I am interested in buying some new wheels for my 95 Z28. I know our cars have a positive offset, but is it possible to use rims with a standard offset with our cars? I don't want my rims sticking out of the wheel well a whole lot. I want that semi deep dish look though. I hate the flat rims. I saw some pictures on Bren's site that looks like standard offset rims are being used. If anyone knows PLEASE help me out.

Mike

 

That's an interesting question. I just bought some american eagle 212's, they're 17x8's with a 5" backspace and they stick out about even with the widest point of the fenders. I think the factory wheels are backspaced at 5 1/4 or maybe 3/4 however my tires/wheels have extented out at least a couple of inches farther than the stock location but they don't/haven't rubbed the fenderwells so no harm no foul.

 

Wow, I bet those give a SWEET "deep dish" look huh? They must be some awesome rims!!

I'm looking to keep the 16" rim size but I want a "deep dish" look. I HATE these flat things. They make the car look like its front wheel drive! I just want to make sure it won't rub because I do a fair bit of driving, many long road trips. I don't mind if they stick out to the end of the fender, as long as they don't rub.

Mike

 

Sticking out to the end is one thing, but sticking PAST is tacky tacky!

 

I agree, I don't want the wheels to stick past the fender! I just want a bit deeper look to the wheels I'm going to buy.

Anybody know the deepest offset I can get???

Mike

 

I ordered american racing cl 205s (torq thrust) w/5 inch backspaceing. That was the most backspace they could build into them. I measured 6.75 bs on the salad shooters. 5" gives the dished look, much less (back spaceing that is) looks skateboardish.

 

Hi,
I have no clue what's what in this area so excuse me if I sound stupid. What is the difference between backspace and offset? What should I look for? 5" backspace sounds like it'll givve me the look I want, but the wheels I'm looking for mention offset. Reverse and Standard. I would go with Standard offset. Any insight would be kool.

Mike
Thanks!

 

In order to determine the correct "offset" you need to be talking about a particular wheel width.

Offset is the distance the face of the mounting hub is displaced from the centerline of the wheel. Positive offset moves the inner edge of the wheel closer to the body, and reduces the amount the wheel/tire sticks out of the fender.

Backspace is the distance from the hub face to the extreme back outer edge of the rim and is equal to:

rim width/2 + offset + bead flange thickness.

The stock 16x8 wheels have a 55mm offset. That means that they have roughly a 6.65" backspace. If you take the "backspace" away from the total wheel width (nominal width + 2 flanges) you get "frontspace", or the amount the wheel sticks out from the face of the hub.

Stock: 16x8, 55mm offset, 6.62 backspace, 2.28 frontspace

WS6/SS: 17x9, 55mm offset, 7.12 backspace, 2.78 frontspace

I've run 9.5" wheels in the front, and the smallest offset I have run is 49mm. That made the backspace 7.14" and the frontspace 3.28". That put the outer edge of the wheel/tire just about where I wanted it. I believe the 17x9.5 Torque Thrust-II wheels for the F-Body have a 7.00" backspace and a 3.80 frontspace. To me, they are out a little toward the edge of the fender, but lets assume you could live with that.

In the rear, you can handle more "frontspace". My 17x11 50mm offset ZR1 replicas have a 7.93" backspace and a 4.00" frontspace. That is the max you can handle in the back.

Soooooooo....

For an 8" wide wheel - To keep a 3.80" frontspace, you need at least a 17mm offset. Any more than that, and you are outside the fenders.

For a 9" wide wheel - To keep a 3.80" frontspace, you need at least a 30mm offset.

For a 9.5" wide wheel - To keep a 3.80" frontspace, you need at least a 36mm offset.

All of this is APPROXIMATE, depending on the actual width of the flanges on the outer edge of the wheels that hold the tire beads on the rim.

 

Yep, they look pretty sweet, I've seen alot of heads turn while riding down the road and have had several compliments as well. Its gonna take some getting used to seeing the rear tires spaced so far apart even though they don't stick out of the fenders and its still got roughly a 10" wide tread width, just having them farther apart sorta makes the tires look narrower so you may want to consider going wider on the rear to compensate for that. Also, I know this probably goes without saying and it really isn't a big deal but when pondering the thoughts of different offsets, backspacing, widths, etc. don't forget to consider if you want the ability to rotate the tires yourself or not, because if you mix any of the variables you will have to take your car somewhere and pay someone to rotate them due to the fact you'd probably have to transfer side to side instead of front to rear, at least with wider tires anyway

 

Thanks for all the great info!!!!! So, if I buy a 16x8 rim, I can have a 17mm offset and not stick outside the fender. That is awesome!! I appreciate the help. I'm gonna start looking tomorrow morning

Mike