Being 9/14 it seems like a great day to post the progress of my version of the 911 hand brake conversion. First off, many thanks to Timo and Wilco for their posts which gave me the direction to get started on such a task.

I just switched the rear control arms on my 911. I got a pair of aluminum control arms and they came with both hubs and hand brake assemblies. Lucky me... I now had a set of 71, 911 hubs for my 5 lug conversion (just got the stub axles from Mittlemotor) and a set of 911 hand brakes.

My front struts have been replaced with the Koni struts and S-Calipers. I had the spindles raised on the struts by 18mm. For the rears I needed some stopping power to match both my S-Calipers up front and the 220hp six that will be going in the car.

Current status after this weekend:

Control Arms off the car. Hand brake cable mount was cut off. Rear shield mount ground off. 2mm ground off the extensions on the rear bearing housing. 911 hand brake assemblies rebuilt. All parts glass bead blasted. Hard parts painted with POR-15. Mechanicals replated in silver zinc. Reassebmled and test fit to the 914 control arms.

What's Next?

Control Arms go off to get sand blasted. Boxed control arm kit welded on. Repaint with POR-15. Mount 911 front M-Caliper. Mount vented rotors. Rebuild CV's and Axles.

Here's some pics:

Shield tab ground off...

Backing plate test fit...

Rebuilt 911 hand brake assembly...

Keep the pictures comin'! I'm sure everyone is very interested in how this turns out.

Test fit of the complete assembly. Next the control arms go off to the sand blaster.

I'll keep you posted!

Eric

been looking at doing the aluminum trailing arm conversion myself - do you know if they'll fit a '71 ?
i know there were a few dimensional changes in the '74 cars and 'm just starting to research this...

Good Luck... I started down the same path, got just about as far as you, but gave up, let me know if you find a source for the cables. Maybe I'll go back down the trail.

Rich,

Dimensionally they look identical next to each other. The only problem I know of is the 14mm lower shock mount bolt verses the 12mm shock mount bolt on our 71 cars. I got the 74 variety with the ball mounts for the sway-bar. You'll need new shocks with the 14mm sleeve

E-mail me off the list and I'll fill you in on any problems I run into while installing these . I've heard the shock holes in the chassis are different and you have to remove your dust covers but others mention this isn't a problem.

We better stop talking about the 11's or the teeners are gonna whack us!

E.

Eddie,

I plan to go a slightly different route than both Timo and Wilco. I want to use a 911 hand brake lever on the tunnel ala some of the factory rally cars. Doing this for two reasons; 1) I have the extra hand brake handle, 2) I have a roll bar that lands in the stock parking brake cable location.

I'll use stock 911 cables. If I need to have them shortened or lengthened that's the route I'll go.

E.

Next time please make sure you establish in the title or subject line that the material is off-topic. I am now thoroughly confused as to what vehicle your discussion is about (911? 914?).

Maybe a new forum is needed for non-914 topics. I'm seeing a decent amount of non-914 topics and all they do is increase the signal-to-noise ratio.

off-topic ?

look at the pictures.

911's don't require 911 E-brake conversions, they already come with 911 Ebrakes.

there are no aluminum 914 semi-trailing arms. i do not understand your confusion.

non-914 topics ? which 914 is this again ?

Unbunch your panties, dude. I know VWs, not 914s. It sounded like a conversion/swap of 911 parts for a 914. I do know some 911 parts fit the 914 and I figured, since I'm somewhat new to the 914 scene, that this was the situation. If people put BMW brakes and Chevy engines on the 914 how far off could some suspension components be?

Uhm, as for the avitar, so what? I see others on here that aren't even close to 914 content. At least Porsche had a part in the Type III on VW's request and the engine was the precursor to the Type IV.

yes. exactly. which is why it is a 914-related thread.

Thoroughly confused now. Would someone please give me the baby-steps version of what the hell is goin' on?

If you do a 5 lug conversion with 911 brakes on the rear you lose your ebrake, unless you do the mods as shown above.
There are a couple of variations out there, but this one is gaining popularity or so it seems.

sure, no problem, i apologize if i contributed to the confusion.
sometimes i forget that the world here hasn't followed along with Eric's progress since it started getting coverage in another forum...

the standard issue with using other calipers on the back of a 914 is that it's hard to retain the parking (Emergency) brake function. 914's use cable-operated mechanical pressure on the inboard pad. 911's have always used a completely separate, fully redundant E-brake system - with two little bitty brake shoes working on a drum integral with the rear disk. cool system.

