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Thunderhill video critique.....where can I go faster

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Old 04-05-2009, 04:56 PM
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IcemanG17
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Default Thunderhill video critique.....where can I go faster

Everyone
http://www.youtube.com/watch?v=386X2Wehh5I
Take a look at this video....its from Friday at Thunderhill with me chasing a sweet 997 GT2 (yes a real 530hp GT2) around thundehill in the normal direction.

I'm looking for advice on where I can shave some time..... On a corner by corner basis here is my thinking:

1: I need to brake later & less hard, make sure I use all of the track before turn in...turn in at the 1.5 mark....and accelerate sooner, be full throttle before the apex...currently I'm taking the corner around 90mph
2: I like this corner....I tend to suck inside, on the "racing line"...but I do think its faster to use the school line since it allows me to be full throttle to track out sooner vs the racing line?
3-4-5: I don't think there is a bunch of time to be made here..maybe a little bit..
6: turn in later and get on the throttle sooner....full throttle by apex and power out to track out....
7: take it full throttle (I do "most" of the time)
8: this is where I'm loosing HUGE time....I need to brake less and carry more speed through the corner.....once again be full throttle before the apex..this is the corner that scares me the most....I tend to take this corner around 90mph..I think the car can do at least 100mph
9: I think I'm doing okay here.....I usually downshift to 3rd to get maximum power out of the corner....however my lap times seem about the same if I stay in 4th gear?
10: I'm also loosing BIG time here....I need to stay full throttle until at least the 3 braking marker.....then brake harder to the proper turn in speed
11-12-13: downshift to 2nd....and full throttle by apex or sooner....maybe hold 2nd to just past 12, but before 13...I'm just afraid of a hard 2-3 shift upsetting the car in the middle of 13?
14: Another big time loser.....again I need to hold full throttle longer and brake harder.....the car seems to understeer the most on this corner....in the video the stupid cone was in the way so I couldn't use my normal exit line for 15
15: Ideally I want to be out in the rumble strips to get max acceleration out of the turn onto the main straight....the cone was in the way, so it limited things a bit....

What do you guys think? One other HUGE thing I need to work on is heel-toe downshifting...I currently don't do it...but really need to to save my transmission synchro's....

Thanks
Old 04-05-2009, 07:39 PM
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Tom W
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Edited, after I watched the video ...
You've answered your own question pretty well... but, without being in the car and feeling what it's doing, it's very hard to give meaningful input about how fast you can actually go in a turn. Do you have Traqmate or similar data for real corner speeds or are the numbers you quote estimates from a glance at the speedo on occasion? If you really can go 95 or so in T1 and 100 or so in T8, then you should be seeing lap times about 2:00, not 2:10ish. (For reference, I'm about 95 in T1 and 105 in T8 and typical lap times are about 1:58 with a low of 1:56.) I found a Traqmate to be a huge help in improving my driving. The basic version with rpm is ok, but getting a throttle position sensor and brake sensor would be even better (then you know when you are at WOT, coasting or on the brakes).

If you don't have to correct in the turns because you are losing grip on one end or the other, you are not at the limit and could likely go faster. If you don't get a little 'pucker' because you are sliding out to the track out at the edge of the track and are worried you are going too fast, you can probably do the turn faster.

From the video, it does appear that turn-in for T1 is a bit early and late getting to full throttle.

The line in T2 is ok, but it doesn't appear that you are WOT until you turn in for the first apex and then brake hard. The double apex at 2 is faster than the student line.

You're way late getting on the throttle in T6 T8 and T9. You appear to slow too much for T10 and late getting on the throttle in 11. I use a later apex in T11 to straighten the esses a bit more.

Are you WOT until about the '4' brake marker for T14 with hard braking before turn-in? It's hard to hear in the video. You can trail brake a bit into 14 to help get rotated. You appear to be doing 14/15 fine and the throttle input and track-out from 15 look fine.

There should be no question about being full throttle through T7 and to T8. You should be full throttle by the apex of T6 and not let up until you need to turn for 8 (other than shifting). I don't brake for T8, a 1 second lift is all I find necessary before turn-in.

You should be able to shift between T12 and T13 without a problem. I do it all the time.

