How to install Power brake booster on completed FFR??? - FFCars.com : Factory Five Racing Discussion Forum

Platinum · 10-03-2002, 02:05 AM

Since I have decided to keep my FFR, I have lined up some future projects.

First is to get some real brakes. After running the car at Run and Gun a few weeks ago, the brake system was the only system on the car that I wasn't absolutely thrilled with. Other than the brakes, I was absolutely impressed with the car's performance. Now it is time to bring the brakes up to snuff.

Current brake setup is;
73mm lincoln front calipers with stock pads
11" front rotors
SN-95 rear end with stock calipers and pads
Stock rubber brake hoses
Willwood proportioning valve on rear line
'84 Jeep MC
brake pedal mod

My plans are to aquire and install SN-95 spindles and brakes. Then replace the '84 Jeep MC with a power booster of some sort with the proper MC.

My question is, what would be the best power booster to use, and how do you install it on a completed FFR? I have read many posts about this during my research. No one has mentioned installing a power brake system on a completed FFR. Please let me know if anyone has done this and what was involved.

David Borden · 10-03-2002, 02:41 AM

Dan,

The stock booster works great. Its a bit tough to do on a built car, but I did it without too much trouble.

There is a bit of cutting and welding, but its pretty easy.

You will need a stock pedal and will need to install the pedal in the stock location.

Also the stock hole in the fire wall will need to be widend to accept the booster.

You may want to try Carbotech Panther pads first though. They will make a drastic difference in the braking performance of your car. The CF is about twice that of a stock pad.

Other than that, the booster brakes are really great. You will also need a 94 mustang GT master cyl to get the right pedal feel.

David

stang8s · 10-03-2002, 04:55 AM

any reason they didnt design it so the stock booster would fit?? Seems odd that they wouldnt have done this if its just a minor change and everyone already has one.

Frank n Sons · 10-03-2002, 11:14 AM

Stang8S - yeah, I've wondered that myself. Seems to me if they had just welded that offending 3/4 tubing down 2 inches it would not make any difference for manual brakes, and if you opted for power, it is ready to go. Got to be a PIA to try to cut out and weld that tube after the car is finished.

Platinum - a couple of things to consider. Both the 93 and the 95 boosters will do the same thing but the 93 is smaller in circumfrence and you won't have to move the 3/4 tube down as far (although, it is going to be the same PIA no matter where you put it). The 93 is slightly longer and if you use a late model MC you will have to make a small hole in the fender well ears (aluminium) to accomodate the front end of the MC. The 95 booster is almost twice as expensive (if you get them new) as the 93 (why? I don't know - third base). It is slightly bigger in circumfrence but is shorter than the 93 so you can probably get away with not holing the aluminium fender aluminium. BTW - power brakes are so nice - you push the pedal - the car stops!

Frank n Sons.

n559br · 10-03-2002, 12:29 PM

The Buick Grand National Cylinder doesn't require any mods to the frame but the lines come out on the other side of the MC. They would be a major PIA to get at with the body on. That said however, I am pretty pleased with the results of my installation. Just with any power booster it seems the center hole needs to be ground slightly to use it without any spacers. I used 2 spacers and no grinding was necessary.

Ben

stang8s · 10-03-2002, 01:04 PM

Ben-
So you used the mc and booster from a grand national? is that the same as on any regal? how much did they cost?
thanks
Jeff

n559br · 10-03-2002, 01:30 PM

The GN master actually doesn't have a vacuum booster. It's called a powermaster and actually has an electric motor that pressurizes a small vessel on the side. It works pretty slick. A rebuilt unit from Autozone cost $200 w/core charges.

Pretty nice and no welding required.

