smlporsche

OK guys, I'm bearing my soul ... so please be gentle.

This is my first attempt at using the Traqmate data. Here is a lap at VIR that I did yesterday before I blew my h2o pump at the top of the uphill esses. The session had alot of traffic as you can see by the black line going down the back straight where I was waiting for cars that I had caught up to to pass.
Green = accelaration
Red = braking
black = coasting

I'd appreciate all constructive comments on where I can improve.

Brian P

Really hard to say... I'm guessing the graph should be brighter green for when you are using more gas and darker red for when you are using more gas, however I see no differentation in color. It looks like you are giving gas in the right place, but I can't tell if you are full throttle or just barely accelerating.

Also, getting a lap where you are stuck in traffic will be extremely limited on the amount of information you can get.

38D

You definitely do not want two sections of red at the end of the back straight. You can trail brake starting at "zero" (i.e. past the braking markers), and then carry that to the turn in of the first sharp right hander. Also looks like too much coasting (like down the hill to the front straight). I assume the black/coasting up the hills is just that your car cannot generate enough Gs to show you are on the gas.

schwank

Eddie, I've found that with the Traqmate in my 944 that you have to tweak the sensitivity for the acceleration/braking charts. Colin was exactly right, the G forces are not enough at the default TM settings. I also can't wait to get a video camera as it will help correlate the laptimes with the existence of traffic to let me more easily see why I might have lifted throttle at any given time.

I have a couple data files from last week at Portland with the TM if anyone is interested. 1.2 lateral G's with 155K stock suspension and Yoko AVS ES 100's

Brian P

Colin, I thought his original post said he was in traffic (hence the coasting). Without video, it's hard to say if he's on the brakes because of traffic or on the brakes unnecessarily.

smlporsche

Colin- (geeze that avatar is distracting...)

On the back straight I had caught up to several cars that I was waiting to pass. Otherwise it would usually be green.
At the end of the straight I usually brake at the 3 marker and downshift from fifth to fourth aim for the inside of the righthander and downshift to third hence the 2 braking zones. In my white run group I am usually carrying more speed into that righthander then others and it has been a good way to make up ground on those higher HP cars that have just passed me on the straights...

Did I understand that you start trailbraking at zero ( at 130+ MPH??) into that righthander?

As far as the climbing esses it is someplace that I am working on improving. Please keep in mind that this is my first year with the car sorted out. I'm able to get to 110 MPH (almost redline in fourth) entering the esses but as the graph shows I more or less feather the throttle and end up exiting the esses at about 95 MPH. I had the opportunity to run with a friend of mine who has been racing in PCA for the last couple of years and he does pull me going up there. I guess I just have to develop bigger cajones.

Does anyone actually go through there at WOT?

Any other comments??

Thanks for the input.

smlporsche

This was my second of three laps. the next one when I blew the water pump between the esses and turn ten I recorded 1.35G's in my spin (WHEEE !)

smlporsche

Eric- Could you PM me and tell me how to tweak the settings. I'm trying to figure this out...

schwank

It actually is pretty easy. On the Brake and Turn Zones map, tweak the Thresholds setting in the upper right to adjust how sensitive the map is when drawing those lines. You shouldn't ever see black sections of coasting in the middle of straightaways where you are on throttle.

And of course it does need to be taken in context of traffic too. This pic isn't the best other than to show you where the fields as this session had almost 40 cars on track, from Miatas and my NA '44 to GT3's. Tons of traffic fun - I spent a lot of time with my hand out the window giving point bys. This is demonstrated by the black sections early on the front straight and in the middle of the back, where I lift to let them by.

Brian P

I thought it was a left hander (I haven't been there in 5 years), but yes, in a low HP car, some brake at zero. Back then, all I had was a 2.5L Boxster (200HP), so I don't know what the higher HP cars do.

I did it once or twice. It gets interesting if you aren't exactly on line. I wouldn't attempt it if there is any cars in front of you because you'll catch them very quickly. Again, with a higher HP car, YMMV.

38D

Even in a higher HP car you can brake at zero off the back straight.

