havasu486

I am going to be purchasing my first Corvette, a Grand Sport, which I will be using for HPDE events. I like the ability to rotate. Does anyone run a square setup that does not require replacement studs or wheel spacers? Please share any suggested wheels and sizes.

chandretti15

Square set ups to rotate are really not the norm for Corvettes that see track use. I know many ask but gotta get over that and just deal with staggered set ups and the inability to rotate. Just the cost of tracking a Vette. 18x11 front with 315/30 18 and 18x13 335/30 18 rear is the hot set up.

havasu486

Thanks for your input.

BrunoTheMellow

I ran 295 front 305 rear on square wheels on my z51 with z06/GS suspension it did great. It all depends on your springs and sway bar setup. Stock gs/Z06 suspension and tires understeer terribly. Stock z51 suspension and tires are MUCH more balanced, so it likes the bigger stagger in my experience.

You can run square by just adjusting the camber and sway bars to balance out I would think.

davidfarmer

I run square

'12GS

I run 335 square on a C6 GS, and the wheels are rotatable 18x12s.

MarkAVette

What wheels, offsets, and camber are you running. I'm also interested in this type of setup for the track. Tried some traction circles in a parking lot on stock rims and the GS understeers so I would think a square would help make it more neutral on track. Would like to run a R comp like 335/30ZR18 Toyo R888R.

Mark

'12GS

I run Forgestar F14s with 3*F/2*R camber. Offset should be somewhere between 56 and 45, depending on how much camber you run. I measured for my wheels with stock camber, and the measurements show they should fit with next to no camber an a 56 offset. The problem was, when I received my wheels, I had changed the camber on my car, and didn't account for the inboard room that I lost. I ended up adding an 8mm spacer, for an effective offset of 48. You could even poke the wheels out more with my camber settings, hence the 45 as the lower range.

crimlwC6

Lots of people run square set ups on C6s.10. 5 to 12s should work on a GS.

anth115

Reviving this thread rather than starting a new one.

With winter coming, I'm thinking of next season's mods and new wheels/tires may be one of them for my 2006 Z06 (HPDE use, not autocross).
Looking for further suggestions on square setup specs (wheel/tire widths & corresponding offsets) for LS7 cars.

My main concern is if the extra HP makes the car feel very loose/unbalanced with a square setup or if it should be manageable.
The goal would be to run a 305 or 315 NT01 on affordable wheel like what Apex is cooking up (or 4 oem rears, etc.).

What do you guys think?
Thanks

havasu486

I cannot answer to the square setup other than to say for HPDE I was advised against it. I would have loved to go with it for rotation reasons alone myself. I did reach out to Apex a few weeks ago and thought I would share their reply....

"We are currently in the process of designing a lineup of flow formed wheels for the C5 through C7 market. For the Forged wheels, they are on their way but it will be at a later date, I would estimate around mid 2020 at this point. The flow formed wheels should be here in Q1 of next year. Those will be using the SM-10 design and will come in a few different fitments for your car, most notably being 18x11" and 19x10" for the front along with 18x12.5" and 19x12.5" for the rear."

Disappointing to me as I have utilized their product in the past with great result but am in the market for the Forged. Waiting until mid year is not an option for me.

strano@stranoparts.com

I would not recommend square, I know people do it, and you can make it work if you HAVE to have the ability to rotate tires. But for all this disucssion it seems to just sail past most folks that things like sway bars and springs would need to be adjusted for balance if you do this.

If you put 12's on the front, or do 11's all around, etc on a widebody C6 you are adding a lot of front wheel and tire, and adding none or taking some away, from a car that already has a BIG rear bar and is setup to be close to balanced (and really pretty good) with the stock 9.5/12" stagger. When we simply align the cars for front camber that makes them looser, which is why I make sway bars mostly designed with performance driving in mind, not just "bigger is better". And in the case of a GS, it's front spring is different than the Z06, and the balance is quite different between those cars too. So while I would not square up wheels myself, I would hesitate even more on a C6 GS.

Things do not happen in a vacuum, but man folks sure love to do one thing and then wonder why things don't work out quite like they thought. I think about this stuff, a lot, all the time because I also compete and race my stuff, and my results play into folks calling me or not. So it behooves me to make sure I really think about things and then verify them.

And.... I have Forged wheel options too. More than one. Plus the more run of the mill "flow formed" type as well.

havasu486

I started this thread previous to even having my 2019 Grand Sport with hopes of discovering my options. I had hoped to rotate but have taken the good advise of not doing so. I have always felt like it was best to trust the engineers who were there from day one yet I keep in mind this is a street car. It is possible there is better for my desires so I question. I hope to have my research done and making a purchase for Black Friday.

strano@stranoparts.com

I do the same kind of things with my C7 GS. In the last few weeks I've run two weekends of Time Trial including SCCA Natinals @ NCM, have an autocross this weekend, and then two more track days after that. And I've put better than 8k miles on since I bought it last October, so it gets driven pretty regularly as a street car. Keep me in mind when it's time to move forward.

TrackAire

I'm running a C5Z so not exactly apples to apples, but the car came with the 18 x 10.5" square wheel package when I bought the car. I've tried running 315's square (did not like the feel of the front) and 295's square. I liked the turn in and steering feel better than the 315's with the 295's on the front. But for the last 3 track events I'm running 295-30-18's on the front and 315-30-18's on the rear and like this set up a lot. I would actually like to get a wider rear wheel to match the 315 better.

After doing this for a while, I found that most of my "rotating" ended up being side to side and not so much front to rear. Just my experience.

Kubs

Sam hit the nail on the head (as usual). You can absolutely run a square wheel setup IF you account for it in the way you set up the car. If you just throw wheels/tires at it and expect a change it most likely wont get you what you're looking for. Im sure you can make it just as fast in one configuration as another if you put the time in. Sam's business is selling parts and cannot always put his hands on the car to help the customer so he has to know they work. This is why he has a lot of experience with keeping the staggered tires and having great success. If he were to sell parts and say "You also have to do X, Y , and Z to the car" a lot of people would not be able to do it or do it incorrectly and blame the part. If you really want to run square wheels/tires be sure to put in the time to dial it in making small changes at a time.

anth115

Thanks guys, that makes sense.
If the balance could be corrected with something quick/cheap/simple (e.g. switching the Z06 rear bar for a Z51 bar) then perhaps a square setup still makes sense to pursue.
But once you start requiring new spring rates etc. (especially if still using leafs) then you've way offset any cost savings you'd get from a square setup (at least for a weekend DIY'er like me).

strano@stranoparts.com

Things aren't as simple as folks want them to be. How many bars do you want to have hanging around? And sure you can do a lot to dial things in, but is that simple? And it's only more complex when you realize that just a tire change (not size, nothing, just from one brand to another) can wreck havoc on the balance or response you had before. EVERYTHING matters.