Metric oversized calipers.

[clean8485]

Thanks to everyone for all of their info/input-as stated earlier, this is a very informative thread. I'm curious, if you switch to the Wilwood calipers, is there a specific type of vehicle that would have the appropriate master cylinder bore size to be a good upgrade for these calipers?

 

[malibudave]

if you switch to the Wilwood calipers, is there a specific type of vehicle that would have the appropriate master cylinder bore size to be a good upgrade for these calipers?

The larger Wilwood 2.75” bore calipers will require a master cylinder that has a 1 1/8” (1.125” bore) if used with power brakes. One problem is the 1978 to 1988 G-body cars largest strait bore master cylinder was a 24mm (0.944”). Second problem is the angle of the firewall puts the reservoir at an angle. The g-body plastic reservoir compensates for this, but older GM cars with larger bore master cylinders did not. I have seen the older master cylinders mounted on a g-body, so I assume they work fine unless there are vacuum booster issues.

The largest G-body type master cylinder, which will work on an angled firewall, is from a 1979 Buick Riviera with four wheel disc brakes. It is 1.0” in diameter, has aluminium housing, and an oversized reservoir for four wheel disc brakes. With power assisted brakes and the larger 2.75” bore Wilwood calipers; the brakes may be touchy and not have much “feel”.

The next alternative is a cast iron master cylinder from a 1973 to 1977 A-body. A power boosted master cylinder is 1 1/8”. This should bolt up to your stock vacuum booster, but you need to check to see if there are any differences in the mounting depth (master cylinder flange to piston height. Are these the same between the A-body and G-body? There should be no differences, but you need to check so there are not vacuum booster pushrod clearance issues. Hopefully that made sense.

 

[L92 OLDS]

For the stock g-body braking system, most braking performance will be found in good, bedded front brake pads. Next on the list would be high quality, big bore calipers followed then by stainless steel braided flex lines.

This thread began with the above statement and may be a bit misleading. The information provided is interesting and useful but next on my list and other G body enthusiasts has been the Blazer braking set up which uses a dual piston caliper and larger rotor. I guess if you want to stick with the factory G body spindle, this information would be helpful. In my opinion, why piss away money on a small rotor and inferior spindle set up?

http://www.gbodycentral.com/forums/show ... php?t=1985