October 2, 2006

The numbers game. Getting lap times down and under expectations!

Part of it is skill and some say art, but there’s a lot of science and numbers in making a car (and driver) go fast around a track. Here I attempt to explain how I got down to 2:12 around the Glen on my 997S.

I’m extremely pleased to report that my long hours with my TRAQMATE paid off. I came a bit frustrated from my first weekend at the Glen with the 997 Carrera S, as I just couldn’t get all corners right in one lap and torrential downpours (all 2nd day) and traffic minimized the time to experiment and improve what I analyzed in between sessions.

Having been again to the Glen two weeks ago with the Elise, a car in which any hesitation or mistake gets translated into multiple seconds of extra time at The Glen, made even clearer what I needed to do with the 997S next time around. A 2:16.9 was my best time with the Elise on RA1s. With brakes working properly and some cooler weather I believe I can pull off a 2:15 (high) but we will have to wait until next year to prove that point.

Back to business in the 997S this past weekend. First track session with GVC-BMWCCA is all about instructor bonding and projecting control and confidence (even if you are in the Very Advanced group you always go out with an instructor, which I think is a good thing for everyone’s safety) and getting that sign-off to go Solo. All went well, so in the 2nd session I tried to start near the front. Started 6-7th, and passed all cars in the first lap (with point-bys as required).. Weather was cool, so I knew the engine would be strongest and the brakes could take more punishment too, while tires still work as good (or even better. See tires comment below)

I knew I had to do the following to get a 2:14 or below on the 997S:

- Flat out the Esses. After researching and talking to the experts at Farnbacher-Loles I concluded that the looseness in the rear was not due to aero lift (at 110+mph), but mostly from control arm bushing flex. So the grip is there, you just need to cope with a 1-2 feet sudden sidestep of the rear when going over the camber change on the first right to left transition.

- Take the proper BusStop line. Approaching the BusStop in the Elise at 120mph makes everything seem slow motion compared to the 140mph+ in the 997S. That made me realize what works best for both cars. Hard on the first and third kerbs. Basically like being ahead in an autox slalom

- Improve entry line on heel of the boot by braking a bit earlier (avoiding bumps) and slower turn-in (less trailbraking to keep the rear in check).

- Slightly wider line on left hand off-camber. That basically, despite increased distance open up more track for more gas and faster exit.

- No prisoners on Turn 10. After taking it full bore on the Elise, it is much easier on the 997S to approach it faster than last time.

All the above was accomplished in my first two clear laps and every section added something to improve all sector times a bit (The exception is the Esses section with a massive 1.4seconds improvement just by flooring it with disregard). Got a frist official lap of 2:12.5 and the following lap was a 2:11.95 pace until I hit traffic on sector 4. Then it was all about dealing with very slow 2:20+ pace traffic…

I’m sorry to report that there’s no video, as my crappy solid-state memory camera continues to fail on me. There’s Traqmate telemetry which I will add to this post.

Tires? A lot of track goers complain about cool weather and R-Comp tires, but in my opinion its all BS. The DOT R-Comps we use all work well in 40F+ weather, you just need to build heat in them (i.e. work them hard). Same principle applies for the rain (No grooves / slick R-Comps are better than any street tire on a wet track unless there’s a good amount of standing water)

Later in the day we had rain and an evenly wet track. It was a lot of fun as the wetness was consistent and predictable once you do a 1st lap to get to understand the grip available. So what are the key trick to going fast in the rain?

• Smooth driving style pays-off more than in the dry. You have to get rid of your “spike” inputs while driving. Dry pavement can take some sudden G-force spikes, that can be quickly corrected. In the wet, those spikes induce immediate loss of traction and recovery is veeeery looooong or sometimes just not doable. Focus on smooth transitions in your inputs and what you make the car do, as if it had no shocks.
• A softer setup helps getting rid of the spikes. For example I run the PASM (active shocks setup in Porsche) in the softer rollie-polly-ollie setting.
• Get heat on the tires. First increase your cold pressure to narrow the contact pach to create more friction, and then work hard the brakes and test the limit of acceleration during warm-up. It is very hard to warm up wet tires just with cornering force.
• Anticipate, don’t react and most importantly don’t drive my memory. In my opinion here is where driving by feel is the most important, you need to make the car be on the edge marginally and keeping it there proactively (not reactive). It is a lose-lose strategy to “test, try to catch and see what happens”. Also beware of marking braking points and turn-in spots as grip can change drastically from one lap to the other.
• Do what feels right. Sounds obvious but I think that’s most of the trick.


  1. Your patting yourself on the back for a 2:12 in a 997 and a 2:16 in the Elise. But in realty these times are way off pase for those cars. I have to compare the 997 to SCCA T-1 cars (stock with good tires) they run 2:03-2:04. The Elise is actually classed as a T-1. But even in T-2 they run 2:12-2:14. So since the Elise is classed T-1 I can only think that your 997 shoould be faster then any T-1 car. I can see how it must feel good to beat a bunch of guys with no experience having fun at an HPDE but don't forget with those times you would be at the back of the grid at any race weekend.

  2. Who are you?
    Show your face.
    Did I ever said that those are THE fastest times anyone can get in those cars?
    I'm just benchmarking my own improvement against myself and what I've done in the past with the use of Telemetry.
    Show me where am I comparing my times to Club racing times? or claiming virtual pole in your Club racing GP?

    If YOU want to do that, then do your homework first. The Elise will be in T2 next year as it is obviously way off the pace in T1.
    Also GT3s which ARE faster than any 997S are classed in T1 and they are not the cars to have in the class (Z06s are). Also PCA nows a thing or two about Porsches and the 997S is one class below the T1 GT3, and that is a good amount of modifications allowed to both cars.

    Relax, why such a complex? what forces you to thread so thin, or are you having problems with your lap times?

  3. I always have a good laugh when posts like that appear. Mr. Anonymous should just ask himself a simple question: do the T-1 cars he mentions have Sat-Nav, air conditioning and heated seats?....oh, I almost forgot the extended leather package! :0)

    I like that we have our very own haters now!


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