I have a 2004 Z06. It seems to follow the grooves and ruts in the road more than other cars I've owned. Has anyone else experienced this and is it normal due to the Z06s suspension?

Thanks

Dave

 

I have an 04 as well, and yes, it happens all of the time. I would say it is more a product of the tires than of the suspension. The F1s have very good dry weather traction and just stick on to the imperfections in the road surface. IMHO, nothing to worry about.

 

Try a little more air pressure, maybe 33-34psi. It will help some but will "roughen" your ride a little.

 

Race tires track groves and imperfections. The F1's are as close to a race tire as you can get today. Learn to control it and love the dry traction. It is normal. Up to 38# per tire will belp but will make the ride rougher and the tires wear faster.

 

Thanks Guys!

 

Food for thought, but my '04 was the same way. It was by far worse than my '02 was so I took it in and had it realigned. The dealer tried to tell me it was the wide tires following the groves in the road only I knew better from having a Z06 before. The alignment was off and they put it back to factory specs and it improved 100%. Take it in and have it looked at. Yours may be off as well.

 

I have been racing my Z06 for a few years with much experience in this subject and can tell you it's a factor of 2 things.

1) extremely wide tires
2) factory negative camber

The negative camber has more to do with it than anything else. But this is a good thing as it helps high speed handling...you can't have your cake and eat it to as many people would tend to beleive.

 

I had mine aligned and it was worse than before the alignment! the shop had it within spec but to the high range. they realigned and set it to the mid to lower end of the range...MUCH better....I did notice it is less noticable above 100 mph...

 

Mine does it more than any other car I've owned but it was only noticeable the first couple days now I don't even feel it. Any car that handles this well is going to track the road more than others

 

It's the F1 Supercar tires. Mine does the same!!!!!!!!!

 

Toe in promotes straight line stability, while toe out promotes increased turn in (and less stability). Excess toe, either way results in abnormal tire wear (outside edge for excess toe in, and inside edge for excess toe out).

See http://www.ozebiz.com.au/racetech/theory/align.html

Also check caster (generally affects steering effort, but also affect stability (example: shopping cart wheel with no caster wiggles). The castor was changed on the C6 to reduce 'dartiness'.

For a street driven car, correct camber will promote the longest possible tire life. On the track, proper (increased negative) camber will promote maximum cornering. Even though the Z06 has more negative camber than other cars, it should not suffer excess inside tire where when set to factory correct specs (the inside does wear faster, but not excessively).

All tests should be performed after the tire pressures have been verified.

 

Toe in promotes straight line stability, while toe out promotes increased turn in (and less stability). Excess toe (either direction) results in abnormal tire wear (outside edge for excess toe in, and inside edge for excess toe out).

See http://www.ozebiz.com.au/racetech/theory/align.html

Also check caster (generally affects steering effort, but also affects stability (example: shopping cart wheel with negative caster wiggles). The caster was changed on the C6 to reduce 'dartiness'.

For a street driven car, correct camber will help promote the longest possible tire life. On the track, proper (increased negative) camber will promote maximum cornering. Even though the Z06 has more negative camber than other cars (for improved street cornering performance), it should not suffer excess inside tire wear when set to factory correct specs (the inside wears faster, but not excessively).

All tests should be performed after the tire pressures have been verified.

Make sure both the front and rear are aligned: before the alignment begins, request that both the front and rear be aligned, and request a copy of the alignment sheet (showing before/after for the front+rear).

Since the car is an 04, the alignment should be free.

 

My 03 pulls very little on crossing over the crown on certain roads but most of the time it has no wander.

I would have the alignment checked and make sure you give the tech the settings you want. The difference between upper and lower ends of the range is big enough that you can have a bad alignment (for your car) that meets spec's. Even though I track my car I always ask for just a little toe in on the front to keep wander down. The spec allows the tech to set it anywhere from toe out to toe in so if you don't tell him what you want you can get some toe out and more wander. They may not be able to get the exact settings you ask for but they will get them closer than if you just say "Align it".
Bill

 

Mine tracks road groves and ruts better than any other car I've owned. I doesn't wander. I goes exactly where and when I direct it. It is, without doubt, one of the best handling cars available.

dave

 

I recently lowered my car, so took it in for an alignment. I spent a ton of time searching for the "perfect" alignment specs, only to learn that there's no such thing. Alignment is always a compromise. You can increase your handling and you'll decrease your tire life, and vice versa. I opted for maximum tire life, since I'll only track the car maybe once a year. How often do I really need to pull a 1g corner? So I found an alignment shop who could knows enough about alignments to set it up leaning towards better tire life while still maintaining most of the handling of the ZO6. I tracked it on Monday at Road America, and while it didn't have the ultra quick turn in of a track alignment, it still stuck like on rails, and I know that I can drive it daily and I'm not scrubbing off my $300 F1s. I can always go back and ask for a more aggressive alignment if I want one. In other words, get to know your alignment guy!

 

0.5-0.7 degrees negative camber will wear the inside of the front tires but the car will turn much better and front tire drag will be reduced. 0.25 negative camber will reduce tire wear but the car won't turn in as well and may track worse.

 

I just had my car lowered yesterday, and took it straight to a nearby shop for the alignment. My two front tires had a negative camber of 0.7 prior to the alignment. The inside of the tires are worn down to the bands. I bought the car new, and it has 12K. The dealer performed an alignment at the 3K mile service. I have no idea how I never noticed this wear, becuase I go over my car almost everyday. Now I am up for a new set of front tires. ....be warned.

 

This is one option that comes as factory equipment. I've owned several different performance oriented cars and all have this same characteristic, I think that the wider tires, that this type of vehicle is equipped with, are the cause.

 

Those are the reason why it tracks and the inside of the front tires wear out first if you don't drive around curves hard. The more focused a car the harder it is to live with.

 

Here's an alignment guide for a company that sells alignment systems: http://www.opto-plus.com/marketing/a...rincip_eng.pdf

Summary from their guide and additional info:

1. Toe is the primary factor for straight line stability ("wander"). However, too much toe in will result in excess wear. Running more toe in for the front and perhaps a little toe out for the rear (to aid in turn in) might be a good compromise. In any case, toe will have to be minimal to prevent excess tire wear.

2. Caster affects how the front wheels will tend to straighten out. This also affects directional stability (again, the C6 has revised caster to improve straight line stability). Incorrect caster will cause the car to pull from side to side when braking or going over bumps.

3. Camber, when set incorrectly, will cause the car to pull (constantly) to one side. Incorrect camber was not listed as a straight line stability factor. From "Race Car Vehicle Dynamics, by Milliken & Milliken", page 726:
"Camber also works like steer: When a tire is cambered it tends to pull the car in the same direction in which the top of the tire is leaning." This explains why a car will pull constantly to one side if the camber is not matched side to side. In cases where the camber angle changes while going over bumps, the car will tend to pull to one side (there's also 'bump steer', see http://www.longacreracing.com/articles/art.asp?ARTID=13 )

4. Kingpin angle, which causes the car to lift while turning, also affects how the steering wheel returns to straight ahead. While caster is a front-back angle, kingpin is a left-right angle. Lifting is also a factor of spindle length (longer means more lift).

The wide tires will track grooves more than narrower tires and affects steering feedback (also a function of feedback torque related to the "scrub radius", see page 711 of RCVD).

My 2002 Z06 was not aligned from the factory. I worked with the dealer alignment tech and we dialed it in nicely, with good straight line stability, balanced left/right turn in, no pulling, and no pulling while braking/taking bumps (and a straight-ahead steering wheel).

Using the above information, anyone should be able to work with their alignment guy to improve the alignment and handling of their car.