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I’m encouraged by the WGI thread and thought I’d post up my lap from Sebring. I know I am leaving time on the table in turns 1, 5, 14, 16, and 17 but am curious to hear everyone’s feedback.
For reference, this was only my third time out in the car and I was on heat cycle 10 for this session with my Pirellis and was driving fairly conservatively.
this was only my third time out in the car andI was on heat cycle 10 for this session with my Pirellis and was driving fairly conservatively.
We'll keep that in mind!
Busy at Chin for the next few days, but I'll take a look and add to other's observations, for sure.
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Mike, I just took a super-quick look at the video. 996 Cup is still the bomb for me!!
A few observations: first, much of your low hanging fruit will come via the brake pedal We will get too that below. Second, really nice relaxed body language in the car!
T1: yeah, there is time here. What jumped out at me were two things, primarily. First, you really spike the brakes hard (based on the red bar) and then spike off them shortly thereafter. Very little trail braking. And as a result, IMO, you had to be very judicious with your initial throttle take up due to the chassis not being settled. If you could reduce the spike a little bit (maybe 10% less?) but trail a bit farther into the corner, the platform would be much more stable & ready to receive throttle, and you'd actually be able to raise vMin by a few MPH. Second, you pinch the second half of the corner a bit, IMO. Look where you are finally tracking out--nearly at the end of the curbing. Given how bumpy it is there and how this causes you to be hesitant with resuming 100% throttle, holding the car in the corner longer isn't helping. Starting the gradual release of steering a tiny bit sooner will put you at or on the track out curbing a few feet sooner, but more importantly, it will give you a bit more stability over the bumps (due to less energy bound up in the steering), thus allowing more throttle there.
T5: choppy with brakes which causes the car to porpoise a bit, which causes you to have to quickly uncommit & then recommit to steering, all of which scrubs speed.. A bit more smoothness with trail braking will allow a little bit more speed and one steering input. Left foot braking helps a lot of people here.
T7: slightly smoother trail braking, a tiny bit deeper into the apex, will allow a bit less overall braking (which means an extra MPH or two of vMin) and will also allow you to begin straightening the wheel a few feet sooner, resulting in more MPH by T10
T10 & T13: excellent trail braking!
T14 (Bishop's): yeah, there is time here too, solely related to your comfort level going to & staying at 100% throttle once you shift to 5th gear. Gradually work up to it, but you AND the car can do it! It will change the dynamic of the brake zone in 15, however
T15: biggest issue I see here is how much steering you are holding (and adding) after detaching from the apex. IMO, if you start rolling the car into the apex a couple feet sooner, but more gradually, which will get you on the apex curbing sooner, but roll over the apex curb for longer, you will be able to be wheels-straight way sooner, before you bend it to the left to set up for 16. In doing so, as you practice it, you will gradually develop the confidence to brake a tiny bit less for 15, since you won't be needing quite as much steering angle.
T16: huge brake spike, which upsets the chassis enough as you begin turning in to cause you to have to be super hesitant rolling to 100% throttle, and even do a small breathe before you even get to track out. Be softer on the brake pedal here, it is really about soft finesse, just getting a bit more weight on the fronts. Maybe left foot brake this one if you are comfortable with that skill?
T17: a zillion ways to tackle this one. What I see most is a vMin that is way below the potential of the car/tire combination. Again, a huge initial braking spike, with relatively little trail braking. You are rotating the car nicely before the bridge. I wonder if a slightly smaller brake spike, but carried a bit longer through your downshift zone, would get the car more planted on all fours here, and allow more latent MPH. In other words, changing your braking profile here, thus necessitating less overall braking, and thus more vMin? Remember, the minute we turn those front wheels, the car slows and keeps slowing. Despite what our eyes tell us in 17, we don't need to do ALL of our braking with the brakes. The turn itself will scrub a bunch of speed .Note in your video, you are at 69 MPH when you release the brakes, and even though you go back to some throttle, you stay at 69 MPH practically the entire turn. Gas adds speed but front tire scrub negates it all. The big leap of faith in 17 is carrying a bit more speed deeper into the corner, and then using this scrub to do the rest of your "braking" for you. The confidence that the resulting stability of the platform gives us trains our mind that, when properly stabilized, our cars will really (and safely) carry a LOT more latent speed here!
