kmagvette

An earlier thread got me thinking about Caster. I have been running 6 deg, with a Camber Kit, because I feel comfortable with the heavy wheel and like the idea of increased negative camber you get when cornering.

However, I wonder if a cost of this much caster is decreased feel in the steering wheel. My reasoning is that the increased return-to-center wheel torque would attenuate feedback - does that make any sense?

My 02 Z will be running -2.0 camber up front and about -1 in the rear. It has poly bushings, Phatty's, and will be getting coil-overs.

All suggestions for caster and overall set-up are appreciated.

BEZ06

Well.....I was reading the forum from my iPhone this afternoon and saw your post. I was hoping by the time I got to check out the forum again tonight that there would be several posts so I could learn about what you're asking.

Butt....I think the lack of posts indicates that most people probably don't mess with caster much. If the cross-caster is in tolerance, they just take what they get for caster after setting up the camber and toe where they want it.

Let me throw out some stuff to maybe get some of the experts to chime in!

Here's some alignment info from Pfadt:

http://www.pfadtracing.com/docs/camb...t-settings.pdf


You can see that they recommend a little less positive caster as the alignment gets more aggressive. However, most recommendations even for aggressive track only setups that I've seen say something like "set caster to +8 degrees (or max attainable)".

I don't know how the C5 adjusts camber or caster, but I assume it's probably similar to the C6. The C6 has eccentrics for the lower control arms/A-arms to move them in/out both front and rear. Up front it has shims (washers) behind the brackets that mount the upper A-arms to the frame. The rear upper A-arms are mounted with fore-n-aft bolts and can't be used to adjust camber.

The rear upper A-arm of the C6 Z06 has the same arrangement as the front - brackets with washers, and you can add or subtract washers (or plates) to move the upper A-arm in/out to adjust camber.

I don't have a camber kit for my C6Z - I just remove washers to pull the upper A-arm in to crank in negative camber for the track. However, a couple of camber kits I've seen have a cam bolt that replaces the eccentrics on the lower A-arm to lock the bottom in place so it can't slip - then all camber adjustments are made by adding/removing camber plates up top to move the upper A-arm in/out.

So....how do you even adjust caster??? I haven't even attempted it. If you have a camber kit that locks/replaces the lower eccentrics, I think you can only adjust it by using different size shims or camber plates behind the brackets that mount the upper A-arms. Here's a picture of my C6Z:



That's the left front, and you can see that I guess you could put more shims/camber plates behind the front bracket, and less behind the rear bracket. That should effectively "lengthen" the front leg of the A-arm and "shorten" the rear leg, which should pull the upper ball joint aft to increase positive caster. If you don't have a kit that locks the eccentrics on the lower A-arm mounts, you could use differential adjustments on the bottom to move the lower ball joint forward/aft to change the angle of caster.

Me....I just adjust camber and take what ever caster I get. I have used David Farmer's method of checking caster one time about 18 months ago, and IIRC I was close to the factory spec for the C6Z of +8 degrees with my street alignment, and both sides were very close to each other. When I cranked in about -2.5 degrees of camber for my Hoosiers I didn't even check to see what it did to the caster - i just accepted whatever it was. I guess I should check it out to make sure what I'm running!

Expert setup gurus - how do you adjust caster and like the OP asked, what should it be?

Bob

kmagvette

The experts must be busy setting up their cars. Since the camber kit locks the lower control arms, the only way to adjust camber and caster is by shimming the upper control arms as you suggest. It is a bit of a screw-around project but once you have the caster you want, then add additional shims to bring the camber to your preferred setting. I started with a nice assortment of stainless steel and galvanized washers; it is amazing how many you end up using.

TedDBere

In my experience most people seem to maximize the front negative camber and just live with whatever castor they can get, but they do try to equalize the castor left to right. FWIW.

I'd certainly be interested in what others think.

rfn026

I try to get as much caster as possible. The only limitation is that I want both sides exactly equal.

Richard Newton
Corvette Race Car File