Input on Sebring laps in 991 GT3
 

Here are two laps from this weekend PCA DE. It is my second event with the 991 GT3 and my 4th event at Sebring, so I know my line and car control need work. The car is stock except for harness cage and safety equipment, Hans, harnesses, etc.

Appreciate constructive feedback.

I thought it was a really nice lap! pretty timely post given the discussion about NJMP and shift points... love the green target RPM area to maximize HP. You are never WOT unless you are in that area. (turn 3/5/7/tower)
Nice job.
Looks like a FUN ride! what kind of tires if you mind me asking?
Question.. How do you integrate the Harry's lap timer to your video?
as i always seem to have to ask... you should put the video back a little so you can see your footwork and steering input. the lap might look great, but no one will be able to see if you are fighting the car in any particular areas. PLUS, its much more entertaining to see the steering work.

Mark, have you ever been there?
I thought not...

Second lap uses more apex curbing which is good. Anywhere apex curbing is smudged, dark gray, you should use it. Use more in 15 and 15a and 16. Try a slightly broader radius arc in 17...that inside line isn't your friend in that car IMO.

Overall some smooth laps!

You are going mental on us.. spare us your petty bickering. My ONLY comment was that he was in the green zone of the RPM range without error.
(a concept seeming very foreign to you) otherwise, i thought those were very nice laps. Do you think between those two comments you needed to air out your ego ? What, did your dog crap in your cornflakes this morning?

Out of curiosity, does that "HP" widget on your video correspond to the power that your car truly makes? I don't think I've ever seen that before.

It's a range of HP sweet spot after gear shift. (Or when you are going to be at WOT, like when he rolls onto the throttle at turn14.) My guess would have to be programed in during set up. That way you know your optimal HP operational range. That's a pretty cool widget. I have the lap timer and would want to integrate it to my video too. just wondering what it will take. integration with go-pro? Looks like its tied into the AIM system or equiv

Oh geez ...

Never learns

Man there's a lot going on in that video! I really need to look into Harry's lap timer...

Was that a Suncoast event? I didn't realize they were putting cones ON the track.
I don't like the cones in T17. at least the 1st 2. I like a wider entry to avoid the bump
But I guess its the safer school line..

IMHO, I'd say you want to be a little later on some of the apexes. T5, T9, T14, T15

over all, nice and smooth... looks good!

Very good given your relatively new ride - I'm jealous of your acceleration!

There are some folks with a ton more experience than me - but from what I can see -

You can carry a little more speed into 1 - slowly inch up your entry speed into the corner - watch your braking into 13 - you can carry more speed in bishops bend - but do a little more arch and start your turn in earlier to position the car on the left side for the right hander. You can use more of the curbing 14 and 16 (and carry a little more speed into 16) - on 17 I like a little deeper entry (as in delay a 1/2 second before you turn in) and get on the gas before the bridge - that will help your car rotate - you need to be closer to the middle of the bridge (under the green dot on the overhead portion) and about a car width from the apex near the flag station to avoid the bigger bumps (one under the bridge, one close to the flag station apex)

A later apex allows you to put on power earlier - it's also safer if you want to slowly and incrementally increase your corner speeds.

Thanks! I am used to Thunderbolt/Lightning where the most curbing is smooth, my first event at Sebring shook my fillings, so I have been staying off the curbs, and slowly learning which ones I can use. Looking at 15, 15a and 16 it seems from the coloration that they get a lot of traffic. Safe to use.

Yes, a Suncoast event. They are forcing a specific arch through 5 and limiting the arc in 17. Maybe it's just me but I have found bumps everywhere in 17! What I am learning is how amazingly stable the GT3 is despite the bumps, side loading and acceleration.

This is a part of Harry's app (Gran Prix version, maybe others) that appears when you identify the car used; if your car is in his database and the profile is downloaded with HP curves and gearing. For the GT3 it uses 469hp not 475, not sure why, maybe European DIN published rating?

Yes, the TBolt curbing is particularly good!

T3 at the end is high (berm), T5 is high, T7 is high. The others, not so much.

