Jack667

Hi -
Please review and comment on the video. That's the main goal: some feedback.

I can be verbose at times, and I get that... So - the rest of the text below is optional!
Not sure if this belongs in "ask the Coach" or it's own thread. Going with the latter...
I've been doing DEs since 2000, and some Club Racing, and for the last ~8 years, been instructing at DEs exclusively. Max days in a season was 22, but it's pared way back since the 3 kids came along! Now, usually 0-2 events per year. Started with a 964 C4 cab, then a 944, and now a 997.1 C2S - my only pcar at this time. I've been on track with the 997 a few times. Fall of 2013 at Road ATL. 2014 was an off year - no events, then a fall 2015 day at AMP - first time there.
I went back to Road Atlanta for March 5-6 BMWCCA DE and had a blast - as always. I'd like to get back into it a bit more. I'll be back again on Monday, March 28th with Chin.
I have Harry's Lap Timer working now, so you see some data overlaid on the video. I just bought an external GPS and an OBD accessory, so expect more data, and slightly more accurate GPS next time - not that there's an issue, but for $80, why not?
Car setup: stock, daily driver coupe, with some track-oriented mods: Bilstein Damptonics, DSC Sport, RSS sways, rear control arms, dogbones, toe links. WEVO engine mounts, Guard TBD LSD, sporty street alignment. 18" OZ Allegeritas w/Nitto NT01s. Pagid Yellow/Black. Stock safety - that's the next thing to go in, but I had the 3rd radiator installed and the MantisSport 2L oil pan is going in prior to the Chin event. it does make it tough to get tossed around in the 3-point belts, etc.

Specific Concerns: I feel like I'm driving at 9.5/ tenths, almost like on a Qualifying lap (example - going over the curbing at Turn 3, 5 exit, and 7 exit), but I feel like I should be about 5 seconds faster. Maybe I should be 2 seconds faster and driving a 8.5 tenths with my street car! I probably overbrake at 1 and really all over. My line is probably a bit sloppy, but how to fix it, specifically? I'm staying in 4th down the front straight and I probably need to go to up 5th and then back down to 4th for Turn 1. I see 1.2Gs on the HLT data for a millisecond at Turn 9 and that kind of scares me - how should I fix that line to cut down on the lateral Gs there? What else have you got?

I can provide more video but let's start with this - tell me what you think!

TIA!
Jack

DOUGLAP1

Since none of the local experts have commented, I'll jump in for you. I am running almost identical lap times to you in a 986S, with a somewhat similar set-up on NT-01's, so take it for what it's worth:

Down the front stretch, I can't get up to red line in 4th, but you may (I think we have similar gearing, and you obviously have more Hp), but I doubt going to 5th would buy you much there. I have to go down to 3rd to pull the hill coming out of 1, where I am again on up there in revs but below red-line. I think one of the keys to a good time at Road Atlanta is maintaining speed through 1, and letting the hill catch you. However, when I do this in 4th, my engine seems to fall off the cam.

Your turn in to 3 is a few feet earlier then mine, though I try to catch about the same amount of curbing as you. Your turn in at 5 and 7 also seems to be a couple of feet earlier than mine, but not a big difference.

At turn 9, I take a significantly later apex, which has me staying up against driver's right going straight down the hill into the braking zone for 10A. I don't normally run with a g-meter, so I don't know what I'm pulling there, but it does not seem like many lateral g's at all for me.

I do sometimes miss the "gravity cavity" days before there was a 10A & 10B. Back then, we pulled a lot of g's in 10 with an immediate uphill braking zone to the bridge. One time in my Lola S2000 car, I didn't finish my braking by the crest of the hill, and it spun me around like a top coming out the other side. I guess it's a bit safer now, though the dirt bank at 11 will always concern me a bit.

Have fun.

ProCoach

Damn. I MISS the Dip SO much. Made the Bridge turn VERY exciting!

Still trying to break 1:30 flat on the "new" (post-1998) track in my 150 bhp Sports 2000. Those are fun cars!

Good luck to the OP. Like most tracks, Road Atlanta is faster than it looks, but to go fast there, you need to know where to go slow...

DOUGLAP1

Damn, you got 150 Hp! I don't think Rollin ever got me more than 145. I managed to get in the high 1:28's in the old configuration, but don't think I could do anywhere near that with 10A and B in the way.

ProCoach

Ok. Got through the first minute and see time to be had. Mostly focusing around raising incrementally the vMin for T3/T5/T6 but MOSTLY, reducing the amount of time, hence distance covered, under a particular threshold speed.

