StanUK951

OK, I know this has been done to death on the board here, but please bea with me...

It is my understanding that I can upgrade my 86 951 brake setup to Turbo S/928S4 spec by using the following parts:

Turbo S/928S4 calipers;
Caliper mounting adapters;
Turbo S/928S4 rotors;
Machining the hub/disc so that the new rotors can fit over the hub;
65mm wheel studs.

If this is correct surely this is a cost effective way of improving the brakes and doesnt tie you in to using one supplier for your brake discs as with Lindsey/Kokeln/PowerHaus.

Can anyone give a simple yes/no???

<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

StanUK951

bump...

Alan C.

The rotors for my Big Red conversion were quoted at $265 per side without hats. I have found them for $150 per side. These are full floaters. Want to bet that the manufacturer is the same?

You can also go with a 993 twin turbo rotor, 928GTS rotor or 94 3.6 turbo rotor. These are listed high to low on price. You woud need the appropriate adapters for each, one billet piece per side, no hats.

I noted the Big Reds since it has been my experience that Big Reds are cheaper than the S4 caliper. The pads are about a wash.

Alan

StanUK951

Alan C. - Your talking about floating rotors whereas I was thinking of solid (non-floating) cast discs as used on the Turbo S/928 S4. These are available in the UK as cross drilled items for £55.00 each ($70ish). The S4 calipers can be bought second hand for £250.00 pair.

I had assumed this would be cheaper as machining the hubs would allow the 928 rotors to fit??

Or am I missing something...

Alan C.

Stan,
You are correct, the hubs can be machined. Mine have been machined and I am using the updated spindles.

The price sounds good on the rotors in your part of the workd. The other rotors I noted are not floaters.

I think you would like either setup. The Big
Reds are easy to lockup on a non ABS car. I took out the brake proporting valve in my car and run full pressure to the rears. Seems to balance out ok that way.

Alan

StanUK951

Alan,

Thanks! I will start collecting the bits ready to convert them.

I didnt know the rotors you listed would work with the S4 calipers (or that they were non-floating!) so I may try a set of GTS or 3.6 911 Turbo rotors as these are drilled OE items.

The fact that the big reds might be too grabby on my non-abs car was why I was considering the S4 setup, as well as cost. Your setup with full braking to the rear sounds good too though.

Thanks Alan.

<img src="graemlins/bigok.gif" border="0" alt="[thumbsup]" />

Alan C.

Stan,

I obviously did not make myself clear. The rotors I mentioned will work on the
big Red setup. I don't think they would work properly on your setup. The radial distance would be too great.

However, I just remembered getting a set of rotors once which were supposed to be from a 94 3.6 turbo. Turns out they weren't. They were cross drilled and I believe they were from an 85 turbo look 3.2. Might want to check those out.

Alan

ken louie

one other thing to consider that if you upgrade to the big red's brakes and rotors, you'll probably have to upgrade to 17" or larger wheels.

ken
86 951
79 930

Danno

Anyone notice what size spare tire the 951 uses?

Clearance for Big Reds depends upon the wheel and the shape of the area where the rim meets the wheel centers. I've got HRE 16x10.25" 3-piece wheels and they fit just fine over Big Reds. Most of the one-piece cast wheels may be too thick to fit. The problem is not radial clearance, but axial. The calipers are wider than the stock ones and will hit the wheel centers/spokes on a lot of wheels. Even some aftermarket 17/18" wheels have this problem as well.

I've spec'ed out a brake-upgrade for my car and it will use full 13"/330mm rotors as opposed to the 12.7"/322 ones used on BR upgrades using 928/993 rotors. It'll be full-floating steel rotors (3x stronger than cast-iron) on custom hats so no warping allowed! heh, heh... AND with Wilwood Superlite 6-piston calipers, I'll be able to fit the entire package under 16" wheels !!! <img src="graemlins/jumper.gif" border="0" alt="[jumper]" /> <img src="graemlins/jumper.gif" border="0" alt="[jumper]" /> <img src="graemlins/jumper.gif" border="0" alt="[jumper]" />

One of the things I've continually advocating is using quantitative analysis and measurements rather than relying on black & white, yes/no, all-or-nothing blanket qualitative statements. Numbers don't lie, they are just what they are. So it's like that carpenters' saying, "Measure twice, cut once."...

P.S. Alan, are you saying you're using an '86 hub on an '87+ spindle?

Alan C.

Danno wrote:
[quote] P.S. Alan, are you saying you're using an '86 hub on an '87+ spindle? <hr></blockquote>

According to VCI, who instlled the brakes on my car, I have machined 86 hubs with 87 spindles.

Danno, Hope you don't maind a little clunking at low speed. I've had people stop me in the pits and tell me I had a 'wheel bearing' problem .

Care to post the details on the brake upgrade off line?

Thanks,

Alan

StanUK951

OK Alan, thanks. I did misunderstand you, back to my original plan of using 928 discs then! I will look into the 930 discs though (as that is what Turbo Look or Super Sport 3.2's use I believe).

One more thing though, are the 87 spindles necessary? I cant see why they would be apart from the obvious debate over strength which some argue is not really an issue...

Alan C.

Stan,

The PO put the 87 spindles on for strength. It does seem to be an item for debate.

Alan