Anyone running 18x10's for autocross or road course?

[jksynergy]

I may have a chance to pick up a set if wheels. 18x10 with 25 mm offset and wonder if, they clear the brembos and what size tire to run. If anyone has this type of setup, I would appreciate the info. Thanks.


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[Synner]

A better first question is what tire type and tire size do you want to run; then pick your wheel around that.

[jksynergy]

I already have 2 sets of 20's so this would just be a set possibly for those wet track days. That's why I asked about tire size. 19's would be ideal though. Just thinking a 18" wheel that weighs under 20 lbs might be nice to have.


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[Norm Peterson]

The big "will they fit" issue with Brembos is clearance to the back sides of the wheel spokes. Not all wheel spoke contours or pad heights will accommodate them. Usually, a wheel that's advertised at 4" larger diameter than the rotors is big enough that way.

Please don't try to fix a spoke interference problem with spacers. Get the right wheels.


Norm

[jksynergy]

Norm, no worries on using spacers. Have seen the results of spacer use one too many times.


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[Synner]

I would ask the same question for a rain tire too. What do you want to run and what sizes are available?

Going too low will cause you issues with axle angle and blowing out CV's hence why tire choice and tire height are critical. The Z/28 runs a 19" for a number of reasons. I think its an excellent compromise between weight, tire height, and tire selection options. Personally I'd be leery of an 18" as total height will start causing issues. Taller tires aren't really available in that size and will cause their own issues if you do find some and go that route.

[jksynergy]

Synner, you are correct about tires. I spent some time looking for a tire which would have a larger diameter and fit the wheel properly with little luck. So I'll pass on the 18's and more than likely just get a square setup in a 20x9 so that a better selection of wet weather tires can be found. Appreciate the input.


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[Norm Peterson]

For a 1LE I'd look at 9" wide wheels only as a last resort. 20 x 9.5's seem to be readily available, and either that size or 20 x 10's will work with 275/40-20's.


Norm

[jksynergy]

Originally Posted by Norm Peterson

For a 1LE I'd look at 9" wide wheels only as a last resort. 20 x 9.5's seem to be readily available, and either that size or 20 x 10's will work with 275/40-20's.


Norm

Thanks Norm. Found a set of 20x10's that should work fine, though the offset is 40. I have a set of 20x10's that the offset is 25 and no issues. See any problems with running the 40 offset?

[Norm Peterson]

Strut clearance? It looks like the backspacing for a 20 x 10 x +40 is midway between the backspacing for your +25's and the backspacing of your 11" wide rear wheels.

All I can suggest is to put your +25's on and see how much room you have between the inside wheel flanges and the struts and anything else that's close. Deduct 15mm from that (about 5/8") and see how much room (if any) is left.


Norm

[jksynergy]

Finally found a set and ordered them up with tires. Should be good to go. Thanks for the input.

[12-motorsports]

I spent a lot of time researching said topic and finally settled with CCW C14 18" x 11" square all around. After speaking with a few dedicated racers and CCW they steered me towards this route. No clearance issues with my factory Brembos, suspension, body, etc. Yes, they stick out about 1" front and back but it works since I only use them for the track only. Here are just a few reasons why and thus far I do not regret my decision especially using NITTO NT-01 315/30ZR-18s because they are awesome on the track!

Factors for going with 18s:
- There are many more racing tire choices going with 18"s - 20"s are limited
- 20" tires are more expensive and less options if you want to use used racing tires
- 18" wheels lowers the car (depending on which tire you go with) therefore lower CG (better for road racing if you do not lower the suspension)
- 11" wide rims is a must if you don't trim weight from your OEM car - it is big and heavy therefore requiring a much larger tire patch all the way around. Going with a square setup helps the front end turn otherwise it is like driving a truck through turns fast on narrow tires, it will push
- 11" wide rims widens the stance of the car and in my setup gives me a very neutral car on the track at VIR and Watkins Glen
- This tire/rim combo is lighter than the OEM narrow tires/rims - better because of the un-sprung weight issue

Wanted to share my findings thus far, enjoy!

Thomas

[jksynergy]

Originally Posted by 12-motorsports

I spent a lot of time researching said topic and finally settled with CCW C14 18" x 11" square all around. After speaking with a few dedicated racers and CCW they steered me towards this route. No clearance issues with my factory Brembos, suspension, body, etc. Yes, they stick out about 1" front and back but it works since I only use them for the track only. Here are just a few reasons why and thus far I do not regret my decision especially using NITTO NT-01 315/30ZR-18s because they are awesome on the track!

Factors for going with 18s:
- There are many more racing tire choices going with 18"s - 20"s are limited
- 20" tires are more expensive and less options if you want to use used racing tires
- 18" wheels lowers the car (depending on which tire you go with) therefore lower CG (better for road racing if you do not lower the suspension)
- 11" wide rims is a must if you don't trim weight from your OEM car - it is big and heavy therefore requiring a much larger tire patch all the way around. Going with a square setup helps the front end turn otherwise it is like driving a truck through turns fast on narrow tires, it will push
- 11" wide rims widens the stance of the car and in my setup gives me a very neutral car on the track at VIR and Watkins Glen
- This tire/rim combo is lighter than the OEM narrow tires/rims - better because of the un-sprung weight issue

Wanted to share my findings thus far, enjoy!

Thomas

Thomas, thank you for the information. May I ask about your offset on the 18x11's? This could be an option for the future for sure.

[12-motorsports]

My CCW Wheels: Model C14 18" x 11" with 6.5" Backspace / 13mm Offset
If you have detailed questions and/or want to place an order John (the owner) is the one to talk to, he is really knowledgeable and helpful when it comes to picking your wheels.