BAD LUK

Under low speed, part throttle acceleration, I am getting a surging (front/back) motion that I can's seem to isolate other than when I take it out of gear and just coast, the motion seems to dissappear.

I have recently replaced the motor mount inserts, trans insert, torque arm bushing (all with poly).
About 5 years ago, I had BMR rubber/poly rear lower control arms installed. They do have over 100k miles on them. Could they be worn out enough to allow for this motion?

I also lowered the car with lower perch Konis up front and heater hose out back. Would this be enough to put the control arms at a "bad" enough angle to accelerate wear?

It's hard to get underneath the car in it's natural height/disposition to see what's happening (let alone while moving).

Could it be the stock torque arm flexing also?

It always feels like there is some binding under initial acceleration and I haven't been able to get much more than a sloppy chirp between first and second for a while now.

Any thoughts?

BAD LUK

After doing some more searching and realizing how the rear suspension works under acceleration, I believe I found the answer.
Looking at the angle of the rear control arms while the car is sitting still and nobody inside, I noticed that the ends that mount to the axle are higher than the ends at the body mount. This would make sense due to the vehicle being lowered (heater hose mod). The angle only gets worse when I hop in to drive.
So, being that the stock torque arm is flimsy, and the control arms really don't help being at that angle, the rear will tend to rotate up with only the the flimsy torque arm to hold it, overpowering it and possibly flexing it enough to cause oscillating back and fourth movements.
Would it make sense that, combined with other areas in the driveline that have worn or loosened over time, this would be what is happening?

Another thing I noticed is that the rear shocks (Koni) that were installed only a couple of years ago have many scrapes on the shock body facing the front of the car. This looks to be caused by the "dust" cover rubbing the shock body (possibly when the rear is rotating up during acceleration or big bumps?)
This could also explain why the rear suspension has not felt very impressive over bumps ever since I installed the shocks and did the heater hose mod.

My next question is, do I need to get adjustable control arms in addition to an adjustable torque arm to properly adjust everything?

The car is driven on the street 99% of the time (Haven't had it to the track yet!!!) with a couple of street races here and there. It handles decent around corners (will be better after fixing the rear suspension), just unhappy about the rest of it.

Greggy

Have you tried stiffening the rear koni's a half turn or so. Try knocking the fronts up a sweep as well.

I have the stock torque arm, stock lower control arm w/ new bushings, same control arm angles as you. The torque arm and LCA angle will not cause the problem you are having. Worn out bushings, shocks, split tranny mount, or broken part will.

Don't worry about rubbing plastic dust boots...no harm no foul.