So i now have 2 HPDE events under my belt. Both at Roebling Road.

My first was on stock Michelin PS2's with -1.5 degrees of camber all around. It was a blast. I was doing so well my instructor moved me from the green run group to blue after the first session. It felt great and the car just felt smooth. Only down side was i trashed a new set of tires (completely bald on the outside - even the sidewalls) due to lack of camber.

This second event was not as much fun. I adjust camber to -2.8 front and -2.3 rear and went with Nitto NT01 per the suggestion of the guys on the 996 turbo forum (mine is a 04 C4S). Tire pressure started at 27 cold. Saturday sucked. I felt like i couldnt do anything right. Although I did hit my fastest lap of the weekend of 1:28.18.... Sunday morning my instructor said he thought we needed to drop the tire pressure. We were running 35 hot and dropped it to 30 hot in stages. This is where the problem begins. Although my final session of the weekend was the most consistant ( 8 laps - fastest laps was a 1:30.10 and the slowest was a 1:30.89) the car was all over the place. Before dropping the tire pressure PSM was kicking in only at the end of turn 7 ( long sweeping right). At that time it was only the light blinking but i didnt feel anything. After we got down to 30 psi hot, PSM was kicking in from turn 5 all the way to turn 9. Several times with throttle cut. It eventually got to the point where the car started to slide so much i just came in to the pits as i wanted to keep it in one piece.

My instructor was very please with my performance even though i wasnt as happy. His thoughts on PSM and the slidding was more due to the fact that i was much quicker this event than i was at my first. Although he wasnt my instructor for my first and i have not data to support that claim. I took the track wheels and tires off this morning and the wear is perfect across the board so i assume camber is in the right ball park.. The only thing i did notice at the track right after my last session was the tires felt like they were rolling over when we dropped to 30 psi hot. The abbrasions on the tire supported that claim.

my concern is the car felt very smooth and stable my first event and did NOT the second. I have signed up for Sebring in March with Suncoast and that is not the track i want to go to with a lack of confidence. I know its hard to give any thought or advice on this since you guys were not with me. But anyone care to share? Is it more likely to be a car setup issue? Tire pressures too low (my thought)? Just a new driver getting faster and scaring himself?

Screen shot from my Apex Driving Coach

 

Were you at the Citrus event that just occurred? Where in Florida do you live?

Cliff

 

yupp. Casselberry

 

You'll have to play with what works for you.

For HPDE I tend to drive a Boxster S/ Cayman S -- ~200TW tires (manufacturer varies). Your camber seems reasonable.

My typical goal is ~32 hot. Which usually has me start ~26-28psi depending on track temps and grip.

The leap that you likely had from your first and second event probably has a lot to do with it, but you also changed tires and camber.

Without sitting in the right seat -- I'm not going to be able to tell you why it felt like you were all over the place.

I was asked to ride with a student who complained his tires were shot -- and another instructor wanted my opinion -- so I rode along.
Turns out he was quick, but he was cheating into corners, early apexing, and basically man-handling the car to get it around the corners.
It felt like the tires were shot -- because he wasn't really letting them do their job.

A couple laps in, I got him to be more patience and be more smooth, car hooked up nice, and he left the track with a grin and tires he was happy with.

Bottom line, on the surface it seems you have the right starting point. You might just be picking up speed and muscling the car and working the tires harder than you think.
As you are learning, it's more about technique than speed, good technique, speed comes naturally, and then you'll have to work on and adjust your technique to the higher speeds.

IMHO, keep at it. Think about your lines, your turn in points, and your smoothness -- if all that seems good and you still have tires concerns -- see if they have a mentor group
amongst the instructors -- in PCA we usually do -- and they're pretty good with helping folks sort things out.

 

I think the above statement is true in my case. I fully understand car dynamics. I get how the concept applies. I think my issue is actually understanding HOW to apply it in the real world is my struggle. I would highly agree that i am pushing speed to become fast instead of doing it right to become faster if that make sense.

I feel like a scene from Days of Thunder is perfect in my case. He runs around the track a few laps and goes very fast and destroys a set of tires. Then runs around the track the way his crew cheif says to and has a faster lap time and clean tires. Perhaps my instructor is right, all i need is time under my belt.

 

at the DE level if PSM engages more than occasionally to save your bacon you are not driving right.
focus on being smoother with throttle, brake and steering wheel while driving a better line (late apex)

a good exercise to do while driving is everytime PSM engages explain why it engaged and what you could have done to prevent it. no need for stories as you need to focus on the next corner but say words like too early on throttle, not smooth of brake, missed apex etc etc.j
it might slow you down initially but it will make you a better and safer driver whilst saving your equipment


btw check your brakepads please as all that PSM engagement is killing your pads

 

Keep at it, and keep asking questions, just make sure you enjoy yourself while you're doing it.

See if you can get a ride along with different instructors. Watch their lines, watch their hands. Remember everyone has their own style too. If you feel (and they feel) comfortable, and you are still questioning your car -- have an instructor that while you were riding around made
it feel smooth and effortless, and have him drive you for a couple laps in your car.

 

Thay was part of my concern. With the exepction of the last session, all other times that the PSM light came in felt completely unnecessary. The turn felt smooth and the car was almost straight. Then as i would go full throttle it would light up but no throttle cut.

I get it coming on when it started to become loose the last session. I'm sure i am overthinking it. God knows the computer is smarter than me.

Brake pads have 50% life left. However i am thinking of changing them anyway. A lot of people suggested i get a race pad for sebring due to my speed and they said sebring is HARD on brakes.