I'd be happy to provide a ride or some coaching next time we are at TH at the same event. I'm there next later this month for TrackMasters on Friday the 24th and then racing the 25th and 26th.
Old 04-05-2009, 08:29 PM
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IcemanG17
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Originally Posted by Tom W
I'd be happy to provide a ride or some coaching next time we are at TH at the same event. I'm there next later this month for TrackMasters on Friday the 24th and then racing the 25th and 26th.
Tom
I don't have a traqmate yet.....but am seriously thinking about it...I judge my speed by looking down at the speedo, which is about 5% low already from the larger diameter tires.....

You bring up a very good point about not sliding the car....currently the only corners where I feel an obvious slide is 11 & 14 and its obvious understeer in both cases....sometime a touch of throttle oversteer in 11, BUT I do need to not snap off the throttle in 11 like I did in the video, I should stay on the throttle and steer through it while still putting power down

I'm thinking about Trackmasters on Friday the 24th.....maybe staying for the NASA weekend?
Old 04-05-2009, 08:40 PM
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Brian,

I won't repeat what Tom said, since he was pretty accurate. Rather, I will say that you are frequently adding steering lock at apex in many corners. This tells me you are giving up a lot of exit speed in those corners by having to delay getting to hard throttle while your cars sets on the proper attitude. This is killing your times. You have a relatively large, heavy car that tends to understeer. You need to be a bit more decisive IMO on turn in. Get 50%-75% of your needed rotation done well before apex, so you can be unwinding lock at apex and be on more throttle for more of the second half of the corner. Translation: a big picture way to go a lot faster. And until you can do this, picking apart any but the lowest hanging fruit corner by corner will not be as productive as you would like.

Also, yes, you need to pick up heel/toe. A bunch of your downshifts were very awkward, and are sucking up lots of time.

However, your car does sound superb.







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Old 04-05-2009, 08:57 PM
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IcemanG17
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Originally Posted by Veloce Raptor
Brian,

I won't repeat what Tom said, since he was pretty accurate. Rather, I will say that you are frequently adding steering lock at apex in many corners. This tells me you are giving up a lot of exit speed in those corners by having to delay getting to hard throttle while your cars sets on the proper attitude. This is killing your times. You have a relatively large, heavy car that tends to understeer. You need to be a bit more decisive IMO on turn in. Get 50%-75% of your needed rotation done well before apex, so you can be unwinding lock at apex and be on more throttle for more of the second half of the corner. Translation: a big picture way to go a lot faster. And until you can do this, picking apart any but the lowest hanging fruit corner by corner will not be as productive as you would like.

Also, yes, you need to pick up heel/toe. A bunch of your downshifts were very awkward, and are sucking up lots of time.

However, your car does sound superb.

Professional Racing and Driving Coach

VR
Good idea on turning "more" before apex....I do find myself steering far too much in 1 & 8 after apex..which I know is slow, even though I'm full throttle...I just need to "trust" the car more in the high speed corners (1 & 8)....to carry me through it.....but after seeing a 997 GT3 roll in 8....it gets intimidating

I have found the car will take a BUNCH of throttle in turns....far more than I thought as the tires are heat cycling in....

Another factor in learning heel-toe is it will sound really cool....since I do love the sound of the motor
Old 04-05-2009, 09:04 PM
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Veloce Raptor
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Originally Posted by IcemanG17
VR


I have found the car will take a BUNCH of throttle in turns....far more than I thought as the tires are heat cycling in....


Yes, FAR more than you will think. Remember, this is a heavy, understeering rear drive front engine car. The more throttle you can add in corners, the more the car will squat and grip. In addition, throttle significantly helps the car rotate, and thus enables you to use relatively less steering input. This saves the front tires, and gives you an exit where the front wheels are straighter sooner....which translates to MPH down the ensuing straight.

Obviously, there are limits to this, beyond which the car will understeer past the limits of front tire grip. But that is why I coach folks to approach the limits of adhesion (front and read) in small increments rather than large bites.

And yes, heel/toe on a car like yours sounds awesome!!







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Old 04-05-2009, 09:48 PM
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race911
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Hey Brian, got your PM and had it on my plate to stop over and say hi at some point......but you know how the day goes with students, etc.

As with Tom, many of us would be more than happy to work with you when we cross paths. Soft spot for 928s, as I helped Bob Devore with the initial development of his in the mid '80's (which led to DEVEK, if you weren't sure of 928 engine development history).

And yes, obviously that was me in the Radical. Took my student, then his fiancee, out. First time at the track, so I was in EZ mode.

