Have You Upgraded Your Brake System?

[jeff denton]

Jeff, there is an ATE out there

Uh, what is an ATE?
Whatever it is it sounds like we need it!
I had thought about mounting up TWO stock master cylinders, one for front brakes and one for rear, like in a real race car. I wonder how bad the tech man would freak? "Hey, they are stock, just doubled!"
Front to rear pressure control would be nice... Rules don't allow any methods of adjusting this though.
It would be nice to be able to get only enough brakes to slow the car but not enough to ever lock up a wheel.
In racetrack test session one I tested the brakes once, they slow the car and didn't lock a wheel but it just felt like there wasn't a lot of brake there, know what I mean? I hate that feeling. I wrecked a big truck once after feeling that, took a Mack mixer head on and lived...
An experienced driver in session two had to use the brakes in the corners and said they were not as responsive as he would like.
Seems like it would be worth a try to install the bigger MC, thanks for all the input. To understand why I'm not concerned with "what bolts up to what" you'd have to look at my Article about my brake pedal relocation. At this point I'm trying to learn brake system theory mostly! Thanks guys.

[nobody]

Almost all GTs came with a ATE brand master cylinder. In the link I posted was a how to use and where to find it.

[rangerrick]

The newer systems have what is called a perportioning valve, that's what my 91 Dodge Dakota has in it's anti lock braking system. It's a known fact your front brakes stop you first as they are closest to the master cylinder, so they would be the ones to grab first.

OGTS states that if you go to the 2.2-2.4 size engine you should think on updating your brakes Of course they are in busines to sell us parts, mine are stock new and seem to work fine; although to me they don't feel like power brakes even with a rebuilt power booster! Had a 1970 Karmin Ghia VW no power brakes, disk in front drums in back. Felt the same as this GT!

Rick

[namba209]

Rick, that's not quite correct, in any hydraulic system, pressure is equal anywhere along that system, which means the fluid/pressure is transferred throughout the system at the same time. The reason the front brakes have more stopping power is because of the weight transfer of the vehicle to the front wheels and less off of the rear wheels, which equates to more traction up front than in the rear. That is also the reason for the proportioning valve, to route a higher flow and pressure to the front wheels and less to the rear wheels. Normally this is done inside the MC and is usually a 60-40 split. For the anti-lock braking system (ABS), there is a magnetic pick-up on each wheel, that sends a signal to the computer or electric solenoid valve of the brake system that a wheel is close to lock-up or doesn't match the wheel speed of the other wheels, and the system bypasses a small protion of the brake pressure from that wheel causing it to free wheel for a milli-second until the speed of that wheel matches the other wheels. When the vehicle speed gets down to about 5 MPH, the ABS system is inoperative, normally. HTH.

[GoinManta]

75' Manta Front brakes, Commodore B 3/4" Rear wheel cylinders.

Havent tested it yet though

Charles

[baz]

Originally Posted by jeff denton Jeff, there is an ATE out there Uh, what is an ATE? Whatever it is it sounds like we need it!

your brakes!!!
jeff they are a part of "continental teves"
http://www.conti-online.com/generato...v_1103_en.html
this link gets you to there web
but you are looking at the brakes for opel, ford europe,bmw, mercs audi ,saab (i think ) just a case of hunting in the junk yards for 1 they normaly have "ats" in raised letters on the cap
bmw would be best bet in the states i would guess
and reading your earlyer post the bigger the cylinder the more fluid moves the more the pistons move so more brake powerjust harder to push

[gtzero]

Originally Posted by bear I think I probably have the biggest upgrade on a GT. I will be running 12 1/4" cross drilled and slotted 3/4" thick ventilated rotors with four piston caliber. That is at each corner. Also have 7/8" master cylinder with an oversized perfomace booster. The rear have a e- brake built into the rotor like a mini drum, The drum is almost as big as the original drums that came on the car. I will be running complete stainless braided lines as well.

