gtenthused

Hi guys, looking for a little advice. Now bare with me i'm new to the forums lol. Before i get started on my suspension i was thinking of getting different wheels for my car. I have an 11 gt brembo and i really dont care for 19's, the cost of an odd size tire, so i was thinking of either 18's or 20's I'll be lowering the car with koni's and steeda sport springs, swaybars, possibly a watt links as well. Of course when that time comes i'll be calling sam strano for that. I've been looking and i was thinking of either 18x9 255 40 front 18x10 275 40 or 20x9 255 35 front 20 x 10 275 35 rear. As long as the wheels are lighter than my stock ones i'll be happy and will i rub if i go with the 20's lowered 1in? My buddy can get me 20in tires cheaper than he can 18's so i was leaning towards the 20's as long as they are light. I drive it daily on a mix of highway and back roads. I also would like to track it now and then. Any feedback is appreciated and again be gentle i'm new to the forums thanks in advanced!

Norm Peterson

I'm not at all a fan of tire sizing stagger in a handling application, so same size front and rear, please. The front end of the car is the heavy end and is the end that gets the turning started, so it really needs the tire load capacity more than the lighter rear end does. Just run the rears at slightly lower inflation, which also helps mechanical grip for acceleration purposes and for minimizing power-on oversteer. Since you do not appear to be bound by any competition class rule limitations, choose a rim width out more toward the maximum width for the tire size selected.


Apologies for the picture quality, but here's what 255/45's on 18 x 9.5's all around looks like when you're trying (think two sets of '08 GT500 fronts on a car without the GT500's power, which your '11 GT doesn't have either). Sam's bars, Koni yellows, about 4 psi pressure stagger, and front camber that I'll just say is "out-of-spec".




Norm

gtenthused

I agree with the heavy front, just wasn't too sure about the rear. So maybe look into 18x9.5 is the better route and keep 255's all round is my better option. what psi do you run in the front/ rear daily as opposed to autox?

Norm Peterson

That's probably the 'easy' option. It fits without issue, and a properly supported good 255-wide tire is always going to beat a mediocre 275/285/etc. that isn't as well-supported. Support being lateral in this case. I know some folks are running 275/40's on the 18x9.5's, but I don't know how hard the driving is (I'd really rather put that tire size on 10's, or 10.5's if they'd still fit under the OE sheetmetal).


For that picture, I was probably at 34 or 35 front and about 30 rear. More accurately, that's where they started the day out at, as I have no idea after how many runs or even which session that picture was taken. It was a rather cool day, runs were coming up almost like hot-lapping, and I was using the event more as a tune-up for me rather than the car, so I wasn't paying that much attention. Daily, maybe 32-33f/28-29r.

The 255/45-18 is a little more tire than the OE 235/50-18, so I run the daily pressures in them a little lower than I do in the 235/50's (which I use during the winter and still maintain about 4 psi pressure stagger even though the sticker calls for 32 all around).


Norm

gtenthused

Thanks man appreciate all the info!

SchneidyP4.6

18x9.5's at all 4 corners FTW