A few notes on your second lap at T15-T16

4:08 pinching center of Bishops causes mid track exit. Need to exit left of center, line up and brake left of center and turn into T15 from left of center.
4:11 the turn in geometry you're looking for is to cross the 12"-16" wide sealer strip in the center with your RIGHT tires NOT BEFORE the beginning of the curb, then work back to the beginning of the sealer, again using the right front tire position to cross at that point on.
4:13 still early...
4:14 coming away from the apex curbing too soon, delays WOT
4:15 part throttle, should strive for full for a short time
4:17 MUST have full throttle applied here for braking to be effective into T16
4:18 straddle the seam between the asphalt on track and the concrete to the left. Why turn AWAY from the desired path? Braking too early by just a scooch.
4:21 MUCH better than the first lap, but need to use more inside curb

Looks like you know the car well. :)

Thanks! The tires are Michelin Cup 2s. Excellent grip. I use an IPhone for the video so the data overlay is integrated in Harry's. I tried a second IPhone mounted on the passenger side with Harry's multi cam app that was supposed to capture me and overlay it in the place of the Ref lap video, but I couldn't get the two IPhones to talk. Will try it at home first next time to make sure I can work it at the track. Harry's has a lot of capability with Apple but I always struggled with go pro sync and Harry's.

The inside and exit curbing of 16 are your friends. Maximize exit velocity for that LONG back straight, check gauges, have a sip of coffee, check in with the wife, then setup for 17 which has as many good lines as there are keyboard cowboys. ;)

As the vegetarian said upon entering McDonald's- I see nothing here that offends me.

Just the little things that Pro Coach and others have offered. Good starting point for lower times.

reflection /projection going on.
Just a quick recap.... i made a comment about the OP's nice laps and a HP/rpm video widget comment , and then you go off a ego turrets outburst. I made a comment as the widget that looks at target RPM ranges to max HP utilization is very cool and useful. the education as to why is something that will probably allude you ....... after all the information ive provided you still think hp is " noise "in the high RPM and that really cracks me up!
carry on Dave!!
do YOU really need to be a jerk and ask a completely irrelevant qustion and dig, about me ever "having been to the track"? do i not have the right to complement a nice lap and a nice bit of technology without drawing FIRE from you? what is your problem Dave.... seriously. you need some help!

Never learns to stop responding to a knuckelhead that just doesnt get it.
But i have learned that no matter what i post...VR will make some smart axx comment..it just doesnt matter to me... if you havent got that yet. i just laugh!

Thanks for the insight... quick question, so you used the iphone here with the Harry's lap timer... but, how does the software get the RPM ? is it audio synched?
you program the RPM range you want to be a target for that "green zone"?
g meter? just in the Iphone i imagine.
reallly cool.. ill have to start setting all this up.....
you said the go pro synch is not that easy? or not preferred?
you just put the iphone in some type of mount pocket and push start and off you go? definitely try and move the video back on your video and let me know the gochas of setting the system up. very cool! technology!!!! :)

Peter,

Thanks for the analysis. Very thorough and an example why we should hire pro coaches.

notes on your second lap at T15-T16

4:08 pinching center of Bishops causes mid track exit. Need to exit left of center, line up and brake left of center and turn into T15 from left of center.
4:11 the turn in geometry you're looking for is to cross the 12"-16" wide sealer strip in the center with your RIGHT tires NOT BEFORE the beginning of the curb, then work back to the beginning of the sealer, again using the right front tire position to cross at that point on.

Yes, I altered my line there. I used to bow more, single arc, 105 mph and come out on the far left, into 15. IMSA drivers addressed the last PCA DE proposing a faster full throttle line through Bishops ending mid left to center. Braking earlier and slower through 15. I was attempting that, ramping my speed 5mph. It seems I flattened the arc as I increased speed. Will need to go back and try your markers. Thanks!

4:13 still early...
4:14 coming away from the apex curbing too soon, delays WOT
4:15 part throttle, should strive for full for a short time

I think taking what VR pointed out about using the curbing here, I can straighten this a bit and apply throttle

4:17 MUST have full throttle applied here for braking to be effective into T16
I see what you are saying, I can carry full throttle to 4:18 and not brake too early.