I think most cars can be flat into and up the climbing esses.

These are not normal white run group moves.

Brian P

Also, a MPH graph would be interesting. I was faster on the front straight than I was through the back straight - you can really get on it in Hog Pen.

John H

Being on the throttle thru the climbing esses keeps the car planted. I had a problem with that section until I got an instructor in the car with me and he told me to stay in gas (within reason for your car of course). I was lifting and unsettling the car. It made for some sphincter clenching moments.

smlporsche

Well, I was only passed consistently by a well driven and modified Z06. I passed several 996 GT3's, C2S's, and Turbos (when they'd let me ) so I would say that I'm ready to try some of the more advanced techniques, particularly at VIR which is my "home track" and I have over 20 days there.

997gt3north

I did 2 days at VIR 6 weeks ago.
It was my first time at the track - previous experience is 25 trackdays and a 3 days skip racing school at Limerock.
I was driving my new to me 997 gt3 and ended up at 2:16.
I had a fabulous husband and wife team as my instructors - their ride was a TT RUF - he did 2:05s

My comments looking at the data would be (these are assuming a clear track which you didn't have and maybe your software needs tweaking for accel / coasting):
1) Front straight foot should be on the floor until braking zone - i was able to brake at the #5 marker doing 145mph
2) foot should be on the gas until brake zone into #3
3) my instructor had me trail braking all the way to #3 apex in order to carry more speed - your braking pattern looks like what i was initially doing but he said to go faster you had to trail it all the way to the apex and brake later
4) same comment as above for turn #4 - carry more speed in and trail the brakes to the apex
5) since you didn't have to brake for #10 (black not red) and having read your earlier posts that you exited the uphill esses at 95mph but entered at 110mph (not sure where you are measuring entrance speed from) but I was able to comfortably take the esses (#7-#9) at 102-103mph and then a short WOT before #10 braking zone with a downshift from 4th to 3rd for my long geared 997GT3 - and I would say that I had only begun to march up the MPHs for the uphill (it was the car's maiden voyage) so I would say that 100mph is a minimum speed that you should be apexing #9 and then WOT followed by braking
6) i was able to do it a few times when we didn't catch any cars into #11/#12 (oaktree) but you can carry HUGE speed up the hill at #11 if you are willing to make it one brake zone, not two as you do, and basically stand on the brakes / trail brake all the way to the oak tree - keep carrying more speed until you are threshold braking all the way to the oak tree
7) i was braking at the #2 marker doing 155mph and threshold braked in a straight line (didn't go left at all) and then finished the braking zone with a trail brake to 14b's apex - i was in 5th gear entering the brake zone and just at the end of the straight braking zone before i trail braked to the 14b apex i heel toe down shifted into 3rd - i don't see any reason you have to complete 2 downshifts here when you could be braking later and carrying more speed

Hope these comments are helpful - I'm basically just repeating what my very fast instructor was telling me to do. Also, from a balance/grip perspective you just have to be feeding the throttle going all the way up the esses - this alone would likely give you the confidence to be exiting above 100mph not 95mph.

Finally, and I warn you that this one takes a little/big leap of faith, but for turn #16, my instructor was very clear that it is not just the racing line but also the fastest line - you should turn into #16 at WOT and then brake in a straight line straight at #17 apex (i.e. you DO NOT go to the left to set up #17) - believe me when I say this takes practice as the road points you to the left as it crests the hill and it feels like you are going off the track when you do this - his logic for this line of a very early apex into 17 was twofold: 1) you can carry far more speed into 17 apex this way as you are braking way later and you are covering less distance by not going left, 2) after your early apex into #17 the camber on the track for what appears to be your early trackout comes to your resque and thus your ultimate trackout speed onto the long front straight is not hurt. I only repeat all of the above as this gentlemen was doing 2min 5secs laps - when I told others what he was teaching me they all disgreed but then again he was a far faster driver than they were. Finally, if you try this method into 17, please do it at slow speed to begin with as I got a little squirely and had to save the backend from coming around when I didn't trust the line that he wanted me to do.


Paul