Tyre Pressures

[AQICLS3]

When doing circuit racing and time trials what tyre pressures should you run for the following tyres...........keeping in mind that the weather is good.

1/ Street Tyres
2/ Semi Comps
3/ Race Slicks

:burnout: Cheers Erik

[Dane]

Streeter .... 45psi

Semi's ....... 40psi

Slicks ......... Have absolute no idea. :D

This is from askin' around on sprint days. :thumbsup:

:cheers:

[JBonDSS]

I think with semi's & slicks low 40's psi when at hot temp

the mid 40's as dane has said is to make up for the less side wall strength

A lot of pressures are measured @ hot temp - :driving:

[DelftMica.SSUte]

What do you guys run when driving normal day driving

[Modena]

36 on the street, 45-48 on the track

[Ghosn]

How much PSI before the tyres go pop?

[mmciau]

IIRC, being told by a Qantas engineer that Boeing tested the 747 tyre system and placed a test set in the middle of an airfield and after a while the rim bead let go at 750 lb/sq in - not the tyre.

I have definitrely seen 80 psi in a mini tyre and it hadn't let go

mike

[CSV Strada SiR]

Originally posted by AQICSS
When doing circuit racing and time trials what tyre pressures should you run for the following tyres...........keeping in mind that the weather is good.

1/ Street Tyres
2/ Semi Comps
3/ Race Slicks

:burnout: Cheers Erik

1) 44 f 42 r
2) 34f 32r (dunlop) 29f 27r (Pirrelli)
3) 24 f 22r (crossply)

U need to check the tyre pressure when hot- for instance my Crossply's had a cold temp of 18PSI, radials dont have such a big variance between hot and cold.
Basically if the car feels loose/on the edge let the tyres cool then have another go or check the pressure as soon as u are in the pits

[AQICLS3]

Had a great time at Phillip Island last Saturday...........spoke to alot of guys on the track and was told never to run more than 38psi when hot.........so ran 30 when cold and checked it every time we came in and was never over 36-38.

:cheers: Erik

[grassy]

I was running 35psi cold in Bridgestone RE540's and the grip was ample. I was told to look for feathering on the outers of the tyre and deflate or inflate to suit the wear :thumbsup:

[andrewslr]

Keep in ming that R specs generally require a little less pressure than street tyres as lower pressures allow the tyre to move around creating friction which = grip.

On the Commodores with street tyres @ 38 psi as a baseline is a good starting point, you don't really want more. On the R specs @ 35 psi as a benchmark then adjust accordingly.

Although my car is considerably lighter I started the day with 36psi cold in the D01J's. I ended up at @ 30psi cold by the end of the day as I found that as the track was not really warm I wasn't get temp into the tyres. Grip got better as pressure reduced.

There's a lot of good advice on club days so no-one's really given you a bum steer. It's a case of experimenting a little on the day based on your seat of pants testing.

[Dane]

Definately found that with the r-spec's i ran at Phillip Island, 36psi to 38psi hot was just on the money. :cheers:

[Sid447]

Each,

To their own and what works best for them.

235/45 x 17 fr. 45psi
265/40 x 17 rr. 32psi

--- Sid447 ---