I've started designing the rear suspension setup on my 54 Chevy. I'm using an S10 rear end and leafs. I'm building it to be as low as possible in the rear without having to add lowering blocks or air bags. The frame will be notched What I am wondering is if moving the axle perches in towards the middle of the axle housing makes any effect on anything. to give you an idea of where I'm planning putting them it would be about half way between the drum. Would doing that be a bad idea?
Probably a bad idea. The truck will tend to lean a LOT in corners, as the springs are now too close together to act as roll control. Perhaps a hefty anti-roll bar would help, but it's putting bandages on a wound that should not be opened. Cosmo
Why so close together? A lot of factors come into play with rear suspension design. You are stepping out of the norm by not using so many other tried and proven setups. Why is that? Are you making giant wheel wells or something? Roll stability is a valid question. Give us more to go on.
its a 54 bel air I was going to move the springs in a few inches on either side so i could mount the spring hangers on the inside of the frame rails on either side to save space underneath. I didn't even think of stability issues. If you guys think moving the springs in would be a bad idea i have another plan have a low profile fixed spring mount in the back and a shackle in the front both mounted to the underside of the frame rail as stock was. sound good? thanks for all your help
you can move the springs to the inside of the rails, lot of newer cars are built that way, i would put a sway bar on your car as they like to lean even stock, i picked up a rancho from an iroc for $25, came with all the hangers and it would work on just about anything.
if i move the springs to the inside Insead of having a 45" center to center spring track it will be 36" or 35" will that be reasonable? could i set up a sway bar on it? This car is going to be really really low to the ground and have a low cog
That's not crazy, but I still don't follow why it would be necessary. You can put a sway bar on anything.
If the spring hangers are on the sides of the frame instead of on the bottom i can get the spring and axle higher up into the car and thus lower the entire car tward the ground. I would prefer to but the springs on the out sides of the frame but theres no room so i would need to put them on the unsides of the frame. I hope that helps you, I have a terribel time conveying ideas that are in my head yeah but but would a sway bar make up for the loss in stability
No big issues with that. You'll figure out if you want a sway bar pretty quickly after you get it in. A lot of those cars have been lowered over the years. You'd do well to call for pics and info on here of any out there in HAMB land.
If you keep the shocks on the outside of the frame rails, that should help with stability. An anti-roll bar should also help. Basically what you are doing is giving the springs less leverage to stabilize the vehicle, and the body/frame more leverage. It's like two people trying to move a really big rock, except one has a screwdriver and the other has a 6' pry bar.
I drew up a quick picture to show what'll happen with the inboard spring. The inboard spring will have to exert more force to counteract the roll of your car. This just means more stress on the spring. The 2/3D is just for reference, it doesn't mean that it'll be 24" instead of 36" or whatever. http://web.ics.purdue.edu/~grbrown/spring.bmp (Couldn't get it to attach)
if you are going to go thru the work of moving the spring just make a pocket and put the spring inside of the frame rails. then weld a tube in the rear for the shackle bushing
Im going to mount the spring really high in the back, to utilize all the room im making with the frame notch, to high to make a pocket but i do like your idea of a tube as a shackle bushing. can you have the rear be a fixed mount and the front be a shackle?
I built a 51 Chevy with parallel leafs in the rear, and a chevy 10-bolt. The leaf springs were from the FRONT of a early 80's fullsize blazer. I only used the 3 largest leafs on each side. I mounted the rear shackle "top" bushings in the frame rails, and the fronts up as tight as I could to the frame rails with new brackets I made. This really was a decent setup. The springs were nearly flat when done.
so you cut out the bottom of the frame rail and mounted the chacke up inside it? how low did that end up getting the car to the ground? was you frame notched?
Another thing to think about is the leverage the wheel has against the spring in bending the housing. The spring perch is the fulcrum, so if it were (theoretically) out at the tire, there would be no bending force from weight against the axle tube. The further you move the perch from the tire, the more the weight on the spring acts as a lever to bend the center of the housing toward the ground. Don't know if it's a real concern, but it sounds like a fairly heavy car, and the tubes in those little 10 bolts aren't really welded to the cast center all that well. If you were dealing with a 9" Ford, I wouldn't even have brought it up... I once saw the aftermath of a loader driver dumping a scoop of gravel into a pickup from a little too high up; the weight hit the springs and broke the rear axle housing in half...the diff ended up laying on the ground. Hate to see that sort of thing happen to you.
i wouldn't worry one bit about the springs mounted inboard of the frame rails causing a big body roll problem. lots of us mount air bags even closer together than that, and i have a 4x4 truck with a high center of gravity that has the leaf springs mounted just over two feet apart. the inside of a 49-54 chevy frame is about how far apart many other leaf springs are mounted from the factory. i'm curious though why you want to have a shackle mounted at the front of the leaf spring though.
I didnt cut the frame... I put a sleeve and bushings through the rails and mount the shackles through that. It was about as low as you can get with 225/70-15's
I just wanted to ask why are you so set on leaf springs? If you want to get it really low you could put a link on it and set it up w/coils, and have a better ride w/out all the issues of leafs.
I just figured that since the rake of the car would be high to low in the back i would mount the rear of the spring really close to teh frame in the back and have more room in the front for a shackle.
Never done coils before, I come from 4x4 chevys (73-87) and Ive always liked them. Thought about coils and links but I like the regidity of leafs and fimiliarity I have with leafs.
I dont think you'd have any problems with it, I think its a good idea. Tons of 4x4's used inboarded springs for flex, but there are a few advantages for a street car too. You get to use a normal arc'd leaf pack instead of a saggy flat pack to get it low, so you retain some spring. I would get some Bilstein 5150 shocks and give it a go. Just mount the shocks as vertically and outboard as you can. You can also add a leaf to the pack to counteract the loss of spring rate by inboarding it.
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