[Fot] Racing tire pressure

[Marx Christian tr4-racing]

In season 2006 I had some engine trouble and no chance to earn eny
championship points so I used the races for testing the car and tire
pressures.

Zandvort race:
The main difference between race I and race II was trouble with the clutch. At
the first race the clutch passed away during the instalation lap and after
half distance of the first lap I was stuck in 3rd and could only shift with
OD......the astounding thing is....that my laptimes of race I and II are only
0.2sec in difference......so without the clutch I was just a little slower.

>From my point of view the tire pressure made the difference:

I started the first race with 22.5 psi cold all around.
The car felt very twitchy and not solid and I had the impression that I'm
close to the edge to leave the tracklane on every corner.
http://www.tr-competition.de/pics/video/tc-2006-74-zandvoort-1.wmv

At race II I had 28.5 PSI all around. The car was very solid and easy to drive
but the laptimes went down during the race....2 fast laps....then I was
sliding.
http://www.tr-competition.de/pics/video/tc-2006-74-zandvoort-2.wmv

To settle the astounding result of tire pressures I went up with the pressure
for the next event.
We had a wet practise.....I went in with rain tires and a cold pressure of 30
PSI which made the car nervous. I corrected the pressure in the pits down to
25.5 which made the car pleasant to drive and gave me a 5th position on the
grid.
http://www.tr4-racing.de/download/tc-2006-74-saisonfin-freepractise.wmv
http://www.tr4-racing.de/download/practise.wmv

The race I was dry and I went in with 31.5 cold. It was okay but the car broke
away on the rear very easy. No pleasure to drive.
http://www.tr-competition.de/pics/video/tc-2006-74-saisonfin-1.wmv

At race II I installed 34.5 to have it more clear. 2 fast laps, spin at lap 3
and then times went down and down.
http://www.tr-competition.de/pics/video/tc-2006-74-saisonfin-2.wmv

So I will use in future races pressures in the range of 25.5 at front and
22.5-24 at rear.

Cheers
Chris