What is an ideal wheel back space when running 8" wide rims?

[gnvair]

On a Malibu with a stock width rear. I currently have 7" rally wheels and want to move up to 8" rims.

 

[79 USA 1]

I have 15x8 Corvette rally's on my 88 Monte Carlo SS 4 inch back space. 245-60-15 BFG's in all four corners. I had swapped them to an 86 El Camino I had at the time and the only rub point I had was at full lock against the front sway bar (Very light) and along the bottom front of the front wheel opening due to having the chin spoiler that installed to the botton of the fender. I have the same rub point with the sway bar on the SS also but it is very light.

 

[lilbowtie]

Depends on the section width of the tire you want to run.

 

[gnvair]

I want to run a 255/60R15. I would like to center the tire in the wheel well.

 

[lilbowtie]

Do the math - you have aprox 5.5 inches from the drum face to the frame. If you have 4 inches of back space and the section width of your tire is 10.5 inches on an 8 inch rim the tire sticks out 1.25 inches beyond the rim on each side or a total of 5.25 inches so your a 1/4 in from the frame

 

[69hurstolds]

Can you get away with a 3.75" back space? I mean, do you get to choose or are you just buying off the shelf wheels? Reason I say that is if you use a 4" bs and if your sway bar lets you "sway" too much, you'll either be skidding that tire off the inside of the wheel well or rubbing any rocks off of it if it doesn't contact it doing any sort of turning perhaps. It's kind of close for comfort IMO.

 

[08Malibu]

I have corvette rally’s on mine and since I lowered the front they rub like crazy with a 245/60r15 tire. So their backspacing definitely won’t work.
edit: They rubbed a little at stock height too.
I’m talking about the front, I completely overlooked that we were discussing the front. The rear I’m good.

 

[69hurstolds]

What about 245s as mentioned? Do you HAVE to have 255s? May want to do some cardboard mockups to determine what you need to do.

 

[TURNA]

I have 255/60/15's on the Cutlass 15x7's with 4 inch bs
and
275/60/15's on the Malibu 15x8 4 inch bs

If you are getting rub with a 4 inch bs with a 15x7 or 8 your rear isnt centered

 

[gnvair]

I am only planning on running them on the rear. From what I gather, some guys run a spacer with the 4" back spacing.
Searching posts on Malibu Racing it seems that guys running Weld Racing rims have issues due to only being available with 3.5" or 4.5" back spacing.
The 3.5" makes contact with the wheel opening. The 4.5" makes contact with the frame. Many buy the 4.5" and run spacers. With the 3.5" they cut or roll the lip.