Have You Upgraded Your Brake System?

[CodeMasteR]

have you opgrades you break system ?

[opelbits]

'69 GT with '75 Manta (U.S.) discs and calipers. Braided stainless lines.

[nobody]

My booster and pedal are still stock.

http://opelgt.com/forums/showthread.php?t=4637

[Killer Texas GT]

Isuzu Impulse, 4 wheel vented disc at 10 1/2" dia., also master cylinder and booster.
rk

[soybean]

When I rebuilt mine this summer, I went with a rebuilt master cylinder from Parts America, new brake hoses from OGTS, NOS rear wheel pistons from Ebay, new pads in front, new shoes on rear. Blew all the metal lines out with air, and reinstalled all, and used new brake fluid. It's one thing to get the car moving, but you've got to stop it. Cost a little bit to do, but definitely worth it. Jarrell

[namba209]

On my 3.4 GT, it's all stock, but all new or rebuilt. From the new brake pedal rubber to new shoes in the turned drums, front to back. Now if I can just get to the point where I can put it all in.

[soybean]

Ron, I just want to see it and hear it, if nothing else by mpeg like Dave's. She should scream. Jarrell

[namba209]

Jarrell, You gotta remember, it's just a stock, 95/6 Camaro 3.4 engine, nothing fancy, like Dave has. If things go right and schedules permit, it will be going cross country behind the motorhome next year, maybe at the right time for maximum exposure and availability.

[soybean]

Come by Carolina Ron. With 2800 Acres here on the farm, I'm sure we can find a place for the Motorhome to set up, and roads to run. I'm not but about 40 miles away from Virginia International Raceway too. They repaved the track 2 years ago and feathered out the 90 at the end of the pit straightaway. Almost as good as Road Atlanta. Jarrell

[nobody]

Me personally I'd love about a 1/2 hour on PPIR (Pikes peak international raceway). Let it all hang out and see the top end for myself. What a total rush and a good place to test braking too. Can you imagine a 150 to O stop?....I can. If I can arrange it I'd need somebody with no fear to hold the camera. Little sis has a friend that invited her to go a few laps so I will see.

[namba209]

This is getting way off topic but here goes anyway:

Dave, I'd like to be there myself on that run. I've been know to hold a video cam fairly steady under adverse conditions.

Jarrell, We are thinking about a trip to Tennessee to see Margaret's daughter and family, if I can get the GT done and have a trailer for it, I'm trying to persuade Margaret that it would be nice to go to Carlisle either on the way or back. It will be some kinda trip, the whole herd of Norwegian Elkhounds inside with us and the GT in back on a trailer. I can just see the RV site managers on the military installations I plan on going to across country as we set up for the night.

[soybean]

Yeah Ron, Grant, we (I), kind got it off topic. But on topic I think, Killer Texas Gt, do you have a thread on your upgrade, notes, or pics? I'd like to go the route you or Dave have done for the next Gt. Thanks, Jarrell

[nobody]

a few post back I added a not so bad link to a tech article on this subject. It has pics and some part numbers to go with.

[Killer Texas GT]

I don't have any pictures of the brake upgrade on my GT as the brakes came attached to the supension upgrade I did using the '86 Isuzu Impulse complete suspension from a donor car ($250.00). Previous to the major suspension modification I was running the Isuzu rear disc and '75 Big brakes combination with the stock master cylinder and booster and it stopped on a dime, straight, no nose dives and hardly any lock up. Once the complete Impulse system was installed the 1/2" bore of the GT master cylinder could no longer stop the car as quike as it had previously, it was like back the to stock braking system, not what I was use to. So I changed out to the Impulse booster and master cylinder 7/8" bore (which I do have pictures of and can do a write up of) and the performance was back, so much more so that it was and is scary, still stops straight, slight nose dive, with hardly any lock up but the distance is now half a dime or less, so quick is the stoping ability you have to become re-orientated to stopping, especially with the new Go-Kart like handling of my GT, I sometimes forget I need to stop or slow down for turns.
GTJim is working on a simular braking system using simular parts from the Piazza(New Zealand Impulse) but changing out the front spindles from the Piazza to the GT to accomidate the front disc and caliper and modifing the rear mounting plate for the rear caliper and disc to fit the GT rear end, and using the master cylinder and booster. Jim's is from a turbo version, mine was from a FI version. His rotors are 10" diameter where mine are 10 1/2". diameter.
rk

[soybean]

Thanks Killer Texas Gt, and thank you Dave, I'll start hunting the post down. Jarrell

[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.

[nobody]

Bear I'd like see pics of that and how it fit on the car.

