So, I'm settin up the front end on the Henry J. I have an unknown application round tube axle and 54 Chevvie spindles. The caster is tenitively set at 6 degrees negative. With my wheels straight, the spindle camber is about 1 and 1/2 degrees positive with no load on the axle. (I think I will gain the 1 and a half with weight on it...) Through the steering range of motion (lock to lock) the camber changes about 14 degrees total. Example: If I steer the car left, the left (drivers side)spindle picks up about 7 degrees positive camber. The passengers side goes to about 7 degrees negative. The opposite is true for right turns. Is that about what I'm looking for? Or does my camber need to stay closer to zero lock to lock? Thanks guys, -Abone.
The camber change is a function of kingpin inclination.This helps create the self centering effect when you let go of the wheel.I think your in good shape.
2 things come to mind.#1 it's not a problem.#2 you can't really do too much about it anyway. Camber,caster,and bump steer are typically checked with the wheels straight ahead.
Is the axle tilting back? If so, that is positive caster and you are in good shape. If it is tilted forward, you may have a problem. The steering could get kinda squirelly at speed.
Fast. The king pin inclination (caster) is top of king pin runs toward the rear of the car. Bottom of king pin is toward front of the car. I've always called that negative. Is that not right? I always set my straight axles at 4 to 8 degrees "BACK" depending on application. Does "back" mean Positive? Fast. You're a sprint car guy aren't ya? So what do you think..is the 7 degree camber gain OK? Thanks, -Abone.
So kicked back means positive? Oh..oops. I've always called that negative....shit. Learn somthing everyday. Thanks, -Abone.
Top of the kingpin back is positive. Who cares what you call itif the car handles good. Right? So-Cal catalog says to set up a tube axle at between 5 and 9 degrees positive. Kinda like "high" gears being low numbers. A little confusing.
I wouldn't even worry about camber gain. Not much you can do about it in any case. Set your straight ahead camber after you have the full weight on the front end. For highway driving I will run 1/4 degree negative (top in) camber on the right front and 1/4 degree positive camber on the left front. This will try to compensate for the slope of the road. Works for me ! Kingpins tilted back = positive caster. 6 degrees should be fine. I'll start with 7 but my car is very light and has an 86" wheelbase. More caster increases steering effort.
If your turning enough to change the angle of the body, the camber angle helps tuck the tire up under the fender and keep it as close to perfect as possible... So expect some movement, but its how you get a contact patch with the wheel to the lock!
Forgive me if I'm wrong, but isn't camber constant throughout the suspensions travel on straight axles?
[ QUOTE ] Forgive me if I'm wrong, but isn't camber constant throughout the suspensions travel on straight axles? [/ QUOTE ] Yes
Your forgiven. On a strait axel car equiped with wish bones (split or original) or hairpins the caster will change as the axel moves up and down through its arch. If its equiped with four bars witch I would****ume most guys here are not using then yes it will not change. Oh hell you said camber not caster. I'll shut up now.
It's true that caster does change with axle movement on hairpins or wishbones but the amount is so small within a typical rod's suspension travel that it makes little or no difference in how the car drives. On a heavy car like a full-fendered sedan I wouldn't recommend any more than 5-5.5 degrees of caster tops. My pal Richard recently changed the split bone front end on his 31 Tudor from 7 to 5 degrees. It decreased the steering effort noticeably and there was an unexpected improvement in the ride. The spring may have been binding a little at the higher setting. It did not make a noticeable difference in the car's highway manners. As was noted above light cars can get away with more caster without the steering effort getting out of hand.
If your worried about it put a pivot on the bottom of the axle and run a pair of radius rods over the top (adjustable). If its too squirly at speed shorten the radius rods (tilt the axle back) it you can't park it or steer it in town lengthen the rods (tilt it forward). Or eat more spinach. Too high tech? My ol' man was doin' it that way in the fifties. Probably in the 40s I just don't remember much before th 50s .
So,Abone,buddy,What kind of motor am I going to have to put together to Whip Up on your**** at the HAMB Drags?Charlie
Thanks for the input, guys. Just like getting a second opinion from a doctor, I'm listening most to the replies that tell me what I want to hear...Correct or not. BUT- I checked this camber change against my I-beam model A ( 6 degrees pos caster and 1 degree negative camber at ride height.)and it has a similar change. And the A handles kick****, so... I'm going to****ume that camber gains positive for the inside tire when heading into a corner and the outside tire sees a gain to the negative. Unless anybody can explain it diffrently.. ElP. You out there? Thanks, -Abone. PS. Feo2. You can build what ever you want..but it better be a BAAAD MUTHAFUCKER!!!!!
'course the camber changes when turning. You can see an extreme example of it when viewing a dragster with mega-caster as it turns sharply. The top of the inside tire leans out [camber, baby] ...Helps keep the car straight unless you turn too sharp and go "over center". Then, the damn thing is really hard to muscle back up straight again but you won't need to worry about that with only 5-9 degrees. And, like has been said here already, you can't do a damn thing about the turning camber anyway. It's built into the geometry of the spindles and hence, not adjustable. I put 5 degrees positive caster into the Rocky 33 and it drove just fine.
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