H-Honza

My problem is that the car is unstable i higher speed ( around 60-80 MPH). Rear section is moving side to side. Almost feels like rear suspension is loose in both control arms - bushings .Car is after alignment, no problem all in spec. Tires new - running 245/35ZR18. Any help would be appreciated.
PLeas help
Thanks

H-Honza

Rear suspension walk side to side in higher speeds. Unstable , rocking side to side till speed goes under 55 MPH

Its 2001 S2K with 78 000km on tacho

RED MX5

Could be any number of things. Rear toe, tire pressure, tire construction, broken suspension ... What type of tires were installed? What is the tire pressure? Can you post your alignment specs?

H-Honza

tires are 225/40ZR18 pirelli Pzero direzionale front, 245/35R18 Pirelli Pzero Asymetrico rear.
Rear tires are new, front 70%.
I try to change tire pressure from 2,2bar to 3,0bar and there wasn

RACER

If the bushings are wasted, the only way to fix it would be to replace the bushings and then have it re-aligned.

H-Honza

today I was 2 times on another places to try whats wrong.
I make control of geometry adjustment, suspension stiffnes test, and shock abrsorber test.
All tests with the same finish.
There is no steering or suspension defect, all bolts, bushings and ball joints are in good condition.
The shock absorbers are in 92-95% condition.
Both of wheels alignment shows the same data value, so there is no place for human mistakes.
I do one test by the ofcial Honda dealer, and the other one by the suspension specialist.

H-Honza

test of the shock absorbers. This is the second, where the result was a litle bit worse then the first test, but its all about 1% difference

H-Honza

geometry settings - wheels alignment

H-Honza

reccomendet settings as shown on Alldata

INDYMAC

I apologize for not being able to understand your language. But from what I can tell, the alignment shop did a good job on the front if you drive on the right hand side of the road. But I believe that that cross caster might be a bit much. I believe the max allowable difference between left and right should be 0.25 degrees or 15' (minutes).
The rear alignment looks like it is within specs, but can be aligned exactly to spec (camber -1.5 degrees or -1 degree 30 minutes). I believe the camber should be exactly the same. I also believe that the entire alignment should be done exactly to spec while you are sitting in the car. If the shop doesn't believe you, do a check without you in the car and then a comparative check with you in the car. It makes a big difference.
I hope this helps. But if it doesn't, maybe you should consider installing a front lower cross brace and a better rear sway bar. Good luck.