Tyre Pressure With My Setup

[Ruxis]

Gday guys,

just wondering what my air pressure should be for my setup on track days.

i have 18/8.5 wheels and 18/40/235 federal 595s.

thanks alot,

Jarrad.

[No Crust Racing]

Mate it varies quite lot depending on suspension setup, spring rates, damper settings, power, weather, track temp blah blah.

I've got 595 RS-Rs and run those at about (err memory failing me as it's been a while) I think around 36-38psi HOT, so starting temps around 32-34psi but that's an on S13 so it's lighter.

Also, if they are anything in the 595 range other than RS-Rs then the numbers will vary too as the RS-Rs are the softest compound in the range.

People here can help you take guesses but ultimately the best way to find out is 1) Call Federal and ask them what they recommend for your car in track conditions (you did post in motorsport so I'll assume you're talking track pressures) and 2) head to the track and start testing. Take a portable compressor with you, get one if you don't have it as you will need it. A good tyres pressure gauge if the compressor doesn't have one, and ideally you also need a pyrometer to measure tyre temps across the tread face as soon as you come in from a session.

I am a budget racer, for fun only, so I don't have a pyrometer and just keep tabs on how the car feels at different pressures and how the tread is wearing.

It not only varies for the items listed above but also due to driving style, how much you care about tread wear versus lap times etc etc.

Get out there and enjoy yourself, you will soon learn at what hot pressure the car/tyre/suspension combo is most happy.

[Ruxis]

Alright thanks didn't think of car weight and suspension but it makes alot of sense.

I'll give it a go mate thanks!

[Funkdoc]

hmm... i think RSR's should be run at lower pressures... maybe around 28-32 HOT... 595s slightly higher 30-34 HOT.... That's for getting max grip, but you will trade off some handling... Higher pressures makes the car less grippy but more responsive... if your starting out, good idea to use higher pressures first... better handling will do you more good than grip... once ur completely happy and confident with the handling at the limit... drop the pressures... you will notice the increase in grip...

If u dont have a temp guage... use ur hands.... if ur pressures are way out of whack... u can feel it... 10+ deg cel is easy to feel with ur hands...

ie. If the temperature on the face of the tread is L60 C75 R55

you will easily be able to feel the centre is friggin hot and cooler on the edges.... clear indicator to drop ur pressures....