teflon vs polyurethane bushings

[badbrad900rr]

I have my car in the shop doing a custom 4 link set up, my question is we are looking into using a teflon bushing or a polyurethane bushing. Will the teflon bushing be too hard? Let me know your input on this matter.

[David Pozzi]

I doubt the Teflon bushings would be too hard. I'm generally against Polyurethane bushings where they bear load, like lower A arms, the material is sticky when heavily loaded and any grease tends to work out of the joint. I don't think it's so bad in a trailing arm application where the car's weight is not carried by the bushing, just engine torque loads.

I've used poly rear spring shackles with no ill effects for example, they do carry some load but less than the front spring eyes. Also they don't move much.
David

[badbrad900rr]

Generally speaking, I am building this to be a street car, but I want the best possible performance I can get. Some people tell me the teflon bushings are a bit noisy at times as opposed to the poly? whats your take on that?

[Skip Fix]

When the grease comes out of the poly and they bind and pop or squeak they won't be quiet.

[Marcus SC&C]

Who`s offering teflon bushings? Or do you mean teflon lined bearings as in heim joints? They`re a poor choice for anythign that will see much street use. They have tiny races that have to maintain very tight tolerances yet they`re exposed to all the swirling dirt and water etc. under the car. They loosen up fairly quickly and start transfering NVH into the chassis. You can get "seals" for them but they don`t last very long and once they crack they just hold the foreign matter in.
Poly bushings are a less than ideal choice for most suspension applications. They cold flow (the holes egg shape and get sloppy) with time and bind when you don`t want them to causing squeaking and erratic handling. Poly bushings that are heavily impregnated with graphite aren`t as bad. Ones with a token amount are just as bad as ususal. Poly graphite bushings can be used with success if they`re combined with your best choice...wait for it...polymer race greasable spherical bearings. This type includes Currie Johnny Joints, Rubicon Express and Chassisworks delrin race joints etc. They`re about the same price as teflon lined heims or prefab poly bushed ends and usually have about 27*-32* of free articulation. They help to isolate NVH, they`re enclosed and greased to seal out dirt and water,they`re quiet and smooth and they last a very long time. If you`re building from scratch they`re a no brainer.

PS, David good points but in regard to trailing arms don`t forget the arms also need compliance in torsion to allow the rear axle to articulate. This is especially true in converging 4 link applications. With rigid tubular arms the bushings are responsible for that so choosing them wisely is hypercritical. A typical poly bushings non linear binding is most unwelcome in such applications and can cause snap oversteer and erratic handling. Mark SC&C

[joker motorsports]

marcus, brads talking about nylon leafspring bushings to use as trailing arm bushings,we didnt know if they would be suitable for a street car they are used for circle track cars,we are making rear suspension for his nova from scratch.i have done several drag 4 link set ups but this will be my first pro-touring car,i try to do everything as correct as possible and as neat and clean as you can make it and function correctly. so thanks for any imput on this matter.JOKER MOTORSPORTS.

[terryr]

They won't flex enough in a four link application. They're fine for pivoting, like a-arms or leaf springs that twist on their own.

[Lowend]

Don't like urethane bushings in general. To go with their binding issues; they also cold-flow over time turning into an oblong shape