power brakes

bravoj · #1 (**permalink**) 04-17-2003, 08:20 AM

Have E-M 427 kit that am now looking to put in power brakes. what is the shortest vacuum and master cylinder unit that anyone has seen. Do any of the Everett owners know what make the factory used? thanks JERRY

Hotfingrs · #2 (**permalink**) 04-17-2003, 09:30 AM

I don't know what the factory used. I do know it depends on when your car was manufactured as to the height of the brake box. I had talked to EM before about this, seems later version had a raised brake box of 4 inches to accomodate power brakes. I believe that the Buick GN setup is about the smallest out there, or there are also units that can mount under the car.

BT SNAKE · #3 (**permalink**) 04-17-2003, 10:08 AM

Jack,
I have an EM frame with a Midstates body. I had the
1987 GNX system on it for 10 yrs. I then wanted to design a newer and less expensive unit that would work on most
Cobras , mostly the FFR. So off to the pick a part yard I went.
I found a unit that had really good measurements and seemed
like it would fit anything as it was really tiny. It came off of a car that weighs about the same as most Cobras. The unit was 7" total including the booster ! the booster diameter was 6". This unit came off of a 91 Geo Metro. Well, I done a small amount of fabrication and fit it to the Cobra. I used a proportioning valve from a 79 corvette. It works very well. I don't think it is as good as the GNX system because of the feel is more precise with the GNX. The only problem with the GNX is that it is not small but very large and some Cobras do not have the clearance between the foot box and the wheel well. It is 11" in lengh. Also I have 88 vette disc brakes front and back.
Right now my Cobra is down for a total rebuild. I will put the GNX system back on at that time cause it works best for me.
I hope this helps.
You can do a search with Buick GN or powermaster as it's called
and you will find loads of additional info.

Hersh

RallySnake · #4 (**permalink**) 04-17-2003, 10:41 AM

Bravo,

An easier solution may be a remote brake booster made by Master Power. It's not small, it's full size vacuum canister and master cylinder. However, you can put it anywhere. I mounted mine in front of the engine. It works pretty well in conjunction with a standard 1 inch master cylinder under the car. It makes driving more comfortable.

The drawback to any power system is the lack of consistancy. Sometimes you get more help and sometimes less. The less part happens too often when you need it most (after accelerating hard with WOT). The GNX system should be better in this respect, being electric powered.

The drawback of the remote power booster is that it is a single circuit unit. If you have a leak, you lose pressure to all brakes! If I were going to rebuild my whole system again for racing, I would use two master cylinders and a balance bar with no assist. For street and rally use the vacuum assist works pretty well. However, I added an electric vacuum pump to ensure help when needed.

Paul