"forced" To Track Isf Tomorrow. Help With Tyre Pressures Pleas

[lotusdave]

the lotus has a minor technical issue - a chaffing hose - that I can't sort before a day at Bedford Autodrome tomorrow. So I'm going to take the isf instead. Eek. What track pressures has anyone run? I'm thinking just letting them down to road pressure when running hot but I've no experience of a heavy car on track... Standard Bridgestone road tyres....

thanks. Should get some go pro footage too so will post that up in due course.

[Stuno1]

Check on the American forum chap as I am sure a lot of them track theirs. Only ever taken bikes on track. Let us know how you get on!

[lotusdave]

ta for the reply Stu. I had a good rummage but oddly they didn't really seem to talk about pressures. I'm sure the folks at Bedford will he able to help. They have a fleet of m3s after all.

historically ive heard two arguments. More pressure to keep shape in tyre. Less (cold) pressure so its about the when being used.

Its going to be a giggle whatever.

[Stuno1]

Interesting. On bikes you reduce pressure so when you get out there and heat builds the pressure raises. If you go out on a bike with normal road pressure they get so firm on track they skip. Assumed similar logic would have been applied to cars?

[lotusdave]

that's what I did for my rx8 years ago. Exciting. Just leaving for the hotel...

[Stuno1]

Have fun, take pictures and share with us how you get on :)

[MrW]

I always ran mine exactly as road pressures and never had an issue. As you say there seems to be two schools of thought generally, some of the more enthusiastic guys run lower for better traction, whilst others insist you need to go up to ensure you keep the tyres on the rims, particularly if there is high speed corners.

Anyway have fun the ISF is great on track.

[lotusdave]

I had a great time yesterday and the ISF was wonderful fun. I wasn't exactly ragging it as I was uninsured (the lotus has a specialist policy which provides track cover).

I ran the tyres at 40psi, somewhere between normal road and high speed road.

My front brakes are a little worn so I didnt overdo the late braking either and besides I needed the car to survive given the lotus is off the road for a bit.

If you get the chance you should do this with your car; really throwing it about and enjoying what it was designed to do.

It feels SO much faster in real life than the video shows...

https://youtu.be/Gb-75kRkKTw

[Motor Man]

I would leave them at std pressures

Over inflation is not good as it will affect the tyre contact with the ground

Under inflation will result in the side walls rolling and causing tyre damage

You need to try and keep a full footprint of tyre contact

Race tyre construction takes all this into consideration and is completely different to road tyres

[lotusdave]

indeed. That's the trade off and balance to find.

[Stuno1]

Nice! Great times. As you say it was developed on track. Glad you enjoyed it. Nice clip, sounds great.

[Corrado]

Great video Dave.