How is the rear end sway amplified by the Nitrons?
I've seen nothing but the Nitrons taking out the slop from the stock non-adjustable Bilsteins that are a death trap and destruction to a Roadster waiting to happen. Toyota Camrys with the stock toyota shock configurations handle better than that. The non-adjustable Bilsteins didn't give the car a roll or slop either, their issue was that they didn't dampen the rebound fast enough, it was too quick allowing the spring to expand to fast. Too quick and too fast of a rebound takes the weight off the rear wheels when you need it most, and that in itself is a HUGE problem and a car I don't want to drive at all. Its an accident that easily could have been avoided with proper testing and driving knowledge paired with the right shock. You'll tail spin in an instant rebounding that fast and you can't chance that in a rear weighted favored car.
You know you could have just went to a higher spring rate in the rear if the issue was that you felt it was too loose in the back. I've honestly never felt any slop or sway back there running the Nitrons on my 1.5 at all pushing it to its breaking point and drifting and I have the stock non-adjustable swaybars. I drive Highway 17 each weekday and push the car very hard each time in terms of handling, acceleration, and braking. Again, I've not see an issue. Also the Nitron's also allowed you to lower the ride height, that also would reduce any sway or slop, so that was another option you could have tried.
If you went to the Bilstein adjustable be aware they fail early, seals, in some cases and not good with backing up their warranties. I'd never put a damn Bilstein on any of my cars or trucks. You're just paying for the name. There's many other shocks that surpass them on the market for the money they charge for a shock. You also don't need 7-way adjustment on the street anyways. Its for again fine tuning things once you've got the basic parts and understanding of your car's handling down where the benefits are mostly seen on the track. Some of the best shocks are only 3-way adjustable.
I personally feel that when you start adding more adjustments like 7-way on your shock you start to run in all types of issues unless you know what your doing. Too much variance, variables, and your average driver does not know what the heck all of those adjustments mean nor do they know how to dial them in. I'm a firm believer in keeping things simple until you understand what's going on with all the components, adjustments, how/what they mean, and how each adjustment affects the handling of the car.
If there was any shock that I was going to replace my 1-way Nitrons with it would be with the Motion 3-ways:
For Sale Moton 3 way shocks - LotusTalk - The Lotus Cars Community