Argh! Wheel Clearance problemc

Matt_West · 09:17 PM

Trying to get back on the road after a long maintenance cycle. And my custom welded 9.5 by 16inch Fuchs are not clearing the 930 brakes. I am very frustrated in that they clear with two quarter inch spacers but not with one.

Some information that would be helpful:
1. Is there a cheap and easy way to solve this problem?
2. What is the best way to identify the contact point?
3. Is it safe to clearance the caliper and if so how much?
4. For those running 17 inch Lindsey P2's:
A. What size / offset rims front and rear?
B. What size tires front and rear?

The car is a 1980 sc with stock flares.

Thanks for the help!

Sincerely,
Matt

Steve@Rennsport · 08-22-2007, 10:06 PM

Hi Matt:

Highly unusual, to say the very least since normal 16" Fuchs clear the 930 calipers without a problem, especially ours that have additional clearance.

Question: Can you bolt the wheel down onto the hubs? Is the same problem on all four corners?

The question about clearancing the calipers depends largely on the above, but if you require 1/2" spacers to clear everything, that "solution" won't do.

Offhand, it sounds like your wheels might not have been made right since all you need are stock offsets to clear those 930 brakes.

While its possible to install 1/2" spacers, that option doesn't work on a narrow-bodied cars since that pushes the wheels/tires into the fenders.

lin7310948 · 08-23-2007, 03:26 AM

matt i am to pickup from ups this morning two 9.5 by 17 lindsey wheels for the rear of my rs flared 71 coupe with 930 rear calipers. i am currently running 9 by 16 fuchs and have no clearance problems,. however, the centers that he uses from 6 by 16 wheels do not have the same configuration and will not clear the 930 caliper without a spacer...hence this has to be built into the new wheel utilizing a suitable spacer. if you order p2s make sure that you know if they will clear the caliper without a spacer. i am hoping to be able to run 285s on the rear.

Matt_West · 06:30 AM

Thanks for the replies:
I am very frustrated as the 930 brakes were chosen, at greater expense; with the belief that I would be able to use my existing wheels and thus avoid the cost of a wheel upgrade. But hey what can you do with custom wheels without an exact build spec... such is life.

I can bolt the wheels to the hub, however the contact pressure is high and the wheels won't turn by hand. With the 1/4 inch spacers there is light contact pressure; the wheels can be spun easily by hand, but there is a groaning scraping noise. I do not have the same problem on the front. I believe my wheels were made using a set of 6&7s'. (Maybe Rdane or Mark could chime in if they remember the build spec.)

I think when I get home tonight, I will cover the calipers with blue tape and try to determine where the contact point is. I also have the original 6"&7" wheels that I will try on for clearance; while that is a step in the wrong direction with respect to tire size perhaps it will get me on the road.

Lin7310948, if you no longer need the 16X9's and they are in good shape please let me know if you will part with them for a reasonable cost. If the finish matches that route will at least allow me to use my existing tires and have me replacing only two rims.

Thanks,
Matt

Steve@Rennsport · 08-23-2007, 07:45 AM

Matt:

Call me.

DW SD · 08-23-2007, 08:19 AM

Steve will get you sorted! He is the man.

I wouldn't be surpised to find out the caliper cooling fins are hitting, as they are on the periphery, for the most part of the caliper. You may be able to grind a few fins down. If you are careful, no one will know that you did the grinding.

Good luck,

Doug

JP911 · JP911's Garage

I had a clearance problem with 930 brakes using stock 7X16 and 8X16 Fuchs. The rear caliper faces had been machined to account for this, but I still had to add a 4mm spacer. In the front, no machine work had been done and the wheels wouldn't even bolt up. I ended up doing a home "refacing" job on the fronts, but still had to use a 4mm spacer. It was a real bummer to grind on those beautiful calipers, but my 911 is primarily a track car so it's function over form.

Steve@Rennsport · 08:23 AM

Doug:

We do all the machining on the outer caliper faces for wheel clearance so thats already done,...

Sometimes the calipers are not installed correctly (spacers/washers out of order) and the calipers are not centered correctly over the rotors.

