Aluminium Suspension Bushings

[nosmanta]

To Bob!

Can you tell me the pros and cons of aluminium suspension bushes? I am planning to fabricate a set for my Manta B. Your opinion is appreciated! Cheers!!

Mario (Hongkong)

[RallyBob]

Pros: No deflection of the bushing material.

Cons: No deflection of the bushing material!

Seriously, this is best left for motorsports use. In fact, bronze would be a better material than aluminium, as aluminium tends to smear or 'drag' should there be a lack of lubrication at any moment. Because of the complete lack of deflection in the bushing material, encountering a bump or hole in the roadway can possibly bend suspension components.

Why not purchase some polyurethane bushes from the UK? There are a number of companies there producing them for the Manta B chassis. Alternatively, you could have them made from a more 'high tech' plastic material. I use 'Delrin AF' because it works well for street or racing use, is lightweight, and does not bind even without lubrication. It is however much stiffer in deflection than even hard polyurethane.

Here is the link to a previous thread showing bushings (or bushes) made from Delrin AF material for my Ascona A
http://www.opelgt.com/forums/showthr...ghlight=Delrin

[nosmanta]

Thanks Bob! I was thinking of putting them on the trailing arms only. For drag race use. Then the rest will be urethane bushings. Cheers!

[Travis]

Your rear will bind with aluminum bushings! If you do anything other than drag with it I'd expect you to bend something.

-Travis

[RallyBob]

Very true Travis. Even with drag racing, the torsional motion of launching the car will twist the trailing arms. With solid bushings, something will break.

Bob

[opelbits]

I know of racers that have used the poly bushings for most areas, but used the original or soft poly for the front leafspring/trailing arm mount. The reason was that as the axle shifts under cornering, there is a little twisting/torquing of the front mount and with very firm or non-deflecting bushings, the load is transferred to the chassis mounts and it cracks them. I have not seen this personally, but when I worked on Alfa's, we repaired many GTV6 front swaybar chassis mounts that were ripped out after the owner installed 'hard' bushings.
Unless you have a 'Watts Linkage" the rear end is moving in a very slight arc as it goes up and down. I don't know how much lateral movement there is with a Panhard bar.
Any thoughts on this Bob? Is it a real concern?

[RallyBob]

There is lateral movement, but more importantly there is the twisting that occurs every time one wheel moves up and the other goes down (as in encountering a bump or with body roll). Without a compliant bushing, this will bind severely.

Bob