Installed H&R Race springs having major issue.

[rb185afm]

I installed a set of the H&R race springs. The Drop is great. It is less then the sport springs. The front did not drop at all and the rear is now level with the front. I am also running 17x11" rims out back with Good Year 315/35/17's with no issues. Now were I am haveing an issue is pretty serious. I got the car aligned after the springs were installed. The car handles great. But when I reach 120 MPH the car starts to violently start shaking back and forth. Like the rear of the car wants to go right and then left, then right, then left again and it get more and more violent as I try to stay on the gas. It feels like the car will flip itself over if I stay in the gas. Does this sound like they screwed up my alignment?

 

[1 bad bullitt]

I know this sounds stupid and is a rookie mistake but check your tires for left and right fitment , maybe left and right got mixed up going back on and if one side was worn slightly more before you switched them that could cause a vibration or tracking issues, and an alignment would not catch mismatched tires. Just a thought, probly wrong but double check.

 

[rb185afm]

I will check that. I did not do the springs myself so it could have been put on reversed.

 

[f2fast4u]

FWIW, my personal experience with H&R race springs are that yes they don't drop the ride much at first, but after about 6-12 months the coils really drop. I have one car now with them and after a full year almost half the coils are literally resting on each other.