[ninetres]

The Good news:
Been waiting to get a chance to edit a LOT of footage from my last day at Infineon Raceway a few weeks back. AWESOME DAY. My CAR was putting up some serious lap time (IMO) all things considered. With lots of Blaine Fab love on the car, it was kicking ass and taking Porsches names. It seemed to understeer and its response to feedback was sort of inconsistent I felt.....but somehow I was ripping off 1:56s, in my FULL WEIGHT+ street driven car.....with a passenger, and a bit of traffic on most laps. I think the understeer might have been due to the fact that I was pushing the car a lot harder than I was on my previous outing here....and its a pig.


The Ugly:

Hurt the motor coming around the carousel near the end of the day. My best friend/mechanic was driving and the car lost oil pressure (25psi at idle) after coming around it. I noticed throughout the day that if I had the entry just right, and the car was biting real hard.....the pressure would dip for a split second at the end of the run-out.... and then shoot right back up. Guess the ol' LS1 got tired of that shit by the end of the day. It likely spun a/some rod bearings. It was knocking GOOD by the time we limped it back into the pits.


Anywho, here is a couple of teaser clips before we compile the full days edit:

Carousel-->double pass
http://www.youtube.com/watch?v=1bcqonLzyEg...;feature=relmfu


Camaro > GTR
http://www.youtube.com/watch?v=3d5CZW2mjUs&feature=plcp

[BPWilliams]

The thing is that if you do the math your car does not need a 315 tire. I sat down with Larry Pond (raced with Bob Bondurant and Carol Shelby) and we did the math, based on the weight of the cars, contact patch, and the speeds we run in Arizona a 255 tire would keep the proper heat in the tire. At 275 I can keep about 185 degrees which is on the low side of the tire rating, 315 would be even cooler. ASA Truck series runs a 10.5 inch tire on a full tube frame chasis so that is something to think about.

So the long and short of it is that the size of your tire should be based on the proper heat range to excite the tire compound, not necessarily bigger is better...

[Mojave]

The thing is that if you do the math your car does not need a 315 tire. I sat down with Larry Pond (raced with Bob Bondurant and Carol Shelby) and we did the math, based on the weight of the cars, contact patch, and the speeds we run in Arizona a 255 tire would keep the proper heat in the tire. At 275 I can keep about 185 degrees which is on the low side of the tire rating, 315 would be even cooler. ASA Truck series runs a 10.5 inch tire on a full tube frame chasis so that is something to think about.

So the long and short of it is that the size of your tire should be based on the proper heat range to excite the tire compound, not necessarily bigger is better...

While I agree that bigger is not always better, and you need to make the tires work perfectly for maximum performance, what car would need 315's if a full weight f-body doesn't? With 2 passengers that's close to 4,000 lbs. Plenty of cars come from the factory with less weight and larger tires than an f-body, like a Z06 or a 911 GT3, and I refuse to believe the engineers put those on for shits and giggles.

The ASA trucks run a spec tire, don't they? I bet they would run a larger tire if they had the option, especially on the right front.

This post has been edited by Mojave: Jun 12 2012, 02:48 PM

[pharmd]

The thing is that if you do the math your car does not need a 315 tire. I sat down with Larry Pond (raced with Bob Bondurant and Carol Shelby) and we did the math, based on the weight of the cars, contact patch, and the speeds we run in Arizona a 255 tire would keep the proper heat in the tire. At 275 I can keep about 185 degrees which is on the low side of the tire rating, 315 would be even cooler. ASA Truck series runs a 10.5 inch tire on a full tube frame chasis so that is something to think about.

So the long and short of it is that the size of your tire should be based on the proper heat range to excite the tire compound, not necessarily bigger is better...

While I agree that bigger is not always better, and you need to make the tires work perfectly for maximum performance, what car would need 315's if a full weight f-body doesn't? With 2 passengers that's close to 4,000 lbs. Plenty of cars come from the factory with less weight and larger tires than an f-body, like a Z06 or a 911 GT3, and I refuse to believe the engineers put those on for shits and giggles.

The ASA trucks run a spec tire, don't they? I bet they would run a larger tire if they had the option, especially on the right front.

Good points guys. The issue IMHO is if you are gonna have all this issue working out clearances...put it on, hammer this roll that, drive (RUBS), hammer more, cut this, drive (RUBS), repeat etc. Is the damage to the car and the hassle in all that really going to produce supeior lap times? versus installing say the 295/35 and while you "might" have to clearance some in the rear, should fit pretty much guaranteed. While Asthetics matter, IMHO a combination of Asthetics, Performance and ride all have to be considered..at least for the intended us of my car. I agree I don't know why companies would put out OE stuff that is huge, if they didn't find performance benefit...Look at the new ZL1...IIRC its tires really aren't that big for the 4100lb weight and performance category of the car.