SWB brake upgrade - summary?

[91167coupe]

I have read many of the treads regarding SWB brake upgrade (front and rear) to vented rotors, but are still a little confused...

Are there of the shelf parts for this kind of upgrade for the 64-68 cars or is it fabricated kits for this(rear)? It would be very helpful if anyone could make a list what parts to use and what has to be modified/machined etc.

Also how to get anti roll bar at the rear on the non-S/L cars, especially the control arm fixing points.

I am greatful for help in these issues!

[gregk1]

i just did all this to my 67 and was told that the 67/68 s and L calipers are what you need but hard to find. this is what i put on my car with drilled/vented rotors the rotors are not easy to find also but was looking on ebay and there is some of both not cheep but there

[gsjohnson]

If you want the correct upgrade then the fronts were wide cast iron M calipers for vented discs as found on the 67/68 S. Not a difficult find and the rotors can easily be found and bought. The rears as Greg alluded to are wide cast iron L caliper with 2 1/4" spacing. A very tough find and expensive if you can find them. The alternative is send your rears to Eric at PMB and have then converted for vented discs. The only difference is you will maintain the 35 mm plungers rather then the 37 mm plungers that the correct L calipers had. Visually there is no difference. But then the rear rotors are also an expensive proposition as they are a one off style as well...$450 for a pair. Hope this helps.

[91167coupe]

Thanks for your answer! I have now bought M calipers for the front and need the thinner hubs or send mine to machining if this is possible.

Wide L rear calipers will be a tough one. Is it possible to modify the rear M to fit SWB other than welding LWB control arms ends to mine?

Or is there other calipers that fit? Modifying standard L as mentioned could be an option, but hoping to have calipers with the 37mm pistons for the right bias.

[super9064]

Ask Eric at PMB about using 944 rotors. They need slight modification and are cheap.

https://www.google.com/search?q=SWB+...sm=91&ie=UTF-8

http://www.early911sregistry.org/for...p/t-34903.html

[gsjohnson]

Thanks for your answer! I have now bought M calipers for the front and need the thinner hubs or send mine to machining if this is possible.

Wide L rear calipers will be a tough one. Is it possible to modify the rear M to fit SWB other than welding LWB control arms ends to mine?

Or is there other calipers that fit? Modifying standard L as mentioned could be an option, but hoping to have calipers with the 37mm pistons for the right bias.

Interesting that you state that you want the proper bias because both the vented and non vented applications call for the same mastercylinder. Plunger-piston size is the same for front vented and non vented applications. Only the rears have 2mm difference. You have a 67 so wouldn't you need the thicker hubs to clear the calipers rather than a thinner hub?

[Fishcop]

Ask Eric at PMB about using 944 rotors. They need slight modification and are cheap.

https://www.google.com/search?q=SWB+...sm=91&ie=UTF-8

http://www.early911sregistry.org/for...p/t-34903.html

I second Rob's advice. Eric is a real early car brake guru... He will have a few options for you.

[gsjohnson]

I second Rob's advice. Eric is a real early car brake guru... He will have a few options for you.

I talk to Eric extensively about the 944 rear rotor conversion as an alternative to spending $450 for the correct rotors. I also spoke with another member here who thought the 944 conversion was a hassle and scrapped the project. I know Eric states that the 944 rotor is a cheaper solution with little hassle. There's a couple of issues that didn't sit well with me. First the e-brake surface is not in perfect alignment to the oem shoes, although close enough. But besides having to machine the diameter of the rotor (easiest part of this conversion) by a few thousands, you have to drill your original hubs to align the securing holes. The alternative is to remove the hubs and have the rotors drilled to match your hubs. A royal PIA. Alternatively I didn't want to drill my original hubs. If you're willing to drill your original hubs and live with a couple of deficiencies, it's not too bad. Just my .02

[Bobs 67S]

944 Rear Vented Rotor on a 1967 911S
Yes the 1983-86 944 rear rotor can be modified to fit the vented rears on the 1967 911S. The outside dimension is machined to 285mm. The machinist used the brake drum lathe and reversed the cutting head to do the outside (as opposed to doing the inside of a drum brake). Minimal material was removed and it leaves the wear indicators on the outside edge still in place.

The two retaining screw holes need to be repositioned on the 944 rotors to match those on the stub axle of the 67. I brought a stub axel along to the machinist. We wrapped brass shim stock around the studs, slid the new over the existing rotor to center them together and drilled the holes. Then counter sunk the holes to match the metric screws. We roughing them in using a wood screw counter sink bit that was shaped to the correct bevel - and finished with a modified die grinding stone bit, total time to drill, shape and finish maybe 4 min each.

From a second post
This set of regular 944 rear's (1983-1986) have been brought into 1967 911S spec's.

The outside is machined (on a truck brake drum lathe) to 285mm.
Add the two set screw holes in the appropriate locations.

The critical spec of "a" is correct at 65mm. (The wore out S disc measured 64mm?)

The inside dimension for the emergency brake shoes is at the correct 180mm.

The differences are:
the hub face hole is at 102 vs. 90mm - but this does not matter cus to doesn't ride on anything.

That hat surface is 6mm vs. 9mm. It is thinner than the original part, but you get 3mm longer stud contact surface.

The vain openings are inset from the rear edge but the Emergency Brake shoe still has 90% contact.

With the wheel mounted you can't see any of those items.

The weight is 11.5 lbs for the wore out and 12 lbs for the fresh disc. With a thinner face and a larger hole I would have thought it would be lighter - so there is more material in the disk surface for heat sink.

Minimal machine cost allowed this to be a good option for the 1967 911S.

Bob

[91167coupe]

Thanks for a great summary regarding the rear discs, 944 discs are sure a good (and inexpensive) substitute for the 67S discs.

To make a conclusion on the caliper subject;
Wide M for front (48mm pistons?) and wide L for rear (38mm pistons) =good match regarding bias effect? The hub on the front needs to be machined 7mm to senter the wider disc to the caliper? (When use of the hub from solid discs?)

If narrow L caliper on the rears are modifyed with spacers and M7 bolts, the piston size will be to small to match the M on front?

I read a tread from 2010-2011 that someone was into this and tried to find another caliper with 38mm piston and 2,25" bolt holes and with use of spacer it can be a good "off the shelf" substitute. Is there a conclusion on this?

I really apreciate all the knowledge and helpful members in this forum!!