Stiffer Torsion Bars vs. Bigger Sway Bars

[911nut]

With winter fast approaching , I'm contemplating my next project: suspension bushing replacement.

I'll mention here that my SC is only used as a road car at this point. I plan on doing some track days next spring.

While I'm in there re-newing my bushings, I'm thinking about ways to improve cornering capability. Let's talk about rear trailing arm bushings first.

Weltmeister polycarbonate or Neatrix? Will the plastic bushings be too harsh? Will I be replacing the Neatrix bushings again in 5 years?

Do I use a monoball for the bananna arm bushing? Wil it transmit too much road noise?

Now on to torsion bars and sway bars. I was planning on upgrading to 22mm front/28mm rear hollow torsion bars. Some posts on the board recommend '86 Carrera sway bars only for road use but Bruce Anderson says that bigger sway bars make for a choppy road ride when compared to stiffer torsion bars. This seems counter-intuiative to me.

I'd like to hear from all you guys who have upgraded your suspensions. I need your guideance and advice. Thanks in advance.
Paul Brewer

[pbs911]

I put 22/28 torsion bars on my SC and love them. Very noticeable difference. Not too rough for street driving. You better double check on the spring rating of the hollow bars, however. I hear that the rating is not the same as with the solid, ie. 28 hollow bars are the same as 26 solid, or something like that. I also went with Neatrix bushings for the swing plates and the poly for everything else. The main complaint I have heard about the poly is the noise. A zirk fitting/channel in the bushing helps. You just can't put a zirk/channel on the inner swing plate bushing.

I also went with 22/20 sway bars from a 89 Carrera. There was not a lot of noticeable difference in ride degrigation, but better performance than the 20/18 that the car came with. Again, with the OEM sway bars they are not as effective as the straight aftermarket type, i.e. 22 OEM is equal to something like a 19mm straight bar.

Overall I really like the handling of my car. It provides some good handling on the track and is not so track preped that it makes daily driving uncomfortable.

One thing you have not mentioned in the shocks to complete the suspension package. Probably one of the best bangs for the buck depending on the condition of the shocks on the car.

[widebody911]

My 2 cents sez to use the poly bushings and not the Neatrix. Here's a pic of the neatrix after about 1 year of use. Some pretty good deformation goin' on.



One caveat about bigger sways before torsions is that you are putting a good amount of strain on your stock sway bar mounts, and could end up with this:



I have 22/29 torsion bars (WM) in my cab, and like it.

[ChrisBennet]

I've run 22/29 t. bars on my '86 with stock sway bar for years now. Best improvement I ever made. They make the car very predicatable on the track and the ride is fine on our sometimes bumpy New England roads.
The hollow bars are sold by their "effective diameter" so if you buy a "29mm" hollow bar is will be bigger in diameter than 29mm but be equivalent in stiffness to a solid 29mm bar.
Whatever you do, don't use poly bushings for the inner trailing arm. It's a crime these are still sold IMO. That joint requires more than the 1 degree of freedom allowed by poly bushings.
-Chris

[89911]

Originally posted by ChrisBennet
Whatever you do, don't use poly bushings for the inner trailing arm. It's a crime these are still sold IMO. That joint requires more than the 1 degree of freedom allowed by poly bushings.
-Chris

Chris is right, the only viable option for the inner banana are bushings are monoballs. I am not sure about the durability of these over time, especially for street use. We replaced these on an 87 that had the engine dropped. Maybe it is the G50, but I see no way possible to change these out without the engine out of the way. Even so, we had to cut the nuts off the trailing bolts.

[911nut]

Thanks to everyone who offerred advice.
89911 and Cris, I agree with not using poly bushings in the trailing arm. I was setting camber last weekend and saw how the trailing arm mount swiveled during set-up.
Guess it's time to start saving for those torsion bars!
Paul Brewer.

[Tyson Schmidt]

Thom, the picture you posted above of the Neatrix bushings is perfectly normal. They are made slightly oversize so that they get a good compression fit into the torque tube and the cover plate. Only about 3/4ths of the bushings are stuffed inside of the torque tube and the cover plate. That's why they look so necked down after a short period of time. They are rubber and will take the shape of whatever they are compressed into.

And Paul, the monoballs are the only way to go other than stock, as stated above. But they are very harsh, and should be used for track/autocross only.