Hello...I have a 1986 Corvette coupe. I want to put torq thrust wheels on my car. I'd like 17x9.5 on the fronts and 17x11 on the rears. The company I'd buy the wheels....Ron's Rim's out of Pa. says an offset of 45mm would fit my 86. In reading articles online.....I have found that an 86 should have an offset from 34mm to 42mm with a backspacing of 6.75 in. CAN ANYONE HELP ME PLEASE ????? I'd like to buy these wheels...but am afraid of buying the wrong thing. Would adding spacers help this at all ???? Thank you. Grant-----R.I.

 

The 84-87 wheels have an offset of 38mm, nothing else. A wheel with 45mm offset will cause the wheel to sit further inside the wheel well by 7mm or about 1/4" which should not be a big deal. Backspacing will be different on the 11" wheel compared to the 9.5" wheel.

Offset is the distance from the wheel mounting flange to the center of the rim; backspacing is the distance between the flange and the inside part of the rim. So backspace will change more with a wider wheel.

What you will have to watch for is sufficient space between the inside of the wheel center and the brake caliper so that the spokes of the wheel will not hit the caliper. On the wider rear wheel, you have to make sure that there is clearance between the inside of the rim and the suspension components and the brake line.

I would ask your dealer if he can get a set of wheels and do a test fit before you plunk down money.

There are some folks here that use the ARE Torq-Thrust II wheel. But check with American Racing to make sure that particular wheel does not have to be custom made for ah early Corvette applicaton.

 

Hello.....Thank you for the advice. Sounds that if I bought the 17x9.5's all around.....everything should fit properly...right ????? Thank you for your time. Grant
P.S. 275/40/17 ...... would be the tires to go with ???????

 

The 275/40-17 tire and the original 255/50-16 tire when mounted on 9.5" wide wheels have very close to the same dimensions. The speedo will not be off very far (if at all) with the 275/40, and the tread width will be within a 1/2" or so (depending on the brand of tire). There will be no issues with rubbing at full lock with the front tires.

My 87 has 275/40-17 on AFS ZR-1 style wheels that were made witht heproper 38mm offset.

With all 4 tires the same size, you can also rotate the tires for longer tire life.

 

Thank you sir for getting back to me with your knowledge of the Corvette. One last question..please????? Now knowing what I have for a car.......would it be in my best interest to buy the torq thrust m 17x9.5 all around with 45mm offset ??????? Would the 1/4" with the 45 mm offset make a difference anywhere ...front or back ????? And not even get into the 17x11's for the rears ??????? I'm sorry to keep bothering you...but I can't get a straight answer from the companies I've been talking to. Thank you again...have a good day. Grant......gnf1953

 

Your 275/17X9.5 45mm wheel/tire package will sit nearly 17mm (.669") closer to the suspension/frame rails vs the 255/16X9.5 package. The 17" package will also stick out 3mm (.118") further than the 16" package. This is "assuming" that you've got 9.5 wheels now!

Now if your wheels on your '86 are only 8.5" wide the new 17" tire wheel package would sit 23mm (nearly 1") closer to the suspension/frame rails than now.

I don't know that the 17mm or 23mm "closer" is an issue or not. I wouldn't think so but it would be wise to measure "FIRST"! If it were an issue a minimal "spacer" would correct the issue.

This fit is based on pure 275 vs 255 tire which is nearly .8" wider.

I wouldn't consider the 11" package at all for a couple reasons:

1. it sits nearly 1.75" closer to the suspension/frame with a 315 tire and I believe it would "maybe" require a spacer, maybe!!

2. with the 275 tire on all "fours" you can "rotate"!!!!!!!!!!!!!

The tire/wheel combination if it clears the suspension/frame would fit the wheel opening well and should look "good". A 4-5mm spacer would improve it's looks.

"C4cruisers" comment all are 38mm only applies to the 16 X 9.5 wheel. The base wheel 16 X 8.5 is only 32mm. I didn't see anywhere that you mentioned which you have so I did both. I hope I've not confused you!

 

Thank you for the great info. My car has 16x9.5's on it all around. I'm seriously thinking of the torq thrust m.....17x9.5 with 275/40/17 tires...and as you said...I would be able to rotate. I'm 56 yrs old...I grew up with those wheels all around me.....the older hot rodders had them on. Thanks again for your help. When I do put them on...I'll look you up and send a picture. Thanks again...... Grant gnf1953 R.I.
P.S. These wheels are offered from ronsrims1 out of Pa.

 

I'm running American TT 2's on my 95 Hot Rod C 4 and with the 315 x 17 Drag Radials I got the Grand Sport 50 mm backspacing and 11 in wide rims.
That is for clearance on the big tires.

On the net several sites have look ups for stock wheel backspacing.

Grand Sports have really large racing size tires stock so they need the extra backspacing.

You have to deside if you want to run stock tires or not.
A word of warning to all that running too large a tire front or rear throws off alignment and geometry and can cause undue stress on your rear outside bearing.

I put stock rears back on for a trip now have to find some drag lites for the big Drag Radial.

I also have C 5 upgrade brakes on the front and the Wheels clear .

I checked on getting a pair so I can have the Drag Radials mounted on them and was told 20 days to build and $ 349 bucks ea.

Oh yeah we have a tires and Wheels forum where you can get more info about back space , just state year and tire size.

I get a lot of compliments on them and I love the looks.

 

Forget Rotating!!!!!!!!!!!!! The 17x11's in the rear are the only way to go!