Hi Bear,

What system are those? Are they StopTech, Brembo, Wilwood, other?

Thanks

[Manta72]

1972 Opel Manta A

Opel Ascona B front rotors and calipers
Opel Ascona B rear wheel cylinders
Opel Acsone B master cylinder and servo unit
EBC front brake pads
Aeroquip stainless steel braided brake hoses
Rear proportioning valve

Works really great. The best part is, the money I spent. Hardly nothing, the most expensive items were the new pads and SS hoses.....

[DennisGardiner]

73 GT
Front: 1975 Big Brake Manta with cross drilled rotors, and kevlar pads, using
stainless lines.
Rear: Straus disk brake with a mini hand brake build inside the rotor hat, similar to older Corvettes & 80's Mercedes.

73 Manta
Front: 1977 BMW vented style caliper with Omega ventilated rotors with
kevlar pads, using stainless lines.
Rear: Heavily modified ventilated Isuzu rear disk to fit stock Manta Axle,
also with the intergal hand brake inside the rotor hat.
Dennis73 GT, 73 Manta

PS. You need serious Wooooooo in CA traffic

[David McCollam]

1975 Calipers with Risse Motorsport expansion kit, Rekord C 2.2i-246mm vented discs, stainless steel braided brake lines with 3/4" rear brake cylinders. All items bolt-on, no significant modifications necessary.

[Mike Preble]

I am running the large 262mm vented rotors and 4 piston calipers from a Volvo on the front of my GT. Also I have a 22mm ATE MC. I don't know what the MC is off of as a guy at a brake place just walked out of the back room and gave it to me. He said it was just laying around in the storage area when he bought the brake shop from some other person. The lines come out of the wrong side but all I did was install longer lines. Also SS lines all around which was interesting as the Volvo calipers take two lines per caliper. You must tee off the main line at the wheel well and use two SS lines per side. Complicated bleeding process as there are three bleeding ports per calipers but was accomplished after consulting with a Volvo mechanic. Could use the 3/4 Manta rear slave cylinders but they are on the Manta already and maybe I will upgrade all the cars to the same systems.

Mike

[nobody]

I've been meaning to write this for a while. use 2 of these.
http://www.partsamerica.com/ProductD...pe=232&ptset=A
and 2 of these'
http://www.partsamerica.com/ProductD...pe=232&ptset=A
and swap the pistons after drilling them out to fit the opel parts then drill out the two mounting holes just a bit and you now have 11/16 bore rear cyliders that cost you 20 bucks a side, and about an hour in labor.

Or you can try to order them for more than double the cost. 45 each or 40 for the pair and now the parts are local and cheap and plentiful. I spent more than a couple minutes on the research and design and they work well so have at it.

[maglinjosvinn]

i'd love to see some pictures of the izuzu impulse switched brakes... if anyone has them?

[GoinManta]

See below..

1985 Isuzu Impulse Turbo Vented Rear Disc Brakes

Took Backing Plates to a Machine shop and had the area for the Opel Bearing Retaining plate routed out and the Isuzu holes filled and Opel pattern redrilled into them.

Parts:
Used Caliper MOunting Bracket (?? The part you dont get of the caliper when you buy remanned)
Used Backing Plate
Used Ebrake Hardware
Used Ebrake Cable
$80 (pick a part)

New Set of Calipers (Remanned off eBay) - $90
New Set of rubber lines - $40
New Pads - $35 (off eBay)

Total cost: $245

Now I spent about another $100 or so on paint, and brake lines, etc.. to prep the "new" 3.67 axle for the Manta too.

I also upgraded the front to 1975 Brakes.

Master is a NOS stock one.. although I have thought of trying to find a replacement for the AC/Delco. So far no luck. but I have connections at NAPA and one day I may go hunting in the warehouse.

Charles

[GoinManta]

Originally Posted by DennisGardiner PS. You need serious Wooooooo in CA traffic

ESPECIALLY the way he drives

been there done that.. and got the skid marks in my drawers to prove it

Charles

[jordan]

Dave, what are those wheel cylinders listed to? I still have the 3/4" lemans from that trial that never panned out, is this a different idea?

