Better Rear Brakes?

[Robert Simpson]

I am helping out a buddy who bracket races his street 1970 Nova. It has stock manual brakes with stock disks on the front and drums on rear. He wants more braking power on the starting line. Is there a better rear brake shoe? Or even a better rear springs for the brakes? Any suggestions would be appreciated. He can not afford to put disks all the way around so that is not a option.

Thanks

[Alan Roehrich]

It might be possible to fit the bigger brakes of an A or B body on it. A trip to a salvage yard might yield the parts.

Springs will not help, the springs are return springs, they pull the shoes back.

A premium non metallic shoe, on a fresh turned (or new) drum, with the shoes properly arched to fit the drum will help. Usually the arch of the shoe is not even close to the radius of the drum, so only 1/3 or less of the shoe really bites the drum.

[SSGN]

Something we tried is buy 2 sets of shoes and use the long shoes only. I am not sure about that particular car but some models that had power brakes used smaller wheel cylinders and going to a non power brake car application for the wheel cylinders made the cylinder bore larger resulting in more pressure applied to the shoe. Hope this helps
Kevin

[Alan Roehrich]

Yeah, two long shoes is a good thing to try. Some times upping the wheel cylinder diameter does help, another good thing to try. You might also try the aluminum master cylinder from a manual brake S10.

[Greg Barsamian]

This is the "bolt in" lightweight master cylinder from NAPA pt# M2456

[Myron Piatek]

Glaze build-up on the shoes reduces holding ability. It's probably more than I need to do, but after every weekend of racing when I swap my rear slicks, I lightly sand the brake shoes to eliminate any glaze and check the adjustment.

It seems like the cheaper the brake shoe, the better it holds. Softer is better, but I don't know how to tell.

A long time ago, I read that they use a slightly different material between the front 1/2 and back 1/2. One was softer. Don't know if they still do that. I'll have to do a visual comparison next chance I get.

[jmantle]

Originally Posted by Robert Simpson

I am helping out a buddy who bracket races his street 1970 Nova. It has stock manual brakes with stock disks on the front and drums on rear. He wants more braking power on the starting line. Is there a better rear brake shoe? Or even a better rear springs for the brakes? Any suggestions would be appreciated. He can not afford to put disks all the way around so that is not a option.

Thanks

Bigger wheel cylinders will help, I've used front wheel cylinders on the rear, look for the biggest you can find that will fit. Not recommended if you're going to drive the car on the street, it does upset the front to rear balance.

Jim Mantle U/V/SA 6632

[Robert Simpson]

Thanks everyone for the help. Jim, yes the car is driven allot on the street. It is not really that fast mid to high 13's. But he can only bring it up to 2k on the converter to cut a light. It has the original small engine in it (307). I was thinking about the using the larger brake shoes from two sets. But, I was not sure. Alan, is there a larger spring set to help the brakes release faster? Suggestions. Thanks to all and the IM's. How do you get the shoes to "set" better in the drum? You can see where they do not touch all the way around.

Robert

[Myron Piatek]

I seem to recall a looooong time ago that someone had a machine that could surface the drum shoe arc to fit the diameter of the drum. But I haven't seen or heard of anyone doing that in recent memory. Perhaps an old timer or old school shop may still have that capability. The practice could have been discontinued due to the dust it created, even after they quit using asbestos. (At least I think they use to.)

On a side note.....the converter is a factor in how high one can go before the brakes can't hold it. One can usually bring the rpm's higher with a looser converter.

[Alan Roehrich]

Robert, new springs might help them release faster, but that's just more pressure opposite the pedal pressure, so it won't help hold it.

Myron is correct, there is (or was) an arch grinder made to correct the arch on shoes, so they fit the drum correctly. Even when I worked in a shop in the very early eighties that had one, they were extremely rare, only a higher end shop that was pricey had one and had anyone that used them. It requires a person to measure the drum correctly, then set up the machine, and correctly set up the shoes. Adds a good bit to a brake job, so no one but the expensive shops used them. Back around 1982 or so, one shop in maybe 30 had one. It does make a real difference. Good luck finding a shop that does it now. Odds are, the owner is in his sixties, or older, and the shop is the highest shop in town, with a lot of long term customers.