Car pulls real well based on speeds reached on straights, I use second gear for a quick squirt out of 10 same reason I use third out of 17.
best race lap in GTC3 at 48 hour Sebring race earlier this year was a 2:16:2 go get him 😀
great lap
Rich
Thanks for the comments Dave and Rich, much appreciated!
My hesitation in Bishops was related to the number of heat cycles on the tires, and my feeling through 11 with a bit of sliding…. Earlier in the day I was more confident and was wide open.
Regarding the braking advice, I’m looking forward to trying this out in my next adventure at Sebring
stay tuned everyone!
Last edited by Mike Roblin; 10-24-2021 at 10:23 PM.
Can’t hold a candle to the expert feedback above, but T5 is what stuck out to me.
If telemetry is accurate, you have a coast zone prior to brake application. Believe you’ll find/maintain better balance with a smooth but immediate transition gas to brake.
Looks like your 3rd steering input in T5 gets you to apex. If you stay right a bit longer after T4, squaring off T5, and then trail brake with one steering motion into apex, believe you’ll find full throttle much sooner. Stopwatch indicates 2.5 seconds of partial throttle through T5 before you open it up on exit. Maybe another 1-2 mph into T7 with T5 adjustments.
Note 7+ seconds worth of partial throttle in T1 as well.
996 Cup fricking moves! 380 bhp?? Nipping at the heels of multiple 991.2 vmax around the lap.
Can’t hold a candle to the expert feedback above, but T5 is what stuck out to me.
If telemetry is accurate, you have a coast zone prior to brake application. Believe you’ll find/maintain better balance with a smooth but immediate transition gas to brake.
Looks like your 3rd steering input in T5 gets you to apex. If you stay right a bit longer after T4, squaring off T5, and then trail brake with one steering motion into apex, believe you’ll find full throttle much sooner. Stopwatch indicates 2.5 seconds of partial throttle through T5 before you open it up on exit. Maybe another 1-2 mph into T7 with T5 adjustments.
Note 7+ seconds worth of partial throttle in T1 as well.
996 Cup fricking moves! 380 bhp?? Nipping at the heels of multiple 991.2 vmax around the lap.
Mike, I just took a super-quick look at the video. 996 Cup is still the bomb for me!!
Remember, the minute we turn those front wheels, the car slows and keeps slowing. Despite what our eyes tell us in 17, we don't need to do ALL of our braking with the brakes. The turn itself will scrub a bunch of speed .
Note in your video, you are at 69 MPH when you release the brakes, and even though you go back to some throttle, you stay at 69 MPH practically the entire turn. Gas should add speed but front tire scrub negates it all.
^^This is the NUMBER ONE concept comprehension needed for most to break through the hardest plateau to going quicker. Well stated!^^
Mike and company, hope you don’t mind me posting some thoughts, soliciting feedback here on T17.
Been experimenting with a couple of approaches:
“A” involves the more conventional line as I understand it, with the left side tires right about on the faded black corner line or just crossing. This approach requires an earlier and/or harder brake at the end of Ullman. The exchange is lower corner min speed (as you wrestle the car into the tighter line) for earlier full throttle potential.
“B” is a later and softer (and straightened) brake zone at the end of Ullman, then allowing the car to track out beyond the left side faded black corner line – all 4 wheels over the line.
By not wrestling the car into the tighter line and taking a wider approach into apex, min speed is kept higher. For me and my base 991.2 it’s a whopping +8.5 mph min corner speed differential.
The downside to “B” is later to full throttle. I’m seeing almost 2/10th’s lost between T17 corner exit and the start/finish line due to delayed throttle. But the upside is nearly 5/10th’s gained from brake zone through apex -- total advantage to “B” being 3-4/10th’s.
