How much caster?

[chevynut]

I got a Speedway straight axle kit with Chevy spindles for the 55 Gasser project and the instructions say to use 6-8 degrees of caster. That seems like a helluva lot of caster to me. The stock tri5 spec is .5-1.5 degrees, and I know most people don't consider that enough. I was thinking 4-6 degrees would be plenty, if not a little too much already.

What do you guys recommend? I know it can be adjusted with tapered shims, but I'd rather get it right when installing the axle.

[Rick_L]

3-5 degrees is the typical recommendation for a stock frame with aftermarket control arms and power steering. Not far from the 4-6 degrees. Lots of the aftermarket control arms have 5 degrees of extra caster built in.

If it's a real 1/4 mile car with narrow tires then 6-8 degrees is not out of the question. If it's to be driven dropping back a little bit is wise.

It's all about the steering effort, and what you have to do to add more (or reduce it if there's too much).

The only other deal with a lot of caster is that a drag race car with much more caster than we're talking about (and a lot less weight on the front tires) will become unstable and start wobbling when you back up pretty fast. We're talking up to 20 degrees with some of those.

[chevynut]

Thanks Rick, I wonder if Speedway's specs assume you're building a drag car, and not a street car. The kit has alot of pieces to it and very few instructions. I have instructions for putting the spindles on the axle using the kingpin kit (with more parts than I need), basic instructions for installing the springs and the axle on the frame, but basically nothing for putting the brakes on. Maybe it's self-explanatory when I get to that point...and I'm sure I can figure it out.

I think I'll set it for about 4 degrees, and he can go a little either way from there with shims. We plan to use the stock steering box and a cross-steer setup.

[markm]

I cannot believe Cnut is involved in such a retro project, hope he don't get billet free withdraws.

[chevynut]

I cannot believe Cnut is involved in such a retro project, hope he don't get billet free withdraws.

Mark, I was asked by the HEMI 55 owner to build this frame for his brother, and I decided to do it for him. Why do you think that's strange? Here's a couple of pics of my Nomad in it's first reincarnation....

gasser.jpg Gasser1.JPG gasser4.jpg



By the way, I must be missing something. By "billet" I assume you're referring to billet aluminum machined parts. Can you show me where I have any billet on my Nomad? The only thing I can think of is my chromed Street and Performance accessory pulleys and Billet Specialties o-ring water neck that I got because it had a 90 degree neck that I needed. Besides, what's wrong with billet parts? They're better than castings or stamped steel parts.