Driftomagnifico

Good god, why does no one else understand the futility of this thread without more info?

You need to know at the bare minimum the size tire you are running, this affects the load index of the tire and how it accommodates load. You could have to run 40 PSI in a 205/50/15 tire but only have to run about 30 PSI in a 245/45/15 to get the same wear pattern / heating pattern.

RKD in OKC

Drifto...
That is exactlly why you start at factory pressure then either heat up and check pressure or drive like a mad man and check temps across the tire.

pjburges

It's just a huge Forum of personal opinions Drifto - dont count on Rennlist for a scientific answer. You can count on Rennlist giving you a broad variety of real life experiences and opinions that can help you reach the right solution for your car though IMO.

LFA951

I have 225/50-16 in the front and 245/45-16in the back, what would I need?

hosrom_951

What is the average temp. on tires (street) and when should you get worried on the track?

Thom

36 PSI when cold, stock wheels and tire sizes.
For some reason '90 Euro cars feature a factory recommendation of 44 PSI for rear tires (against 36 PSI for '89/'91 Euro cars). I tried it once, it was way too much.

Driftomagnifico

It's based on weight distribution, if you are somewhat factory I would say you need about 36 PSI cold in the fronts and about 33 PSI in the rears. That will make the car handle more neutral than 36 in all of them.

The 245/45 will have a higher load index than the 225/50 so at the same pressure you are going to loose out on contact patch on one or the other unless you have unequal weight distribution (not an issue on the 951).

Driftomagnifico

The temps just have to be in an effective range of the tire. Average temps will vary quite a bit due to ambient temps, pavement design, and the cars design. That being said it's generally a smaller point than focusing on equal heat distribution on the face of the tire.

Measuring the temps off the street you'd pretty much have to blast down some twisty roads and immediately pull over to get a good reading. Use a probe type pyrometer, the surface ones don't work as good.

For the track, you will know when the tire is getting hot. It will feel like you are on ice if you are overheating the tire. If you want to know what it feels like, do a burnout and then try driving in a circle and give it a little throttle; it will break away much sooner.

hosrom_951

Im planning on installing a tire monitoring system when i get new tires soon, it informs you of tire tempreature and pressure.

LFA951

I put 36 on the front and 34 in the back

Perry 951

Same here with 225/40/17 front and 245/35/17 rear. My RE-730's have lots of meat even after 15K miles. FYI, most of them didn't make it past 20K miles.

That being said, I check pressure and wear often and do adjust up and down for temp. Like Mario says, "Check your tires, often!"

Jake951

36 psi front and 33 psi rear is exactly what I run with 225/50/16 and 245/45/16 tires. I arrived at that by trial and error.