Looking for advice on which direction to go with a leaf spring car for auto x ? Not many street miles so not worried about comfort so can be aggressive! Has anyone ran the global west cat 5 bearings in a leaf spring car? Does it work ? To allow the leafs and axle to rotate Or do you prefer the direction of solid bushings and a panhard bar ? Car is a 76 nova 3100lbs w/driver thank you
You might be surprised at how much good a panhard bar will help. Some cars, the leaves have enough side flex that it really can make the rear a little less planted.
What kind of power is it getting? If it's enough to wrap springs, that could cause some unpredictable traction coming out of the corners.
Upgraded sway bars front and rear?
Not much to do on a leaf spring.
On both my AMC Spirit and my Plymouth Duster I found very good success with a flat leaf pack and leaf spring sliders instead of rear shackles. That limited the amount of side to side Flex and really made the rear end act much more behaved especially after being paired with good shocks that were very vertical and orientation
I always wondered if taking some of the roll-understeer out of a leaf spring car for lower-speed auto-x, by using rear shackles and flattening the springs, would help or hurt. Someone else would have to say. I wouldn't suggest it for high-speeds.
In reply to Curtis73 (Forum Supporter) :
Power is roughly 425 to the wheels, small block with a 4 speed. Yes upgraded front and rear sway bar. Just seeing if anyone has experience with those global west cat 5 bearing kits for leafs
In reply to Dusterbd13-michael :
As soon as I saw this thread I thought of you and what you worked out on some vehicles you have owned. For curiousity's sake, as I don't currently own a leaf-spring equiped vehicle; where did you get the sliders from and what are they like to live with on the street? Did you also use a Panhard bar or Watts linkage? I know you've explained this before...
If it doesn't have a rear sway bar of ample proportions start there.
"the best suspension is the one that doesn't move unnaturally."
Sliders, solid metal bushings if not ball bearings, and the best shocks money can buy are my gotos. Autocross, road race, drag racing.....
pres589 (djronnebaum) said:In reply to Dusterbd13-michael :
As soon as I saw this thread I thought of you and what you worked out on some vehicles you have owned. For curiousity's sake, as I don't currently own a leaf-spring equiped vehicle; where did you get the sliders from and what are they like to live with on the street? Did you also use a Panhard bar or Watts linkage? I know you've explained this before...
The sliders came from speedway motors and afco. The besring style was the better of the two. No panhard or watts was tried by me.
On the street, the car rode softer than the rate suggested it should, but was far more planted with less wheelhop. It also transferred a lot more noise into the interior.
Just seeing if anyone has experience with those global west cat 5 bearing kits for leafs
I was pretty interested in these as well, but like you I was not able to find any good info. Global West does not offer a size that works for my application anyway, but I'm fascinated by the idea of allowing the springs to rotate as the axle articulates and it sounds reasonable in theory.
Absent good info though, I'm left to guess that it may not lead to profoundly better handling or there would be more examples of this setup in use.
Watts links are better than Panhards if you have the space for them.
I set my MG race car up by installing spacers between the top and bottom leaf spring plates so the spring could slide between them, and adding traction bars, an upper locating link (some use two, one on each side on the top of the case) and a Panhard - locating the ends as far apart as possible. Worked quite well, although traction out of a corner was not quite as good as with another IRS car I ran that used the same engine power. It took an LSD in the MG to equal the IRS times.
I haven't used the Global West parts but I ran spherical joints in the front spring eyes and sliders in the rear on my 640 HP road racing Camaro with good results. The car responded to chassis adjustments in a predictable way and was able to put down the power as well as could be expected.
I would second this. Throw some kind of third link on top of the punkin (or traction bars underneath) to stop the wrap. The panhard will do amazing things, though.
Leaf spring sliders do help to eliminate the side-to-side, but they have downsides, like a complete and utter lack of precision (location) that will speak to you loudly when going over bumps. They only work right when the car is fully weighted.
If you don't have a welder, none of this matters.
Curtis73 (Forum Supporter) said:You might be surprised at how much good a panhard bar will help. Some cars, the leaves have enough side flex that it really can make the rear a little less planted.
What kind of power is it getting? If it's enough to wrap springs, that could cause some unpredictable traction coming out of the corners.
Upgraded sway bars front and rear?
Not much to do on a leaf spring.