[GoinManta]

More pictures of the rear isuzu brakes and axle... What you all think?

[soybean]

Looks very good Charles. I'm impressed. Good documentation too.
Jarrell

[69GTLEE]

Rear disk brake from Toyota MR2
I copied a wilwood bracket
It took an afternoon and cost $45

[asdasc]

69GTLEE, could possibly start a new thread on your disk brake conversion from the MR2, or write a short tech article with any drawings and pictures of parts, installation, and brackets you made? This sounds very interesting.

Thanks,

[GoinManta]

Originally Posted by soybean Looks very good Charles. I'm impressed. Good documentation too. Jarrell

Thanks.. I noticed I forgot to take pictures of the Drum setup installed.

Since I have to take one side apart anyway to install a missing piece (thats on order from Isuzu.. believe or not they had it available..)

Speaking of which.. does anyone want me to ask the Isuzu dealership how much the "Dealer components" (Backing plates, ebrake assembly, and ebarake cable) would cost and if available, then this woudl be a purchaseable upgrade not a Part-a-Part one.

Charles

[GoinManta]

Originally Posted by GoinManta Speaking of which.. does anyone want me to ask the Isuzu dealership how much the "Dealer components" (Backing plates, ebrake assembly, and ebarake cable) would cost and if available, then this woudl be a purchaseable upgrade not a Part-a-Part one. Charles

Well I did anyway... and OUCH.. $800 for Just the dealer parts (This includes the backing plate, hardware, shoes, and ebrake cable). That doesnt include the flex lines, calipers or rotors.

The vented rear disc like mine came on the 85' Impulse Turbo, if anyone wanted to surf to http://www.car-parts.com and get the setup off a junkyard. Usually less than $200 for everything used.

Charles

[GoinManta]

Since I started to hijack this thread, I guess I will finish on it..

here are some pictures of the ebrake assembly, AND a technical diagram. For any future Isuzu brake swaps.

I also threw some finished and mounted to the car pictures.

Wanted to mention a few things..

The Ebrake Cable is the exact length of the Manta cable so it fit perfectly.

The brake lines fittings are a match as well so the flex line connects perfectly to it no modifications needed there either.

Truly the only things I had to do were get the backing plate machined, the holes redrilled and put hardened 12mm washers over the lugs to space out the rotor from the backing plate. Otherwise it rubbs the backing plate, the Opel axle seems to sit a little furthur in than the Isuzu one did.

Your results may vary on a GT. I think from other threads the GT is a better match to the Non-turbo imuplse (non-vented rotor). Otherwise it looks to be about the same setup.

Charles

[GoinManta]

One more thing.. I just figured out (well more like rememebered after a failure).

There is a check valve in the rear line of the Manta master (at least the AC/Delco). You remove the rear barke line from the master and then remove the brass fitting. Behind the fitting is a spring and cup valve. Remove them. Replace the brass fitting and reconnect the line.

If you don't too much pressure builds in teh rear line and you will blow the seal in one of the calipers or both.

Charles

[show no go]

Just got my front brake conversion done. Used 1988 Volvo 240DL four piston calipers and 1988 Honda Accord rotors. The only mod needed is a slight machining of the center of the rotors to make them fit. Cost new/rebuilt for standard parts was about $100 and easy work.

One thing on fittment though is that it will NOT fit with stock wheels! Also the stock master cylinder will most likely need to be upgraded too. I didn't try with the stock unit but I am using one from a Mazda rx7 with proportioning valve.

I paid:
$ 30 for each caliper
$199 for EBC drilled and slotted rotors
$ 20 Machining for both rotors

Substitute rotor choices:
$ 19.95 each for standard rotors at Champion Auto
$ 149.00 each for BAER drilled rotors
$ 154.00 each for Brembo drilled and slotted rotors