Wheel Tire Sizes

[CasperIV]

One consideration I haven't seen mentioned in this topic yet is backspace. You can gain some backspace (I think you have roughly 4.5" stock) by going coilovers with the smaller springs. With a lot of coilover kits this can mean gaining about an inch of backspace which means an inch of wheel/tire if you compensate with offset. The backspace changes with wheel width and offset combined, so don't assume if a 16x7 with 0mm offset fits a 17x9 with 0mm offset will fit.

 

 

When I started this build on my 73, I grabbed a cheapish 18x8s & 18x9.5s set off ebay to use (I went to 5 lug with my brakes and needed something in 5x114.3 so I could at least roll the car). They aren't my preferred style, but getting wheels in offsets for these cars is quite a pain in the a** so I grabbed what was available.. I'm trying to find the details on what the offsets were, but I am pretty sure the fronts were 0. I would have preferred smaller wheels, but the problem is that I needed clearance for the brakes, but also performance tires are getting hard to find in non-low profile. I grabbed some 225/40ZR-18s for the front and 235/40ZR-18s for the rear (the rear are stretched a bit to help with clearance, but I'll be going wider on the final set). These wheels/tires gave adequate interior clearance, but like others have said, 8's push out of the fenders. Here is a couple pics of them with stock fenders, and a couple after the flares were on the car:

 

 

 

 

When I get my final set of wheels they will probably have to be custom (I want a nice flush look, but also to use every inch of back space I have). At least these are generic muscle car enough, in 5x114.3, and an old school offset that I should be able to sell them off to someone with an old Mustang or something pretty easily.

Edited April 2, 2014 by CasperIV

[helghast7]

I wasn't assuming a 16 x 9 0 offset would fit, I was assuming a 16 x 9 0 offset would put me in a better position then +20 would and then with a small spacer should put it far out enough to clear the strut and fit decent with flares. But that's why I asked because I didn't want to pull the trigger on a set of 16x8 0 offset and 16x9 0 offset wheels only to have them fit so horribly I would need a 1 inch spacer just to make them work.

[CasperIV]

I wasn't really directing it at anyone in particular, I was just stating that it can't be a determining mindset. If you can, getting an exact maximum size by measuring what backspace you have and what width you can accept is best. Most people think it's a matter of guessing at wheels sizes when really they should be measured just like everything else. The first diagram outlines the details you need.

 

The correct answer to the situation is that you should buy a professional tool... then let me use it

 

http://wheelworksinc.com/

 

I'm going to just try to make myself a tool here one of these weekends. Looks simple enough and I actually want one that doesn't have a tire involved. I will just make it expand to the overall diameter and width of the wheel and tire combination, then math backwards.

Edited April 2, 2014 by CasperIV

[helghast7]

Thanks for the info, I think I actually have the tool at my job, have look for it lol.

[seattlejester]

Wow, thank you so much, really. It means a lot to me for you to take the time to explain that so thoroughly.

Sure thing, always fun looking at pictures.

 

 

And I think the reason backspace wasn't mentioned verbatim is this was originally a tire size thread. 

[CasperIV]

Thanks for the info, I think I actually have the tool at my job, have look for it lol.

 

Color me jealous. If I had one of the tools available I would be able to be much more accurate. Usually I have to use a piece of cardboard and a tape measure