Loren_SD said:I always wondered if taking some of the roll-understeer out of a leaf spring car for lower-speed auto-x, by using rear shackles and flattening the springs, would help or hurt. Someone else would have to say. I wouldn't suggest it for high-speeds.
This used to be the go-to thing to do for this reason on Pintos and Capris, in the US. Loooooong shackles and lowering blocks. You pretty much need a Panhard at that point.
I mean, one could also go full Group 4 Escrot and cut the eyelet off the front of the spring, install a roller, and use a parallel 4 link and Watts to locate the axle, so the leaf springs only function as springs, but this is probably well beyond the scope of the project.
Friends did a panhard in the back of their 64 Fairlane and said it was the biggest improvment they've seen of any suspension modification.
In reply to Pete. (l33t FS) :
That Ford Econobox set up sounds interesting. Did they retain shackles on the rear mount of the springs or do something different? How is the front of the spring held up?
What class are you running in?
Some s10's use a anti hop shock as a 3 link with movement to prevent binding.
Panhard rod works well in one direction and lifts the inside rear in the other. Watts is center based, works better
Racingsnake said:In reply to Pete. (l33t FS) :
That Ford Econobox set up sounds interesting. Did they retain shackles on the rear mount of the springs or do something different? How is the front of the spring held up?
Technically the body holds the spring down 
https://www.doublegmotorsport.com/rsprep/prepindex.html
It's 5.9 in the rear suspension PDF.
also exact measurements for making a 4 link, which was copied by many other manufacturers.
I love the gearbox section. Make the transmission a 2 minute swap by leaving the input shaft on the bellhousing, and two bolts accessible from inside the car!
This is all well over 50 years old at this point and amazing to see what was done back in the day. And Ford was essentially freely giving this information out so privateers could run and be successful too.
porschenut said:Panhard rod works well in one direction and lifts the inside rear in the other. Watts is center based, works better
Yup - but on many cars there isn't enough room between the diff and the gas tank to fit one in. I guess that is a good reason to go to a trunk mounted fuel cell on a race car, but that's a bit radical on a street non-competition car.
Panhard rods don't work like that unless they are installed really, really wrong
The problem with a Watts is that you really want to mount the center to the body and the ends to the axle, so the roll couple stays consistent. Most rear drive cars have the gall to put a fuel tank right where you'd want to do this.
One of the big issues that first generation RX-7s had was that the Watts was mounted 40mm above axle centerline, which is pretty close to the car's center of gravity, so the roll couple would change dramatically depending on the rear ride height. Not as bad as, say, a swing axle car where the roll couple could actually change signs, but it would lead to some interesting moments. I am 99% sure that this is why Mazda originally used a REALLY REALLY BIG rear stabilizer bar. A suspension that doesn't move doesn't do anything wrong, or something.
This is a lot of why serious racers would ditch the Watts for a nice consistent Panhard rod.
A Fay's II watts link transformed my 68 Mustang. Urethane front bushing ,stock soft rubber rear.
Front half of leaf pack stiff,like 4 1/2 leaf,rear soft ,Main leaf with eye,next 2/3 from axle,3rd 1/3. It is very soft compared to what is thought as normal. Double adjustable Viking shocks.
I have no data but just by watching videos of my car I lack forward bite at the start and slow turns. Medium to higher speed exits the car will roll to the rear and drive out pretty good.
The F2 mounts the propeller to the chassis ,the center is never above a line from the axle center line and the bottom of the spring perch in my set up. Massive (fun) oversteer results when the RC gets above the axle center line. I know many don't like the Goodguys small auto cross set ups but a tail happy set up makes for great turn in!
Pete. (l33t FS) said:I mean, one could also go full Group 4 Escrot and cut the eyelet off the front of the spring, install a roller, and use a parallel 4 link and Watts to locate the axle, so the leaf springs only function as springs, but this is probably well beyond the scope of the project.
Would it be easier at that point to ditch the leaf springs entirely and run coilovers? 4 link + Watts (or Panhard) and the leaf is there for the spring action only, but it seems like coilovers would offer better availability of different rates and possibly weigh less. Right/wrong?
My opel GT had a panhard rod, would lift the rear tire when turning hard in one direction which was a real problem with an open diff. In the other direction it would corner great with no wheel lift. So I guess opel didn't know how to do it.
In reply to pres589 (djronnebaum) :
Rules depending, that's what they did. Or ran coilovers and a technically-a-spring.
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