custom rear disc brake brackets

[dusterbd13]

im about to make a set of mounting brackets for my rear disc setup. ill be using the rear brakes off an 89 300ZX turbo nissan. they have integral parking brakes, 11.1 inch vented rotors, and a general design very similar to C4 corvettes. ill need to mae adapters to bolt it to my rear axle.

i was thinking of using 3/16 steel, as thats the thickness of the factory drum backing plate, and i wont have to screw around with machining axles or anything.

my only fear is of this being too thin, and folding up under hard use.

other though was to use 4 out of 5 of the axle retention studs and 1/4 plate. cut the backing plate up to use as a spacer, and just bolt these puppies on the outside. (mopar 8.75 housing)

what do you think? 3.16 be enough? 1/4? bigger?

thanks
Michael

[MrQuick]

I'd go 1/4" or sandwich 2 1/8" plates. Easier to work with.

[BOBBYA312]

MrQuick is right at least 1/4-if you look at kore3 and flynby's brackets.They look to be at least that thick.

[Apogee]

It all depends on the design, but 3/16" is too thin IMO, even for a rear brake application. A flat plate is very different than a formed/gusseted bracket with a greater cross-sectional area to provide greater rigidity. It's important to keep in mind that "failure" for a caliper mounting bracket is measured in terms of deflection under load and not catastophic failure, so it doesn't take much movement of the caliper to cause issues both at the caliper to rotor interface as well as at the pedal.

A good example of a poor bracket design is the stamped 1/4" steel bracket that GM used on the first-gen F-body applications running the 4-piston C3 type calipers. We commonly see those calipers twisting sufficiently far such that the caliper body hits the rotors inside and out at opposite ends due to deflection. Granted, it generally takes track level CoF pads to create enough torque to do this, but any amount of deflection can contribute to poor pad wear and other issues.

Tobin
KORE3

[Motorcitydak]

I made some for the rear of my truck using 3/8, its not the place to skimp on material. Im not sure if you can see em very well in the pic tho

[Motorcitydak]

double post....sorry

[Bigblue73]

Material is cheap so design in the maximum material thickness. If you need some water jet cut - send me a PM.