I am dong the 911 rear brake conversion using m calipers. Maybe i will get aluminum some day Eric. So i have the 911 brake backng plate. It fits. But what about the original bearing retainer? Do i cut that down so it fits?

The 911 PET shows a retainer inside the brake backing plate. They are available new, although that would probably be pretty much the same as the 914 plate without the strenghening flanges.

I am guessing that the brake backing plateis now meant to be the bearing retainer, and also adding more would offset the rotor in a bad way. Help?

Second question is about stiffening tubes in the trailing arm. When i see a torsion box, i automatically think about diagonals. Yet, in Erics version, which is all i have seen, the tubes go straight through. Easier and strong enough?

As always, thank you for your time and effort. My 3.2 came from Pennsylvania. Rusty guide plates between the cylinders, and Lots of gunk! Getting cleaner though, so thinkng suspension soon.

Warren,

There's no need to change the bearing plate if you're just using the 911 calipers.

Diagonal would be fine. The current setup offers about 50% more stiffening for very little weight gain. Better than the 4lb box units. I don't think any more is needed. If anything gives it will be the chassis beyond that.

I added the 911 e-brake backing plates/boxster calipers to my 914 rear control arms and this is what I came across while doing this.

The bearing mounting holes on the control arm need to be ground down a little for the 911 backing plate to fit flush.

There is two pieces to the 911 e-brake backing plate that you need. I'm not sure if the later version is different but I used a set off a 70 911 which came with a backing plate(holds the e -brake pads) & a bearing support plate(kinda like the 914 piece but all flat). If you use the 69-73 911 5 lug hubs they fit the 911 bearing w/o any problems. If you use the 74-89 hubs you will need a spacer between the hub and bearing surfaces.

You will need to weld a 30 mm bracket to the control arm to support the e-brake pads when they are at rest. You will also need to weld in a pivot mounting block for the bellcrank(if you go this route).

Then you need to figure out how the e-brake cable is going to actuate the e-brake pads. I used a small cable along with the factory cable to pull on a bellcrank.
You could just buy the Tangerine cable kit and call it a day or make something up like I did.

Here's a few links to check out.

http://www.914world.com/bbs2/index.php?showtopic=88772

http://www.914world.com/bbs2/index.php?sho...=106793&hl=

http://www.914world.com/bbs2/index.php?sho...c=54987&hl=

http://www.914world.com/bbs2/index.php?showtopic=95956

http://tangerineracing.com/brakes.htm

So there is room for the bearing plate underneath? I realize I didn't check.

I figured the weight is the same diagonal as straight through, essentially, but the holes need to be ovaled. Probably don't need to do anything, but if I am doing it...and anyway, I was wondering what your thoughts were.

Great thread. I'm doing the same thing, and will be watching to see how yours works out. I've got the Tangerine kit, so that part is a little easier for me.

I'm also going to weld cross-tubes instead of the boxed plates.

Here's the basic process:

Drill 1" holes through the arm:
Click to view attachment

As the arm gets thicker you can certainly add a lateral or, experiment with diagonals. That said, I'm back to the point of "why?" For "me" this is probably as stiff as I would want the arm. For any more meat in the rear (fatter tires), I would look to Chris Foley's inner ear supports that weld to the inner ear and transfer load directly to the firewall.

Test fit:
Click to view attachment

Grind, Weld and "Paint" (do not powder coat... powder is too thick for the handbrake and softline clips):
Click to view attachment

We add gussets as well:
Click to view attachment

That's a big help Eric. Also...great tip on nixing the powder coat.

You may want to read what Richard (Moggy here) has to say about them. He's active in the UK rally scene:

http://www.pmbperformance.com/albums/album...174/7520437.htm

Thanks Eric,
As you might guess I had seen those photos and that is why I asked. I was just thinking of offsetting the holes on the two sides to brace against forces that would rack and try to collapse the box. I think the torsion does that, but all of the cool space frame is a bit beyond my ken at present, so I am going on intuitive mode. My son is the ME and he doesn't want to buy the software. I found I had ordered the brake shoes twice . Nice they fit the SC.

First time for everything I guess.

I would venture a guess that if there were to be a force that would collapse those arms in such a manner, it would probably render you... dead.

Oh.


Speaking of which, I asked about the bearing retainers cause the right rear axle of my 47 Dodge PU shot straight out while I was doing 60 a couple of years ago. Apparently wheel and axle tried to pass me at one point according to witnesses. I was fortunately going up a gradual hill at the time. I inherited the truck. Pontiac rear, 66 Malibu engine, transmission?

Besides which, I was speaking in terms of stiffening the durn thing, which I thought you was in favor of, not volunteering for destructive testing

Hey Warren,

If you're using the 911 handbrake assembly then use the 911 retainers.

If you're using the 914 arm relatively stock then use the 914 retainers.

The original post reads like you'll just be using the 911 calipers for now. If it's just a caliper swap, then that would have nothing to do with the bearing plates and, they are both the exact same bearing so, I'd use the 914 stuff.

Again, for the arm strengthening, I don't see any reason you couldn't run diagonal tubes, I just don't think it would be needed.

E.

Warren: I think you're looking to do what I'd talked about and illustrated here.

http://www.914world.com/bbs2/index.php?s=&...t&p=1930551

Putting them at opposite diagonals would theoretically give added stability, but I was going at it like that to help any water or debris drain too.

Question for Eric: What kind of pipe do you use for that mod? I was going to just use 1" gas pipe that I have handy. It's mild steel, thick sidewall, and if I'm painting anyway, I don't see an issue with rust. Thoughts?