4:18 straddle the seam between the asphalt on track and the concrete to the left. Why turn AWAY from the desired path?

Boy do I wish I had a rational excuse for this, especially when you ask it like that! LOL. All my instructors told me the same thing. I watch too many other drivers go to the outside on 16 and even though I tell myself it isn't faster, I get out there. Discipline, drive my line, I know better than to follow a bad line.

Braking too early by just a scooch.
Yes my entry speed is also low as a result.

4:21 MUCH better than the first lap, but need to use more inside curb

Agreed, as VR pointed out I need to learn which curbs are ok to use. 16 is one. I tried to use the inside curb of 10, not good, pushed the car and unsettled it. I have lots of video, so I can study it and look for friendly curbing.

Thanks for all the help!

Mark,
The car data (fuel, rpm, temp, throttle, GMeter etc) transfers real time over Bluetooth from an OBDII port analyzer. Depending on the car data may not be available to the OBDII port.

You download the track you will drive (Harry has hundreds globally) and GPS starts and stops the recording automatically as you pass start/finish line. It also positions you on the track map to provide max speeds and segment times.

The iPhone is the main video source. You can add a second source to the upper right corner. A second iPhone will sync and record realtime to that small picture in picture. That allows you to video drive control and car/track effect. You can use a GoPro. Harry's app will turn your go pro on and off automatically but overlaying the PIP is a manual effort done at home after the event and time consuming.

Thanks.. I just noticed all the other inputs on the video. (gas level, temp, etc) and was worried it was a ODBII input as well ,and i dont have that. anyway, just the video, lap times, and the g forces (and maybe speed?) would be very cool. i have a second phone so i can use that or use my phone for the controller for the gopro . I have a lot to learn about here... thanks for pointing me in the right direction

Comments on lap 2

You short shift in T5, not sure that's necessary

You feather the throttle in T9, could stay flat. Same for T12.

Given you short shifting into Bishops, could be more aggressive with the throttle

The jog left in T16 just loses you time.

Overall nice lap(s) and my god do I need a PDK-S equipped car!

Good job. Just curious, are you manually shifting or running in full auto mode?

Peter gave you good advice for 14-15-16. Agree with others that you are braking too early into 17. Agree with VR that your single arc inside line before the bridge is not the fastest way around. You need to make it more of a double apex turn in a high HP car like yours. You can do that by driving straight toward the cone that appears at 4:42. At 4:43, you should be closer to where that cone is which is about where the turn-in point is for the 2nd part of the turn. There is a black patch on the pavement on driver's right across from the cone which is a reference that you can use when the cones are not there. By turning down toward the 2nd apex at the inside of the track (where the corner worker is but not necessarily at the edge of the track (1 or 2 car widths is fine)), you will be pointed farther down the track (where the track out cone is in your video) than the point where you are currently tracking out.

Agree with everyone that the 2nd lap is much better than the first.

Hah! Our epic Turn 17 thread here: https://rennlist.com/forums/racing-a...turn-17-a.html :D

i liked watching this...
although im not a coach, nor claim to offer any advice cause i wont, having the pca cone's out there give's some interesting perspective's to study...
driving looked good to me for a de day..

how did you guys mange to get through a whole sebring page without being "kiborted"

Thanks Mike,

I have the car in PDK-S full auto.

38D,
Not sure why it short shifted at 5, probably the part throttle at 4 and soft brake. Hard braking will always cause a downshift. Most places on the track it seems to be where I want it, when I want it.
Honestly, I am still getting used to the amount of acceleration in this car, so I am part throttle way too much. I played with earlier, harder throttle application on corner exit of 5, 10, and 14 on other laps until I got the nannies to kick in then backed off, maybe too much. Agreed I am too light on throttle through 8 and 9, it's my brain self limiting me.

I need to get more knowledge of the car's limits and slowly work up to them.

No one challenged the OBVIOUS! thats how! ;)
In other words... Dave - VR didnt post something just to make himself feel better! :roflmao: there is still time... maybe he will comment on my missing apostrophes in the word " thats ".. (should be that's) ;)

:corn:

:banghead: