mlongo99

Sorry about the long post, but please bear with me.

Here's my dilemma... In a couple months I'm taking the C6 to it's first trackday since last summer, and I feel I really need to do something with my suspension. But since I've found a trackday friend that can transport our motorcycles, I've been focusing on the 2 wheel thing and ignoring my vette. So basically, my vette doesn't see a lot of track time, and I've been putting this off since I haven't gone in a while.

I've got the Z51 package, and while it could really use something firmer, I'd rather leave that stuff alone since I enjoy it's comfort on long trips. What I really want is corner weighting and alignment settings that will make the most of what I've got.

Right now alignment is very close to OEM prefered settings. Camber is at -.5 front and rear and that's my biggest concern. I'm sure you guys can imagine how much it sucks at the track, and my old tires really suffered from that. The tires I have now (BFG KDW2) only have a couple hundred miles on them and I don't want to ruin them.


So my first thought was the Hardbar camber kit and stud kit, so I contacted Gary and he answered some questions for me. I really like the idea of being able to switch between aggressive/conservative camber, as well as not having to worry about anything getting knocked out of place. Do you guys have any reasons why I shouldn't go this route?

I then contacted a reputable Vette shop reasonably close to me to inquire about corner weighting. That conversation didn't go as I had hoped. First, I was told that the camber kit wasn't a good idea to use with my soft OEM components, and that I'd be better off having them dial in alignment settings the normal way. Second, they were against using shims with the stud kit, saying that I might run out of range with the tie rods and possibly induce bump-steer. What are your thoughts on these comments?

They told me they could do the corner weighting and full alignment for $300. That sounded reasonable, is it? What concerned me was that they said a set of adjustable end links was $400. Now they did say that they were similar to my OEM links, in that there is teflon or something in the joints, which would keep them quiet. They said they had somewhat cheaper ones, but they would end up making noise. That sounds excessive. (I haven't heard back from LGM yet about their end links) It seems to me that $700 is too much just to get the car balanced and aligned. And then what happens if it gets knocked out? Or if I do some maintenance/repairs that messes up the settings? Then I've got to spend another $300 just to get it setup again. Am I out of line here?

I'm kind of thinking I should just invest in the Hardbar parts and some tools and learn how to do my own alignments. With the settings locked in place, all I'd really need to do is dial in toe once, and figure out how far to adjust the tie rods when swapping in/out the shims. This would solve my worries about tearing up tires, and allow me to make adjustments in the future. The only downside is that it wouldn't be balanced. I want the car balanced, but at the rate I'm doing trackdays, it doesn't seem worth the expense, and that shop won't want me to use the Hardbar kits.


I'd like to hear suggestions on what to do. Get the hardbar stuff? Suck it up and spend $700 on a balance/alignment? Keep shopping for end links? Do the balance, but get the camber kit too? Do neither and just get a street/track compromise alignment?

trackboss

Adjusting camber may have a little effect on bumpsteer, but what really changes it is caster. I have been road racing, real racing not open track stuff, for several years now and have lots of experience setting up cars. I can tell you that doing a full setup correctly can take a lot of time and its hard work so depending on exactly what that shop told you they will do their pricing may not be way off. I know, to regular folks who don't do this sort of thing it sounds outrageous, but it can be hard work. I personally would go for the hardbar shims. The rubber bushings do have lots of play and the shop has a point. It would be easier for them to just use the stock eccentrics to get the alignment exact for left and right, but eccentrics can move. The other thing to keep in mind that most don't know is that if you are doing any alignment changes using the lower arm you may change ackerman. It would be better in my opinion to lock the lower arms with hardbar pieces and adjust the uppers using the stud kit and shims. That way there is no change in ackerman or track width. Changing caster will also change ride height and corner weights. Camber can slightly as well. Good rule of thumb is to set desired ride hieght using a solid important point on the car like a suspension pickup point, not the wheel arch or any bodywork(make sure all tire pressures are the same), set alignment, re-check ride height and adjust if necessary, recheck alignment adjust if necessary, then cornerweight car with desired fuel load and driver in car. To get it perfect you may have to go around and do this several times. I am speaking from a racing background and this is probably a bit much for open track guys but take what you want from it. Bumpsteer should be done last if you choose to do it.
You can spend lots of money toying around with this stuff, but it all depends how far you want to go. There is really no set alignment that will give you the best performance. The only way to do that is through testing and taking data like tire pressures and temperatures as well as seat of the pants (experienced driver). I mess with all this stuff on the race car all the time. If I was paying myself for all the hours it would be super expensive and thats why I rarely do this kind of work for others simply because they don't fully understand all this. What I would suggest is to make a budget for yourself and a goal as to what you want out of the car. Then go from there.
good luck!
-V

mlongo99

Thanks. Good info so far. I get that it can be a lot of work to dial everything in to a specific setting. That's why I'm a bit concerned about setting everything with the eccentric washers, and risk something causing all that work to go right out the window.