Eric has started down the challenging path of utilising the 911 drum (E-)brake mounting plate on a 914. there are 'issues' but it looks like he's got most of them addressed.

anyway - Eric posted his progress, including what modifications must be made to the trailing are, and how the 911 Ebrake mounting plate bolts up.

and mentioned in passing that he was doing the aluminum banana conversion on his 911 - the rear suspension parts that came with the brake parts he wanted. i was interested in that because i'm planning on doing the same thing on my early 911. this was probably where most of the introduced for which i apologise.

being able to use the 911 EBrake parts on a 914 would be very cool, because there are lots of attractive calipers people would like to be able to use on 914's - especially track cars and those with HiPo engine conversions - but an EBrake is A Good Thing - and required by law for street cars in many jurisdictions. having a completely redundant EBrake system a la 911 would be a tremendous step forward, because 911 EBrake parts are plentiful and 914 rear calipers - especially the higher-capacity 914/6 calipers - are in short supply.

Short version...

911 E-Brake conversion going on a 914
Aluminium trailing arms going on a 911

As Rich alluded to...even though my particular car is driven more on the track than the street, and is "barely street legal" (I'm being optimistic but no law-enforcement hassles so far), it would be a big plus to have a reasonably simple, lightweight e-brake.

Don't ask me why I came to realize this , but suffice to say I live in a very hilly area and I keep folding wheel-chocks in my glovebox now

Looks good Eric !!!

I am happy you decided to do it. Congratulations. I am also VERY interested in about your plans of center mounted hand brake.

Ahhh...got it! Very cool and I hope, once it's done, we get a web page tutorial on how to do it

Thanks Timo,

The last thing I did yesterday was move the original hand brake cable mount to the bottom of the control arm. at a 90 degree angle. I fitted some early 911 cables to it for a test fit and the come straight out. Out came the MIG welder. The mounts were a bit long after they were installed at that angle so I trimmed them down with a cut off wheel. I'm not sure this step (mounts) is necessary but I did it anyway. Seems the cable could use some support. By looking at the factory ones on Jon Lowes site I didn't notice the mount. They both came out the bottom like yours and mine though.

I'll try to get one more picture of the control arm with the new cable mounting location before it goes off to be sand blasted.

Sorry for the confusion Toby... see Rich, I told ya we'd get whacked talking about 11's here

E-out.

yes, please add a picture! don't sweat the Type 3 guy, what does he know? Welcome to the board Air Cooled Nut! For someone new and not of the 914 persuasion you sure were fast to jump and b!tch about noise ratio. Relax!

Here's the newly placed cable mount...

Eric,
Keep up the excellent work. You need to write a complete how to when you get done.
Thanks
Van

It's the wanna-be engineer in me

Eric,

Couple of things I have to comment.

1. I hope you have noticed that cover of the cable must move free. The end of the cover pulls the other expanding bow, that spreads the shoes. The ending of the cable pulls the first expanding bow.

2. In your pics it looks like you are not going to use any support for the brake shoes when they are in rest position. If you look your 911 control arms you will notice that the shoes have a support in the control arms so, that when the shoes are in rest position, the expanding bows are not in tension. I added 40mm wide support between the shoes and welded it to the back plate. See the pic.

NICE..

Now to stop the powder coater from coating the rear control arms I sent him..

also.. I'm now in need of a 911 rear ebrake setup. Hopefully it will work with our 930 turbo rear calipers and rotors.



B

Timo...

You're create'n more work for me

Thanks for the pics... I saw thw piece on the trailing arms but wasn't sure it was needed. Should be no problem to moidify the backing plate at this time but what do you think the implications of running without would be...?

Thanks again!

E.

Brad, I'm using 930 rotors and calipers as well, so far everything fits nicely. I'm sending my calipers out to be machined this week, I'll let you know how everything works when I get them back. i still have to make some cables.

Sorry Eric I didnt mention that earlier. I thought you know it....



Hmmm...... I have no experience, but I think the shoes may hit the drum in the rest position. At least I dont suggest to leave it away.