“A” is the red trace,” “B” is blue.
I’ve been looking around trying to find “B” and I see Keen took it in a ’70 3.0. My thought is, for cars that don’t necessarily have the strongest bite on the front axle – base GT3, older 911’s, maybe a 996 cup (wish I knew!) – there may be more speed in demanding less out of the front end through T17 (approach “B”). Let the car run wider in the brake zone, open up the corner, keep min speed higher, focus on advancing full throttle as much as possible, even though you probably won’t be able to quite match the full throttle timing of the tighter line (approach “A”).
If you have the front axle bite to carve a tighter line and keep your min speed up, then this approach is maybe n/a. You're wasting time tracking out into the parking lot left of the faded black line in an effort to open up the corner.
Considering Leh is doing 68-69 mph vMin with a nearly fifty-year old car (albeit well prepared, with worn out R7's), your better execution of fundamental skills, as opposed to the line you both take, is the reason you're able to match that vMin, in my experience. That said, I think there is a way to reduce the distance covered at that vMin (too long, in my experience) in the "B" run.
The linear deceleration in the "B" run is what every driver should shoot for, but the "hiccup" at the end of the vMin period, premature throttle app that had to be "fixed," is indicative that the whole EoB/vMin period/throttle app phase can be pushed closer to corner entry.
If you do a search for "Turn 17 Sebring" in this section of the forum, there's a great multi-page post with aerial shots and data that has input from a lot of folks.
It's the definition of a great corner! One that while exiting, you curse under your breath and say "I could have gone just a little bit quicker,,,"
Congrats and good analysis of your own performance.
Considering Leh is doing 68-69 mph vMin with a nearly fifty-year old car (albeit well prepared, with worn out R7's), your better execution of fundamental skills, as opposed to the line you both take, is the reason you're able to match that vMin, in my experience. That said, I think there is a way to reduce the distance covered at that vMin (too long, in my experience) in the "B" run.
The linear deceleration in the "B" run is what every driver should shoot for, but the "hiccup" at the end of the vMin period, premature throttle app that had to be "fixed," is indicative that the whole EoB/vMin period/throttle app phase can be pushed closer to corner entry.
If you do a search for "Turn 17 Sebring" in this section of the forum, there's a great multi-page post with aerial shots and data that has input from a lot of folks.
It's the definition of a great corner! One that while exiting, you curse under your breath and say "I could have gone just a little bit quicker,,,"
Congrats and good analysis of your own performance.
Appreciate that, Coach. I'll take a look around for the T17 analysis. Agreed on pushing the whole EoB/vMin period/throttle app phase closer to corner entry.
Yes, the "hiccup" was my getting greedy, attempting to double dip with much improve vMin and earlier throttle application Don't think T17 exit real estate was going to give me that one, so I backed out and ended up close to my usual accel. Progress with approach "B" will be keeping that brake zone to apex advantage (improved vMin), then getting close to matching "A's" full throttle acceleration trace on exit. If I hadn't gotten greedy on this run might have been able to come pretty close.
I’ll add my $.02 which echo some of the braking advice above, but put in the simplest term that I’ve ever heard, and for me simple is good! I’ve had two pro coaches ride with me at Sebring, and one of the most beneficial things either taught me was to retrain your brain, and instead of referring to a “braking point”, refer to it as a “stop accelerating point” and then work on transiting from full throttle to full brake as quickly as possible.
The screen shots below made me think of this, as your “braking point” of just past where the surface changes into T7 is spot on, however you begin to lift sooner (first image below) and coast for 1/2 second before moving to the brake. If you were WOT until the second screen shot, you’d eliminate that 1/2 second of coasting, and save .2 in every brake zone.
I lowered my previous PB by over a second immediately by using this tactic, and I had a very respectable lap time prior to doing so.
10-16-2021, 02:52 PM
Critique My Lap of Sebring
