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Will this fit on the rear of a 2017 GS. Wheel is an MRR 755 12.0 ET55...
I think it would, but concerned about the taller tire rubbing the wheel guards...
Will this fit on the rear of a 2017 GS. Wheel is an MRR 755 12.0 ET55...
I think it would, but concerned about the taller tire rubbing the wheel guards...
This would be for AutoX, on hoosiers A7
Thanks
I'd prefer to have a good wheel on a car as heavy as a C7 when you're running a Hoosier, but the fitment should be fine. I have no clue what the off set and fitment of those wheels is, but physically a 345 Hoosier will fit on the back of a Grand Sport. A 12.5 or 13" wheel would be better, but a 12" will work.
If the car is lowered much it will knock the rear fender liners out, but stock or close to stock height should be fine.
Last edited by RichieRichZ06; 05-14-2019 at 10:42 AM.
My concern is more the taller tire than the width. Tire will be 20mm taller (0.75 inch)than my stock 335/25 20 Cup2...I'm slighly lowered on stock bolts.
As far as the wheels these are flow formed which is way better than cast, and they are probably stronger than the stock ones which are bending very easily...I've run extensive roadcourse on cast wheels in France (Rota P45) and never had an issue...
My concern is more the taller tire than the width. Tire will be 20mm taller (0.75 inch)than my stock 335/25 20 Cup2...I'm slighly lowered on stock bolts.
As far as the wheels these are flow formed which is way better than cast, and they are probably stronger than the stock ones which are bending very easily...I've run extensive roadcourse on cast wheels in France (Rota P45) and never had an issue...
I see this post is a few months old. I still thought this might help from a guy who has a few years of tire experience. I've used the following calculator hundreds of times and found it to be very accurate.
To calculate a metric tire size (diameter) into inches you multiply the first number by the second number divided by 100 which gives you the sidewall height in millimeters, divide it by 25.4 to convert it to inches. The overall diameter is 2 sidewall measurements plus the wheel diameter.
By the calculator a 345/35/18 would be 345x35=12075, 12075/100=120.75, 120.75/25.4=4.75, 4.75x2=9.50, 9.50+18= 27.5 inches overall diameter.
That being said, different tire brands can be the same size marked on tire and clearly be be different diameters and widths when set side by side!
I also get 27.5 for the 345/35/18. Not sure how Rich got 26.8. That can't be correct.
This site seems to have the correct calculation also. https://tiresize.com/tyre-size-calculator/
Hoosier doesn't follow conventional sizing. The kinda make it up as they go to suit the market. Here's a table rom their website showing 26.8" for the 345/35/18 on an 18x12 - last line of the table.
I'd prefer to have a good wheel on a car as heavy as a C7 when you're running a Hoosier, but the fitment should be fine. I have no clue what the off set and fitment of those wheels is, but physically a 345 Hoosier will fit on the back of a Grand Sport. A 12.5 or 13" wheel would be better, but a 12" will work.
If the car is lowered much it will knock the rear fender liners out, but stock or close to stock height should be fine.
What's wrong with MRR wheels the track? Here'e a forum vendor selling a them specifically for the track. Don't see them being any different than Forgestars. Need to be inspected thoroughly for cracks between track days, but they look solid.
I see this post is a few months old. I still thought this might help from a guy who has a few years of tire experience. I've used the following calculator hundreds of times and found it to be very accurate.
To calculate a metric tire size (diameter) into inches you multiply the first number by the second number divided by 100 which gives you the sidewall height in millimeters, divide it by 25.4 to convert it to inches. The overall diameter is 2 sidewall measurements plus the wheel diameter.
By the calculator a 345/35/18 would be 345x35=12075, 12075/100=120.75, 120.75/25.4=4.75, 4.75x2=9.50, 9.50+18= 27.5 inches overall diameter.
That being said, different tire brands can be the same size marked on tire and clearly be be different diameters and widths when set side by side!
Originally Posted by fatsport
Hoosier doesn't follow conventional sizing. The kinda make it up as they go to suit the market. Here's a table rom their website showing 26.8" for the 345/35/18 on an 18x12 - last line of the table.
I agree with Hoosier Vs a calculation based on the so called tire sizing standard that uses section percentage X tire width to determine sidewall depth. That standard has been around since the mid 70s. A number of tire makers don' always follow the standard.
Will this fit on the rear of a 2017 GS. Wheel is an MRR 755 12.0 ET55...
I think it would, but concerned about the taller tire rubbing the wheel guards...
This would be for AutoX, on hoosiers A7
Thanks
I am running those exact tires on my 18 GS. 2 AutoX days so far this year with no rubbing or problems at all with stock ride height.
What's wrong with MRR wheels the track? Here'e a forum vendor selling a them specifically for the track. Don't see them being any different than Forgestars. Need to be inspected thoroughly for cracks between track days, but they look solid.
You could ask me. The 345-18 is taller than the 345-19, which is what I run. And what I would recommend. And yes, that can rub a little (I have a small rub through on my rear, worse on the left than the right from that tire, let alone the bigger 18".
I can not testify for how the 345/35/18 will fit on your Vette, but if you are interested in buying a used set before spending a pretty penny on a new set, I have a set of used Hoosier A7's off my racecar that I am ready to part with; 7 heat cycles on the tires - 295/30/18 fronts, 345/35/18 fronts. Let me know if this sparks any interest..
05-14-2019, 09:47 AM
345/35 18 rear Hoosier A7 C7 Grandsport
