Rear disc brake caliper bracket

[sin-city-customs]

My friend owns a small machine shop and is making a set of rear disc brake caliper brackets for my 91 out of 6061 aluminum plate. He can make them for about $110 per set. I was sondering what you guys thought. I looked a North Racecars and they are $150. He says he can make them for either off-set, 4 lug or 5 lug rotors.

Thanks,
Dave

 

[Got N2O]

Is that strong enough? Aren't the north ones steel? That would be cool if they were lighter and cheaper, but I don't know what kind of load they have to endure. I wonder if any OEM applications use aluminum brackets... I'm intriqued... lol

 

[sin-city-customs]

6061 has a higher tensile strength than the stamped steel Northcars is using. These are machined from one piece of solid aluminum, not bent into shape. Plenty of newer cars use aluminum brackets not to mention calipers.

 

[Mustang5L5]

Plenty of newer cars use aluminum brackets not to mention calipers.

Name one. (That uses aluminum caliper brackets)

Aluminum calipers is one thing. But aluminum brackets will never hold up under fatigue of long term repeated stress....especially the twisting forces exerted on them when the caliper grabs. It's durability that matters and the aluminum doesn't hold a candle to steel.

 

[Mustang5L5]

6061 has a higher tensile strength than the stamped steel Northcars is using. These are machined from one piece of solid aluminum, not bent into shape. Plenty of newer cars use aluminum brackets not to mention calipers.

But the aluminum will be under shear so you need to look at the shear modulous as well. The shear modulous of the strongest grade of 6061 is 3770 ksi.

Low carbon steel is one of the weakest steels out there. Even using that, the shear modulous is 11,600 ksi.

Again, that's of the weakest compositions of steel and it's still 3 times stronger than a bracket made out of 6061 aluminum.

I'd rather spend the extra $40 for the NC brackets and have peice of mind. Last thing you want is your caliper braking off and losing your brakes completely.

 

[sin-city-customs]

Thats strange, because the Corvette Z06 uses aluminum brackets and I don't think they shear off too often.

 

[Mustang5L5]

Hey if it's worth risking your car for $40 then go ahead and do it. I still wouldn't recommend making such a critical braking component out of soft aluminum.

You asked what we though. I'm a mechanical engineer and i think it's a bad idea. Just my opinion on the subject so don't get mad at me for recommending against it.

If you do decide to go for it, remember to factor in using an Anti-moan bracket similar to what the SN95's use. Otherwise you will get some groaning in the rear brake system when under braking. I would imagine it would be amplified through the softer aluminum more than it would through steel. There is just more flex present.

Good luck