RSR 17" wheel/tires dont fit!

Tspringer · 11-11-2007, 11:26 AM

Assembling my RSR rep racecar... dang front wheels and tires are a real bear to try and have fit.

My car has fiberglass RSR front fenders, they came with the car. The car has coil over bilsteins with dual springs, SRP anti roll bar and ERP lower A-Arm and cross member so its all adjustable.

When I got this car it had 16" wheels and Goodyear slicks on it. I never attempted to run it but rather immediately took it apart as it needed paint and tons of other stuff.

I had a set of 17" 3 piece bolted Fuchs type wheels made by Dave White racing. He basically made them to the same offsets as the 16" wheels that came off the car.

I have Hoosier R6's in 275/40R17 mounted. They rub on the outer lip when the suspension is loaded up. I have played around a bit with the adjustments (and thus got them to fit without rubbing at the front bumper or rear of fender... though its tight) but I see no way to get them to not rub on the upper fender lip.

Except, perhaps by having the wheel spacer milled? There is a spacer being used (I have not measured it yet) and it would seem that I could run a spacer perhaps 3/8 of an inch less thick and still have brake caliper clearance and that might get the tire to fit.

I would really rather run 275 fronts rather than 255.

Any ideas or experience with this that could help????

Jeff Alton · 11-11-2007, 11:38 AM

I have basically the same suspension...... Have you condidered narrowing the front track (simple adjustment)? This would only work if you still have enough adjustment range at the camber plate to get the correct camber angle back and if you still have enough clearance for the spring up inside the fender.

Are you running custom sized wheels and spacers? Are these made from 6 inch fuchs? If so, I could understand the need of a spacer to clear a larger caliper.

Cheers

sfoster13 · 11-11-2007, 11:42 AM

probably a stupid question, but are you running max camber?

Tspringer · 11-11-2007, 11:59 AM

I just removed the front spacer to measure it... 1 1/16 thick. These spacers are not adaptors, they work with studs in the stock location though the studs do appear to be longer than stock. These spacers simply slip over the studs and they are are "star" shaped, ie. not perfectly round.

I am not running a camber plate but rather am using the stock shock towers with the adjustable camber plates (they have multiple holes in a stock type camber plate) with mono balls. They are set to maximum camber. I figured this would work fine (and its what the car had before) given I can gain camber by lengthening the track at the lower A arm with the ERP adjustments.

I had a couple of other spacers lying around that I have used on the back of my '69 911S when running 205/50 street tires. Doubled up these are 1/2 inch. I gave them a try for the heck of it and I definitely require more than 1/2 inch of spacer as with these the caliper rubs. The car has big red calipers.

I am guessing I need a spacer that is around 3/4 inch or so? Or have these milled?

Jeff Alton · 11-11-2007, 12:04 PM

Okay,

All you need to do then is meaure the brake caliper overhang, how much it goes past the face of the hub, then you can mill your spacer down to thickness just slightly larger than that. But, make sure you will not pull the inner edge of the tire into the spring when you do this. Double check you enough clearance between the tire and the spring...

Cheers

Jeff Alton · 11-11-2007, 12:05 PM

Here is the measurement you need.

Don't use mine, your calipers are a little different.

Cheers

Tspringer · 11-11-2007, 12:11 PM

Thanks Jeff... I will take that measurement, check the spring spacing and see where it leads. Sure would seem that these 275's should be able to fit.

Jeff Alton · 11-11-2007, 12:17 PM

You will probably get them on their, not to worry. I can measure my set up to give you an idea about what maximun backspace you can run and still clear the spring if you would like.

How much extra clearance will you need at the fender to make it work?

Also the shape of the inner wheel half, where it meets the out wheels half, may play a role as well. The crossover pipe or bleeder screw can run there as well. SO, you MAY need a little more clearance that the pic suggests....

Cheers

Tspringer · 11-12-2007, 04:34 AM

Yup... I need more clearance than the measurement you posted would suggest as the wheel contacts the brake caliper at the outer corners near the bleed screw.

To try and figure out exactly what size spacer I need I used the two 1/4 spacers I have and then used washers on top of them to test various total spacer thickness.

The bolts for the wheel rims also protruded past the nuts on the back side of the wheel by almost 1/4 inch. So I had some fun with the die grinder and cut all the bolts back flush with the nuts. Such fun.

Once the bolts were flush I was able to get clearance to the brake caliper with a total spacer thickness of 3/4 inch. Lowering the car back to the ground it appears that the wheel will now fit up into the fender. I suspect that if I widen the track further at the lower ERP A-arm I will not only get more negative camber which from eyeball it could use but I will get an even better angle for the top of the tire to fit up into the fender.

I also seem to have good clearance for the spring. There seems to be at least 1/2 inch or more spring clearance. So, while its going to be tight I do think the wheels/tires will fit.

Thanks!