Once in awhile we find that a 3mm spacer is needed due to variations in Fuchs wheel spoke thicknesses.

lin7310948 · 08-23-2007, 08:23 AM

matt, i just installed one of the rear wheels..requires a quarter inch spacer and removing just a mm or two from one of the alignment bolts on the spring arm. i put 286-40-17 on the rear. might have to roll the lip not sure yet...275 should be no problem. i do have one good 9 inch fuchs. the other one developed a crack in one of the petals, so i opted for the londsey p2s. 450 plus shipping for the single wheel...thanks, larry

barney911rs · barney911rs's Garage

I thought the 930's would fit under 15" Fuchs, so I don't understand why there would be clearance issues with 16's?? If these are "custom" wheels, is it with the offset, or the design of the wheel halves being used?

DW SD · 08-23-2007, 09:05 AM

Barney,
Sometimes it is the shape of the inner wheel flange and spokes which cause the interference. It is not only diameter. This is the issue with the Lindsey 17" fuchs, which use a 16" center. You must plan the offset to use a 5/16" or so spacer.

Doug

rdane · rdane's Garage

Matt, not sure what wheels you got, but the pair I spec'ed and then sold would clear 930 brakes with no additional spacers. I spec'ed a similar clearence as the factory 9" Fuch for both the 8" and 9.5" wheel. My 930s were put on with a VCI conversion kit. Also the fins were cut off on the front calipers. I ran the same 930s with factory 7 and 9 Fuchs. There were at least two sets of wheels made, not sure what the spec was on anything but the set I had.

The centers were from 6" Fuchs. IIRC the 9.5 wheels had 1/4" spacer fixed to the wheel. Any way this set did bolt right up to my 930 brakes with no issues.

I believe the other sets ( one or two not sure) were made to bolt to Carrera or SC brakes only and didn't have the clearnece or offsets for 930 brakes.

These are the ones I had built.
"Custom offset to fit under a Carrera or SC with little or no effort with 225/245 tire combos. 225/265s fit as well. Made from original Fuchs centers. Fully polished and deep dish.
These will fit regular brakes or 930 brakes."

don911 · don911's Garage

When I did my 930, 911 7x16 fuchs would not clear the fronts. They rubbed right at the outer part of the wheel spoke as the spoke curved in. It sounds like you have a clearance issue in the wheel ring section.

IIRC, a spacer was needed on either the front or rear caliper to center the caliper on the rotor. Do any of your calipers have spacers?

Bill Verburg · Bill Verburg's Garage

Quote:

Originally Posted by barney911rs

I thought the 930's would fit under 15" Fuchs, so I don't understand why there would be clearance issues with 16's?? If these are "custom" wheels, is it with the offset, or the design of the wheel halves being used?

It's not the radial clearance that is at issue(though it is close) it is the axial.

944 7" Fuchs clear fine 911 7" Fuchs w/ the same o/s have less room behind the spokes.

here is a pic that shows how tight the radial clearance is

barney911rs · barney911rs's Garage

OK, so it's both the offset and wheel designs that come into play. Thanks guys

Matt_West · 08-23-2007, 08:32 PM

Great news! It turned out not to be caliper to wheel... but brake line to wheel clearance. So the next question is does anyone have a preferred machine shop on the Eastside? When bending one of brake lines out of the way we noticed the banjo was loose. Unfortunately on close inspection it appears that we only had a 1.5 threads of engagement...

So caliper is pulled. Helicoil is ordered and I don't have the courage to throw it in the drill press and try to run a plug tap.

Scooter · 08-23-2007, 09:25 PM

Machine shop on the Eastside: I would call Monte at Redmond European to see if he can either help you or lead you in the right direction.

Steve@Rennsport · 08-23-2007, 09:35 PM

Quote:

Originally Posted by Matt_West

Great news! It turned out not to be caliper to wheel... but brake line to wheel clearance. So the next question is does anyone have a preferred machine shop on the Eastside? When bending one of brake lines out of the way we noticed the banjo was loose. Unfortunately on close inspection it appears that we only had a 1.5 threads of engagement...

So caliper is pulled. Helicoil is ordered and I don't have the courage to throw it in the drill press and try to run a plug tap.

Which line was interfering? The caliper cross-pipe or the steel U-form one connecting the caliper to the trailing arm?

Jeff Alton · 08-23-2007, 11:32 PM

I had the same problem with these wheels, and I believe I owned this set of wheels at one point. Mind you, I had trouble fitting boxster calipers behind them and the problem was the cross over tube between the caliper halves......

cheers

fty · 08-24-2007, 05:54 AM

I have 16 X 9 BBS's in the rear with Turbo brakes as well with no clearance problems. Thats wierd that they are rubbing.