Thanks for the pictures...the stock tire is taller than 25" but it's good to see the Nitto is not taller.

LVDell, I run at Mosport so my comparison is at that track..the slow corners are not realy slow at Mosport.
There is a difference out of slower speed corners with a taller tire...gearing on lower torque cars is noticably sensitive. I used a 285 V710 which is around 24.7" ..next threw on a set of Hoosier 315 25.6" and saw a large drop in jump..less thrust out of corners. The Hoosier were quicker in corner 4 & 8, which are fast long turns and the Kumho were better every where else.. I like the kumho V710 better.

In a perfect world I would like to see a 315 that is actualy 25." and no taller for and a front tire 245 or 255 for smaller tracks at the same 25" diameter.

 

Wow! You can tell the difference between 3/10 of an inch on tire rubber. I'm not even close to being in that league.

 

Easy now... It all makes a difference, I run in Solo 1 so a few tenths here and there make's a difference and if you can feel it in your seat there is something there.

With my back to back driving test which I was not alone in testing, there is a noticable difference but again this was with tires that were closer to 1" apart in diameter. Knowing this I would prefer to have a smaller diameter tire and nothing measurably taller than stock.

The written specs on tires are no always acurate.

 

Easy now? I was NOT being argumentative. I was honestly stating that I am impressed you can feel those differences. Geez, do you have to put a smiley next to everything on the internet so nobody jumps your *** these days?

Anyway, back to the topic at hand.......
FYI.....I consider myself an advanced driver that can hang with the best of 'em in Red. However, by no means is my timing done in tenths. Mine is done in full seconds.

 

Are you running the Nitto 315s on OEM rims? (You must have told me this five times, but I'm brain dead now.)

 

Jim H,

Were you there last year? I remember amother white GT3 last year, with red tape.

Looking forward to meeting you! See you there.

 

Z06,

could the weight of the 2 different tires be what is causing the difference out of slow corners?

 

I think everything helps, the wheels I use are BBS Magnesium with the Kumho V710 which makes a very light package, tranny has been regeared lighter exhaust the cars a rocket.. on a roll it's even with a GT2.

LVDell, No problem, thought you were being sarcastic. .3" does not sound like much..maybe I will crunch the numbers and see how much it actualy changes.

 

Nope. I was honstely impressed. Even though I am running red and consider myself a very good and skilled driver I still have a TON to learn and when I hear stuff like you said I realize just then how much there still is to learn.

No biggie on the misinterpretation of intnet. It's all good.

Funny Chris. Get some ginko biloba in your diet BTW, yes I am running OEM wheels.

 

On my race car I could tell the difference between different size of tires and how it would change the effective gear ratios. .3" seems small but it certainly would make a difference. The two tire sizes I ran had about a .8" difference in circumference and it would sometimes mean grabbing an extra gear before the next corner.

 

Good to know about the gearing. I will be heading down to CMP next month and will be able to know immediately if the ID on the Nitto's change the gearing at all since that track is very short and tight with alot of gear changes. There is especially a few sections where I am already out of gear right at the braking zone. I haven't run the Nitto's there yet. Up until now, I have been on PS2's.

 

This is an update on something I discovered after getting the tires on the car. I mounted them on the OE GT3 wheels. They look awesome from the rear and really fill out the wheel wells front and rear. 2.4° neg camber and 128 mm rear ride height.

In the rear I discovered a problem, least with my car. I encountered a rub when hitting hard dips that compressed the suspension and I don't think I even reached the bump stops. It hits a body seam just inside the rear bumper cover up where the bumper cover tapers into the wheel well. The seam protrudes straight down about 3/4". After inspecting we found we could roll the seam toward the outside of the car and flatten the sharp edge that could cut the tire on a hard compression. Least now there is 1/2" more clearance and a flat surface that won't cut if rubbed hard.
Just FYI...

 

Thanks,

 

David, can you post a pic or something that explains what you did a bit more?

 

Dell, I know you said you get some rub in the front at full lock when new. Are you getting rubbing in the rear also?

Andy

PS: may be somewhat academic for me now, since Nitto has no 245s available.