Mk1 Commodore Caliper, 278mm Magna rotor conversion

**Pete Mk1** · 14-01-2008, 08:46 PM

Have started doing some comparison research on this conversion,
Sourced this information from DBA brake disc catalogue.
I have found that the magna 1985-91 models TM,TN,TP,have discs that should do the job,
and when fitted with calipers ill provide significantly improved stopping power for budget cost.
The discs can be sourced from most wreckers for about $30ea. The centre hole in the disc that goes over hub is 4mm larger but should not present a problem.
The disc needs to be drilled to 4 x 100 to suit, am having some done at present.
Thats all info for now,hope this helps
pete mk1
A = Diameter
B = Original Height
C = Original Thickness
D = Min. Thickness
E = Centrel Hole Diameter
F = No. of Bolt Holes

GOLF MK1, 2
1.5, 1.6 Petrol MK 1 1975 - 82 FRONT 240 3 Solid A=239 B=35.2 C=12 D=10 E=65 F=4
Diesel 1975 - 82 F 242 3 Solid 239 39 10 8 65 4
GTi 1991 - 92 F 444 3 V ented 239 38.5 20 18 65 4
GL 1994 - 97 F 446 3 V ented 256 39 20 18 65 4
All models rear disc 1991 - 97 R 832 3 Solid 226 71.2 10 8 39.8 4
MAGNA
TM, TN, TP 1985 - 91 FRONT 22 1 3 Vented A=266 B=45.5 C=24 D=22.4 E=69 F=4

R 222 3 Solid 251 49 10 8.4 Hub 4

**golfnutracing** · 15-01-2008, 02:40 AM

Great work pete, i do seem to remember the discs being larger diameter tho, for some reason i thought 278, would be worth testing with one from the wreckers.

Unfortunately i cant help a lot anymore, my rally car is off to its new home in QLD. If it does help, i didn't know what size caliper spacer i needed when starting, it was a matter of sit the caliper on the disc, pack it with washers until it fit well, critical thing is to make sure it dose not rub too much and that the disc runs true.

The stopping power is far far greater than mk1 GTi (mk1 gti setup on the rear of my rally car was not good enough for gravel! i used camira front calipers with mk1 gti vented discs on the rear, i would go quite a bit larger for tarmac racing)

**golfnutracing** · 15-01-2008, 02:53 AM

This appears to be the disc, 5 stud, vented, 278mm

TR/TS v6 1993-on DBA #425
also
TF/TH/TJ/VR-X/SPORTS V6/TL (ES/LS/VR/VR-X V6) 6/1997-on

page 89 DBA catalogue
http://www.dba.com.au/2006/PDF_CATAL...e_17122007.pdf

you can buy them brand new with no holes drilled, i would personaly get second hand and have holes drilled.

**Pete Mk1** · 15-01-2008, 06:29 PM

Thanks for reply, the discs you mention are 278mm dia but in light of wanting to run 14" rims i thought the 265mm would be a better option.
Have my discs drilled and ready to fit but just need time to do.
Discs owe me $78ea purchased,drilled and machined. they look to be a much better casting than the golf disc.
so i will continue with the exercise.
Pete Mk1

**Preen59** · 15-01-2008, 09:15 PM

Great info guys. I'll be doing this mod for sure some time in the next few weeks, so i'll post how mine goes aswell if there's anything interesting to say.

**golfnutracing** · 16-01-2008, 02:57 AM

The biggest problem is the commodore caliper does not fit under 14" wheels, but if you go thru the dba catalog and spy out something with similar offset (or more) to the golf disc and similar diameter to the magna disc you will be okay.

I got my commodore calipers + 278mm dics under 14" alloys, you need to grind down most of the bleed nipple, you need to space the wheels out 7mm (or more) and get happy grinding the front face of the caliper (paint the inside of the rim, or use bearing blue and test fit, give a spin and take off where ever there is a mark left). Because it was a rally car i also made adapters to extend the hub and welded them in and turned down the weld, because the hub takes the bulk of the load.

Great to see people picking up where i left off, soon we will see a mainstream budget big brake conversion for the mk1 using local parts!

**Preen59** · 16-01-2008, 06:56 PM

Originally Posted by golfnutracing

Great to see people picking up where i left off, soon we will see a mainstream budget big brake conversion for the mk1 using local parts!

As soon as i've done mine and worked out all the issues, if people are interested, i'll start making some kits up..

**dom123** · 21-01-2008, 02:27 PM

does anyone know if this coversion would suit a mk3???

**Preen59** · 04-02-2008, 05:01 PM

Originally Posted by dom123

does anyone know if this coversion would suit a mk3???

Don't 'quote' me on it.. But i think the Mk2 and Mk3's have a different setup. I'm pretty sure the Mk2 calipers have a cast 'arm' that goes around the disc and mounts differently.