Dip in road - Tires hit wheel wells. Shocks?
 

67 Firebird convertible. Stock height tubular control arms. Correct height and tension new springs. Bilstein shocks. Rides great. Bumps are no issue.

However, hit a dip in the road and the tires hit in the wheel wells and make an awful racket. Any ideas? Need a stiffer shock maybe?

Bonus question, what size tire are you running on 15" rims up front with stock ride height?

If it were my car, I'd address the issue by using a set of wheels & tires that fit better rather than stiffening the suspension. That seems like putting a band-aid on the problem. The suspension should be able to fully articulate in all directions and not allow the tires to touch anything.

What are your current wheel specs (diameter, width, and backspacing), and tire specs?

The rims are vintage American Racing Vector. 15X7. 0mm offset. Tires are 215 70R15 up front. Rears are 255 60R15.

I don't want to go with a different tire in the rear and the overall diameter of it, to try and match the overall diameter up front, the current tire is the only thing close. Anything different is a much smaller diameter.

Seems like the 0mm offset of those wheels is what's probably making your life hard. I think you'd ideally want 6mm+ offset for things to be happy.

Thanks

Might be something to think about. I'll check if my lug studs are long enough to safely run a spacer and try that, if they are.

The 215/70-15 is a pretty tall tire at 26.85”, that fact combined with the 7” wheel that has about 1/2” less backspace than a stock 7” Rally II wheel is creating the interference. I would be looking at a 215/65-15 that’s 26” tall to alleviate the rubbing issue.

In the rear you have the same problem, the wheels kick the tires outward by 1/2” creating interference. One size smaller 245/60-15s would likely stop the rubbing.

You don’t want to space the wheels out, tucking them in by a half inch (impossible unless you can find different wheels) would be ideal.

Unfortunately the 4” backspace on your wheels is far from ideal, they need 4-1/2” or better yet 4-3/4” to have a chance of working with your current tire sizes. So many aftermarket 15x7” wheels are made like this, with 3.75” or 4” of backspacing which isn’t enough to enable you to run any decent size tires.

A spacer will make the issue worse, no? You want the wheels to be more inboard, not outboard. The lower the offset number, the more outboard they go. You have a 0mm offset, which means your wheels are more outboard than the factory wheels. Adding a spacer will give you negative offset and won't help.

Actually, the more I look at it, I think the wheels need to come into the body more, rather than out. I think the tire is hitting on the fender lip bolts. I'll put button bolts in instead and hammer them a bit. See if that fixes it.

Thanks guys. I love my rims, so replacing them is a no go. I misunderstood the offset part. I went out to the car and see what you guys mean now. The rear doesn't rub at all. I think the front is hitting the bolts. I'll do button bolts and tap them in with a hammer a bit too. I love the way the car sits, the tire size, stance, and LOVE my rims.

Pic of car

It’s also possible to cut the wheel to drum or rotor mounting surface a little to tuck the wheels inward.

Removing say 1/8” to perhaps 1/4” isn’t unsafe depending on the thickness of the wheel in this area, there are shops out there that offer this service.

I had the same issue on my old bird when I added 8" rally ii's. I had to massage the inner fender only slightly to make them fit better or they would slice thru my front tires...

Hmmmmm, maybe the bolts are saving my tires and going to button bolts might be a bad idea. LOL

stiffer spring maybe. springs do the work shocks smooth it out.when the weather breaks we can measure your backspace etc..

Car looks great. Wrong tire size and wheel offset though. Running a stiffer spring may help, but probably not as much as you'd think. You'd have to get pretty stiff and you'd notice it everywhere.

As already mentioned, the First Gen birds typically run a bit of a positive offset. Remember Positive offset, pushes the wheel in towards the center of the car. Negative offset pushes it out away from the car.

Get out your measuring tape and some straight edged and see how far the wheel needs to go inside. You can achieve some of that by going to a narrower and shorter tire, or you can get new wheels with a proper offset.

You can also use a tool like this to help you out.

https://www.wheel-size.com/calc/?whe...scl=2in&sr=0in

Either way, I think your tire is too tall. Unless you nail the wheel backspacing and get the tires inside the fenders completely, they need a 26" tall tire.

Thanks

A couple of button bolts and some tapping with a BFH and I think I’ve solved the issue.