How much room do I need for 12" wheels?

[Moabdude]

We mini tubbed my 1969 Nova.
I have 13.5" from side to side in the wheel well.
Can I fit 12" wheels?

[srh3trinity]

If I am not mistaken, the bead adds a half inch to both the front and the back. So a 12 inch wheel is actually 13 inches wide.

[Schwartz Performance]

What he said^

You'll probably want 14" of space if you run a 335.

-Dale

[parsonsj]

Another question: how big are your front wheels? 2" difference front to back is a good rule to follow. If you are putting 10" wheels on the front, then a 12" wheel can work. If you are putting 9" or 8" wheels on the front, a 12" wheel is too big.

[Moabdude]

Another question: how big are your front wheels? 2" difference front to back is a good rule to follow. If you are putting 10" wheels on the front, then a 12" wheel can work. If you are putting 9" or 8" wheels on the front, a 12" wheel is too big.

Not sure yet. Don't know what size I can go with stock subframe. Want to go with 8" or 9"

[parsonsj]

Want to go with 8" or 9"

With a stock sub-frame, 9" is difficult. So you'll be wanting a 10 or 11 inch wheel in the back. You've got plenty of room.

[Forgeline Wheels]

I agree with Dale and John. For a 12" wheel you need at least 14"s of room. You may want to consider an 11" wheel and a 315 tire.

[540z28]

Newb question. When it is said you need to have a 9 or 10 front wheel with a 12 " rear is that for handling, looks or ??. I have a set of 12s I am really wanting to make use of on the rear of a 69 Camaro but will be running a stock front subframe. So I will have limitations there.

[parsonsj]

When it is said you need to have a 9 or 10 front wheel with a 12 " rear is that for handling, looks or ??

Putting in massive rear tires for "looks" is like adding a cam to improve the engine's exhaust "sound".

Rear tires that are too big compared to the front will cause a push on the track. Our front engine, rear drive cars are front tire-limited. The right way to get the best handling (and that's what Pro-Touring is all about, right?), is to maximize the front tire, and balance it with the back tire. 50mm is really the biggest difference between front and rear tires (30mm is even better) that will allow reasonable balance in handling. 50mm in tires is about 2" in wheel size.

Hope that helps.

[Forgeline Wheels]

I agree with John, that doing it for looks is not always best. I will add this. If your car has enough HP that you need the rear tire for traction and you stay with a narrower tire in the front, your car will not handle optimally. The car will push because you will not have enough tire in the front to bite and turn in. Ideally, you will want and need the wider wheel/tire in the front. We work with customers daily that are on a budget or time restriction and they are building their car in stages. One benefit of a 3 piece wheel is that you can go wider down the road for less money than buying 2 new wheels. This does limit your backspace options as once the wheel center is cut, you can only adjust the backspace in 1/2" increments and a thin spacer may be needed to get the ideal backspace. I would strongly suggest if this is your plan, decide on the front subframe that you will upgrade to and discuss this at the time of ordering your wheels. Sometimes we can build a wheel that may not be optimal for the current set up but would be ideal once the upgrade is complete. This also applies to brake upgrades. I hope this makes sense. None of this may even be relevant since you already have 2 wheels that you are wanting to use. These are all things to consider if you are building a Pro- Touring car and not just a show car.

[supernova70]

We mini tubbed my 1969 Nova.
I have 13.5" from side to side in the wheel well.
Can I fit 12" wheels?

Just finishing up my 72 Nova PT project. I tried real hard to get the 335s to fit with the DSE mini tubs. No way, not without more major mods like: cutting the tubs to make them another 1.5" wider. Which in turn requires another 1.5" taken out of the trunk floor pan. Which also removes the rest of the unibody frame. So frame mod, gas tank considerations, ect ect. But all doable if you have the will. My project looks cool enough with the 315s.

[Forgeline Wheels]

Most 335/30-18's are going to be 13.2" to 13.5" wide. 315's should be fine

[blu72nova]

We mini tubbed my 1969 Nova.
I have 13.5" from side to side in the wheel well.
Can I fit 12" wheels?

Just finishing up my 72 Nova PT project. I tried real hard to get the 335s to fit with the DSE mini tubs. No way, not without more major mods like: cutting the tubs to make them another 1.5" wider. Which in turn requires another 1.5" taken out of the trunk floor pan. Which also removes the rest of the unibody frame. So frame mod, gas tank considerations, ect ect. But all doable if you have the will. My project looks cool enough with the 315s.

Do you know how much room you ended up with in your wheel wells?

I ended up cutting all the way to the inner vertical wall of the framerail. I added a little over 1/2" to the tub width. At the end of the day, i have 14.5" of clearance. The plan right now ia to run 19x12s in the rear with a 325 series tire. Thoughts?

[Forgeline Wheels]

Most 325/30-19 tires are going to have a section width of 13". So I would say 13.75" minimum room would be good.

[Moabdude]

Thanks for all the help and suggestions.
Now I really measured with the actual rear end in place

OK, so I bolted up the narrowed rear end and took a measuring tape:
room is 35cm, I have 17cm to the outside fender and 18 to the inner side of the fender.
I am thinking of 5.75 or 6" back spacing. I want the lip as deep as possible!!

315's sound good to me but I want to go with 19x11" in the rear. The 315 tires in 19" are hard to get.
There are 325 and 305. Would like to go with as wide as possible...

[Moabdude]

Anyone any advice?

[Forgeline Wheels]

I personally would not go any narrower than an 11.5" wheel with the 325/30-19 tire.
The Michelin SS is 33cm wide ( on the 11.5). this would leave a cm on each side for clearance. If you went with the 17cm on the inside, you would have a 6.693"bs. You may want to double check my math with the conversion....
Remember, an 11.5" wheel measures 12.5 inches total width.

Anyone any advice?

[richs71Nova]

just saw this thread, i'm in the same boat. trying to find the best tire/rim size combo for my 71 that's mini tubbed. i too want a deep lip in the rear, how much did you have the rear end narrowed?

[Moabdude]

My rear end is narrowed 2" on each side. its 143,5cm( 56,5") mounting surface to mounting surface.

Been to Sema. Awesome those rides over there!! lots of ideas....
Thinking of 12" with a 315 or 305 tire. This way I can go with maximum lip because the tire does not "bulge".
11" seems to cost more money than a 12"

I have airride so I can raise the car when I drive and lower it when parked.
This way I can have the outside of the rim almost against the inner fender......