subframe bushing: poly or aluminium?

[formulafr]

hi all,
i don't know if it's the right place for my question.

1- i'm about to replace my old rubber bushing by solid ones. i also have poly ones. should i put the poly or should i go with solid, my firebird is a street car but i like taking hard corner. I'm planing to use sub frame connector next.



2- solid aluminium bushing seems to be higher than stock, must i machine them? to what final size?

[Bandit]

I would recommend solid bushings for your car--Global West has about the best there are, stock height or lowered available, with subframe connectors to match. I have their bushings in my TA and I don't feel like it sacrificed any ride quality, but definitely stiffened things up.

[vanzuuk1]

I agree.

[6'9"Witha69]

Solid if you are using weld-in subframe connectors only! Otherwise poly for now.

[formulafr]

i plan to use bolted on connectors. the solid bushing i have are from Competition engineering.

6'9"Witha69, do you really think it's a bad idea for my combo?

[Bandit]

Solid if you are using weld-in subframe connectors only! Otherwise poly for now.

What's the problem with running solid bushings with bolt-in subframe cnnctrs? I currently have bolted-in Competition Engineering cnnctrs and GW subframe bushings, should I be worried? Are they going to fall off or something? I could always weld my bolt-ins and get the same effect, right?

[hotroddr]

I believe what he was getting at was if you have welded in subframe connectors you can ONLY run solid bushings, no poly. It would be a good idea with bolt in subframe connectors as well because if you have subframe connectors you are probably trying to get away from flex in the chassis and solid bushings will accomplish this. I noticed no loss in comfort when ditching my stock bushings, only more steering response and less weird noises when cornering.

[68Formula]

I'm not sure why you'd need to stick with poly without welded subframe connectors either.

I didn't install subframe connectors yet on my convertible (yes it is in the plans), and noticed only better steering response, less lean, and no degradation in ride quality.

I say go solid regardless.

formulfr: are you comparing the solid height to the stock ones on the car? The stockers are probably a little more compressible now after years of use. I was pretty sure my CE solids kept it at about stock height without machining, but I have a 1st gen.

[David Pozzi]

I'm not sure why you'd need to stick with poly without welded subframe connectors either.

I didn't install subframe connectors yet on my convertible (yes it is in the plans), and noticed only better steering response, less lean, and no degradation in ride quality.

I say go solid regardless.

Well put, I agree. I don't see any reason to allow the subframe to move relative to the unibody. There is next to no difference in ride quality between polly and solid mounts. If you are concerned about ride quality, use rubber A arm bushings and softer springs and shocks.

GM "tuned" the subframe mounts to work with the tires of the day, skinny bias ply tires. Polly mounts are not tuned for any application.
David

[68Formula]

If you are concerned about ride quality, use rubber A arm bushings and softer springs and shocks.

GM "tuned" the subframe mounts to work with the tires of the day, skinny bias ply tires. Polly mounts are not tuned for any application.
David

Or even delrin A-arm bushings with "soft" (read factory) springs and shocks? I think if properly maintained it the low friction should allow the shocks to do their job better (less stiction) improving the ride quality whicle the lack of deflection improves the handling.

I did the body bushing change first. Then later I rebuilt the suspension with a larger stabilizer bar, better shocks (valved just a little stiffer than stock), stock replacement springs, lowered the control arm mounting points, delrin bushings, and added low profile tires. Handles very well and rides nice too. I would say the larger bar, and lower profile tires would tend to make it the ride worse, so somthing else must be compensating.

[formulafr]

are you comparing the solid height to the stock ones on the car? The stockers are probably a little more compressible now after years of use. I was pretty sure my CE solids kept it at about stock height without machining, but I have a 1st gen.

yes, that's what i compare.

[Bandit]

yes, that's what i compare.

Don't worry about that--your old ones are squashed. Just go with stock height GW solids and you will be happy, it's a cheap and easy upgrade that counts for a lot.

[ProBell]

I am a fan of solid. Used the short alum. bushing and they worked well. R