deputydog95

Agreed.

However, it was 85 degrees out that particular day. Not as hot as it gets, but still pretty hot and probably a good representation of the average here in FL.

I was just about keeping pace with Randy on Sunday after loosening the front sway bar and eliminating the push.

Not sure I can go much faster on these particular tires. Maybe a hair, but there aren't seconds left on the table.

When I ran a hoosier alignment on the Nittos (-3.5 front and -2.5 rear 4mm toe), I came up with these temp numbers:

225 225 190 185

167 165 155 143

So I was able to get higher temps at much more aggressive alignment. However, I'm only using probably 2/3rds of the tread based on the huge temp delta from inside to out. Orbit says 10% delta should be max. I'm clearly way over in front and way way way over out back.

I know Nitto says to run high 30's and hoosiers says the same thing. Yet hoosiers work better and last longer at 30 hot.

Maybe I try maybe 36/34 hot and keep adjusting down till the temps get where they need to be. I think the alignment I'm at now is good.

85Gold

Dawg

What times were you running on the NT01

Peter

deputydog95

I have yet to upload data. Freaking busy... Maybe tonight. On Sunday morning I went out late (student) did 50mph waiting for a rabbit. It's just boring doing laps by yourself. Randy came by about halfway through. There was a bit of traffic but I kept him within 50 yards for the remainder of the session. So maybe 223-224's?

deputydog95

My alignment guy, after speaking with a couple racing buddies, says I really need to try coming in super hot. As in ***** out through 17 and bring it in at the last minute.... Before making any judgements about temp. The brakes were literally smoking the last time I came in, but I did back off about halfway down the straight before T17. Apparently there is rapid cool off to a certain degree the minute you lighten up even a bit.

GT3DE

should have mentioned this before:
tire temps and pressures need to be taken IMMEDIATELY on pit road after hot laps, no cool down.
Here is the procedure (need 2 people to get it right)
person #1 - take tire pressure starting LR, then clockwise around car, LF, RF, RR.
person #2 - take temps in same order as above. always start outside to inside taking 3 readings across tire.
FWIW - not taking tire pressures when taking temps is not very informative.

FYI - temps tell a story (assuming pressures are correct). temps that are relatively even across a tire show that the tire is being used evenly. Duh. This will likely result is more even wear across the tire. BUT it is not the fastest way around the track. The fastest around the track does not equal even tire temps. Therefore you as the car owner/driver must decide the balance the is right for you -- tire wear vs. lap times. You can go really fast and wear out tires fast. Or you can go really slow and make tires last a long time. Not both.

My setup is on the aggressive side and eats tires. So I have to rotate and flip tires frequently to get longer wear out of them.

DavidNR

Clarke,

This seems counterintuitive:Could you elaborate?

Thanks, David

85Gold

Accepted wisdom from Hoosier and others is a 15 to 20 degree difference from inside to outer with the inside being hotter. Also to add to Clarkes info the probe must be inserted deeply in the tire to get accurate temps as the outer surface cools fast. Or as Clarke said you can have even tire wear or you can be fast at the expense of the inside of the tire.

Peter

DavidNR

Makes sense, thanks Peter. So if I have even tire temps coming into hot pits then generally speaking I am less negative camber than ideal. Then increase negative camber until you see the 15 to 20° temp difference. No wonder, time for another alignment!

NJ-GT

An AeroBeetle 3.6 with a Cup wing on NT01 is a 2:20 car at Sebring.

Running slower lap times helps to increase longevity on the brakes, and helps the tires to run at colder temperatures.

85Gold

It pains me to have to have to agree with Rad but I do believe he is spot on with this one.

Peter

deputydog95

A 2:20 in a 3.6 with 32k miles on nittos is a little optimistic. Maybe I'll let Rad take my car out and show me how to do it


This seems a little counter intuitive to me regarding camber and tire wear. I'm only asking because I don't totally understand. How does excess camber improve handling? It would seem if you're using a lot of the inside, with heavy inside temps, then you're not using all the tread available from the middle to the outer edge? Please explain as I don't get it.

mdrums

Now that we are all getting super technical...wouldn't tire temps change at different parts of the track? Coming in hot at Senring you have a long straight for tires to cool and then a huge long right hander with T17. You dive into the pits to take your temps and the left side would read different than the right side...correct?

Next you go to a different track with different surface, track temps and corners and get different temps

85Gold

Mike & Dawg,

In a ideal world with race engineers you would vary setup for each track you drive. Us peons need to just ballpark it and try and win our DE group ie moving Chicane for me.

The reason we look for the inside to be slightly hotter is it gets heated up more under braking than the outside which gets the majority of it's heat during cornering. You are correct in that we want the tire flat with full contact patch during cornering but to much - camber can compromise braking. Tire pressure, sidewall stiffness also can affect the amount of - camber you need.

All of this is MHO and YMMV

GT3DE

in a relaxed state, your car sits on the inside edge of your tires. Going down a straight, same thing. In the corners, the outside tire flattens out when the suspension rolls -- for maximum grip turning. Most time on the track is on the straights. Heat will build up on the straights, accelerating and braking - on the inside edge more than the outside because of camber. Only in the turns do the tires get used to their potential. You need a lot of camber to make a tire lay flat in a turn under load. As the car rolls over, the the tire then stands up straight thus giving you an even flat surface at the bottom of the tire -- max grip. Then you straighten up and go down the straight wearing out the inner edge.

DavidNR

There you have it... Makes perfect sense. If you were cornering 100% of the time then even temps make sense. Other wise, not.
Thanks for all the clarification guys!