Tyre pressure for track work

[Chris32]

Just want a general idea about what tyre pressure's to run for light track duties on normal road tyres

Tyres are Dunlop FM901's, 225x50x16 on 16x7.5" P1 Racing rims

Thinking around 36-38psi hot, but not sure, as I run them at around 36psi on the road?

Cheers, Chris

[Duncan]

yeah really hard will be good since they are road tyres, and have a 50 profile. Up to 42 hot I would suggest.

Pump em up to 40 cold, go out and do 3 hard laps. pull into the pits nice and quick and let them back down to 42 from 45ish they will be at. Easy

[dangerous_daveo]

Out of interest, why would you want more pressure on the track? I've never really found out the reason why.

[Duncan]

Well, to a point a higher tyre pressure helps your handling. The pressure in the tyre acts like a firmer spring/shock combo to give more direct handling, with lower pressure the car moves around on the tyres more.

But, over a certain pressure, different per tyre compound, they will start to give less grip as they get too hot. Road tyres (hard) can take much higher pressures, while if you were using something softer like r spec tyres they generally have a lower optimum temp like 34-36.

[Chris32]

Cheers guys, its for a advanced driver course which involves a few laps, so I will start of at 40 and then check them after a few laps

[Bl4cK32]

good luck with the course Chris, and we'll have to catch up again soon Im looking forward to seeing how your car goes....i wanted to go for a run with ya, but had to get ready to go to work...sorry

Oh well....another day i spose

[Chris32]

Cheers mate, it was good to catch up! Still in awe of the torque of the 3L, oneday I wouldn't mind a bigger motor.

Dump pipe still not done, been delays with the fabricators, so its going up there as it was previous, but running less boost for safety sake, will take you for a drive someday soon, I am working through christmas but have a month of mid january, so I will have plenty of time to catch up

Got my brakes on too, R33GTSt calipers, slotted 33 rotors and Racebrake Comp 9 pads up front and Comp 2 pads on the back, it stops awesome now - still bedding them in so it shoudl get even better

[Roy]

Im looking forward to seeing how your car goes....i wanted to go for a run with ya, ...  

Dont, once you feel the wrath of the RB20 you will kick yourself for playing around with that truck engine of yours...it runs on diesel right:)

How are the comp 9s on ths street, bit grindy/noisy or not too bad?

[Bl4cK32]

LOL Troy I actually pulled up the other day at the lights along side a b-double, and when we took off, i noticed i was actually changing gears at the same time as the truck driver No joke ....

Ill have to get you to run me through your brake setup chris....might be worth doin ometime in the new year for myself...have you checked out if there anymore firewall movement with the bigger brake setup?

My clutch (os twin) gives a shietload of movement in the firewall when u put the clutch in...so much im a little worried about it, and may have to make us something up

[Targa Tom]

Just want a general idea about what tyre pressure's to run for light track duties on normal road tyres

Tyres are Dunlop FM901's, 225x50x16 on 16x7.5" P1 Racing rims

Thinking around 36-38psi hot, but not sure, as I run them at around 36psi on the road?

Cheers, Chris

We usually start at round 28psi, with a target pressure of 35-38 (air) I have tried them higher but personally I don't like them.

Either way, it is a good way to learn. When they are where you reckon its OK, drop a few PSI out and note the difference.

The FM901's are a street tyre yes? they will like to be a bit tighter than a "r" type.

"Which way does the track go, and whats the lap record?" Graham Crosby

Have fun...

TT