Ok, I've been thinking about different rims and I was thinking about the weld racing pro starXPs in 17x8, what backspacing will I need with 17x8s and what tire size. I want the tires to be as close to stock diameter as possible. Thanks in advance.


Tim:rockon:


p.s. if you have 17x8s (any rims) please post pics, rim type, and tire sizes. Thanks again.

 

here's a pic I found of a thirdgen with these rims.

 

As for tire size, you will want to go with either a 245/45/17 or a 255/45/17.

Your stock size tire (245/50/16) has an overall diameter of 25.6"

The 245/45/17 has an O.D. of 25.7"

The 255/45/17 has an O.D. of 26.0"

Probably the 245/45/17 is the way to go to keep the same O.D.



As for offset I think it is 0mm for the front; and positive 16mm in the rear. I am 90% sure those are good numbers for an 8" wide rim.

 

My wheels (see sig pic) are 17x8 Centerlines with 4.5" backspacing. The tires fit to the outside of the wheelwells, but under the fender lips. The tires are Bridgestone Potenza SO-2's in size 255/40/ZR17. They are only 24-1/2" tall. I would suggest going with a taller tire as my tires don't fill the wheelwells like I really wanted. BTW, different manufacturers' tires will have different measurements, i.e. a Goodyear 255/40/ZR17 might be 25" tall instead of 24-1/2", etc. Good luck.

 

4.35" front and 5" rear backspacing will make them fit identical to stock. But my car also has 4.5" front and rear and it fits fine, and gives the back an aggressive look

 

That's actually about the way I like 'em to fit. Thanks for the info.


Tim:rockon:

 

would backspacing be the same on a 17x9in wheel?

like these eagles


model 212


model 220

 

http://gs.tolan-hoechst.com/tirecalc.htm

This will tell you the diameter, change from stock.... etc.

AJ

 

My 17X9 rear wheels have 5 1/2" back spacing.

 

do you have pictures of your wheels on your car?

 

check out my website in my signature.

 

will 5in of backspacing work all round or will the 5.5 work all round i want to keep wheels all the same
if i get 5in backspacing will they rub anywhere?

 

5" is the absolute max you can run up front, and 5.85" is the max in the rear.

http://www.skulte.com/adapterfaq.html

 

for the record, that can vary by car. I was with a friend of mine when he got new tires put on his 87 formula with it's stock 16" wheels. One of the rear wheels, which has 5" backspacing, was put on the front of the car accidentally, and made a horrible scraping/rubbing noise backing out of the garage. It did NOT clear everything properly. another 1/10 of an inch might have done the job, but 5" backspacing did not.

 

4.5 all the way around it is then

 

Wraith,
Thanks for letting me know. I used to have 4.85" listed, but some folks were running 5" w/o problems, so I changed it. Did the rubbing happen on the lower ball joint or a tie-rod end? I've seen some aftermarket (non-GM) replacement parts that would rub, while the GM stuff didn't. If you could find out, that would be a huge help. I'd love to add that detail to the wheel spacing FAQ which should help a few folks out. Thanks!

Andris

 

andris, i wish i could tell you, but this was over 6 years ago, and that car is long gone, so i can't reproduce it.



This is an exact clone of the car though. 87 LG4/auto formula, rear drums, with those 16" wheels.

Maybe those wheels specifically came with a slightly different backspacing even?

 

I know this is a backspacing topic but you can figure out how to stay close to stock diameter by this: For example 275/40/17 Tire diameter computes as follows. divide 275 by 25.4 (this will give you inches across the tread) which in this case is 10.8. Then take 10.8 and multiply it by the series size. In this case again that would be .40 (for 40 series tires). The outcome is 4.32. This is the size in inches of one sidewall. Now you have two sidewalls in figuring tire diameter so multiply your answer by 2 and add 17 for the rim size and you have your tire diameter. The tire diameter for 275/40/17 is 25.64 inches. Wala.

 

That will happen with nearly every car with stock rims. However, increasing rim size to 17-inch will aleviate the clearance issue and allow for larger backspacing. You have to pay attention to what is rubbing and how that can change with rim diameter.

17x9 with 5-inch backspacing fits all the way around. I have it on my car. 17x9.5 with 5.5-inch backspacing fits all the way around and sits in the same position on the outside of the car. The extra width is placed inward. Your turning radius from lock-to-lock will likely be reduced, especially if you have aftermarket sway bars. 18x10 with 6-inch backspacing will fit on the rear. Other wheel combinations can be used, too. Just be sure to measure up and double check fitment before purchase.