# Backspaceing?



## MadGoat04 (Feb 28, 2009)

Will a 6.875 fit on the front without any rubbing?


----------



## danfigg (Sep 27, 2009)

*re*

well first of all It all depends on the offset of the rim not just backspacing, how wide the rim is, and what size tire your using. There is a way to figure out how wide of a rim and tire can fit a car but it is a little work. I took some measurements at the rear of the car which is easier due to less movement compared to the front and found that in the confines of the inner quarter and the fender lip only allows a 10 inches of clearence. This is not including tire flex and suspension travel. If you play with backspacing and all that you have to find the closest thing that may rub the tire (rear shock is in a bad spot) and also the inner quarter is not flat across. At the top of the tire its 10 inches but the bottom towards the front of the tire, kind of tapers out to 9 inches. Not to mention the suspension travel will also have an effect of how much tire clearence is needed. So know to the front. You have the strut in the way not to mention the steering lock to lock and what the tire may rub against. Inner fenders, fender lip, and any steering components that may be in the way. With the factory size tire I think they figure out all the possiblilties of where the tire will not rub. Once you change the tire size, rim size, offset, backspacing, you create new issues of rubbing in many different directions


----------



## AlaGreyGoat (Jul 6, 2006)

NO Way! 
The stock 8in wheels are +48 offset = 6.39in backspace (actually measure +50 = 6.47 in) and they rub the struts
on some cars. So moving them .485in toward the strut won't work. It would take at least a .485in spacer to fit.

Larry


----------



## MadGoat04 (Feb 28, 2009)

How far would the wheel stick out from the car with an applicable spacer?


----------



## AlaGreyGoat (Jul 6, 2006)

Depends on the width of the rim/tires. On stock 8in rims and
245 tires, there is little to no clearance to the strut.
I've ran 255 on the front and had to make a .200in spacer to have any clearance.
With a 6.875in backspace and a .485in spacer on 8in rim and 245 tire would
be exactly the same as stock fitment. Any wider tire, 255 up will require a thicker
spacer and will stick out the extra width of the tire and the extra width of the spacer.

Larry


----------



## danfigg (Sep 27, 2009)

*re*

will that rim fit on the rear of the carIF so a wider tire might fit better...Danfigg


----------



## AlaGreyGoat (Jul 6, 2006)

Not sure about the rear fit. It will be close to the inner fenderwell.
Maybe up to a 275 would fit and not rub the outer fenderwell lip.
A thin spacer may be needed.

Larry


----------



## MadGoat04 (Feb 28, 2009)

The rear fit nice with 255/50/16 M/T ET Streets.The front with 225/45/16 fit with a 8mm spacer.Will post pics of how it looks when I can get my camera back from my brother.


----------



## danfigg (Sep 27, 2009)

*re*

I mounted a set of slicks on a set of 15 X7 95 S-10 blazer rims. They have a 6.00 inch back space and fit perfectly. SO I would say as you go wider you will need more back space----danfigg


----------



## motoristx (Apr 27, 2010)

I did some Measurements as i'm preparing to do a mini tub on my car. 

for the rear this is what i have so far: 

control arm:
the stock wheel is 8" x 17" and has 6.39" of BackSpace
I've measured the maxium about of backspace to be used before you hit your rear control arms. 8.64" or 2.25 inches more then the stock wheel. if you go 2.5 inches, it will rub without a spacer. this is with a tire on it so i might be up to .25" off. 

wheel well:
again stock 17" wheels 8" wide. I've put a 295 tire on the stock wheel, and I have less then .5". i'm afriad if I any more backspace with this tire, it will rub. (also, i'm not happy with this size tire on the stock rim, it's too wide and wears the center of the tire out too fast)

hope this helps. Like i said i did this myself and with the help of some other people who have tubbed out cars before, this should give you a very good idea of what you can fit.


----------



## danfigg (Sep 27, 2009)

*re*

The rim is not the only factor its the tire as well. The rim is a good starting point but you have to also check to see where the tire will rub and there are about 3 places besides the control arm where the tire will or may rub. Look closely at the inner quarter and you will see what I mean. It is not completely flat. You wanna bring the tire as close to the inner quarter as possible and also take into consideration of the suspension articlulation as this rear is independent. As long as you can figure out the closes you can get the rim to the inner quarter, you next area is the outer quarter and that is the direction that the rim width needs to go if you want a wider rim.
------Danfigg


----------



## firebird (Feb 6, 2011)

ok i need some major help.

i just put a 285 35 18in the rear and it's rubbing the fender lip, which i will roll shortly. but i am affraid that under full throttle i might get some touching still on the lip. 

question. does the backspacing bring the wheels outside, or inside towards the differential housing?

i have no issues on the inside and i have some room to move the wheel to the inside. is this possible?

what does wheel chamber change? will this help any? i need somone to educate me on this stuff.


----------



## svede1212 (Nov 1, 2005)

The back spacing on our cars means a larger number brings the wheel in towards the center of the car. You can maybe get your wheels shaved a bit on the hub to help increase the back spacing number. As the wheel goes up under load the top of the wheel tilts in. Look at some other independent suspension cars with a back sag and you'll see they tip in. To check my wheels after I did them I disconnected the bottom of the shock and removed the spring. I could then move the wheel up and down to check clearances.


----------



## firebird (Feb 6, 2011)

so you think by buying spacers, i would be able to move the wheel in 1cm, which is what i need and have about 2cm or so inside. so the inside should be okay. am i understanding this right? and what spacer would you recommend?

i am trying to get ahold of someone with a roller tool, i don't want to shell 250$ for it. 

is there a good link that you know of where i can see how they set the rear camber on rear for the gto or similar car


----------