The GPS sample rate is WAY too slow to be of accurate use in speed charting, and the accelerometer is not particularly snappy, either. You could fix that, but you'd need a VBOX Sport to do it. As it stands:

:05 Lazy off throttle/on brakes. Too early, wait until 100 at least, then brake harder for a shorter period of time.
:08 EXCELLENT turn-in and NICE steering wheel speed and amplitude effecting a very good trajectory through T1, but late on throttle.
:11 EXCELLENT apex positioning.
:14 Too quick back to the right, elongate arc.
:16 Too quick hands to the left, bisect center seam longer.
:17 WAY too early against the left edge, need to end up where the Bimmer is.
:18 Too early turn-in to the right, which is not surprising, considering the poor trajectory begun at :16 and early apex at :17. You're a passenger...
:20 Completion of not optimal angle of incidence at the T3 apex because you're pointed at the dirt, not at the track downstream. More rotation earlier would help. You want to "slide across" to the left, not have to drive there.
:20-:22 Nothing going on, no commitment to brakes or power, speed stays the same through T4 way too long.
:22 Pinching exit. Let the curb stop you and stay on it for as long as you can.
:25 Not enough power application
:28 Hands turn the wheel too quickly to the right, but turn in point is correct.
:30 Early...
:33 Bad trajectory/early. Like T3 but flipped. Follow the last left curb around a car length or two more to OPEN the T5 entry a little more. There should be space between the right side of your car and the BEGINNING of T5 outside entry curbing. Your goal is to end up at the same point and duplicate the same heading of the Bimmer.
:35 Continuation of the sub-optimal trajectory established at :33. Coming away from the curb TOO SOON. Should be, at this point, aimed at the telephone pole in the distance with the transformer on it. Bimmer overshot the apex... Should have carried brakes in a little more to get the car to turn quicker.
:37 Late to power, not a good angle, similar to your exit of T3, aimed at the dirt, not downstream, could benefit from more rotation sooner.
:50 GREAT braking and brake point Highest decel number noted. Good turn-in point, just holding brake a little too long and aggravated by late power application.
:50-:52 Not much happening with either pedal...
:52 Good apex placement, maybe carried a little too long, function of late/soft power application
:55-:56 Lackadaisical braking. Ideally, THIS is where the decel rate that you demonstrated you were capable of in T6 should be used, if only for an instant.
:56 GOOD turn in and hand speed.
:58 GOOD apex but need to use a LOT more of it. Maybe carry brakes just past steering input to nose it down MORE? Then, you would be able to apply WOT sooner. Also, more rotation sooner would prevent the next note...
1:00 Trajactory to trackout too far left, too soon. You should hit the ext curbs parallel to them, not so acute, like this example. You're pointed at the dirt for too long a time after apex...

You've got the tools and not a bad drive. But I can see why you're stuck.

That's enough out of me...

Jack667

Wow! Now we're talkin'! The turn one thing - addressing comments from both - is (I believe) related to the gear shift choice - or really lack there-of. Where coach says: ":05 Lazy off throttle/on brakes.", I think that's due to flirting with the redline in 4th. I may be wrong though, but if I don't go up to 5th and then back down, i find myself coasting to the braking zone.
Excellent feedbak including late apex on turn 9. All advice from Coach is spot on. I can see that - early...
I was spoiled in my 944. People say it's hard to drive a slow car fast, but I would go WOT through esses (and all over) and I'd never get fast enough to cause any problems. Now I have way more power and it's a challenge to modulate the throttle (totally new concept!) and I need to be way more precise with my line.
I'll be out again on the 28th and I'll have a new external GPS with a faster sample rate, as well as the OBD sensor for throttle position and RPMs.
I really appreciate the feedback!!

tkerrmd

amazing how much you can learn and improve when you actually hire a pro coach

Jack667

I think I would like to do that, but I need to find one available, and - somewhat more importantly - I need to commit to doing this more than once every 2 years. I'm in the right track (!) with 2 events in March, but I'm not sure when I'll get back out again.

I've given plenty of advice here on Rennlist over the past ~15 years, so I don't mind asking for some once in a while, especially as a Rennlist member.

jdistefa

Yup. And that was very generous of Peter re. donating his time for very good professional advice.

Jack667

I agree!!

I posted:
"Wow!"
"Excellent feedbak including late apex on turn 9. All advice from Coach is spot on."
"I really appreciate the feedback!!"

I'm even more excited for the advice than the words can articulate, and I hope my gratitude was conveyed appropriately.

mkd944

At :40 in your video, exit of T5, there is an audible thump and the car loads and unloads because there is a dip at the end of the painted rumble where it meets the pavement. The line in my Miata takes me completely to the right of that dip. That may not be optimal in your 911. It may not affect you lap time, but I try to avoid the dip just because it really jars my car and I don't like the way it feels. Also, 10a, I like to hit the rumbles and square off the turn just slightly more than you did to set up for 10b where I will also hit the rumbles. If I get it right, I hear brrup...brrup. I only here your brrup in 10b.

Great feedback from Peter and DOUGLAP1. As stated previously, your turn-in at T9 is too early for your high HP car. Doesn't make any difference in my Miata, but I did a check ride at the Chin event 2 weeks ago for a red group driver in a 996 GT3 who had not been to RA in 10 years and was actually breathing off the throttle because he was turning in too early in T9. Once I got him to the later turn-in point, he carried full throttle all the way to the brake zone. Your turn in point should be somewhere around the black flag station.

Overall, I thought it was a pretty good lap with some room for improvement. And that's why we keep on doing this. We're in search of that perfect lap.

Jack667

Awesome feedback Mike! Thanks!!
I can't wait to get back in two weeks and try out all of this great advice!!

ProCoach

And it's my pleasure to help, when I can.

007DT

AGREED!
Great input..
Very Generous and Analytical based on video alone...

Veloce Raptor

I just had a chance to watch .
Adding to Peter's points: get into apex of 6 sooner and hold it longer due to tons of good camber there. Also makes a gentler arc=less braking needed. Also, get a bit closer to the apex curb at 7. And use lots more apex curb in 10A