Lastly, the disaster of the day in that 430! After he nearly chopped me into a wall (I know, I know, up to me to make clear passes), I ended up riding with him on the last session. Ugh. Let's put it this way for anyone who wants a laugh.........dude was driving the car hard, full on the gas, full braking..........we pass a not-even SM into T1...........and he's on our *** still at the exit of T6. And this was a Miata that I passed in my SM in an earlier session to the tune of 5+ sec/lap quicker pace. Do we have a WWVRD (what would VR do) acronym yet?
Old 04-05-2009, 10:26 PM
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Originally Posted by race911
Hey Brian, got your PM and had it on my plate to stop over and say hi at some point......but you know how the day goes with students, etc.

As with Tom, many of us would be more than happy to work with you when we cross paths. Soft spot for 928s, as I helped Bob Devore with the initial development of his in the mid '80's (which led to DEVEK, if you weren't sure of 928 engine development history).

And yes, obviously that was me in the Radical. Took my student, then his fiancee, out. First time at the track, so I was in EZ mode.

Lastly, the disaster of the day in that 430! After he nearly chopped me into a wall (I know, I know, up to me to make clear passes), I ended up riding with him on the last session. Ugh. Let's put it this way for anyone who wants a laugh.........dude was driving the car hard, full on the gas, full braking..........we pass a not-even SM into T1...........and he's on our *** still at the exit of T6. And this was a Miata that I passed in my SM in an earlier session to the tune of 5+ sec/lap quicker pace. Do we have a WWVRD (what would VR do) acronym yet?

Ken
I figured you were busy.......ya I thought it was funny that during the afternoon download session for group A drivers Bonny mentioned the "unsafe driver in the red car"...... I've seen this guy before on the track, but he's never been in my group before...he always did seem to have passengers.... I was never close to him on the track...since I was chasing the GT2 most of the time and that guy is GOOD....plus the car has stupid power...

I got a bit of video when you passed me in the radical.....of course its SHORT..since you quickly disappear :>(

I am VERY interested in some instruction.....the more the better in fact! I signed up for Trackmasters on April 24th & might sign up for NASA over the weekend too....we'll see if the work on the car is done by then? I am open to both having experienced drivers ride with me and have them drive my car too.... I'm always open to ideas about adjustments that make the car better...since I'm still pretty new at this

Its funny you knew Bob Devore....that guy was a serious pioneer in the 928 world.....he had some WICKED 928's......
Old 04-05-2009, 10:41 PM
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Some excellent comments thus far.

I strongly suggest installing a small red light somewhere in your dash area that becomes illuminated with your brake lights. Somewhere in the camera's FOV that is clearly visible. A second light, perhaps green, that comes on at WOT might also be helpful. This of course if you don't have data acq. See picture in the 911 classifieds of one set-up I made, that includes a sequential shift light for RPM's in the camera's FOV.

Exit speed focus will help you at Thunderhill.

Some find that it does not help to go all the way over to the track edge for turn 1 entry. Perhaps unnecessary extra ground to cover. Also, focusing on braking later for turn 1 may not be as productive as focusing on doing what you have to do to get to WOT ASAP. As indicated by exit berm rpm, not mid corner mph. Looking at the speedo mid corner moves your eyes down when they should be up. Sneakin a peek at the tacho on exit can probably be done right before instrument and mirror check.

Experiment with turn 2... it is somewhat car dependent once you are past student phase.

Not sure you how anyone beyond student phase could be less than WOT through 7. Perhaps you could describe why this is mentioned.

I would never, ever, tell anyone to just lift for turn 8 on the internet. Especially in a car that is different from mine. I might tell a student I am working with at a particular t-hill event to consider "losing less speed" there. I do not think my car can go through there with just a lift, but I haven't driven thill a lot in the past couple of years, and the track has most certainly changed. I think I could sometimes could go through there with just a lift with my previous heavy, front-engined, turbocharged car...

I like to get folks beyond the basic student phase to focus on a kind of "attack" feeling in 9 and 10... focused on doing what it takes to get to WOT ASAP. If steering has to be put in after initial turn in, ASAP WOT can be compromised. WHen I ride with someone, typically in the afternoon and they get that feeling at 9, then i like to see them adjust for the extra speed they have at 10 entry... and the same thing with 10 and 11 entry. It is really cool when they get more exit rpms there and take full advantage. It is not so cool when they fail to adjust and blow the subsequent corner, giving it all back.