[soybean]

Nobody, there's a picture of one side of the front in the Carolina Opels Photo gallery. http://opelgt.com/photos/showphoto.p...at=3047&page=2 & another http://opelgt.com/photos/showphoto.p...at=3047&page=2
Jarrell

[jeff denton]

Well, I must have the most modified master cylinder location of all, but it is hardly an upgrade. Described it in my last Article, the photo never made it there but it's in the thread about Articles.
Anyway, I have a question, is that Isuzu 7/8" bore master cylinder quite similar in appearance and mounting to the stock GT master cylinder? I wonder if I could get better stopping using it on my car with otherwise stock brakes but no booster. Would it pass as "stock" to somebody who didn't know anything about Opels?
Any thoughts?
Everybody check out the photos Jarrell mentions. Awesome!!
I don't know how to vote in the poll; did I upgrade my brakes or make them worse? But I can step on the pedal from the "back seat"!

[soybean]

Those were taken at our last Carolina Club meeting by Roy Bell, and the setup is Keith Franks,(Bear). I must say the setup was to droole over. Very Sweet set up. Jarrell

[Killer Texas GT]

Anyway, I have a question, is that Isuzu 7/8" bore master cylinder quite similar in appearance and mounting to the stock GT master cylinder? I wonder if I could get better stopping using it on my car with otherwise stock brakes but no booster. Would it pass as "stock" to somebody who didn't know anything about Opels?
Any thoughts?
[/QUOTE]

No the Impulse master cylinder will not bolt to the stock Opel Brake Booster, to use it both the Impulse Master cylinder and brake booster are needed, also you have to modify the connection between the brake booster and rod connection of the Opel, the line ports (two only not three as the Opel) are on the opposite side of the cylinder of that of the Opel and so is the vacuum intake for the booster, the bolt patern of the Impulse brake booster is approximately 1/4" wider all the way around than the Opel booster. If you would like pictures I can take some and post.
rk

[jeff denton]

Thanks, Killer, sounds like it will bolt up to my bracket by just moving the holes a bit as I use no booster...
But would I get better braking with it than I do with the stock cylinder?
My instinct tells me that a bigger bore puts out less hydraulic pressure than a smaller one, the opposite of how it works at the receiving end.
Or am I mistaken? Any hydraulic experts out there?

[rangerrick]

Originally Posted by namba209 On my 3.4 GT, it's all stock, but all new or rebuilt. From the new brake pedal rubber to new shoes in the turned drums, front to back. Now if I can just get to the point where I can put it all in.

Surprised Ron that your'e running stock brakes with that V6, even if they are totally rebuilt. Is this going to be enough? & I take it this means stock 13" wheels as well??? Got a parachute or anchor to deploy just in case? Already got a small fortune and many hours of time in the beast, why skimp on brakes?

Regards'
Rick

[nobody]

Jeff, there is an ATE out there that will mount to stock, again opposite side line location. It will haul a car to a dead stop in very short order. I use it with the Kiwi rear discs and 75 front brake setup. More neutral bias and it is easily adjusted. It's a good way to check your seatbelts, mounts or get whatever you lost under the seat back out. For me it just pulls all the mirrors off location. Use the information at your own discretion.

http://www.opelgt.com/forums/showthr...=brake+upgrade

[namba209]

Well, here's a milestone, kinda, 1500 responses to threads.

Rick, the original intention of this V-6/T-5 swap was to keep everything original, or as close to that as possible, initially. Just to see if it is feasible to change only the engine and tranny and see if everything else holds together. Granted, I've got the ZF posi and new poly bushings front and rear. But, aside from the ZF, it's something anyone with a GT would do anyway, hopefully. My thoughts on the brakes were, if I could lock up all 4 before the swap, why would I put in bigger and better brakes to have the wheels lock up even easier than they do now. Everyone knows, or should know, that there is no control with locked brakes and even less braking power than if the wheels were turning and brakes not quite locked up. Now, if the brakes aren't up to the job, that will be a future mod to the car, and rest assured, I will look hard and fast at the mods that "nobody" has already done to his 2.0 rocket ride. Also how and where you're driving is a prime concern on the brake capabilities. For twisty/turnies, stab and go will work just fine, but for sustained speed on highways/freeways, hard long applications without locking the tires is needed. So we'll see how the brakes perform first, then make mods, if they're needed for my driving conditions.

Jeff, A larger bore MC will put out more fluid in the same stroke as the standard bore MC. Basically it means less pedal movement for the brakes to lock up than before at the same foot pressure on the brake pedal. The reason it works this way, is, it's a closed system. The same amount of fluid will actuate the brake cylinders/calipers as before, you just don't have to push down the brake pedal as far to get that amount of fluid to the cylinders/calipers. HTH.