My buddy bought this car recently and said it drives terrible. After quickly looking it over I see several basic issues that are wrong on it right from Speedway. The first issue is the angle on the shackles while at static ride height is way off. About what I think they should be at full compression. Next the shock mount are mounted so low that there was only about 1-1 1/2” of compression travel. It didn’t matter though because the way the leaf springs are now it’s pretty much solid anyways. I’ve already cut off the shock mount to replace with some that are taller. I would like to see it with about 1 1/2 to 2” of rebound travel and about 4 inches of compression travel. So thinking about it I see a couple of options to correct it. The first option is to remove the rear shackle mount and move it back about 2” which will put it pretty much all the way back on the chassis. I’m also toying with the idea of lengthening the shackles a bit that will increase the arc and also add a bit more caster to it. I haven’t checked the caster angle yet but by looking at it It doesn’t look to have much more than about 2-3 degrees. My second option would be re locating the front mount forward about the same 2” and then moving the axle back on the spring to it’s original location. If I do that the axle will have longer spring out front and shorter in the rear than it does now..I know this can have an affect on roll steer sometimes, but it seems to me having it a bit longer to the front might be a good thing. Here’s some pictures of the current set up. I would like to hear some opinions or ideas on ways to correct the geometry on it. I also plan to remove a leaf to soften the spring rate if it still seems to stiff. Also this is a street car and isn’t likely to see any track time. He does do those stupid burnout contests sometimes which I’ve advised him in the past is about the hardest abuse you can put on a drivetrain.
The need to re-locate the upper shock mount is just the beginning: The entire steering linkage from the steering column to the steering box needs a make-over (crap welds on the u-joints, it looks like the end of the steering column was cut off and then welded back on off-center). Are those even automotive springs?, in other words, do the rolled ends have bushings or just a thin nylon sleeve like trailer springs? You're right about the lack of travel on the front spring rear shackle, easiest quickest fix is to have the shackle end of the spring shortened and the spring eye re-rolled as there isn't any room to move the spring shackle mount rearward. Also, it looks like the bolt holding the drag link to the pitman arm is a mile long with spacers and washers and who knows what else holding it together. That thing is an acre of snakes I wouldn't wish on my worst enemy, maybe my ex-wife, but not my worst enemy.
Yeah I haven’t got to any of the other stuff yet. The entire rear suspension was apparently welded by the same guy too. I’m gonna be very busy on this one but first thing I’m sorting out is the spring mounts. This entire set up is sold as a complete package by Speedway. I didn’t t believe it at first either, but he showed me on the website and sure enough it’s sold with the spring mounts in place and comes with those springs. I’ll get to the rest of it too. Side note, you should see the wiring if you think the steering linkage is bad….
A set of springs to built to fit the rest of the layout may be a better approach than to make everything else fit around the original springs which seem too long under load.
Looks like the easiest fix would be to move the front mount forward. It would lengthen the wheelbase, but many people think the wheels pushed forward looks better anyway. On my Henry J, I'm only running the 3 longest leaves and angled the shocks a little bit to soften the ride. It's still firm, but the best combination I've tried so far. Gary
Are the springs for a lighter engine? Looks like they are too soft and maxed out against a notch that looks like it was cut to clear the spring eye. Did you try taking the rear shackle loose and seeing if the spring has any travel at all? Looks like too long of spring or way too soft to support the weight. Just tossing out an idea. Have you called Zach at Speedway and asked him for support? I think they built one of these a few years back. Maybe he can provide the as delivered dimensions to see if someone else modified this somewhere along the line.
Don't gassers normally have the shackle at the front? I've never built one but something I've noticed in other posts on building Gassers.
It's pretty common to put the shackle at the opposite end of the spring, than the steering is at. But it probably doesn't make much difference, really. I have speedway axle kit, but not the subframe, in my Chevy II. I took out half the leafs, so the springs are almost flat when it's sitting. It rides ok. The spring mount will need to move for you to be able to do this, as you know.
Spanners, I've seen builders do it both ways but if you have the shackles in the front the front axle will move forward when you hit a bump, resulting in a "choppy" ride. If you put the shackles in the back, the front axle will move rearward when you hit a bump, resulting in a "softer" ride. My old Ford pickup, the shackles are at the front, my old Dodge pickup, the shackles are at the back.
My thinking on that is that if the steering linkages are in front of the axle the stationary mount would be in front and if behind (rear steer) it would be in the back. It’s hard to say what transpired before he got it but it’s not a well built car at all. I will get it sorted out but literally every aspect of the mechanical part of the car is poorly thought out and or built. The body Interior are pretty nice and it has a ZZ502 so it should run pretty well and potentially very strong with some mods.
That’s what I’m planning to do although it will likely be a trail and error process to get the spring rate to what I think it should be or as close as I can get it. I think it’s sitting a bit too tall as it sits now so that should help out on that too. Squirrel, how much caster do you have in your axle. And if you remember how much rebound travel do you have above the static ride height if you remember?
Caster is around 5 degrees, iirc Mine has 2" travel between spring and bump stop, and just under 3" rebound (how far the axle drops when I raise the body of the car) My springs might be longer...I don't know...
Looking at that subframe if it was me I’d just unbolt the axle and start over. I also don’t like the way the upper bars bolt on and curve. There is no triangulation. I had a 63 Dick Harrell built Nova years ago that worked really well, but scared the hell out of me.
I have the same axle on my 40 Plymouth and I set the caster at about 8 degrees and I still get the death wobble at about 40 if I hit the right bump on one tire, but occasionally.I also lengthened the shackles about an inch or so and that seemed to help the ride and wobble. My shackles are in rear and are about maybe 30 degrees. I really wish I had bucked up for the larger rotors. It stops, but with manual brakes you REALLY have to push on the pedal if you want to stop fast with those pinto rotors. One problem I did have was I thought the king pin bushings were going out on me with only 800 or so miles on it and I grease the hell out of it. After buying a king pin kit and tore it apart I found the problem is the allen set screw for the king pin. Tire had alot of play like pin was shot but found out with the single set screw it was getting play in the axel itself and pin hole. I drilled and tapped the axle and put a set screw above and below the factory one and have put 1500 miles on it since and stays solid. I had to leave all the springs in, but I'm sure my coupe is a bit heavier. 3500# full of gas and with my ass in it.
I’m not sure what they figure the engine weight at but this is an aluminum heads and intake bare bones big block. It’s really no heavier than an iron headed SBC with a few extra pounds in Accessories heater ETC.
Thanks Squirrel, I’ve seen yours in action and it seems to work pretty well and I KNOW you drive it after meeting you at Drag Week a few years back. I got around to checking the caster on it yesterday and it’s + 0.6 degrees so damn near level. I’m gonna have to break the news to him tonight that this thing basically needs taken down to a bare stub and started over. I suspect he already knows this cause he trailers it usually. For now I’m planning on moving the shackles putting shock mounts on that have travel in both directions and removing a leaf of two and getting some caster in it. I’m figuring 4-6 should work although I’ve ran 7 in most of my ford axles. Thanks for the replies and info I’ll update this with results as we go along incase there are others that end up in a similar situation.
5-7 would probably be a good number for caster. Hardly anyone with an axle has the springs as flat as mine, I guess they all think that the idea is to have the axle mounted solid to the car, with the car sitting as high as possible. It looks neat, like a picture out of an old magazine. But if you want to drive a car, the springs have to move. I don't know why no one figures this out.
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