Ben

cobramd · 10-03-2002, 04:28 PM

Go with the Powermaster setup. I will only take about 3 hres to install on a completed car. It uses the exact same brake line fittings as the Jeep MC. There is no cutting or welding You do not have to grind any holes just shorten your mustang push rod and drill 2, 1/4" holes in the 3/4" tube to relocate the motor. Get the casper electronics harness and it's a breeze to install. Total cost with harness for a reman without core should be in the 300-400 range.

stang8s · 10-03-2002, 05:12 PM

You should be able to get this setup for free or next to free. The GN guys hate them and are converting away from them.

http://www.hotrodssuperstore.com/85buicgranna.html

http://www.gnttype.org/techarea/brak...um_brakes.html

cobramd · 10-03-2002, 05:19 PM

I don't know why I really like the brake feel and amount of assist. Initially it was way too sensitive but with bigger calipers (lincoln 73mm) in front it is close to perfect.

n559br · 10-03-2002, 05:25 PM

I think for those of us using IRS and who don't want to weld the GN is a great alternative. I personally didn't want to cut that tube and sister another tube in its' place. Just doesn't look right to me. I haven't gotten to drive mine yet but so far so good. My only problem was shortening the pushrod but the use of a friends' lathe helped a lot.

imported_admin · 10-03-2002, 08:04 PM

In case you didn't know this, the FFR FAQ has a lot of good brake info, including the GN MC set-up with pictures: http://www.ffcars.com/FAQ/brakes_gn.html

The link to the FFR FAQ is at the top of every page on this site.

Platinum · 10-03-2002, 08:24 PM

Thanks for all the input guys. Keep it comming!

ADMIN,
I have searched the database and found no real help in making this upgrade on a finished car. It looks like the GN is the way to go on a finished car, but will look closely at all options. The suggestions recieved so far are exactly what I need to know based on my situation. FFcobra.com is awesome!

Thanks guys,

fourcammer281 · 10-04-2002, 03:22 AM

Does the electric power unit get in the way of the 3/4" frame tubing? Is this why it is relocated?

Why is it relocated so far away? It seems like a bracket could be made so it would be right on the tubing that it conflicts with? [EDIT]: Nevermind, I took a better look at n559br's setup and that is exactly what I was talking about.

Were GN's originally rear disk or rear drum?

[ October 03, 2002, 11:28 PM: Message edited by: fourcammer281 ]

n559br · 10-04-2002, 10:44 AM

FourCammer,

I believe that they were 4 wheel discs.

Ben

fourcammer281 · 10-04-2002, 11:48 AM

so that means it should be easier to swap to rear disks.

Do the people who have done this still need a proportioning valve?

And do you run the lines to the Ford distributing block?

William Miller · 10-04-2002, 12:43 PM

I retro-fitted a Powermaster to my FFR that had been on the road for a year. It replaced the stock mustang MC. Grand Nationals came from the factory with front-discs & rear-drums (I used to have one).

It took me longer than 3 hours (~8 hrs). You have to remove the side pipe, and work through the louver-hole in the fender. It's not very fun. The biggest problem installing in a completed car is that you have to totally redo your brake lines to the MC. The mustang MC ports are on the engine side, but the buick MC ports are on the opposite side. The Spina wiring harness was very nice and I would suggest it to anyone going with the Buick unit.

The powermaster motor will hit the 3/4" tube if left attached to the MC. I had also ran ALL my bundled wiring along the 3/4" tube where other people were mounting the electric motor for the powermaster. Because of this, I couldn't mount the motor there on my car, and made 2 brackets to relocate the motor.

I would definitely put an afternarket prop. valve in to the rear, even if you still have drums....you never know when you are going to upgrade to discs.

In a nutshell, these are the big items in a retro-fit:
1. Make current brake lines connect to new MC (with different size & number of ports on opposite side of MC)
2. Modify Mustang pushrod to work with new MC. (I used a side grinder and my vise)
3. Enlarge the MC mounting holes in the footbox mounting plate. (I drilled them out a size larger)
4. Somehow mount the Powermaster motor.
5. Eliminate the sensitivity of the new system with larger calipers, old pedal pivot, etc. (subjective and optional)

Here's a link to an earlier thread with pictures from my install

Shawn Whalen · 10-04-2002, 03:16 PM

On my build the 4 into 4 headers run smack into the powermaster motor. I had to fab. some brackets to move the motor away from the pipes.

Platinum · 10-05-2002, 01:15 AM

William Miller,
that was exactly the info I was looking for,
Thanks a million to you and the rest whao shared your info. I am sure I will have more questions as I dive into this.