Gainesville Test Track Day Report - 10/30/10

My co-driver setting tire pressure before the event

Enjoyable weekend again. I had a co-driver today also, who fortunately didn't flip my car or destroy my transmission. His name is Brian, and I think you'll be seeing him on this forum more often.

Unfortunately, I do not think I will ever achieve Project OLDAZENIS.

I was only able to turn in a time of 1:02.49. No improvement since the last event. This is with me figuring out more parts of the course and benefiting from the added horsepower from the RX-7 AFM and a further 30lbs of weight savings. I had at least wanted to get in the 1:01.XX range, but the course was run in reverse for the second half of the day and I did not get to work on my driving.

But I have some good news. I had put together an endlink for really cheap. It is by far much cheaper than the other endlinks available on the market. It held up fine.

The RX-7 AFM gave me measurable gains. The previous Vmax (maximum velocity anywhere on the track) was at approximitely 72.6 ish, with my benchmark driver Grant driving the car. My previous Vmax is very close, but I believe it was a bit lower. Today, with temps in the low to mid 80's, my new Vmax was 73.6. This is probably partially for the 30lbs ish weight loss from removal of the passenger seat. To offset this influence, I was running almost a full tank of gas when I recorded this. Gasoline is approx 6lbs per gallon.

I also learned to squeeze out some more speed out of the course:
The insides of various have more grip. It might be cambered less. It might also be more abrasive, but I have yet to verify that. I am getting better at feeling out how much grip I have left on the rear wheels, helping me accelerate out of corners.

And finally, my driving continues to improve. I have to be smoother and keep better car control. This is just going to take practice. Every time my rear end slips out a bit I am losing speed. So if I do a very good lap, and then have the back end kick out or the car veer off line a bit, that lap will be wasted. I will keep shooting for consistency. I did have much more fast laps than last time, so my consistency must be improving.

Tire aging and grip
My driving keeps improving on this circuit. Because of this I find it difficult to gauge how fast my tires are wearing, and heat cycling because my driving is changing. My lines are changing, which makes the peak cornering areas different in each corner. Also, compared to my previous sessions, I am spending more time closer to the limit. However, the peak G forces are a bit higher on my old runs. Therefore, I conclude that my driving is getting better, and my tires are losing their grip. That is the only explanation I can come up with to explain the fact that my laptime has not improved, since I am driving better and my car is faster.


Results
Best time: 1:02.5
Temperatures about low 80's.

Changes in the car since last event
Custom RX-7 AFM mod
Passenger seat removed
Rear sway bar completely removed

Effect of removed passenger seat
With the passenger seat removed, the car cornered to the right much faster. Peak Gs are noticeably different, and I can feel it as I am driving also.

Driving improvements
I am being more consistent with my lines and hitting all of the apexes. However, I still come out too wide while entering turn 9. I should be closer to the inside. If I can be smooth consistently going into turn 4, I can hug the inside of the turn instead of being pushed out. No doubt faster. Please check out the videos at the bottom of this post.

My co-driver being chased down by a vintage formula Ford

Link to videos:
Jerry Lee 2nd session
Brian Inacay 2nd session

Link to pictures from this event