I couldn't give someone advice over the internet on what marker they should use for braking. It is hard enough from a passenger seat at a given event. Without data acq. or a ride in your car with a much faster driver or a ride in a similar car with much faster lap times, it has got to be hard to know where the limits are. But you can keep some tabs on your exit RPMs, and try to improve them in key areas as you creep up on 100%. And remember, 100% on this day on this track with these conditions and these tires... can vary.

When I started at LRP in 1987, I hadn't read anything but Bondurant, or seen anything but Going Faster! I still watch that video a couple of times each winter now more than 20 years later. Toward the end of Going Faster! one of the instructors narrates laps citing exit RPMs in several corners. You can do that with video in your race car by talking to yourself... if you are careful. A second tach or shift lights can accomplish the same thing. All of course if you don't have data acq.
Old 04-06-2009, 12:44 AM
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icemang17: Don't have much to add to the good comments above. I was in the GT2 and taking it easy as it was my second day in a new car and the LSD was behaving badly. Good to run with you.
I admire the courage of race911 for riding in the F430. On the first run of the day he went by me in a corner and passed two other cars all under a full course yellow. I knew to stay out of his way the rest of the day. I could say something about all Ferrari drivers but think it was just this guy. I also remember the Radical flying past me.
Old 04-06-2009, 01:09 AM
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i know of several very fast and safe ferrari drivers. but there are also some very dangerous one's. that goes for porsche drivers too.
Old 04-06-2009, 01:13 AM
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Originally Posted by rodjac
icemang17: Don't have much to add to the good comments above. I was in the GT2 and taking it easy as it was my second day in a new car and the LSD was behaving badly. Good to run with you.
I admire the courage of race911 for riding in the F430. On the first run of the day he went by me in a corner and passed two other cars all under a full course yellow. I knew to stay out of his way the rest of the day. I could say something about all Ferrari drivers but think it was just this guy. I also remember the Radical flying past me.
You have a VERY nice GT2..... One thing I enjoy doing on the track is following better-faster drivers....I think I learn more following someone than trying to figure it out by myself.....

One thing that impressed me was the power of the GT2...granted I have about 360hp, but the GT2 really pulls on the straights...the only other comparison I have is following C6 Z06's and the GT2 pulls harder from what I can tell (watching both disappear).....

It was fun following you around.....hopefully I'll see ya on the track again soon!

It appears many people had issues with the F430.....I never really saw him on the track other than in the grid..... On e guy posted a youtube video of the F430 passing him on turn 3......granted its "safe"....then the F430 almost gets T-boned....heres the vid

http://www.youtube.com/watch?v=tDMpt...e=channel_page
Old 04-06-2009, 01:29 AM
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icemang17 Thanks for the kind words. I am not faster and better but was doing it all on power. I am stillnot up to my times in my old GT3 but will be soon. the GT2 really pulls on the straights--I am impressed with the power. It is also pretty easy to drive.

Mooty My attempt at humor fell flat. I also know some fast and very save Ferrari drivers and bad drivers of all makes
Old 04-06-2009, 02:15 AM
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Originally Posted by rodjac
icemang17 Thanks for the kind words. I am not faster and better but was doing it all on power. I am stillnot up to my times in my old GT3 but will be soon. the GT2 really pulls on the straights--I am impressed with the power. It is also pretty easy to drive.

Mooty My attempt at humor fell flat. I also know some fast and very save Ferrari drivers and bad drivers of all makes
i didn't mean it as a response to you. i have two ferrari driving buds who are real drivers. but there are many "pretenders" too.

btw, what color GT3 did you have in past. sounds like you track a lot, i must have seen you in the past? did you have both 6 and 7gt3?
Old 04-06-2009, 02:17 AM
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race911
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Ferrari guy is actually OK. A bit over his head, but he's not resistant at all to coaching. NOT knowing Ferraris much at all, seems that car had a big brake kit installed and it had TOO MUCH rear bias. Not even funny too much in the rear. Coupled with 225 front tires, he has to do unnatural things to make it work even at a 10-sec-slower-than-Spec-Miata pace. Ultimately, we all have to know who we're with out there, and be responsible for our own asses.

Obviously, I got to see the day unfold from (slowish) Radical laps at a '55 pace (previously mentioned new to the track passengers), usual sucky 2:13-15 in the SM, and the ____ing disaster of my C4S on street tires that probably didn't go sub 2:15. No way THAT happens again!


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