IIs it wise to go to aluminum drums if the GN is a everyday driver? I was told by mechanic it wasan't a good idea.
Don't see why not. Afterall, some TRs came from the factory with them.
GM droped the alum drum some time ago. When they did I called and asked why. The engineers said the iron drun was just as good in tests. I do use 100% metalic shoes. GM used them on the 81 Malibu police car and they are used on the S-10 Blazer and pick-up.
Phil
I know I can't find them. Any ideas?
check the junkyard:
Aluminum 9 1/2" brake drum. Hollander interchange number 1132.
83-84 Blazer VIN S/T
80-85 LeSabre (RWD)
82-92 Camaro
78-81 Century
86-89 Chevy Passenger (?)
78-82 Cutlass
82-92 Firebird
78-85 Grand Prix
83-84 Jimmy VIN S/T
78-81 LeMans
78-81 Malibu
78-81 Monte Carlo
80-85 Delta 88 (RWD)
80-81 Pontiac (?)
83-85 Bonneville
86 Parisienne
78-87 Regal
81-85 Riviera
82-84 S10/S15
78-81 Sprint (Truck)
As far as being a bad idea for a turbo car... I run them and have grenaded one (the iron lining cracks and separates from the aluminum) and If you are one of those people that likes 15+ psi foot brake launchs, stay far away, because I never leave at more than 10 psi and I still broke one. They are slightly thicker and help 275 wide tires to fit better, but since they only come used, you don't know for sure what you are getting when you find some (my grenaded one measured good)
http://perfauto.tripod.com
but do they actually help in 60 foot times because of the less rotational mass or do they make any difference on that ? Mag wheels help alot though I bet, is a huge difference in their weight over a steel wheel.
I think personally think wheel weight is overrated. Every little bit helps, but don't expect even a .1 difference in the 1/4 switching to lighter wheels AND aluminum brake drums. I've switched back and forth between them and couldn't.
The difference between the VERY heavy GN wheels & some aluminum ones like the Pro Stars IS a lot of difference! Not only in TOTAL weight(4-wheels) but unlike taking weight off say in a fiberglass hood or seats, or f'glass bumpers, you are also getting weight off a rotational device. No, you may not see a dramatic difference in your ET but it's all these "little" things that DO add up. An aluminum driveshaft is another example also. HTH. Take care, Jay.
Ooops, thought we were talking about aluminum wheels. Sorry guys. But then again evry little bit helps(drums). :-)
I have an 87 GN that has the aluminum drum brakes but no posi. I have read that aluminum brake cars did not come with posi(do not remember where I read too much) Am I remembering that right or have I got things mixed up? I want to add posi. Thanks
You are correct Mike. If the car had posi, it received the iron drums, and vice versa. Of course someone will always say their car had posi and aluminum drums, but those are the rare exceptions to the rule. You should always run a posi in a car that you intend to race/go fast with.
What was the purpose of puttting iron brakes on a car with posi? Is there any down side to adding posi to a car with aluminum brakes?
Alum drums came out on G bodies in 1979 on the V-8 models. They flip floped around on different models thru 1987. When they got discontiued by GM I call GM tech assist to ask why. They told me GM enginering found no difference between iron and alum in stopping. The alum drum looks much nicer with some open wheel applcations. Posi had nothing to do with it.
Phil
Actually, there were not alum. drums offered on posi cars. Additionally, they were available in 1978.
Matthew
I got them on an `85 T Type it was option J-42 I belive. Also the car has posi. Could be a later addition as I bought the car used.