Opel GT Forum banner

Conversion of rear drum brks to disc.?

3806 Views 6 Replies 5 Participants Last post by  GoinManta
Has anyone (here) converted their rear drum breaks to rear disc?
How complicated and how rewarding would this conversion be? Are there shops out there that will do this conversion. Or can I tackle this myself (rem..newbie)?

P.s. Anyone have a solid unrusted (metal belly pan)?
I don't want fiberglass....OGTS, has.
1 - 7 of 7 Posts
It's not a worthwhile conversion unless you are driving VERY fast and have enough power to get there....
The standard rear drums are very large for a car this size, but the front brakes could use some help. Standard rear drums with larger wheel cylinders and metallic pads will stop the car repeatedly from 130 mph with no problems. The stock front brakes, however, cannot.

belly pan

Write to : [email protected]

Last I heard he thougt he might be making metal belly pans by September of this year. He is already making the rear tail panel and deck lid.

No info on pricing or shipping.

Good luck on finding a metal belly pan.

front disc. brakes

What would help the front disc. brakes, better pads, discs,? One of the brake packages from OGTS.?
The factors involved are the friction coefficient of the pads, the heat capability of the pads, the diameter of the rotors (which affects the brake torque), the piston diameters of the calipers (which affects the clamping force), and the thickness of the rotors (which affects the capability to absorb heat). At the minimum, I'd go for the 1975 rotors (they are 9 5/8" diameter as opposed to 9 3/8" for all earlier years, and they are .500" thick instead of .440" thick as the earlier ones are), go for a metallic or carbon-based pad, and try to get better air flow to the rotors and calipers to reduce temps (see the thread in the archives on this...with photos). If your budget allows it, then ventilated rotors are a nice upgrade, and while they themselves won't reduce braking distances, they will retard brake fade from repetitive braking from higher speeds.


its a mostly for looks mod

and a dam nice mod if you do it

contact GoinManta for details


Isuzu Discs

http://www.opelmanta.com in the library.

The directions are there. I have converted my Manta and I loved the rear discs.. The brakes become very responsive.. and don't require adjustment like the drums.

Its is overkill? Probably.. but they look cool and improve braking emmensly.

But if you just want better brakes, 75' Opel Manta/1900 brakes help a lot for the front of a GT.

1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.