Rear wheel help. Distance from center hub to Willwood high point for solid axle

[Blitzboy54]

I think I may have made my first mistake. I purchased a set of 17" wheels that fit the same size specs as the Halibrand wheels offered by FFR. They have the same offset and backspace and are 17". My Wilwoods are going to be coming soon and it finally occurred to me to make sure they will fit. Based on the attached if this is truly the clearance I have a problem. Is it really over 8" from center to the top of the caliper in the back? That seems big. Does anyone have either the ID measurement of the FFR rear wheel or the length from center to the top of the caliper? This is for a solid rear end not the IRS

Thanks

143367

The fronts clear fine, based on there clearance sheet I have plenty of space. The rear brakes are smaller so something isn't adding up

143371

[FLPBFoot]

It's hard to see in these pictures but yes from what I see it is very close to a full 8 inches from enter to the outer most point of the brake caliper. Again hard to see but the 17" Hallibrands have a good 3/8" clearance from top of the caliper to the wheel.

Steve

143374143375

[Blitzboy54]

Thanks. I think I’m toast. I have a significant inner diameter reduction. I have to make a new plan this was literally the only thing I purchased that I didn’t scrutinize first. Its even my avatar, so dumb

143378

Now I'm feeling it. Do I go with Halibrands and keep my tires (not the look I originally wanted) or go with 18" wheels/tires.

[NAZ]

The rear calipers on the FFR brake kits from Wilwood take up way mre room than need be. I have 12.19" rotors on the rear of my car and 15" wheels -- yes you can have 17" wheels on the rear with the 12.19" rotors. You need to ditch those bulky calipers with the integral parking brake and spec a lower profile caliper. Then you have two choices of parking brake, either a drum and shoe version that works with rotor in kit #140-12049 or use a hydraulic block valve made for a parking brake, which is the route I took. Valves similar to these are commonly used for parking brakes on aircraft. https://www.speedwaymotors.com/Speedway-Park-Lok-Universal-Hydraulic-Parking-Brake-Line-Lock,1970.html

I used Dynalite four-piston calipers on the rear of mine to gain the clearance I needed to run 15" wheels. Also, forged wheels usually have more brake clearance than cast wheels as they can be made from thinner aluminum as the forged material is much stronger than cast. I have the experience to spec my own system components but if you're not comfortable doing that, contact Wilwood and discuss your needs with one of their engineers. They do this stuff everyday on wild one-off custom builds. Better to ask for help than to throw in the towel.

[Blitzboy54]

Thank you for this, what a relief.

I'm glad their are other options besides just replacing the wheels. I have a set of FFR Halibrand wheels now ordered with my kit. This gives me options, if I go with modifying my brakes I can easily sell the wheels.

This will cost me money either way, just an expensive lesson in due diligence.

[txboiler]

if you want additional option I would recommend reaching out the Gordon Levy. He was able to spec me a competition brake package that worked for my 15" Halibrands. Maybe he can do the same for your 17s

[totem]

Make a scale cardboard template to see if it fits. The small inboard protuberance is the parking brake lever. You might be able to trim it.

Otherwise, look at Wilwood 140-7146 which I think is a better offer than what FFR propose.

R.

[Blitzboy54]

Make a scale cardboard template to see if it fits. The small inboard protuberance is the parking brake lever. You might be able to trim it.

Otherwise, look at Wilwood 140-7146 which I think is a better offer than what FFR propose.

R.

Will do. Based on all the measuring I did last night the kit you listed above will absolutely fit. I'll have to wait until I receive them first and see what if anything can be done if not I'll see if I can exchange kit with Wilwood. I assume that should be doable

Thanks guys

[Avalanche325]

If you are running a 3-link also check the right side panhard bracket. You may need to clearance that. There is plenty of material. I can tell you for a fact that the old style FFR Halibrands scrape it under track and autocross use.

[Blitzboy54]

if you want additional option I would recommend reaching out the Gordon Levy. He was able to spec me a competition brake package that worked for my 15" Halibrands. Maybe he can do the same for your 17s

Gordon Levy for the win. Just got off the phone, fantastic conversation. He got me straightened out.