Team Camaro Tech banner

1 - 9 of 9 Posts

·
Gold Lifetime Member
Joined
·
1,351 Posts
Discussion Starter #1
I am getting very frustrated and need some help. I just bought a set of restored 15x7 American Racing Torq Thrust Rims that were made about 1980. I purchased a set of Goodyear Eagle GT IIs 235 60 15 for the front and 255 60 15 for the rear. The rear size is perfect. The front tires rub, but not by much. I converted the front drums to Discs. Could anyone recommend a Tire Size for the front? I am even considering a swap to the original 14x7 Rally Rims and replacing the Goodyear Polyglas F 70 14s with 235 60 14 Tires or 245 60 14s. There is no offset on the Torq Thrusts, but it looks like they come out further than the original rallys. Any comments will be greatly appreciated. Thank You In Advance.
 

·
Registered
Joined
·
717 Posts
235 15's are fairly wide for a camaro, I know because thats what I have on the front of my car and it sits high in the front. They rub at times also, go down to a 225/60x15.
 

·
Registered
Joined
·
1,290 Posts
I am in the process of selecting tires for mine as well. I recently went to a 6308 coil up front and my 235/60/15s will rub on a tight corner, or going up a steep driveway. I am thinking of going to a 225 as well. The are supposed to be about a 1/2 inch different in both height and width. I had a big block spring in her before and it was too high. I am using stock 15inch rallyes right now.
Just a quick question? Did you go with a stock rotor size, and how do the Torque Thrusts work with the discs? I am thinking of getting 15 inch TTOs for mine. I also did a disc conversion recently.
 

·
Gold Lifetime Member
Joined
·
1,351 Posts
Discussion Starter #4
Hi Stewie,
I am going to use 225 60 15 Tires on the Torq Thrusts, but I have one additional question for you. The Torq Thrusts have 3 1/2 inches of Backspacing while the Factory 14x7 Rally Rims have 4 1/4 Inches of backspacing. Am I still going to have a problem? The Torq Thrusts look great and do not interfere with the Disc brakes at all. I went with Stock Rotors. I went with a complete kit from The Right Stuff. It even came with Stainless Steel Lines.
Thanks for your help.
Tory
 

·
Gold Lifetime Member
Joined
·
1,351 Posts
Discussion Starter #5
Hi Johnny,
Thank You for your input. I have also one additional question for you. The Torq Thrusts have 3 1/2 inches of Backspacing while the Factory 14x7 Rally Rims have 4 1/4 Inches of backspacing. Am I still going to have a problem with a 225 60 15 Tire?
Best Regards,
Tory
 

·
Registered
Joined
·
827 Posts
i have torq thrusts on my 68Z with the original 4 piston set up same tire size and yes they rub. that is why i just spent a small fortune on original ralleys.
 

·
Gold Lifetime Member
Joined
·
1,351 Posts
Discussion Starter #7
Hi Jason,
This just might be more trouble than its worth. Do you think 225 60 15 would fit on the front? What size tires should I put on the 14x7 Rally Rims?
Best Regards,
Tory
 

·
Gold Lifetime Member
Joined
·
1,351 Posts
Discussion Starter #8
Greg aka South Side Goons & Hitmen, wrote several responses to my questions. Greg, Thank You Very Much, I really appreciate it.
Best Regards,
Tory


Tory,

That's what I was afraid of (you had either 3 1/2 inch backpsacing or 3.75"). :sad: There are only 2 ways to go about fixing the rubbing problem of the P235/60R15's on your 1968. :( The wheel backspacing should be increased to about 4.25". Or go with P 215/60R15 on the front. Right now you have a slightly negative offset.

In plain English, that means replace you will need to replace the front wheels or go with P215/60R15's on the front...The P215/60R15 is right about what the metric equivalent of a E60x15 is..... Please keep in mind some tire manufacturer's have wider footprint's than others even if you compare 2 exact same sizes by different manufacturers you may find one tire is noticeably wider than the other.

Don't just take my word for it. I worked in the auto service industry from 1989-1998. But, I went from 1998-2006 without caring about any of this stuff until I bought another Camaro last year, which was 12 years after I sold all my Camaro's. That means I am shaking off alot of rust the past 12 months.

Ok here is the deal. Check out this link. It will help explain what I am talking about. https://www.rsracing.com/tech-wheel.html#backspace


Then check out this one and scroll through the 15 photo's. http://www.carcraft.com/techarticles/fitting_tires_wheels/photo_06.html


I would definitely not just take my word for it. I encourage you to seek the advice of a professional at a tire shop near your home or work. It's not that I don't know what I am talking about. I feel that I do. But I have been out of the game since 1998. Nonetheless this was my specialty even when I worked at new car dealers or Goodyear, Firestone, Kelly tires etc. I worked at the service counter mostly as an assistant service manager or service advisor. That means what I am telling you another shop may confirm. Feel free to copy & paste this anywhere you want or in any forum you want to get a second opinion.

The SSG&H Bottom Line: You will either need to go to a smaller front tire or increase the offset/backspacing on the front wheels which means the current wheels would have to be replaced.

Please feel free to respond if you have any questions! :beers: :thumbsup:

Thanks!!

SSG&H aka Greg






The Backspacing is 3 1/2 inches and the disc brake conversion is already installed.
Best Regards,
Tory


Tory,

I believe the backspacing on the OEM Torq Thrust wheels was less than that of the Rally's. I think Rally's were 15x7 w/ 4.25" backspacing. Some Torq Thrust wheels like this one here were less http://cgi.ebay.com/ebaymotors/15X7-TORQ-THRUST-D-CHROME-5X4-75-3-75-BACKSPACING_W0QQitemZ120108428248QQcmdZViewItem

From what I understand, is that on 1967-1968 Camaro's, you can get more tire on the back of the '67's & 68's cars than you can on a 1969 Camaro. However on a 1969 Camaro you can get more tire on the front of the car than you will be able to on a 1968 or 1967.

If I am not mistaken the 1968 Z28 had either E70-15 or E60-15. This equates to around P215/60R15. Bias ply tires also have more of a square shoulder where as radials have a more rounded shoulder to improve handling & cornering. But the rounded shoulder also will cause tire rub as it increases the contact patch which is known as the footprint of the tire.

Here are 2 helpful links. http://www.turbinecar.com/tires.htm

Drag your mouse over the photos to see how skinny the tires were on these cars.
http://www.kelseytire.com/pages/preformancetires.html

Two Questions:

1) You said 1/2" backspacing Did you mean 4 1/2" or 3 1/2"?
2) Did you put the disc brakes on the car as of yet or does it still have the drums on there?

Thanks!!

SSG&H




---Quote (Originally by Camaros-n-Chevelles)---
Hi,
I have a 68 Camaro that was originally a Drum Brake Car. I purchased a Disc Brake Conversion Kit. I did not go with the Drop Spindles since I wanted to keep the rise height unchanged. It was originally a 327 A/C Car, but now has a 383 in its place. The A/C is installed with the exception of the compressor. As far as the backspacing, the American Racing Torq Thrust Rims are early rims made in the late 70s or early 80s. There was a 1/2 on the back of the rim if that helps.
Thanks A Million for your help.
Best Regards,
Tory
 

·
Registered
Joined
·
827 Posts
i think the 225s may rub on a torque thrust 15x7 with original height spring with agressive driving, the 15x6 torque thrusts have a better back spacing i think they would fit, with a 70 series tire. as far a 14s go, generally they will not clear the disc brakes, i tried a set on the frt of a monte carlo, no go.
 
1 - 9 of 9 Posts
Top