Setting tire pressure for track day.

[johgar]

Hi, I am start doing a track day with NSX.
I have basic questions regarding tire pressure set up.

Info of the track day:
The Ridge Motorsport. With road course for track day.
https://www.ridgemotorsportspark.com/track-days

I am using Advan Fleva V701.17” front and rear stock OEM 2002+ wheels and 25mm spacers on front and rear.
215/40R17 front and 255/40R17 rear.
After 2 sessions (20 min each) of the track, I have melted rubber stuck on my tires. That causing not to have traction.


What tire pressure you start with?
I started with 32psi front and 35psi rear.
When I am back from the 20 min session, the left front tire seems to be always 3psi higher than the right front.

The car it self is a 1991.
JDM short gears with NSX-R final drive.
NSX-R front lower chassis bars.
Front upper chassis bar.
Intake.
Pride headers, exhaust, and test pipes.

 

[docjohn]

the rubber is likely pickup of discarded tire bits=marbles...The goal of any track day is to have your peak hot pressures at whatever give you the best grip which will instill confidence and lower lap times. In general the hotter the track the greater the rise in pressures. As a general rule of thumb most R compound treaded DOT type tires like 37-39 lbs max...you need to check pressure as soon as possible from coming in. Bleed off pressure to keep the max in that 38 range...

 

[Honcho]

[MENTION=23696]johgar[/MENTION] docjohn gives good advice here. I tracked a very similar setup to you on the older version of the Flevas. I found that 32 lbs cold F/R gave me pretty good hot pressure traction (~36-37 hot). I would not stagger the F/R pressure on the Yokohamas. Your rear pressure at 35 is probably putting you over 40 hot, which will create a lot of oversteer. Your front tries are gripping a lot more than the rears when hot.

 

[docjohn]

yep at a xpo I drove a students car and the car was super loose/oversteer...checked rear tire pressures and they were 50...

 

[johgar]

@Honco and [MENTION=4282]docjohn[/MENTION], thank you for the advise. I will try again for the time I am doing the track day.

 

[johgar]

Finally did another track day earlier this month.

Set tire pressure at 33 psi hot all around.
Using 215/40/17 front and 265/35/18 rear. Falken Azenis RT615K+.

It was a good day. 5 session of 15 min each. By the end of the day I had to adjust front tire pressure to 34 because notice the front start getting too hot.