Tyre pressures for CR 322

[buroz]

Anyone got a clue.

 

I got up to 30psi (warm... couldn't get them hot).

They seemed to get better the higher I went. I ran out of time to take them any higher at Bentwaters.

I know that the grads lot run them quite high, I've heard of around 35psi. Are these pressures hot or cold?

 

 

Cheers

[Martin H]

I'd best not start a long discussion on tyre pressures on Grad cars - they've filled the Guestbook on the Grads website far too often . Hopefully enough to say that I've heard of pressures in the dry between about 24 and 30 (cold) for the track - with the majority probably in the middle of that range. Also if anything, about 2 higher at the front. Therefore your figures of 30-35 warm sound about right.

 

I find that below about 26 they scrub too much, and above 30 things get a bit skittish, although it's down to your driving style.

 

On the road, I think Caterham Midland suggest about 20 all round.

 

CR322s do take a while to heat up, but they do also go off! Found this at Anglesey and Mallory in particular. On the whole I quite like them - progressive, VERY hard wearing (keeps the cost of racing down no end biggrin.gif), enough grip to corner hard, but not so much that you don't have lots of sideways fun at trouser preserving speeds teeth.gifteeth.gifteeth.gif.

[Graeme Smith]

I run mine at 28/26 (F/R) cold pressures on the track in the dry. They maybe go up a max of 4 PSI when hot. I thought they went off as well, but didn't get any problems with 40 laps of Silverstone in the Birkett at the weekend. The times were very consistant all the way through. Perhaps its because the weather's a bit cooler and they don't overheat?

 

BTW, was that you in the background on Driven last night Martin?

[Martin H]

Errrrrr.......don't know, didn't see Driven - what was the feature?

 

Probably the reason the tyres didn't go off at Silverstone was the three long straights. I've had no problem with them going off on the longer circuits, just the short & twisties.

[Graeme Smith]

Driven was at the Driven alternative to the motor show

[Martin H]

Wasn't my car then (unless someone from Caterham Midland had taken it for an outing before handing it back to me!).

[Tim Sture]

I run mine at 26 front 24 rear on track but I am sure that's not the reason that Graeme beat me by 2 secs at Curborough!

 

On road in the winter somewhere around 20 all round, although at a track day at Elvington a couple of weeks ago I ran at 21 all round and the car was nicely balanced (started very wet, dried out a bit, went greasy, rained again, dried a bit, etc - so mostly wet or damp but with some dry lines). On a dry day at Elvington I had to have the left rear 2-3 psi higher than the others to prevent it overheating.