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Discussion Starter · #1 ·
I have finally managed to complete the brake upgrade I have been working on forever! Fronts are Baer sport drilled and slotted rotors for a Prelude using Volvo 240 calipes, rears are Baer drilled/slotted rotors for Prelude with CRX calipers.

To mount them I made a new backing plate to replace the one for the drum brakes. After a few versions, it fits like a glove!

Just need to make up my rear brake hoses and good to go. Still debating to keep the e brake or not, this isn't going to see any street use, but it may still be nice to have.
 

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Über Genius
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I have finally managed to complete the brake upgrade I have been working on forever! Fronts are Baer sport drilled and slotted rotors for a Prelude using Volvo 240 calipes, rears are Baer drilled/slotted rotors for Prelude with CRX calipers.

To mount them I made a new backing plate to replace the one for the drum brakes. After a few versions, it fits like a glove!

Just need to make up my rear brake hoses and good to go. Still debating to keep the e brake or not, this isn't going to see any street use, but it may still be nice to have.
Cool. Looks great.

Don't forget to add a metering valve to the rear when you add in the brake lines.
 

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Discussion Starter · #3 ·
I have finally managed to complete the brake upgrade I have been working on forever! Fronts are Baer sport drilled and slotted rotors for a Prelude using Volvo 240 calipes, rears are Baer drilled/slotted rotors for Prelude with CRX calipers.

To mount them I made a new backing plate to replace the one for the drum brakes. After a few versions, it fits like a glove!

Just need to make up my rear brake hoses and good to go. Still debating to keep the e brake or not, this isn't going to see any street use, but it may still be nice to have.
Cool. Looks great.

Don't forget to add a metering valve to the rear when you add in the brake lines.
Thanks! I plan on a proportioning valve, but since the front got upgraded big time, I'm not positive I'll need it. Four piston up front, single rear, larger booster and master... it should through people through the windshield.

I also gutted all wiring replaced the harness with a new lightened one, deleted the battery in the nose, and mounted a 780 amp Lithiim Ion battery under the dash.

Starts like a champ now!
 

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Looks great!

Well done!
 

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Just Some Dude in Jersey
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I've never heard of anyone who didn't need the proportioning valve with rear disc brakes. Those GT rear ends are really light and you can lock'em up with the 3/4" drum brake cylinders. You've done a nice extreme mod, why go cheap as you near the finish? Or maybe it's the PIA of installing the valve? Yeah, it does kind of suck to have to graft one of those valves into your brake lines. Me and PJ both added the valves and we keep them set at 50% or so reduced fluid pressure.

:veryhappy
 

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Discussion Starter · #7 ·
Well done!
Thanks, finally got my new hoses made up and in today, bled, and tested. Work like a champ!!!!!!!!!!!! Need to create a little more room by the passenger side panhard mount, but that is minor and will eventually get cut out anyway when I swap rear ends and build a new suspension setup. But for now, the brakes stop the rear axles for the first time in over 20 years! LOL

Just need to weld my hose mount brackets onto the rear end and pull the e-brake hardware out of the car and the brake system is officially done.

Moving on to cutting seat rails out to weld in floor reinforcements to mount a Kirkey Pro Street seat too and then I can sit in it!

Flares and air dam are on the barge, wheels should be cut and shipped by the end of the month so I can start cutting out all the metal needed in the front to let 275's have full turning capability... then.. testing time!

I think I am at about a year and a half to get to this point from a rotten basket case with missing parts and nothing underneath solid and usable as delivered. Ugh.
 

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Discussion Starter · #8 ·
I've never heard of anyone who didn't need the proportioning valve with rear disc brakes. Those GT rear ends are really light and you can lock'em up with the 3/4" drum brake cylinders. You've done a nice extreme mod, why go cheap as you near the finish? Or maybe it's the PIA of installing the valve? Yeah, it does kind of suck to have to graft one of those valves into your brake lines. Me and PJ both added the valves and we keep them set at 50% or so reduced fluid pressure.

