The importance of tire pressure when racing


rvm

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Unfortunately I found out that tire pressure is as important as having the correct alignment on your car, or as having your correct suspension setup. :nono:

I went to the track and started racing with 30 PSI on all tires, after a couple of laps the car had good grip, it was 11 am, and I can barely see the sun, so the track was a little "cold".

The race came, I started in the 22th position and I managed to go up to 9th place.. but ...

I had serious problems after the third lap, the car wont grip at all, I suffer from serious under steer and I had to attack the corners slower because I lost a lot of grip specially exiting the corners.

I'll share a video of that race:

YouTube - DC2 AutoX run #2

In that race I was able to make a "hot" lap of 1.36.400.

When I went to the pits all my tire pressure where about 33 to 35 psi, BUT the front left tire had a incredible tire pressure of 45 PSI.

I was like wtf happen here? maybe I made a mistake and instead of inflated it to 30 psi I inflated the tire to 40 psi.

Time passed, and I went to the track again, I ran for 10 - 12 laps, and again, the same problem, after the 3rd or 4th lap I started loosing grip, so I again went to pits, drank a gatorade, and a friend of mine passed in front of me, he is a experienced driver, he has been racing for like 10 years now, and in that track since 2003. So we chatted a little, and I mentioned him my issue with the fron left tire pressure, he started laughing, I wanted to kick his ass lol, and he said to me OF COURSE that will happen, 80 % of the corners here are clockwise! run 27 PSI MAX on your front left tire. That tire suffers a lot of stress during the race, and it gets hotter so the tire pressure rises.

Ok then, I did what my friend told me and VOILA, hehehe I had 2 good hot laps, one of 1.35.6 and one of 1.35.1 Almost 1.3 seconds faster than my last time laps :nice:

So my recommendation is, ask to the experts and analyze well the track, then choose your tire pressure, but a good way to start is to run 30 psi on all tires.

I forgot to mention that I was using potenza RE01-R on 16 inch wheels.

Hope this write up to help you guys, and sorry for my bad english :p
 

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he started laughing, I wanted to kick his ass lol, and he said to me OF COURSE that will happen, 80 % of the corners here are clockwise! run 27 PSI MAX on your front left tire. That tire suffers a lot of stress during the race, and it gets hotter so the tire pressure rises.

I don't get it, maybe i am missing something. But what does 80% of the corners being clockwise have anything to do with the heat of the tires?
 
if you turning hard in to a corner clockwise the left hand side is taking all the wieght of the car thats why rvm was saying is front left psi had rising because that tire will get hotter quicker but it may be different at another track as more corners could be anti clockwise
 
Very interesting experience. ...i guess you could go all out like race teams and fill your tires with nitrogen (i think thats what they use?) which isnt affected by tire temperature causing gas-expansion. Great write-up dude, post some more experience, you probly go to track alot!
 
yep I heard that you can run different pressure to left and right depending on whether most of the corners are left handers or right handers (more left handers mean our right tires will get hotter than left ones as its loaded more for longer times, hence the pressure increase relative to your left. so ideally you would run slightly less cold pressure for your right side tires compensating for the extra pressure increase)
 
if you turning hard in to a corner clockwise the left hand side is taking all the wieght of the car thats why rvm was saying is front left psi had rising because that tire will get hotter quicker but it may be different at another track as more corners could be anti clockwise

Correct! :p
 
I don't get it, maybe i am missing something. But what does 80% of the corners being clockwise have anything to do with the heat of the tires?

if you turning hard in to a corner clockwise the left hand side is taking all the wieght of the car thats why rvm was saying is front left psi had rising because that tire will get hotter quicker but it may be different at another track as more corners could be anti clockwise

:secret::secret:
 
Great advice m8, liking this new section too :nice:
I have found on my experience of trackdays, tyres & tyre pressure are the most crucial thing about getting the most out of your day. Everybody likes the car to perform in a different way, understeer/oversteer/grip etc. As you say, start with a low pressure then increase it (note some tyres heat faster so watch out if you stay out too long), feel how the car reacts & change to suit your style :)
 
There is a track like that local to us here, Pukekohe Park (don't try to pronounce it :p). It runs in a clockwise direction and has only tow anti-clockwise corners.

It's customary for the left hand side of the car to take a real beating tyre wise, pressures are usually around 3-5psi lower when cold, but they come up to the same when thrashing it for a few laps.

Ideally on a 16 inch wheel you shold have something like 32psi hot on all four corners. Do this by going out for a few laps and heating your tyres, then come back in to the pitsadjust the pressures accordingly. After you've finished racing let them go cold and record the pressures so you'll know what they're supposed to be so you can set them before you return to that track.

I remember seeing a guy in a Subaru WRX who thought he knew it all and wouldn't listen to anyone who tried to talk him out of it; he had all four of his tyres at 50psi cold and went out onto the track, and what do you know, he had a huge spin and wrote off his car.

Idiot.
 
There is a track like that local to us here, Pukekohe Park (don't try to pronounce it :p). It runs in a clockwise direction and has only tow anti-clockwise corners.

It's customary for the left hand side of the car to take a real beating tyre wise, pressures are usually around 3-5psi lower when cold, but they come up to the same when thrashing it for a few laps.

Ideally on a 16 inch wheel you shold have something like 32psi hot on all four corners. Do this by going out for a few laps and heating your tyres, then come back in to the pitsadjust the pressures accordingly. After you've finished racing let them go cold and record the pressures so you'll know what they're supposed to be so you can set them before you return to that track.

I remember seeing a guy in a Subaru WRX who thought he knew it all and wouldn't listen to anyone who tried to talk him out of it; he had all four of his tyres at 50psi cold and went out onto the track, and what do you know, he had a huge spin and wrote off his car.

Idiot.

:nice: do you have any photos of this track? or a video ?
 
people dont realise how important tyre pressure is when trying to get the most out of their cars, it's amazing how many people,on and off track dont check+adjust their pressures! make sure you have a good quality pressure gauge too :thumb:
 
nice vid! yeah definitely true about the direction of circuits. experienced this on tarmac rallies and track days. usually end up taking about 10psi out of normal road tyres, more from one side of the car than the other. Nice vid aswell mate! nice to see the good old b series showing people the way on track.
 
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