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I have a 1969 CAMARO that has front disc brakes(recently added)and rear drum. It had 14 inch wheels on the front and 15 inch on the rear. I ordered a set of rally wheels that are 15x8 with a 4 & 1/4 backspacing and a -6 mm offset. I put a set of Cooper Cobra 245/60/15 tires all around. My problem is the driver side front tire rubs the fender a bit. It actually caught the crome wheel well trim and bent it out. The rear tires are tucked in nicely but the fronts are further out toward the fender.

I’m not a wheel/tire guy so not sure where to go to correct the issue. Back to 14’s on the front? 15x7 with +6 mm offset wheels? Different size 15 inch tire? I’m truly lost and quite frustrated and would appreciate any feedback. Thank you in advance.
 

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Disc and drum use different backspace/offset. 15x8 w/ 4.5" would be better. (centered)

How is the gap on the passenger side ? Guessing its pretty good ?

I'm thinking your subframe may be off a bit ?
 

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Discussion Starter #3 (Edited)
Gap is better but still tight on pass side. Not rubbing at least

Actually after looking at it again the pass side is tucked nicely. I wonder if classic industries boxed one of those wheels incorrectly. Driver side stick out quite a bit further. Too hot out now, I’ll check it out tomorrow
 

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Here are the generally accepted correct backspacings for a first gen regardless of diameter. You missed it by a half inch.

17x7 = 4.25"bs
17x8 = 4.75"bs
17x8.5 = 5" bs
17x9 = 5.25"bs
17x9.5 = 5.5" bs

What are your front end alignment specs? You could try to add some negative camber to pull in the top of the tire, roughly -.5 degrees.

Don
 

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Discussion Starter #8
Disc and drum use different backspace/offset. 15x8 w/ 4.5" would be better. (centered)

How is the gap on the passenger side ? Guessing its pretty good ?

I'm thinking your subframe may be off a bit ?
I’m thinking you may be right. How do I check that?
How does one correct that?
 

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The more I read other posts with similar issues the more confused I get. 😒
You used wheels with insufficient backspacing. It really is that simple. Difference side to side is most likely a difference in front end alignment imho...

Don
 

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First thing would to be checking sub alignment. (check alignment holes under car at firewall next to the body mounts...5/8's bolt should slip in easy)
Second thing would be panel alignment (just run a string line down both sides to check straight/even on both sides)
Third thing I would do is swap wheels side to side and make sure it's a car issue and not a mismarked wheel

Yes, last alignment ? could be a caster/camber issue ?
 

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Here are the generally accepted correct backspacings for a first gen regardless of diameter. You missed it by a half inch.

17x7 = 4.25"bs
17x8 = 4.75"bs
17x8.5 = 5" bs
17x9 = 5.25"bs
17x9.5 = 5.5" bs

What are your front end alignment specs? You could try to add some negative camber to pull in the top of the tire, roughly -.5 degrees.

Don

Wouldn't the OP's 15x8 4.25" bs put the outer edge of the rim in the same position as 17x9 5.25"bs and inboard of the recommended 17x9.5 5.5"bs? I suppose putting relatively narrow tires on the rims would make a difference but then why bother going to the wide rims.
 

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Wouldn't the OP's 15x8 4.25" bs put the outer edge of the rim in the same position as 17x9 5.25"bs and inboard of the recommended 17x9.5 5.5"bs? I suppose putting relatively narrow tires on the rims would make a difference but then why bother going to the wide rims.
Nope. Out a half inch further. Specs I gave are a fixed +6 mm offset....

Divide the width increase in half when calculating lip position changes.

Don
 

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Nope. Out a half inch further. Specs I gave are a fixed +6 mm offset....

Divide the width increase in half when calculating lip position changes.

Don

Looks like I'm missing something but that's not new.



I thought of it as an 8" rim with 4.25" bs would be 4.25" inboard of the wheel mounting flange and therefore 3.75" outboard of the wheel mounting flange. A 9" rim with 5.25 bs would be 5.25" inboard of the mounting flange and there fore 3.75" outboard of the mounting flange. Making the outer wheel side have he same position with respect to the mounting surface.
 

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Looks like I'm missing something but that's not new.



I thought of it as an 8" rim with 4.25" bs would be 4.25" inboard of the wheel mounting flange and therefore 3.75" outboard of the wheel mounting flange. A 9" rim with 5.25 bs would be 5.25" inboard of the mounting flange and there fore 3.75" outboard of the mounting flange. Making the outer wheel side have he same position with respect to the mounting surface.
You forgot to add an inch to the width for the lip. An 8 inch wheel is 9 inches wide. At least I think that is what you are doing.

Don
 

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You forgot to add an inch to the width for the lip. An 8 inch wheel is 9 inches wide. At least I think that is what you are doing.

Don



Yes I'm just comparing inner lip to inner lip. The added 1/2" for the outer lip would apply to the OP's 8" wheel and the 9" wheel referenced in the chart. I still don't see how the OP's example is out an extra 1/2" but I'll keep thinking about it.



It was just two weeks that I learn that I messed up putting 295s on a 10" rim instead of 12" so I'm trying to get current with my thinking.
 

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Wouldn't the OP's 15x8 4.25" bs put the outer edge of the rim in the same position as 17x9 5.25"bs and inboard of the recommended 17x9.5 5.5"bs? I suppose putting relatively narrow tires on the rims would make a difference but then why bother going to the wide rims.
Ok thinking about this a little more, that chart is for front and rear but you really can’t run much more than an 8” on a stock first gen. 8.5 if you nail it and run negative camber.

I once generated a similar table that held the outer lip constant but I stopped posting it because it can just cause confusion.

Don
 

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Yes I'm just comparing inner lip to inner lip. The added 1/2" for the outer lip would apply to the OP's 8" wheel and the 9" wheel referenced in the chart. I still don't see how the OP's example is out an extra 1/2" but I'll keep thinking about it.



It was just two weeks that I learn that I messed up putting 295s on a 10" rim instead of 12" so I'm trying to get current with my thinking.
295 recommended rim is 10-11.5. Not sure why you had an issue. I have run 295 on a 10” without issue.

295 on a 12” sounds like hella flush...

Don
 
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