heinrich

I have my 87 spare brakes and rotors; and my '86 and '80 lined up in a driveway ..... I need your expert advice on the logic below ... is it right?

Take the 80 brakes and rotors and give them to a friendly Rennlister
Take the 86 brakes, and rotors and spindles and instal them onto the 80
Take the 80 spindles and spare S4 brakes and rotors and mount them to the 86.

Sound right?

Shane

Yes

jcb928

Yes but just giving the 87 spare brakes to a friendly Rennlister sounds easier..... Hello friend!!!

Late Night.....

Garth S

Yes and no ....
The '86 to '80 transplant will work, assuming they are the 'fist' single piston calipers.
The '80 spindles ( w. steel ball joints - a clearance issue) will go to the '86: If ABS is involved on the '86, some swapping of hubs and remounting the sensors is req'd. Adapter brackets are needed for the S4 calipers .... and a set of 993 rotors IIRC: the S4 rotors will not fit.
I would be happy if that were incorrect, for it would be an easier conversion for my '80 ( S4 calipers and mounting brackets ... plus ?rotors?).

heinrich

Garth can you elaborate on the hub swapping and ABS? What's different about the 993 rotors vs S4? Let's get the efinitive answer right here, it may help many...

heinrich

I'll polish the '80 brakes and send 'em right over JCB

heinrich

Wow. Looks like more trouble/expense than it's worth .... so I have the S4 brakes and rotors, but the rotors are unusale on the '86 and I'd have to buy a) S4 brake lines; b) spacer kit and c) 993 rotors/discs



https://rennlist.com/forums/928-forum/40449-early-928-s4-brake-conversion.html

heinrich

Or maybe not? Specialists say:
"Milled from 6061-T6 aluminum, our Adapters bolt on to the existing caliper location of 78-81 928s (for 82-86US and 80-85 Euro S you must replace your front spindles with the 78-81 style spindle). You slide on the specially selected Genuine Porsche Big Brake 2-peice Cast-Hole "BIG Brake" rotors or "S4/GT" Rotors, bolt on the "Big Red" "GTS Black" or "S4/GT" Calipers with the proper bolts, install the pads/sensors, connect the hoses and bleed the system.

The rear kit is even easier requiring only special spacers for the rear S4 calipers and utilizes any S4/GT/GTS rear rotor. Again you connect the hoses, bleed the system and you are ready to go out and enjoy the new stopping power of your 928 !!

Note: Some factory and aftermarket wheels may require the use of a 1/8" to 1/4" front wheel spacer for proper caliper clearance. Due to clearance reasons you must upgrade to the newer style steel cased ball joints which is also highly recommended on all 78-84(up to Vin# 92 ES 860403)."

Garth S

The quoted info above suggests the S4 front rotors are usable .... so I do not really know. I'm still under the assumption that 993 rotors are req'd to clear even the lower profile steel ball joint vs. the original aluminium cased ones. Perhaps a redesigned adaptor bracket permits use of the S4 rotors????
I found myself in the same dilemma .... it's pretty easy to drop a couple of grand or more to update the early brakes: much cheaper to go to the 'S' style fist caliper on the '78-'81 for street use.
Regards ABS, if the '86 is so equipped, then to retain that function, the toothed ring ( which means hub) and sensor/pick-up must be retained.

heinrich

Garth I think because it actualy lists a 993 part on their site, this may be a different way of saying "993 rotors" Either way this is too expensive I guess. Oh well.

SharkSkin

I'm working up to this as well. I have my calipers and am simply waiting till my rotors need replacement.