:veryhappy
Putting one in is easy, just want to feel it before I commit to it, getting the rear end to slide around will actually help on our courses. Plus it will be shod with Hoosier 275 A7 slicks for autocross.. aka.. duct tape.. stick side out. LOL

If/when I put one in, I will route the lines up into the compartment so I have the adjuster within reach for fast changes on the fly as needed. Maybe where the e-brake handle used to be.
 

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Discussion Starter · #9 ·
very cool indeed! how easy would the backing plate be to reproduce? do you have a shopping list for your brake setup?
Backing plate is easy to reproduce, I drew it with a 3D Cad program and had it CNC machined.

I did leave the actual caliper mount holes out of the file though so I could locate and drill them on the car after lining up the caliper how I wanted it. I can probably measure them and get them into the file.

As for parts, I used all the parts for the Honda/Volvo swap that was mentioned earlier for front and rear. Then had stainless hoses made locally to fit how I wanted them to.

Fronts are Honda Prelude replacement rotors (Baer Sport drilled/slotted) with the hub milled out, and then I drilled the mounting holes to bolt to the Opel hub. Volvo 240 non ABS caliper with 1/16" milled off the mounting tab to center better on the rotor.

Rears are Prelude replacement rotors (Baer Sport drilled/slotted) and CRX calipers. I had some centering rings made to line the rotor up perfectly on the rear axle hub.

I won't be using the e-brake since it will never see the street, but my understanding is that an Accord, possibly CRX or other Honda rear cables will work or can be adapted without too much misery.

I still need to weld my hose mounts onto the rear end and paint them, but that's pretty much it. Brake hit hard and fast, stalls the engine easily in 2nd gear on the stands.

I also have the 22mm master and 9" booster in this car as well. My intent is to hold WOT until the second to last cone, then through the ride along through the windshield.. seat and all! LOL

I also need to cut some off the panhard bar mount to give a bit more room for the passenger side caliper mount for now. As well as make sure it doesn't hit through full suspension travel range. I can re-clock the mounts a bit as needed if it does help.

But so far I am happy with it.
 

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Putting one in is easy, just want to feel it before I commit to it, getting the rear end to slide around will actually help on our courses. Plus it will be shod with Hoosier 275 A7 slicks for autocross.. aka.. duct tape.. stick side out. LOL

If/when I put one in, I will route the lines up into the compartment so I have the adjuster within reach for fast changes on the fly as needed. Maybe where the e-brake handle used to be.
It's all a matter of how to present it ...

http://www.opelgt.com/forums/member-projects/17215-79-kadett-c-j-germeister-5.html#post364402

 

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Nice Job. Pretty much the same thing I did a few years ago except I used Accord calipers all the way around. If you plan on running it and don't have E brake cables yet the 09 Accord cables fit perfectly.
 

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Discussion Starter · #12 ·
Just an update on the brakes.

After five races on the car with various stages of debugging, the brakes have been the ONLY part of the car that has not needed any tweaking, or repair.

As for brake bias, there is NO lock up in the rear even with it as light as it is now with it being gutted. The custom backing plates for the caliper mounts have performed superbly with no signs or fatigue.

The issue I do have is when startled and I am not gentle on the pedal, the front outside will lock up a bit and smoke the slick something fierce, a light release and it sticks and snaps the car back into the proper route.

This is with the 22mm master, 9" booster, Honda Prelude drilled slotted rotors an all four corners, Girling Volvo 240 caliper up front, CRX caliper in rear, and steel braided lines to replace the rubber ones.

Once I have the larger tires on this thing outta punt a person through the dash on braking.

This coming race on the 19th they will be tested with even less weight on them. I should have the car right down near, or under 1700 with no fuel.

All in all, the brakes are bad ass!!!!!!!!!!!!!!
 

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Your Noble Friend ;-)
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Pictures, please?

Dieter
 

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Doug
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Ryan

Would it be possible to include the part numbers for the rotors, calipers and hoses?

Great write up!
 

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Don't think the OP has been posted since March of 2019.

Maybe he still lurks here.

Might look to see if heliman has posted a tutorial on his four wheel disc brake set up. Even if he hasn't maybe you could talk him into it.
 
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