[JitteryJoe]

Title says it all. I have an LT1 so no magride. Killer deal right now on Tire-rack but wondering if the fronts will fit? I think the 28 offset puts the fronts about 8MM closer than what is recommended but not sure if the non-mag cars have a little more clearance? Has anyone run this offset and will I need a spacer in the front? Another noob question if a spacer is required is a small one safe without extending the wheel studs?


Title fixed, offset is 28 not 38

[c4racer]

I am running 19x10.5 ET35 with 16mm spacer, so effectively ET19

That's on a .5" wider wheel, so remove half of 25mm or ~12mm to compare to a 10" wide.
So that puts me at a 29mm effective offset if I had a 10" wheel instead of 10.5 - if I am doing the calculations right.

Somebody check my math, but I think it will work!


I am about at the max inboard possible and needed to grind the shock towers a bit to make it work. Probably depends on the exact wheel design and lip etc.

Also - non mag car - 1SS, so should be same suspension as the LT1.

[foshjowler]

I have 19x10.5 et 22 on 305/30-19 and it just fits. I had to get camber plates to get the camber I wanted out of it.



I think you might just get away with getting them on without spacers, especially if you run a low amount of camber. But be prepared to get some 3mm spacers to help out. From what I've read around 3mm is a safe amount to not need longer studs.

[Msquared]

Agreed, at most you'd need 5mm spacer without magride. 5mm is about the limit for running stock studs. It gives you six turns of thread with most wheel designs, which is enough.

[Dabjbr]

Not exactly the question you asked but a free tool that will provide insight....

Go to the App Store and download WheelWillFit.

[NotFast]

Originally Posted by Dabjbr

Not exactly the question you asked but a free tool that will provide insight....

Go to the App Store and download WheelWillFit.

Thank you. Any idea how I find out the offset of the stock 20x8.5" LT1 wheels on my car (to input into that app)? Is it 25?


It's not real easy to find, GM doesn't publish it.

[Dabjbr]

Originally Posted by NotFast

Thank you. Any idea how I find out the offset of the stock 20x8.5" LT1 wheels on my car (to input into that app)? Is it 25?


It's not real easy to find, GM doesn't publish it.

I don’t personally know but hopefully someone chimes in.

Sometimes the offset is inscribed on the back of the wheel though. You could remove one wheel and check.

[Msquared]

It's 25mm fo the stock 20x8.5 wheels. However, for your question the more relevant info is the offset of the 1LE 20x10 with 285/30/20 tire. That wheel has 20mm offset. wheel-size.com has all this info:



You should probably be looking at 285/35/19 or 295/35/19 tires for those wheels if you get them.

[NotFast]

Originally Posted by Msquared

You should probably be looking at 285/35/19 or 295/35/19 tires for those wheels if you get them.

Thanks Matt. I'm unsure what size @JitteryJoe was looking at, but I know I was planning on going to 19".


However, I feel that unless I get all the measurements -- I can't be 100% sure the tires/wheels will fit and I should be ready to install a spacer. I'm not very interested in using spacers but it sure beats needing to sell a set of new wheels that don't fit...

[JitteryJoe]

FWIW I was looking at 19's. I think in the APEX thread they were saying wider 18's ran the risk of rubbing against something else (steering knuckle or something?). Its a brand new car so while I want an aggressive square setup I have zero interest in cutting into anything to force fitment. I think I've settled on some 285/35/19 tires. Any bigger than that and the prices really shoot up.

[NotFast]

Originally Posted by JitteryJoe

FWIW I was looking at 19's. I think in the APEX thread they were saying wider 18's ran the risk of rubbing against something else (steering knuckle or something?). Its a brand new car so while I want an aggressive square setup I have zero interest in cutting into anything to force fitment. I think I've settled on some 285/35/19 tires. Any bigger than that and the prices really shoot up.

Do you happen to be looking at Flow One wheels also? Have you called the Tire Rack? I wanted to talk to them but their level of "auto enthusist tech people" is pretty low lately.

[JitteryJoe]

Yeah, those bronze F2's are like 125 a wheel which is absurd. Although it looks like the F5's are a lot lighter so I might just keep an eye on them to see if they go on clearance later. But the new Conti DWS06 Plus is like 26lbs a tire in 285/35/19 unless that's a typo which is a good 5lbs lighter than anything in it's class (or pretty much any class for that matter). So a 26lb + 22LB wheel would be 48lbs which is probably significantly lighter than the stock plus 16-17% wider plus a better tire. Just really not looking to drop 2K plus in wheels and tires right now when I have <1K miles on the car. I'm not sure I could stand buying the F2's and watching them sit in my basement for over a year before getting tires and mounting them. Then to potentially find out one is defective in some way and no replacement is possible on a discontinued wheel and Tire rack won't take them back since they were discontinued wheels bought a year ago.


So yeah, pretty much my typical indecisiveness on anything expensive


Oh, and I have not called tire rack. I would imagine that would not be any more helpful than just searching on their site. They also seem to no allow you to put 285s on a 10in wheel even though the tires say 9.5 to 11" wheel fitment.

[c4racer]

you can run 275's on a 10" wide wheel no problem too. Or 285, or even a 295.

[NotFast]

I've been poking around, looking at wheels while waiting for this horrible winter to finish, and had this question/concern: wouldn't a wheel's backspace (or how concave it is) affect clearance over the front brakes? I'm not even sure how to determine this without a wheel to verify.