Installed Polyurethane bushings, rear end feels "loose"
 

Ok. So I intalled the polyurethane kit on my car. The car will turn right where you put the wheels and corners really flat, even on the stock sways.

But when I make a turn from a stop or I put a little gas when I exit out of a turn, the rear end feels loose and floaty. It seems if I really it the gas the rear will come around really fast. Also I still have my winter tires on but they squeal a lot more when I corner hard than they have before.

So what did I do wrong? Or is that normal handling attributes of the polyurethane bushings? :dunno:

did you remove the dtss yet?

what springs and shocks do you have?

Misread, ignore this post. Sorry.

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Assuming that you've properly reassembled everything, what you're experiencing is completely to be expected.
When you replace suspension/drivetrain bushings- which are engineered to absorb/dissipate input energy- with less compliant units, the energy doesn't disappear, it just finds another path to take.
In your case, energy loads previously shared by all of the bushings (I'm going to assume you were replacing worn, stock components) are now being channeled further down the chain (ultimately, into the chassis itself which ain't getting any stiffer with age *insert "she said" joke here*).
So you get to play catchup and just keep going down the line.

A graphic example of this progression can be seen in the Honda GP bikes of the '90's.
Chassis stiffness was the holy grail, pursued to the point (and exacerbated by improvements in tire technology) that the bikes became too stiff and wound up like springs, leading to a few years of spectacular highsides.
The cure was to intentionally loosen up the chassis.

Another instance would be that of new radial tires on old, wired wheeled Brit sportscars. Many handle much worse (and suffer accelerated-if not catastrophic- failure of the wheel) because the newer, stiffer tire passes along input previously absorbed by the older, more compliant rubber.
Something's gotta give and the wheel itself is next in line.

Sorry if this is more philosophical than practical.
I guess the point would be- you have to watch out when upgrading an old car, once you start, it doesn't end quickly. Fixing one area just bring flaws elsewhere to the fore.

Thanks clokker for that post.

I still have the stock shox and springs on the car. I have Tokico HP shox and a back ordered set of eibach springs that will eventually make its way to my door step.

Also no, I do not have the dtss on the car. Has the bushings amplified the system? I don't mind the system, but if it is making me feel unsecure in turns I'll replace them with the dtss.

What about the squealing of the tires? Is this normal? It does it a lot more than it did before. (correct me if I wrong) I though squealy tires meant a sign of poor susp. dynamics.

I shouldn't think the DTSS would play any part in "a turn from a stop", which presumably is a low speed, low G input to the chassis.
Something else is going on.

my back end felt a lot looser and sloppier when I replaced my shocks and springs with eibach/tokico HP. replacing DTSS helped a little bit, but I think I am going to try and install a stiffer sway bar or rear strut tower bar. My Turbo II has a roll bar and rear strut bar and the back end is completely solid... until I boost it in a turn hahaha

I want to say this could have different suspension reactions depending on how hard your accel and at what speed you are at when you make a hard turn from the stop and how hard you accel while in the turn from the stop.

I only have half a poly kit in my car, feels weird, car acts stiff in one direction and not as stiff in another :) I will finish it some time.

Perhas it is your rear subframe bushings?

did you change the mount of the front of the diff as well?

No, all I installed was the poly kit. Thats it.

with new bushings on the two rear ones you may have torn the front mount of the diff

Did you get a 4-wheel alignment after reassembling the rear suspension? If not, than that may be your problem.

Hot_Dog
90 RX7 GXL