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Im running a 275 tire on a 17" summit star wheel with 6.00" of backspacing....exactly what i measured, and what the tech departmentat summit told me would work. When I launch my car the tires rub pretty bad on both sides....Fenders have been rolled three times.....still can roll more though. When launched the car squats alot, and would tuck the 275 on a stock wheel, over half way down the sidewall.....

Would Drag Bags be the solution to stiffen up my car to keep it from squatting to much?

All help will be greatly appreciatied!!
 

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Are the rims 8 inches wide. Also I think you need more than 6 inches of BS more closer to seven inches. I would guess 6.50 or 6.75 of BS so figure out your measurement by how much space you have on the inside closest to the inner quarter I think you need 3/4 of an inch then measure to the inside of the fender lip. You want the tire at least 1/2 inch inside of the edge of the quarter panel. Most likely you will not find a rim that will meet these measurements since pontiac didnt give our rims the correct backspace. If you look at the tire you will see that it sits just under the quarterpanel. It should sit inside the quarter not under it. So if you have the wrong Offset or backspace your rim and tire will sit to far outside the rear quarter hence forth tire rib. If anyone has the correct measurements please post it. I also had this problem with a set of 15 inch rims I put slicks on. Now I have a set of 94 S-10 4X4 rims that have 6.75 inches of back space and with the stock S-10 tire which was like a 255-75-15 (A hugh tire) it tucked in nicely with no rub----danfigg ----I think it is 171.45mm of BS------------6.75 X 25.4=177.45-----Someone please correct me if im wrong:confused inches X 25.4 converts inches into mm
 

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Are the rims 8 inches wide. Also I think you need more than 6 inches of BS more closer to seven inches. I would guess 6.50 or 6.75 of BS so figure out your measurement by how much space you have on the inside closest to the inner quarter I think you need 3/4 of an inch then measure to the inside of the fender lip. You want the tire at least 1/2 inch inside of the edge of the quarter panel. Most likely you will not find a rim that will meet these measurements since pontiac didnt give our rims the correct backspace. If you look at the tire you will see that it sits just under the quarterpanel. It should sit inside the quarter not under it. So if you have the wrong Offset or backspace your rim and tire will sit to far outside the rear quarter hence forth tire rib. If anyone has the correct measurements please post it. I also had this problem with a set of 15 inch rims I put slicks on. Now I have a set of 94 S-10 4X4 rims that have 6.75 inches of back space and with the stock S-10 tire which was like a 255-75-15 (A huge tire) it tucked in nicely with no rub----danfigg ----I think it is 171.45mm of BS------------6.75 X 25.4=177.45-----Someone please correct me if im wrong:confused inches X 25.4 converts inches into mm
I think you have it (except I think you meant the highlighted word). I'll bet he has too narrow of a rim too. 275s would need at least a 9-9 1/2" rim to not bulge the sides in addition to the back spacing issue. As I've stated many times also it depends a lot on what brand of tire as they all run different actual widths. Drag bags are a hack fix to a mismatched wheel but it may be the only real solution to the problem if the OP wants to stay with that tire/wheel combo. It will look like a 60s throwback with the rake and ride like a buckboard but. . .
 

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As stated above, the section width changes between different tire brands. Not saying that you are but some people get hung up on having the look of a wider tire. That's cool but wider doesn't necessarily mean better performance. One thing you can do is take your wheels to a reputable wheel shop and see if they can "safely" remove a few millimeters from you wheels. That's what I did. I had 3 mms removed from my rear wheels for $35 a wheel.
 

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Discussion Starter #6
The tires are nitto 555R's They dont actually bulge much at all since nittos section width is smaller than most. The rim measured approx. 8.4" wide and 17.2" tall. the tires are actually even with the lip of the fender as of right now. the car actually sqauts a little much for me, some squat is good, to much is bad....but i think the shocks could have something to do with it. You can actually watch the car squat and raise back up when pulling the car into reverse or drive....Theres not any good tire shops around here. Im in Northern AL. The only thing around here is a few machine shops that probably could handle it.... I'll try and get some pics of the car and where the wheels are on the fender and post them. Quite possibly even a launch pic.. Thanks for the info guys!
 

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Drag bags are ordered and will be here tomorrow. Ive gotten most of the rub out by rolling the fenders again. With the help of a soft mallet.... Decided to jack the front of the car up on the front corners to see where the fender was still rubbing....gave me a great idea and got 98.9% of it by doing that.....Thanks for the help though guys....any other suggestions will be appreciated though!!

Thanks,
Tyler
 

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Drag bags are ordered and will be here tomorrow. Ive gotten most of the rub out by rolling the fenders again. With the help of a soft mallet.... Decided to jack the front of the car up on the front corners to see where the fender was still rubbing....gave me a great idea and got 98.9% of it by doing that.....Thanks for the help though guys....any other suggestions will be appreciated though!!

Thanks,
Tyler
Tell your fat friends to get out of the car before you do any racing. ;)
 

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Discussion Starter #11
The fat friends get left far behind when i head to the track...or when we go racing period... As for stock springs and shock, yes theyre still stock. I cant quite afford adjustable shocks yet..... Installed drag bags lastnight, fixed problem, launches better, no california rake either, and rides better IMO
 

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Which springs would be some of the best ones for the money? I havent looked into springs that far... shocks on the other hand i have. QA1 Adjustables are waiting to be paid for right now. Ive ordered them and theyre on the special oprder shelf at work right now. I've just got to get the dough to afford them....
 

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Which springs would be some of the best ones for the money?
All the major players in the Gto spring market have excellent products. I'm a fan of King because i like stiff springs but Lovelle and Pedders are wise choices too. There are other brands with cheaper springs but not much feed back on them.
 

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When I had the car up in the air to install my LC-1, I rotated the tires as well, and found out that I'm a new member to the Strut Rub and Spring Sag clubs. :( It wouldn't even come close to passing the pencil test.

Rear springs are an easy (and hopefully cheap) fix. Its the front stuff I'm worried about, because it'll probably end up by being more than just one or two parts that'll need replacing...
 

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When I had the car up in the air to install my LC-1, I rotated the tires as well, and found out that I'm a new member to the Strut Rub and Spring Sag clubs. :( It wouldn't even come close to passing the pencil test.

Rear springs are an easy (and hopefully cheap) fix. Its the front stuff I'm worried about, because it'll probably end up by being more than just one or two parts that'll need replacing...
Strut rub isn't the springs but usually the rubber strut mount bushing on top of the strut assembly

 

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I will be figuring out an air shock set up simular to the coil over set up some had made awhile back. Just waiting for the warranty to wear out. I must have searched the Monroe shock listing a million times and will come up with something---Danfigg
 
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