Front wheel backspacing question
Thread Starter
Racer
Joined: Feb 2007
Posts: 273
Likes: 0
From: NAPLES FLORIDA
Front wheel backspacing question
Has anyone used an 18" x 8" rim with a 4.75" backspace on the front of (in my case) a '74 Corvette?
If I am to understand backspacing correctly, this backspace will pull the rim 3/4" of an inch closer to the wheel well than a stock rally wheels with a typical 4" BS - correct?
Is this too much to look right?
I plan on using 225 45 18 tires...
Anyone see a problem with this?
Thanks in advance!
RR
If I am to understand backspacing correctly, this backspace will pull the rim 3/4" of an inch closer to the wheel well than a stock rally wheels with a typical 4" BS - correct?
Is this too much to look right?
I plan on using 225 45 18 tires...
Anyone see a problem with this?
Thanks in advance!
RR
3rd Gear
Joined: Aug 2009
Posts: 3
Likes: 0
thats my understanding for the backspacing, i have a 74 as well, im flaring the the wheel wells though. im trying to figure out the most backspace i can get. i got it at 4 3/4 right now with 15" rims. im going to try and stuff some 345/35 pirelli's in the back.
Race Director
Joined: Jan 2007
Posts: 14,998
Likes: 3,373
From: NYC NY
If I am to understand backspacing correctly, this backspace will pull the rim 3/4" of an inch closer to the wheel well than a stock rally wheels with a typical 4" BS - correct?
Is this too much to look right?
I plan on using 225 45 18 tires...
Anyone see a problem with this?
Is this too much to look right?
I plan on using 225 45 18 tires...
Anyone see a problem with this?
Yes 4" is typical.
Yes I think it's too much to look right.
You can fit way more tire on the front. A 245 or 255 with a 4" backspace would look better. Problem with the set up your talking about is the front of the car will look like it has "space savers" on it.
You won't be anywhere near filling the wheelwells. Stick to something near what most others are doing. You will be much happier with the results in the long run.
Racer
Joined: Nov 2008
Posts: 297
Likes: 3
backspacing
On my 80 vette with stock fenderwells, I tried different size and backspacing and discovered that with the stock alum. factory wheel with 255/60/15 tires, the tire bulged out approx. 3/4" from the lip of the wheel and a 275/40/18 low profile tire bulged out approx. 3/8" from the lip of the wheel. With that difference being 3/8", I determined by trial and error that you could push the 18" wheel out approx. 1/2" more than the stock wheel if you use low profile tires. The low profile 18" tire then looked as if it were at the stock backspacing because of less tire bulge. After some careful trial and error fits, I found that a 18" by 10" wide wheel with a 1/2" negative offset fitted with 275/40/18" tires would fit my 1980 vette on front and rear without any clearance problems with the frame, sway bar or fenderwells. Just remember if you are switching from stock size tires to larger diameter lower profile tires, you may be able to go a little more negative offset than stock wheel because of less tire bulge.
