Wide rear tires on stock 240z body

[getoffmyinternet]

So, yes I've searched, and found a dozen threads called "how big can I go?" most of which speculate at the definition of "big."

 

I don't care to increase the diameter any, I'm sure getting smaller rear wheels even couldn't hurt, however for appearances sake, I'd like to stick with 24" or higher. Basically, I'd like to get the widest tires possible. I can't afford coilovers at this time however, and I don't really want the tires to stick out of the wheel wells. Also I'm considering going up in rim diameter a few inches as a secondary goal.

 

The stock tires: 185/70R14 (some 240s came with 195s or so?)

I looked them up on a chart, as my tire knowledge is lacking, and it is said that they have a 5.2" tread. (overall is 8" or so fwiw).

 

My starting point is that the distance between my springs and the lip of the fender is a little over 9.5" and I don't think anything else is in the way.

 

I really like these tires, I'm sure you'll all think I've gone mad when I spec them...

 

MTT-3751R

 

24x9 R15

Overall width: 9.1"

Tread: 8.2"

Rim: 6-8"

Dia: 24"

 

The diameter is roughly the same, slightly larger wheel and thicker rim. Now, in a perfect world these would fit right? The possible obstacles I see already are: 1. Wheel offsets come in .25" increments, so the wheel could be barely too far out or too far in, depending on the hub spacing 2. When the suspension compresses, the wheel track changes distance. The latter might be moot, and I suppose if the former became a problem, I could trim the lips on my fenders or something, but I'd have to check to see if they still clear vertically, or in worst case scenario I could hold off until I can afford slimmer coils, such as the azcar roadrace assembly. If the rubbing was like microscopic, I could fit a narrower rim and that might clear it, but I'm sure I wouldn't know to do so until it was too late...

 

Perhaps I should work backwards now that I have an idea what size wheel and rim is commonly available. Ie. dimension a wheel with the proper backspacing etc and see what size tire will fit on that (although it might involve more guesswork.) At first I thought odd sizes like 15" rims would be harder to find, but it seems they are a dime a dozen. Any larger and they become far too wide. That said, 14" rims this size are almost nonexistant. Thus, it seems that 15"x7+-1" is a practical fitment for this application. I just don't know the proper offset because I haven't measured it yet. I suppose I would just find the relative distance between the center of the wheel well and the mounting flange then make the offset half that to center the tire.

 

If anyone has already fitted the widest tires they could muster on a stock setup, feel free to chime in with the overall tire width and the rim backspacing/ofset.