rear caliper mounting position

[brddog7683]

Hi guys, I have a question concerning my rear disc brake kit for a 76 Pontiac Firebird that I bought from SSBC. If it matters the kit# is WS125-42 which is a 4 piston competition setup which does not have a parking brake setup. Anyways I am just now into the installation and I came across this in the instructions. Says when mounting the caliper brackets on the rear axle it does not matter which side you pick for the caliper mounting tab as far as towards front or rear of car.
That's my question....does it matter which side you mount the calipers on? Is it better to mount them towards rear of car? Keep in mind this is for a Rear disc brake setup. According to SSBC it doesn't matter. I was going to call them and ask on this but I figured I'd ask you guys first. Thanks!

[MrQuick]

we had a discussion about this a few years back and going by all the super cars out there in front of the axle was the most popular way.

Theory is stopping momentum of rotating force would increase downward force with calipers on the front.

[John Wright]

Never really sat down and thought about it.....seems that it would not matter the force is in the same direction regardless of where the caliper is mounted on the circumference. Maybe it is in the packaging....that determines fore or aft of the axle....ebrake cables pulling from a certain direction vs another.

[ammoyer]

I thought the reason for putting them in front of the axle is to have them closer to the center of gravity. Lower moment of inertia, etc. Now I realize that it's cutting hairs, but every little bit helps right?

[Yelcamino]

According to Baer, the only thing that matters is ensuring the bleed fitting is pointing up. Front/rear of axle is irrelevant.

[GenPac]

Never really sat down and thought about it.....seems that it would not matter the force is in the same direction regardless of where the caliper is mounted on the circumference. Maybe it is in the packaging....that determines fore or aft of the axle....ebrake cables pulling from a certain direction vs another.

I placed mine behind the axle for ^this reason. Less in the way for the cable and fixture.

[6'9"Witha69]

I thought the reason for putting them in front of the axle is to have them closer to the center of gravity. Lower moment of inertia, etc. Now I realize that it's cutting hairs, but every little bit helps right?

This is some of the more popular thinking. Yes, it can be splitting hairs, but the old saying is "worry about the ounces and the punds will come".

[brddog7683]

After looking at all different setups online I'm seeing a mixture of both, but mounting forward seems to be the most popular. I guess too its a thing of what could interfere with suspension components.
Being that my Firebird has staggered shocks on the rear, I think first I'll try mounting forward and see how that goes. Thanks again for all your input.

[MrQuick]

You might run into clearence issues unless you are mini tubbed.

I had to stagger the LS set up on my non mini tubbed 69 Nova. Similar suspension.

Vince

[John Wright]

If the car came with the staggered shock set up to help with wheel hop and whatnot.....you may want to stagger the calipers also. I looked at keeping the calipers on the same side of the axle because i liked the way it was symetrical....but I ran into shock orientation problems and the awkward angle of the one odd shock position...so I ened up putting it back like the factory had it. I know you can totally redo the whole deal and get the shock angles to work out, I just didn't want to mess with all of that. I ened up with two C5 calipers for the same side and staggered them on my car opposite the shocks and it also positions the bleeder to the top for proper bleeding.

[silver69camaro]

Basically it boils down to, in order:
1. Bleeder position
2. Packaging
3. Lower polar MOI

That's about it.