Help! Poor handling; poss suspension issue?

[The Crazy Brit]

I have 2006 convertible with the selectable ride control shock option & the original F1 Goodyear tires.
If I have any steering input (with either ride option selected “Tour or Sport”), and I hit one of PA’s ruts in the road, the car side-steps across the road & looses the direction selected, especially if the rut is not perpendicular to the direction of travel selected.

At the Carlisle Vette show last weekend they (some vendors) said this is a well known problem with pre 09 cars, where they apparently have “Slowed down” the steering rack.

Any suggestions of how to correct this serious “Hi pucker factor” situation?

The car’s suspension is stock & I believe I can drive OK (as an ex 125cc super Kart champ). Not that you wanna hear this, but my 993 Porsche never reacted over these ruts in this manor. I love the Vette, but would sure like to reduce the “Pucker” issue..HELP!

Thanks…The CB

 

[Hib Halverson]

It's called trough-wander and is typical of states with liberal legislatures and crappy roads. It's worse in cars with wide tires and if the roads are asphalt with deep ruts.

Get used to it. The car won't wreck.
Or maybe you're better to not have big steering input crossing ruts?

On the other hand, maybe the 993 was a better car for you.


I've driven 05s and 08s. I've experienced some trough wander but nothing like what you're talking about.

 

[muddywaters]

Crazy Brit, My 88 and 99 do the same thing, the 99 is worse. We used to call it" Nibbling", but it's a wander no matter what you call it and it does add to the "Pucker Factor.".............

 

[gmjunkie]

The Big Boys down at the frame and alignment school called it Bump Steer!! I can probly get most (If Not All)of it out of there,but your tires will last twice as long and you won't be able to drive over 140 anymore!!
It damn sure won't feel like driving a shallow V bottom boat going across a battleship wake!!!

 

[muddywaters]

That's great Junk, when are you bringing your alignment rack up this way?????

 

[muddywaters]

Let's see if I got it correct, A little more caster (adds weight) a little less camber (tire sits more vertical) I'm all ears..........

 

[gmjunkie]

That's great Junk, when are you bringing your alignment rack up this way?????

In at the Top,out at the Bottom = Negative Camber
Out at the Top,in at the Bottom = Positive Camber
Striate up and down = 0 Camber
Upper Ball Joint back,Lower Ball Joint forward = Positive Caster
Upper Ball Joint forward,Lower Ball Joint back = Negative Caster

More positive caster the nose is Heavier!!
Less positive caster the nose is Lighter!!

 

[yellow_2002_germany]

Make sure to see if the shock stuffers have ben removed. The selective ride cars had them installed for delivery and some dealers did not remove them on the delivery inspection.

 

[NORTY]

Has the vehicle always exhibited this condition or is it just since the front tires became bald?

 

[The Crazy Brit]

Has the vehicle always exhibited this condition or is it just since the front tires became bald?

I have only owned the car since the beginning of the year & the tires were low when i got it. Some of my local buddies have suggested changing the tires out to non run-flat's (like the BF Goodrich’s) to remove some of the hard sidewall input (like less spring rate)....still on the fence as to what direction to do.

Thanks for your input.....Ian

 

[The Crazy Brit]

Make sure to see if the shock stuffers have ben removed. The selective ride cars had them installed for delivery and some dealers did not remove them on the delivery inspection.

I have been under the car a whole bunch as i have a lift at home, but have not seen anytyhing like you describe....what should i be looking for?

Thanks..ian

 

[c4c5specialist]

HI there,
You should have your alignment checked, that should be your FIRST course of action. Request a printout so you can verify the measurements.
Allthebest, c4c5

 

[The Crazy Brit]

Thanks...Good point, my tire buddy has a laser alignment system with a printout option. From when i have used this before they have perameters to be within, anything perticular i should be looking for?
Thx Ian

 

[yellow_2002_germany]

I have been under the car a whole bunch as i have a lift at home, but have not seen anytyhing like you describe....what should i be looking for?

Thanks..ian

I believe the stuffers have a yellow or red tag hanging down from them. They are put in place during shipping to keep the shocks from compressing during shipping. One person here on the site found stuffers in place on a car that was 4 years old!!

 

[The Crazy Brit]

I will look when i get my car back. I loaned it to a buddy who just got married this weekend for his H'moon. Many thanks.....ian

 

[c4c5specialist]

Thanks...Good point, my tire buddy has a laser alignment system with a printout option. From when i have used this before they have perameters to be within, anything perticular i should be looking for?
Thx Ian

Just because its within parameters, does not mean its exactly where it should be.
Allthebest, c4c5

 

[NORTY]

Just because its within parameters, does not mean its exactly where it should be.
Allthebest, c4c5

Very true. The GM specs are very wide indeed.

Here are the GM specs:
FRONT:
camber....-1.1 to 0.2
caster......7.3 to 8.5
toe.........-0.05 to 0.15
cross cam....-0.6 to 0.6
cross cas....-0.6 to 0.6
total toe.....-0.1 to 0.30

REAR:
camber.....-1.0 to 0.1
toe.........-0.1 to 0.10
cross cam...-0.50 to 0.50
total toe....-0.2 to 0.2
thrust angle -0.2 to 0.2



C6 "preferred" specs:

FRONT:
cam...... -0.45
cas.......7.90
toe (ea)..... .10
str angle.....0.00
cross cas....0.00
total toe.....0.20


REAR:
cam.....-0.45
toe......0.00
thrust angle....0.00
cross cam.....0.00

These will improve "turn in" & straight line stability.

These are good for C6, Z51, & Z06

A change in tires (like the Firestone wide oval run flats) may be a good alternative too.

 

[Hib Halverson]

I disagree. I think the Firestone Wide Oval is a poor alternative.

Anyone who recommends the Firestone RFT also needs to give the full story.

The Firestone is quieter and rides nicer because it has a weaker casing than does the Goodyear. The Firestone does not meet GM's specification for run-flat tires. It can only go 50 miles at low or no pressure and then, after the run flat incident, the tire must be scrapped, which, of course, negates any price advantage. Of all the RFTs only the Goodyear and the Michelin can be repaired after low/no pressure incidents lasting 50 miles or less.

As for the "spring stuffer" issue, that's an important point. It is surprising to me how many F55 cars had this problem. It doesn't surprise me that there have been cars that were driven for four years with the stuffers in place.

 

[NORTY]

I disagree. I think the Firestone Wide Oval is a poor alternative.

Anyone who recommends the Firestone RFT also needs to give the full story.

The Firestone is quieter and rides nicer because it has a weaker casing than does the Goodyear. The Firestone does not meet GM's specification for run-flat tires. It can only go 50 miles at low or no pressure and then, after the run flat incident, the tire must be scrapped, which, of course, negates any price advantage. Of all the RFTs only the Goodyear and the Michelin can be repaired after low/no pressure incidents lasting 50 miles or less.

I only suggested the Firestones as a friend of mine has a C6 F55 vert and really likes them. I wasn't aware of the GM spec failure. I think I'll send this link to him. Thanks for the heads up!

 

[Jim Hudspeth]

I only suggested the Firestones as a friend of mine has a C6 F55 vert and really likes them. I wasn't aware of the GM spec failure. I think I'll send this link to him. Thanks for the heads up!

I am the guy NORTY is talking about. I just called Firestone and asked if the tire had been run flat for more than 50 miles would Firestone replace the tire under the terms of the warranty. They assured me that they would as that is part of the road hazard warranty. There would be no charge as long as there is more than 2/32nds tread left on the tire.
Maybe the fellow that told him that erroneous remark about the run flats needs to get current with whats going on in the tire world.