Mixing 15" (front) and 17" (rear) wheels

[richard]

For my 914/6 TT car I'm considering keeping my 15" wheels on the front but going with 17" on the rear (to have a greater choice of rubber). Assuming no fit problems and that I would lower the rear to compensate for the increased ride height with the 17" wheels, would I be creating any special handling problems?

Anyone got any 9.5 X 17 or 10 X 17 track wheels for sale?

[kurquhart]

If you keep the rear tire diameter the same (i.e. with a shorter sidewall), you won't need to adjust ride height.

[pdy]

There are 275/35-15 DOT competition tires available. Only Hoosier makes them (so far), A6 or R6. Fit 9x15 to 11x15 wheels. Keeps the car low.

[richard]

OK. I agree I could "solve" the problem by your suggestions BUT this limits the tire choices, which is what I am trying to avoid. So ASSUMING I end up with different diameters (TOYO 225/50-15 at 23.9" front and TOYO 275/40-17 at 25.7" rear) would this upset the handling significantly? Thanks.

[pdy]

Agreed, there are a lot more choices in 17" diameters. The only limitation would be the ride height versus suspension travel trade-off on the rear.
Given that, I am sure a competent shop or individual could set up and align the car with any handling characteristics you desire.

[Greg Phillips]

There are 275/35-15 DOT competition tires available. Only Hoosier makes them (so far), A6 or R6. Fit 9x15 to 11x15 wheels. Keeps the car low.

Just ran across theses tires on special at Sierra Tire in Las Vegas for $175 for the R6.
http://www.frisbyracetire.com/misc_tires.asp

Greg

[Steve Grosekemper]

Richard,

The key to upgrading tires and preserving balance is keeping the same tire sidewall height. There is only 2mm difference in your 225/275 choice so that is good. You will have to lower the rear suspension to maintain the proper rake which will increase the rear camber also OK. The smaller front diameter will increase turn in and the much larger 275's will increase push...

Will this change handling? Absolutely.
Will it be better? Only one way o find out.

225's are really too small for your setup IMHO.
If you have 275's in the rear, you really need 245/255's up front.
If you are buying 17's for the rear, why not for the front as well?

[richard]

I wanted to stick with the 15's on the front just to avoid spending ~$700/rim on the front. The largest Toyo in 15" is 225/15. Looks like I would have to go to Hoosier for a 245/15 or to 16" rims for Toyos. I need to do more homework!

Got any good source for 17" rims with the correct offsets which dont cost $700 each and good for TTs?

[Steve Grosekemper]

Richard,

How much room do you have under the fenders (914-6 GT?)
How big can you go if price was no object?

[Kim Crosser]

How big can you go if price was no object?

Why? Are you trying to sell the old "oil barrels" off your 914? You should include a photo of those.

[Steve Grosekemper]

How big can you go if price was no object?

Why? Are you trying to sell the old "oil barrels" off your 914? You should include a photo of those.

No sales motive...
Can't offer a solid tire option w/o all the information.
No need to put 225 where 255 can live.
And I do have wheels Richard could try out for size, but I doubt they would fit...

[richard]

Steve,
I have the 914GT flares.
I know 275/40-17 on 9.5" rim will fit on the rear with 2.5 degrees camber with about 1/4" to spare.
I havent studied the front at all. I fear that the 17" tire will hit at full lock, but havent done any fit checks.
Hope to do more engineering after spring Mt.
Richard