 

I thinks thats the plan...... if a Sebring next month i feel the same way i will have the instructor take it for a few laps. Then maybe i can get a feel of how the car should feel at sebring

 

So you jumped right from a street tire to an r-comp with very high limits. You also added some camber which will make the car feel much different, especially at turn in. Not what I would recommend for someone doing their second DE. 30 psi hot is too low for the nittos, especially with a car as heavy as yours. I have run countless sets of nt01, love them for a DE tire, and I shoot for 35 psi hot on mine and my car is probably at least 600 lbs lighter than a c4s cabrio (meaning you can probably go higher and be fine).

I also wouldn't recommend focusing on your lap times so early in your efforts here, maybe don't even time yourself. I didn't have any data at all for probably my first 10-15 events. You have enough to focus on, beyond how your times compare to your previous times or other peoples lap times. As an instructor (and a former student) I see the same trend over and over. Students want to go fast before they know anything and the fixation on lap times makes it worse!

My advice would be to slow down. Put the old tires back on if you liked them better. Don't time yourself. Focus on the line, being smooth and keeping your eyes looking ahead.

 

Although I have a Cayman (and before that a Boxster), so I don't have rear engine experience, I seem to have the best results closer to 34-35 hot all the way around on both 200TW tires like Hankook R-S4 and 100TW tires like Nitto NT-01 and Maxxis RC-1. I have tried running lower pressures, and I personally don't like the way it feels. It feels mushy. But others swear by it. Maybe we are measuring our tires at different times or our gauges are 1-2 PSI off from each other?

Roebling has so many long sweepers that if you do get the tire pressure too low, you sped a lot of time with the tires rolled over onto the edges. If you mostly had good even wear on your tires, at Roebling, then that is great!

In my opinion, a consistent 1:30 pace is a really good novice pace at Roebling (1:28 on your 2nd event ever, great job!), but at that pace, in a car like yours (with good camber setup all around like you have, and Nitto NT-01 tires), you shouldn't be sliding the car significantly. It may be caused by technique or tires pressures or a combination. If you didn't like the way it felt at the lower pressures, and if you like the feel of 34-35 hot then I would recommend you go back to that. With the note that all my experience is in Boxster/Cayman so maybe things are different in the 911 world?

As a data point, when I take a green student out in the blue group in my car for a demo at Roebling (on Hankook R-S4) I run a 1:30'ish pace, with no sliding whatsoever.

I won't be at the Suncoast March event at Sebring but they will put you with somebody good (just like the first 2 times, you might even get the same instructor? it cam happen...), and your confidence will come right back! It is a different kind of track, with less of the really long sweepers like Roebling (although it has a couple), but also has some "non-sweeper" corners that are a lot of fun, and don't wear your tires out as much as the big sweepers of Roebling, but does put a little more wear on your brakes than Roebling.

I will be at the Feb Suncoast event so if you make it to that one, come say hi

Steve

 

Before i purchased the Nittos i heard both sides of the argument. I can see both sides and wouldn't disagree with either one. My first instructor was the one who suggested doing so.

As for the timing my self. I did and i didnt. I knew if i was actively watching i would get myself into trouble. What i did was mounted the apex in a location that i couldnt see it. The cell phone was thrown in the center console. I would save the data after each session but did not review until after i got back to the hotel room. And in truth, i was more interested in the data the apex device showed in the corners than i was the lap times. I dont even know what to base my lap times off of. My instructor was the one who was paying attention to the lap times. I assumed my lap times sucked and it wasnt even worth the data point. My instructor was the one brought it to my attention for two reasons. One being the lap time consistancy and the other being his fastest time for the weekend was only 2 seconds faster than mine.

I am aware that a ton of people come out and have watched too much fast and furious and think they could keep up with Lewis Hamilton. I am much more humble in my approach.

When it comes to going fast. I would assume thats up to the instructor. Both of my events ended with my instructors giving me nothing but positive feedback. My first instructor had even mentioned he thought i would be going solo very quickly. My instructor this event had even said he would have suggested a check ride for solo but we both discussed it and agreed it was not a good idea as Sebring was my next stop and that would not be a good idea. If at any point in time i was told to slow down i would have. Both of my instructors felt my performance was on point. I am the one that disagreed.

The decisions i have made were not of my own. All of my car setup, tire choices, pressure, driver aids and driving lines have all been at the suggestion of instructors or people with many years of experience. As a matter of point, i was the one who was thinking we were heading the wrong direction with the air pressure. But i did as the instructor suggested. While it was obviously the wrong decision, i learned a valuable data point from it.

 

In my opinion, totally normal. On my old Boxster if I didn't forget to turn off the "TC" (less featured predecessor to PSM) it would come on every corner just like that (inside wheel spin?), and in my 987.2 Cayman the PSM also comes on just like that, even if the PSM is on standby. So those first sessions, totally normal. That last session where it was coming on all the time, and that was the session where you lowered your tire pressures even more, I bet those lower pressures were letting the car wallow and slide and triggered off the PSM.

 

the more i read the more i am confident majority of my issue was air pressure. When i ran the session with the 1:28 everyrhing felt good and i could feel the car rotate like it was suppose to.

When i say the car was slidding i think i may be over stating that a bit. I only had one situation where the rear end actually stepped out a bit. That was due to my own fault of touching the gator on the outside of turn 1 and 2. I believe the left rear just started to touch the sand and we drifted for a moment before it came back. Other than that it was more like you could feel the sidewalls rolling over and it was pushing to much.

Who knows. My instructor was happy. Tire wear was great. Maybe i am just being overly critical.

 

thats what i was assuming as well. At one point i thought of turning PSM off. Then my brain took over and i thought that may be a little more advanced than what i am ready for.