I installed a set of Bilstein sport shocks which were the stiffer of the 2 types available for the C5 and C6. Cutting right to the main question, no they didnt get rid of the deadly wheel hop.

Every source I could find on wheel hop stated that stiffer shocks were needed to handle the problem. Logic dictates that since these didnt stop the problem that stiffer ones than these will be needed. I guess adjustable HAL's would work especially since the compression and rebound could be tuned differently so as to keep the two from being coincident in a waveform sort of way.

I susect that the transverse spring in this car could be largely to blame at this point. I'm sorry but bushings arent going to do it. I will try just to satisfy the minions but I doubt it will work. Tires used were both my runflat superdupers and also a short run with my KDW's which are the best handling tire in the world for the money; 1.04 on the G meter with the shocks installed. There are no pressure sensors in the wheels with the BFG's so the set-up works only long enough until the car tells me that I have 4 flats and limits cornering to .7g's and I didnt buy this car for doing sub .7g turns.

Getting back to the review of the shocks. The cost of the shocks were 299 delivered in the 48 lower and I received mine in about the quickest UPS ground delivery in the history of the big brown truck. I got them in 35 hours.

The shocks are not at all offensive as I was expecting since the ride of the Z51 borders on annoying to me. Well it is stiffer but more comfortable. Figure that. It turns out that the changes were that while it was stiffer and more controlled, the dayum bounce was history. The car leans less in the turns and takes bumpy NY roads better than the stock ones. Since I sold my stockers for 70 my net for this mod was 230. For those destined to pay another soul to install these sticks of handling joy, it may not represent such a great upgrade in performance in cost/gain ratio with labor factored in. I doubt I would have made the switch to these had I known that the wheel hop gremlins would still be at my early edition 2005 rear carrier's lifeline but since they were installed at such a small expenditure, I will let them stay.

As Dave Farmer already told me, a good wheel alignment in as far as camber setting front and rear, will do more for handling than tires, sway bays, and these yellow and blue things.

One side note, if you have the base suspension, run, dont walk, to the computer and order these shocks immediately. Having been in a base 2006, you need them. The Z51 has just not as great a need.

Almost forgot to add...got that price and speedy delivery from Eshocks.com.

 

Going from Z51 in my 05 to base suspension in the 06 I couldn't agree more. It is almost pathetic the way my car handles corners (with base suspension set-up) at the moment. It is by far the weekest link on my car. I have very little concerns with the straight-line performance when it comes to challenging most other stock for stock cars (on the track of course). However through the twisties I have some serious doubts without a suspension upgrade. Just last weekend I was followed through Mullhulland Drive by a 911 and this guy stuck to my rear like glue. As I was strugeling with body roll, front traction issues, and so on, the 911 guy was following close behind with ease. Certainly I am fully aware of the Porsche's cornering ability but it was a far cry of what a C6 vette should be able to do. My only savior was due to the torque that enabled me to even up the odds in the small straight-aways. For me: shocks, sway bars, tires, and alignment are my first upgrades and take priority over engine mods.

 

Try the Z51 sway bars first. That may be all you need. And...why did you get the base suspension?

 

Spinmonster,

Good shocks give you strong damping at low speed wheel to body motion. This controls the floaty feeling.

But, their valving is sophisticated enough that it blows off and lets the wheels move easily enough that fast wheel to body motion like you get from small irregularites in the road don't knock your fillings out.

The fact that it has a transvers leaf spring has nothing to do with the problem. All the spring does is hold the car up and allow relative movement between the wheels and body.

The hop is coming from stuff in the suspension flexing that isn't supposed to flex. Busings are a definite possibility. Someone here must have solved the problem and actually know.

 

I would have loved to get an 06 with Z51 however with constraints I was limited to what is on the dealers lot. Any of the C6's I came accross were loaded with option, which I did not want (other than the 6-way power seats). The dealers in So CA (and I visited many) that had a non-loaded Z51 wouldn't discount the price like I found on a base 2LT. I was planning on upgrading the suspension anyways. I felt even my 05 with Z51 could use some improvements by far. However I was suprised at the limited cornering ability of the base suspension and tires. The supercar tires that came with z51 rock compared to base tires. It appears to be a fairly easy fix with tires, sway bars, shocks, lowering, and alignment, etc. I am waiting or a fully adjustable shock to throw on.
Back to the point of the thread:
In the MN6 05 I did suffer from wheel hop. However with a lot of seat time (34k miles in 16 months) I learned to compensate by using the clutch and accelerater to keep it to a minimum/eliminate it. In the 06 A6 I have logged only 1400 miles and havn't hammered it enough yet from a standstill to see if this is a problem. I wonder if others with A4's or A6's have wheel-hop issues like MN6? I think a good fully-adjustable shock enabling you to control rebound is the clue to solving wheel hop issues. Olddog mentioned he was having a shock made and would be tesing this theory soon.

