[roy@gambitmotorsport]

I have a 335i coupe sport package, manual transmission, Bridgestone run-flats. My tires are at 32psi front/35psi rear. I recently drove some twisties for more than 10 miles, sat behind a slow truck for about a mile, then pulled over for lunch and measured my tire temps with a MicroTemp Pro. I wrote down the variations, rather than the exact temps, as I was damn hungry. But, I double-checked them all. Here is what I got:

Front - inside cool, mid hot, outside medium

Rear - inside hot, mid med, outside cool

These were all within say 140 to 150 degrees, so hot and cool being 10 degrees apart.

Questions:

- Did I not even get near warming up my tires?

- Does the data show that the rears are cambered more than the front?

- Should I change pressures?

[leftcoastman]

Rear does have more NEGATIVE camber, so it makes sense. Your fronts are a bit odd, as my outsides get toasting hot due to the neutral/pos camber.

Try this exercise on a track. I'd be curious to see the results. I should show you a pic of my front tires. From afar, my tires look like slicks. Up close, you can see tread increasing as you look towards the inside.

[roy@gambitmotorsport]

Originally Posted by leftcoastman

Try this exercise on a track.

Will definitely do that. Just finished break-in, so I'm looking at something in the near future.

[S4to335]

To be honest..I dont think you can tell much by running street tires on a canyon run and then checking tire temps with a pyrometer...now if you were on full race tires..or even R compounds...and on a track during a test day...then you could tell something. General rule I go by is...If the center is too hot...you have too much pressure. I try to hit 40-41 lbs hot with my R compounds when I am on the track...and for right this second with my existing setup...I lower pressures right after I get off the track to try to maintain that 40-41 lb pressure range.

Having a pyrometer if you are not tracking a ton..IMHO...maybe a bit of overkill.

When I raced in Spec Miata...I didnt even have a pyrometer...however a few other fellow racers did. I was also not a front runner.

[elbert]

What kind of pyrometer did you use, infrared or probe? You want to use a probe type because it can measure the internal core temp. An infrared pyrometer measures only surface temps.

[S4to335]

I have seen both...the infrared is not that far off the probe type unless you are a team manager for a race crew. :-) Some of my friends have the infrared type...guys who track a lot.

[roy@gambitmotorsport]

Originally Posted by S4to335

Having a pyrometer if you are not tracking a ton..IMHO...maybe a bit of overkill.

No doubt. I plan on tracking it and on changing tires in the near future. Just playin' around with the new toy.

[roy@gambitmotorsport]

Originally Posted by elbert

What kind of pyrometer did you use, infrared or probe? You want to use a probe type because it can measure the internal core temp. An infrared pyrometer measures only surface temps.

It's infrared.

[elbert]

Originally Posted by S4to335

I have seen both...the infrared is not that far off the probe type unless you are a team manager for a race crew. :-) Some of my friends have the infrared type...guys who track a lot.

ok, keep doing it the wrong way