Thread: Beam Suffering

Actually most of the movement is in the beam itself. It's designed to twist for better ride quality. That's why we add an additional bar on there to stiffen it. I'm not saying the bushings shouldn't be replaced with stiffer ones. But I don't think they take the place of an additional anti sway bar.

As far as the left to right movement goes, it does move quite a bit. It's really the main issue this thread is trying to address. The question is how to control left to right movement with solid mounts and not have it bind. It's the whole point of going with a panhard or watts setup (both solid mounts) vs. the SRL setup (big squishy rubber mounts).

How much of a bitch was that to press in? Same as the front control arms?

Just to get the creative juices flowing, here's a picture of the Chevy Cruze watt setup:






In case you're lost, the watts setup is oriented behind the axle on the Cruze. So in the picture, pretend we're looking from the front of the car to the rear.

Perhaps we need to raid the Chevy parts bin? hehe

The only problem is the watts link is a far superior axle locating device than a panhard bar but the roll center of a watts link is still way above the axle so you are not reducing the roll couple that much from stock. The panhard bar on the other hand you can adjust the roll center to be just below the axle giving a very tight roll couple (more stability in a turn) and for our chassis reducing the roll couple is much more important than the axle moving a negligible amount more when we turn one direction versus the other.

Do everything and anything possible to stiffen the rear suspension. Bushings, upper and lower bars to connect more parts together at different spots. Remove SRL and replace with something better. Have the toe-in bent back out that Nissan gave to cripple it for the 98% demographic mass of people it was targeted for.

I gave up, BUT good luck to all who try to improve that goofy thing!!!!! I am truly glad this thread came up. In recent years, I ran out of resources that I took for granted that would have made dealing with it easier. Live and learn.

You could always just upgrade to a P10

I stand by that te Stillen rear bar is the way to go. In addition the movement in the bushings is engineered in to the entire package. I preferred my car with OEM bushings to the solid super pro bushings back there. This on a 2300 lb B14 with me in it, r compounds, Koni 8610's, and a dedicated track car.

I also think you are going to spend all of this time on the rear beam only to find there is more to be had out of a better damper and spring combo.

I guess I really don't understand how a watts setup raises or lowers the roll center/roll couple then. To me it's just 2 panhards tied together.

The roll center is based upon the moment of all the suspension geometry that is in the same plane as the axle. So the panhard bar is basically a right triangle with the moment near the lowest point of the hypotenuse where as the watts is a more complex shape with a moment near the highest point of frame attachment this making the roll center much higher than the panhard bar.