If you use a drilled rotor you can simply use a locking pin that engages the drilled holes. Very light and simple. Wouldn't work as a brake, but it'll keep the car from going anywhere.

Jim

About the only example of a catastrophic brake failure with no warning that I know of, was a line failure on a single circuit system where rust pitting allowed the line to rupture. No there is one other, a drum brake system, again single circuit, where one of the adjusters had a propensity to pop out of place. All other brake failures that I am personally aware of involved warning signs or were partial failures, still allowing the vehicle to be stopped. So you have to ask yourself, how likely is it that the e-brake will ever be used for stopping the car? If you want to use it to initiate skids or to play in the snow that is a different matter. But with a dual circuit system which is anywhere near properly maintained it is highly unlikely that full braking ability will be lost without warning, and even blowing a line would leave the second circuit intact, providing equal or better braking compared to the e-brake.

Historically, when hydraulic brakes were first fitted a mechanical back-up in the form of cable or rod actuation was retained because people just didn't trust the new hydraulics. The e-brake is the last vestige of that mistrust, yet these days most drivers put it in park and never touch the thing. If their brakes failed, very few would have the presence of mind to look for and effectively use the e-brake. This tells me that it has probably out lived its effectiveness and has become a back-up system that is never used, and if your car is a bit overpowered as most are for our segment, then the simple expedient of downshifting and switching off the ignition will quickly slow our vehicle to a stop. In short, the e-brake has become doubly redundant.

Still, I will admit to having slavishly installed and connected the independent e-brake calipers on my Jag IRS. I even bought the reverse locking pawl for the brake lever. Not that I consider locking the rear wheels the "correct" way to initiate a slide mind you, because I don't. It's just something else to play with.

Jim

As a Phantom jock - had more than my fare share of Hydraulic failures. 
So, maybe I am just being a bit overcautious.   With the jet - we always had the Barrier & Hook option.
I'd hate to flunk a Tech Inspection if they wanted to see some sort of "back-up"system.
(And, No, I haven't checked the rules - but I'd expect them to change a few times before I'm ready.)

Cheers - Jim

Daze - Thanks for the complement.
I try and do a bit of research - and sometimes my researched posts run long -- but hopefully saves someone else more than a few "clicks."

My adaptation is for a car that will initially lose the floor pan then build it back -- today's plan.

So DAZE - what is your opinion of the spot calipers - did I do ok for this venture?  Mechanical - I expect I'll add a spring to make sure they do release, eh?

Cheers - Jim

Some early disc brake motorcycles came with a cable operated caliper which was very small and light, but of course they also used very thin rotors. I think some dirt bikes still use them as well.

The JAG uses a separate caliper for the parking brake, also cable operated. The mechanicals are less than ideal and they are prone to squeak but they work well otherwise. Several imports used a rear caliper that included a cable actuator for the piston but the ones I've seen are single piston sliding calipers, which I'm not that crazy about. I've even seen a small disc with a button caliper on a tractor's transmission input shaft. Cute but not particularly effective. And then there is the bicycle stuff. Extremely light and effective for it's size, perhaps good examples for a custom set of calipers?

If you want to stop the car with it, good luck as weight balance already has you doomed. Holding it once stopped isn't much of a job. I guess you could always throw out an anchor.

Jim

irstang wrote:

Wilwood Combination P-Brake Calipers

These combination hydraulic/mechanical calipers from Wilwood look like something we could adapt to an IRS system.
"Caliper uses hydraulic pressure for stopping and a mechanical locking mechanism for a parking brake."--Wilwood
http://www.wilwood.com/Calipers/CaliperList.aspx?subname=Combination%20P-Brake

I think I can assume this would be thier version of the GM eldorado caliper. Uses a threaded ratchet system to keep the piston adjusted in. Perhaps they have streamlined it a bit to cut back on the mass?

I'm running a conversion kit that uses the GM styleon my van. they fit the bill and may work ok on an outboard mounted IRS system ok. Be alot of unsprung weight added tho if that was an issue.

Daze, what is the main hardship of finding rotors that work ok? The center hole , stud size or the diameter?

Think he wants ventilated inboard rotors...

I have talked to them and they don't want to venture in to a market that already is supported even if what is out there is way overpriced