Hi all,

I have a 2011 C6 that has some aftermarket suspension parts (bought it that way). And I have been fighting the rear end swaying since the day I purchased it. The car is procharged, has a built rear end, 6 speed, etc. When I first bought it every time I slightly pressed the gas peddle the rear end would snake/sway left and right, felt very unsafe and not normal. Got an alignment done and it drove like an absolute dream as long as the road was perfectly even afterwards, can take my hand off the steering wheel, fresh alignment things ya know?

BUT, I still fought the same really weird uneasy pulling left and right when I would drive on uneven highways, changing lanes, etc. Feels like the rear tires are fighting or playing tug of war. Fast forward, I ended up getting new tires (345 rears, previous were 355) this past weekend thinking my bald rears were the culprit and finally this can would feel stable finally, false. Even with a new quick alignment adjustment, same problem. Rear end just walks all over the place still at higher speeds, I am talking just cruising from 60-75 on the highway. The alignment guy said nothing looked out of the ordinary, all bolts are tight nothing was loose, alignment is dead nuts on.

I am just at a loss of figuring this out, its really frustrating and the car just isn't as enjoyable as it could be because it just does not feel planted at highway speeds. What would your next move be in the diagnosis of this? I've had a few friends tell me I'm just not used to rear wide tires, but when I tell you it doesn't feel safe I mean it, and passengers have mentioned the same thing.


For clarity one more time this is under normal driving conditions, no hard acceleration

Please help me enjoy my car lol.

 

What aftermarket suspension parts, and what wheels/tires? Are your front tires stock sizes?

 

Hey there,

It has Pfadt Johnny O'Connell shocks and sway bars, FDF race rear toe arm upgrade.

Front tires are Toyo R888R 295/35/R18
Rears are 345/30/ZR19

Not sure on width of wheels themselves to be completely honest, they are aftermarket cup style.

 

are you running the R888R on the rear too?

 

I’ve heard that the R888’s can feel a bit squirrely, might be worth swapping wheels/tires out with someone local for a quick drive to see if the issue goes away, in any case it would rule out a wheel/tire issue. The Pfadt stuff shouldn’t be a problem as long as it’s all in good shape

 

No it's a different tire on the rear, but the tires that I bought the car with and that I also replaced with are two different brands that didn't seem to be a factor in the issue I'm posting about. Replacing them with brand new tires has the same exact feeling as when I had the previous bald ones so I ruled tires out completely as the issue for now.

 

On mine, the butt wiggle was toe in on the RR, but
when I was researching it, I came across a video where theirs was getting squirrely at the drag strip and in order to find it, the suspension had to be down on the ground, regular weight, stick something in the rim to pry it back and forth and they found it, it was a part with just a little play in it, but, it didn't show up by just grabbing the wheel and trying to shake it. and it didn't really happen if the wheel was off the ground.
Hope you find it because I know exactly how it feels.

 

Can you post a pic of the final alignment measurements? All green isn't necessarily good.
Corvettes are super picky about rear camber and toe settings. If they aren't right, the rear end likes to dance around a LOT.

 

yes, what is the rear camber and toe. A 15" wide tire is going to find every imperfection in the road, but you want the tire to roll as true as possible to minimize it