tire pressure?

[sparfel]

Does anyone know what pressure I should run for the Blue Streak's I have on my SPF Cobra? Thank you. PS; they do look great!

[Silverback51]

I run 22 front and 18 rear in my BillBoards.

[1985 CCX]

I am running 25 front and 22 rear with BB.

[sparfel]

Thanks guys.

[wtm442]

Buy a simple infrared thermometer ($50-$75) and check the temp across the tire. If the center is hotter than the outside, reduce the pressure. If the center is cooler than the outside, increase the pressure.

[Godfather]

I was also wondering what pressure I should be running in My Goodyear Billboards? Is 25 front and 22 rear good for street use or is that track use only? Sounds a little low??? but I dont have any experience with these tires yet. Thanks

[HI Cobra]

It does sound low compared to tire pressures in daily drivers but remember
these Cobras are light weight and the contact patch is large (big tires) so a
little goes a long ways. On my first drive there was 30 psi all around and
the car felt like it wanted to skip on any bumps - I dropped it to 25 and that
took care of that.

[wtm442]

The SPF user manual says 18 psi (cold) for normal driving and 25 psi for performance driving. No mention on tire type.

I do not have Billboards, just regular Goodboot tires. I find that 19 PSI in all tires is the best mix for traction and ride quality for me. The tires act like shock absorbers, so the lower pressure gives a much better ride around town. With 25 PSI around town, the ride is rough and the car wants to skip around on rough surfaces.

[Bob In Ct]

Warren's advice is right on the money. When all of the tread is at the same temperature the inflation is correct.

Bob

[Silverback51]

Originally Posted by wtm442

Buy a simple infrared thermometer ($50-$75) and check the temp across the tire. If the center is hotter than the outside, reduce the pressure. If the center is cooler than the outside, increase the pressure.

Up to a point that is true. However, if you run more negative camber, it will not work.

I personally run 3/4 degree negative camber so it corners better. The spec calls for 1/4 degree for street, and 1/2 to 3/4 for competition. I pay for that in tire wear, but figure it's worth the trade off.

[McD00]

Originally Posted by Silverback51

Up to a point that is true. However, if you run more negative camber, it will not work.

I personally run 3/4 degree negative camber so it corners better. The spec calls for 1/4 degree for street, and 1/2 to 3/4 for competition. I pay for that in tire wear, but figure it's worth the trade off.

Then you average. For example from outside to in....109-114-119 degrees would be perfect for running more negative camber. Now if the temp was 109-125-119 then I would drop 1 psi at a time until I get a nice average. If the temp was 109-100-119 I go up just 1/2 psi at a time until I get that nice average. Just remember with more negative camber the inside will always be the hottest.

McVette

[RonNichols]

McDOO,

Do you do this(take temps) immediately after you session? Or do you have people waiting in the pit area to take the temps? It seems like your tires could cool some by the time you get back in the paddock area.

Thanks in advance.

R