Well i am really getting annoyed now. I cant figure out why this car rides so bad and bumpy. It does it around 60-64 mph... and before 60 its pretty smooth and after words its smoother but a lil rough.

Ok so i figured my balance that just got done to try to fix it might be off so i just took it back in and they said it was off a little so they rebalanced but it cured absolutely nothing. The feeling i get at 60-64 is like what you would think on a lopsided ball... its not a vibration but that slight. lump lump lump but also with a shakey side motion.

I dont know what else to check or do. Does anyone have any suggestions? not much is spinning.. i was thinkin driveline check but i figured that would do it at the same rpms and not mph.. correct me if im wrong.. Any help would be greatly appreciated, im bout to scrap this thing haha.. ok not that far but damn i cant take it on road trips or anything cause the ride is so terrible. Car is in my sig.

 

Maybe you need to play with your shock settings a bit? Also, try it on other roads rather than just the same one, I have a few spots of highway here where if you drive at a certain speed, your car gets into a rythym and keeps bouncing and bouncing, does the same thing with my neighbors C6. The bounciness can occur from small bumps if they are at the right interval. Kinda like bouncing a basketball, if you put force on it at the right times it will bounce higher, but if you push at the wrong time in it's cycle you take away kinetic energy.

As far as other parts go, it wouldn't hurt to do the common suspension checks on the ball joints, tie rod ends, sway bar ends, and wheel hubs. Also, check your RPMs and match those same RPM's in like 4th or 5th gear, and see if it's the exhaust giving you vibration.

 

i have been on all different roads.. i went on 1 road trip from where i live to spokane, wa.. 6 hour drive roughly and it did it the whole way no matter what part of the highway i was on. Also everything on my suspension has been replaced, all ball joins, bushings, shocks, springs, etc. everything is brand new...

can a bent control arm possibly cause this kind of effect? thanks for the response

 

Maybe you have a flat spot on one of your tires from if you locked them up for a decent distance? Either that or you have/had a bad alignment and one of your tires wore unevenly. If you have a friend with a camaro or firebird and their car has no issues, try swapping one of your tires at a time to find the culprit wheel at least, if it is one of them.

 

The driveshaft could vibrate, and it would be at specific MPH, not engine RPM. Or your tranny mount could be broken.

 

excellent.. i will give the driveshaft a try and see if that helps it.. had alignment and everything done and it still did it.. never had any long brakes of locking up or anything and tires look worn even...

 

Sometimes balancing your wheels/tires wont cover up a defect, that speed range/the way you describe it, to me sounds like a wheel or tire issue. Id figure theyd catch something like a bent wheel or cupped tires if you were complaining about a vibration, but who knows.

That or one your tire/wheels could have excessive out of round. You might take it a place that can roadforce match your tires/wheels.

 

have you also checked your rotors? if 1 is warped slightly it will shake the entire car, it did on mine. also have you ever had slicks on it? i bent a set of strange s/t axles. i took the tires off and you could watch the hub wobble (sp?).

 

Well, I know that this has been said before, but if you have a polyurathane transmission-mount, it can & (most) will cause vibrations at certain speeds!
I threw mine away just as soon as the LS1 mount got here. (the original mount would break when I pushed it too hard...)

Try revving the engine to the same rpm as you cruise 60-65 at- while you're in neutral, & if the same vibration is still there, even if you are sitting still, then I'd suspect the tranny-mount 'cause that's what mine did.

BTW I saw that Energy Suspension now has a disclaimer about transmitting vibrations in our vehicles, on their box!