 

Tires, tires tires... on the C5 when they ran all three suspensions with Z51 tires the F55 lapped the fastest.

 

Not sure what you are saying there about tires there but if you read my review again you will see I used non-runflat BFG's for some of the test drives. I had wheel hop on all of them. If you are trying to talk about handling, I assure you I have no complaint about handling at all and want for nothing in that department. (re: g-meter)

 

Can't be correct as coil overs eliminate wheel hop. Energy storage in the length of the leaf is longer in duration than the coils. Wheel hop as defined in the searches I have done come from inadequate damping of the unsprung weight. More unsprung weight with the same damping=more wheel hop. Part of the damping does come from bushings so I may be wrong in overlooking that variable.

Please state the source of your info so I can research it. Do you have any race/suspension experience? Did you get rid of wheel hop before? I know I can be wrong.

Anyone know of a complete kit I can use for the suspension bushings or which ones should be changed?

 

Just a quick info update. BMR fabrication is currently working on a package solution for the wheel hop issue. They have a bushing package available now for the C5 but they didnt test the C6 for fit or effectiveness. If you wish to take a look:

http://www.bmrfabrication.com/C5.htm

 

Wheel hop is alot more complicated than all of you are tryin to make it out, its a combination of suspension geometry, bushing compliance, tires and pressure, shocks, springs, and the harmonics associated with the torque being transmitted, so much so the drive shaft is also involved.........otherwise it would easily be designed out, just another compromise for other things/benefits you take for granted.

 

I've got some suspension design experiance and a lot of mechanical design experiance. Stuff vibrating when you don't want it to is a common problem in mechanical design.

A jumping rear end is just a tuned system that's tuned to vibrate when you don't want it to vibrate. To stop it you change something so it isn't get excited enough to vibrate by your driving. There's nothing special about ajumping rear end, it's just another mechanical design problem. Work on closed loop control systems and if you you really want get your face rubbed in it.

The easy approach is to find out where the relative movement you don't want is and either stiffen that element enough that it doen't move or damp it. That's why a lot of people change bushings to stiffer bushings.

Someone fed you line of bull pucky about the duration of energy storage in leaf vs coil springs. Other things were changed when it was changed for leaf springs to coil overs. It was one of those other things that fixed the hop.

Even with a comptent $$ engineer working on your problem there would be some trial and error. Your best bet would be to find someone who has fixed the problem and do what they did.

 

In the last paragraph you called it my problem but I assure you that everyone with this car has wheel hop. I have posted to find at least one person that has fixed it but only found a C5 guy that did so with coil-overs. So as far as C6 guys are concerned, no I can't copy what anyone has done since no one fixed it. I am not a suspension expert but I am willing to try anything that comes from a prior experience. I have read on other researched websites that shocks are a major contributing factor so I changed them; no effect. I keep hearing that runflats are the culprit; I have wheel hop with or without them (BFG's bounce just as much). If you say bushings will do it then I will change them too. I don't know how to solve these issues but I am looking to find opinions that may help. So far, all of these opinions just cost money and yield no results. So much for the experts.

I appreciate your feedback and help and I will try other things. I'm not sure what the above highlighted sentence means. Please clarify.

The coil overs involved only a shock and spring change.

 

switch to eurathane bushing in the rear control arms and that will stop the wheel hop it worked great in my c6 z51 with calloway big sways and also switching to a dual disk clutch but i think mostly it was the bushings and the sway bars

 

Yeah I read that too. Any suggestions?

 

The highlighted sentence refered to a type of mechanical design problem that can be a lot harder to solve than wheel hop and a whole lot more dramatic, but is caused by the same types of problems.

Your "only shock and spring" change changed spring rates.

Sounds like the bushings helped Nicky D.

 

Oh man I am sorry. I thought you were suggesting it and didnt actually do those mods.

Did you use the BMR bushings or was it another brand? Also, do I have to change the front bushings too? Just more work.

Thanks.