What is that? I've never heard that term used before.

That sounds very smart. I know it's easy be to go overboard when planning updrades. In this case, $400 for end links plus the corner weighting labor would probably be more money than I need to spend.

gkmccready

$400 for end-links better be Aurora rod-ends with a fancy center piece. Sheesh.

I think I paid $260 for just an alignment without ride-height adjustment or corner weighting. Subsequent alignments are $110ea. That said, I've got an order in to Hardbar for the stud+camber kit and his alignment plates... I want to be able to swap track and street just like yourself.

I will say I'm currently -1.1deg front, -0.9deg rear, a little toe-out, and a little toe-in, on stock F1 Supercars and things are wearing pretty well. The biggest change I've made is the Pfadt Pfatty swaybars and they've been awesome...

glen

mlongo99

I didn't ask about the end link manufacturer, all I know is that they won't make noise. Either way, I was not expecting them to be anywhere near that price.

Your camber settings are right about what I'd like to try out first. -.5 and the big sweepers at WSIR wreaked havoc on the supercars I had, especially the front left. The inner tread block had maybe 4mm left, but the outer one was completely gone! And the rears suffered from chunking along every single inner tread block. I really don't want to have to toss out tires prematurely again.

Sway bars might be something I'll upgrade in the future. If I want to carry more corner speed I'll definately need them. How have they transformed your car's ride/manners on the street?

trackboss

Ackerman is the relationship of the steering arm to the lower control arm. To put it simply, when turning, the inner wheel when set up right turns sharper than the outer. Helps with turn-in. I'm no suspension engineer, nor have I done enough testing to tell you the correct angle to set it at. I'm just trying to point out that its better to keep both sides the same and align with the upper arm. The hardbar parts allow you to do that very well by only having to adjust the upper arm.
On the tie rod ends. All they really do(bumpsteer kits) is allow you to dial in the steering arm so bumpsteer is eliminated or at least minimized. Like I mentioned before, changing alignment (specifically caster), will require that the car be re-bumpsteered. More positive caster requires more spacers between the tie rod end and the steering arm on the spindle.
If I were to suggest something and be required to leave some parts out I would say set the ride hieght, corner weight and dial in the alignment. Save up and do the bumpsteer at another time when you have found out what setup you like. Once you have two alignment specifications you like, one for track and one for street (assuming dual purpose cars here not dedicated race cars) You can machine spacers for the upper arms with the desired thickness (thinner for track, thicker for street)so that all you do is swap ou the spacers and simply reset the toe. You can do this on your own at home pretty easily. If you keep caster the same you can avoid having to bumpsteer. If you change caster then bumpsteer with both alignment settings and machine spacers for each and do the same swap. I'm trying to put this as simply as possible so if you don't understand just ask and I'll try to explain.
For ballpark alignment specifications check out the Van Steel catalog. Paul there is a very knowledgable guy.
You know for quite some time now I've thought about teaching somewhat of a class on this stuff, but never have put it all together. There seems to be enough interest where I could probably make it worth my time. Even for those who don't want to do this stuff themselves I've found that it helps when one has an understanding of what is going on. I can set up a car and if I've helped someone learn what I've done to it they can give me better feedback or at the very least they have a much better appreciation of what I do.

-V

Maineiac

Do nothing...save your money, just drive it. There's no substitute for seat time....

gkmccready

My current belief is that if I went with the poly bushings instead of the pillow blocks they'd be quite quiet on the street, and the ride on the street is perfectly fine -- the only difference is less body roll. On the track it's such a different car now it's hard to believe... went from an understeering-oversteering pig mid-corner and on exit to a very controllable confidence inspiring car!

Either that or I'm finally learning how to drive it, but I'm pretty sure it's the bars giving me the chance to drive it now...

roysvett

If I were going to do aneything with the vett call danny first . I searched the net far and wide and spent 100's of hrs looking for the answers for all the questions you seek. Mc Clusky motors Cinncinati OH .Look I will drive 250 miles one way to get his help. He made my vett handle like a dream.

C6RAPTOR

I am in the same boat as you about the camber kit game. I think I am going to try the Pfadt Race Engineering Camber Adjustment Kit in my Z51 C6. I had my camber adjustment change big time on the CMP track. The Pfadt ad said that will not happen with their kit.

http://www.pfadtracing.com/products/...&search=&page=