Eric,

I like your progress so far on the handbrake conversion, but I'm trying to visualize how the e-brake cables will be routed. It seems to me that they'll end up being under the engine after coming out of the center tunnel, which would imply heat issues and more complications when the engine is dropped. Or are those cables longer than I think?

Not to steal the thread... but why where'nt you with your dad at the German Autofest.. ?? he is a character. He stopped by the WEVO booth.



B

He didn't even tell me he was going. I called to ask him where some tool was and he just says, "Oh, I'm talking to Hayden right now." I had to put two and two together to figure out that he was up there.

Besides, my dad wasn't coming back down to San Diego until Monday morning. I had to teach that morning, so I wouldn't have really been able to go up with him.

Glad you got to meet him. Did you talk him out of that pull clutch setup of his?

Hayden tried to talk him out of it...LOL

Sometimes the wheel doesnt need reinventing.

B

Hi Marc,

The photos of the factory cars on Jon Lowes site show some shielding around the cable where it crosses under the exhaust. I plan on shielding the cables and then running both up the center line of the engine into the tunnel.

That and keeping my fingers crossed oughta do it...

Timo,

I'll probably cut and add the piece but... I'm not following this;

The 40mm spacer (which would force the pads "out" another 2mm total) should force them "out" toward the disc. Meaning, if left out you would actually have more disc clearance. This would have to be compensated for with the star adjuster but... there shouldn't be "dragging" issues.

I'm wondering if there's enough adjustment room with it out... both on the cable and the star. Doesn't seem like 2mm is that much though.

I have plenty of time to contemplate this one while the arms are off being blasted and while I weld on the box kits.

Anyone care to add their $.02?

We have a M471 in the one of the shops close by.. I'll look at that car and see how they did it. It has vented rear rotors and the 908 brakes.

Oh.. my .02.. dont stiffen the rear arms (you asked)


B

OK... I think I'm figuring this out as I type:

I think that 40mm spacer is there for the adjuster to work properly. The top of the brake shoes need a solid resting point for the star adjuster to pivot the shoes properly, otherwise is a constantly changing relationship. Meaning;

The more you adjust the star adjuster out, the more the shoe retainers would compress if the hard spacer weren't there.

How's that for a load of bullshit?

(I think that's it...)

Oh.. my .02.. dont stiffen the rear arms (you asked)[QUOTE]

Porque?

You nailed it.

GM drum brake cars have a similar setup on the rear and require the pads to be supported on one end.


B

You posted: "anyone care to add their .02." I read that you where stiffening the rear arms. Real life structural engineers have tested and tested our rear arms (recently..not 30 years ago) and have found them to be plenty strong for cars with slicks up to 10 inches wide. It adds weight. I find them useless. If you ask around.. everybody says our arms flex.. but no one has proof. They are "following" what the factory did.. and the factory was having problems with the rubber bushings moving around not the control arms.


B

Got it Brad... recent studies show the boxed kits add 3lbs. weight and over 40% in stiffness.

Now it's off to find a couple 40mm spacers to weld on.

That would have been a fun learning experience w/o the list huh? Timo, you rock.

E.

Hey Gang,

A friend of mine may have an additional set of 911 hand brake assemblies for sale off his 71 (that year fits) if anyone is interested. He may switch to aluminum 911 rear control arms and they use different assemblies.

E-mail me off the list if you're interested and I can get you in touch with him:

ericscottshea@cs.com

P.S. Hubs as well...?

I dont need the hubs.. but I would like a price from him.


B

Here's my modified arm. I was going to have the cables run through the arm. I welded the spacer that I cut off my donor 911 arms. I couldnt figure where to put the spacer, if the spreader was at 6. Let me know if the eBrake handle on the center tunnel works, with stock 911 cables.

Eddie have you test fit the ebrake shield?

I wonder if you removed metal in the areas where the bearing cover goes.

The reason I ask is cuz it still looks squared and if you havent already test fit the cover it may not fit.

Just lookin out for ya!

Yes I have, it fits. I ground it flat. Thanks for the extra set of eyes!

Went to work on them again this weekend. Got them back from the sand blasters on Friday...

Here's anothe shot of the bearing housing. I like the way the sand blasting smoothed everything out (like anyone will ever see it!!)