Not early, not late. It's a nice point to adjust from. A late apex seems like the right thing to do if the car is pushing but it's not. If you can, you want the car rotated without taking a late apex line.

3) Try carrying a little more speed and maybe a higher gear. A slow in, fast out approach will make the push worse. At least give it a try. It should allow you to be a little lighter on the throttle in the second half of the corner which will reduce your understeer.

So, brake longer, lighter and though turn in. (Hard and late can come later) Focus on getting the car rotated as much as possible before the apex. Apex where it's right for the corner. Late is seldom the right answer. Carry a little more mid-corner speed. Exit with as much throttle as you can while managing the push. Push is not all bad. At least it's easy to compensate for.

Finally, forget the 330. I have a 650 I took out on the track for fun earlier this year. There is nothing like a few laps in a (non M) BMW to make you love a Porsche.
Jim

russo

There is no substitute for seat time, and more seat time. Tire pressures were way to high, a good starting point would be 31 psi cold.

BimmFiniti

Interesting comments on tire pressures. So you set them up so differently on the track (same pressure F/R, lower pressure) vs normal driving (significantly higher rear pressure)?

BimmFiniti

I can see how this might help me gradually let off the brake, too, in addition to helping the car rotate better.

I was wondering about trail braking with a late apex. They don't seem consistent with one another, which I think is what you're saying. If you're getting the car rotated right after turn in, you're not gonna' hit a late apex!

I'm a bit worried about coming in too hot, though. For me, I think I need to slow the car down, then gradually come off the brake to keep it smooth. I think I'm doing things too suddenly and I'm afraid a late braking might make that worse.

I'm not ready to drop the 330 just yet. I enjoyed my track days with it much more than this last one with the Porsche, which was a bit disappointing. I need to get back out there again. I want to like driving the 996 more at the track, not less, that's a big reason why I bought it. If that doesn't work out, a switch to an M3 may be in order.

Ahmet

I don't want to try to diagnose your issue over the internet, but the answer to understeer is to have more weight on the front tires... I remember taking a student (and friend, is the only way I drive student cars) out in his 911 where he was complaining about understeer at the end of turn 1 at VIR, all it took was coming in hotter, I was actually getting some oversteer...

I've known a few people who've switched from M3s -I'm actually one of them- to 911s, the 911 is more fun. Don't judge it from one track event, your first back to the track at that. It is more capable, but more importantly FAR more satisfying to drive. I will voice my opinion on the suspension one more time though, I think the stock suspension is far too soft. You're also not running a lot of camber, about 1.8 degrees front and rear makes the car more balanced but you don't NEED to mess with anything other than getting more experience, in my honest opinion.

JimB

No need to come in too hot. You have a softly sprung car which is good for grip but not good for transitions so minimize your inputs. Brake a little longer, a little lighter and through turn in. As you are dialing in steering and coming off the brakes you should feel the car rotate a good bit more as it's rolling over on it's suspension. Once your suspension is set roll through the apex and begin applying just enough throttle to feel the front start pushing a bit. You can correct by either unwinding your steering ever so slightly or feathering the throttle a bit. 996s are very fast is stock form if driven right.

Remember, driving fast is all about managing weight. In a car without much platform (race speak for soft) you need to move your weight around carefully. If you are not careful, it's easy to allow your weight to work against you in a soft car. Think about moving it to where you want it slowly. Slow being relative of course.

Does that make sense? Discussing driving on the internet is very difficult.

DCP

Thank you for posting this. Your points one and two make sense to me. I am struggling with the third point because coming in faster seems to make the turn in to apex understeer much worse. Do you mean that I should be coming in faster in order to trail brake to the apex to help the car turn in?