Traction bar question

This is just a quick sketch I made in paint of the traction bar setup I am making for my truck.
I have a couple of questions reguarding bracket and axis locations.
1. The distance between axis A & B?
2. The distance between axis A & C?

A. axle center line
B. Rear traction bar bracket that is captured by the U-bolt.
C. Front traction bar mount location.

Edit: This is with leaf springs.

Jones If I were You I would seriously consider the Cal-trac bars if you are keeping the leaf springs.

lghting94 wrote:Jones If I were You I would seriously consider the Cal-trac bars if you are keeping the leaf springs.

Save some money and try this, I figure I build these for less than $100. I have heard some folks not like this type but there is a lot of Lightnings out there running some fast times with this type of setup. What is the draw back to these?

Depends on how you plan on mounting the ends of the bars if both ends are mounted without a slide or shackle then i believe you have lost all you rear suspension it will be to rigid with no up or down travel. The factory lightnings have an inverted spring in the leafpack that acts like a slapper bar and it works pretty good on a factory truck(i know because i have one) but with the torque of a big block i dont think that will work to well, on my mud truck i have 2x4 box tube welded to the rear differential and going forward to around the front spring mount where it has a poly bushing that hits the frame when the rear rotates much like old slapper bars but not hitting the springs because it will bend them after some hard launches. I am getting my truck to hook up in mud enough to lift the front tires 4-6 inches in the air on a good track.

If you are building something, build a cal trac copy.

http://www.bangshift.com/forum/index.php?topic=7555.0

My Ranger


Another set I made for my buddy's Chevy II

Yea Jones the longer the A to B bar is the more defect you will have and the spring will still want to rap. Hope this helps You want the rear end not to roll but you want a free moving.(no bind) hope this make sence

BigBlockRanger wrote:

Another set I made for my buddy's Chevy II

I like this setup but i would but a few mor holes in the top and one more hole in the bottom thats just me but this right here looks killer good work BigBlockRanger..

Good read! I also enjoyed reading this page. http://www.hotrodsandhemis.com/Traction.html

Question, I thought that truck guys have been having problems with the bell crank lower bolt not being low enough. Did't Dirtmover have problems with his back tires coming off the ground at the hit of the throttle? I thought he ended up making new bell cranks and moving the bars as close to parrell with the ground as posable?

Looks like I am going to have to flip the rear axle also.

Yes he did, and calvert now offers longer bell cranks for pickups too. Dirt_worker's axle was not flipped.

One of his pics before the longer bell cranks were made.


A guy on RPS welded a bracket to the axle tube for his non-flipped axle:

[/QUOTE]

Leafsprings & big at-launch torque numbers are always going to be a pain in the ass. And a relatively high C/G isn't helping matters either.

While a simple "torque bar, plant bar, Shelby bar" (or whatever you want to call it) traction bar like Jones's drawing might halt/slow pinion rotation & spring wrap-up to some degree for a drag car/truck, they do have their problems. The greater the difference between the forward leafspring length & the bar length will increase fighting/binding between the two. And the closer the two are to the same short length, the more violent the suspension will be in a drag racing application. And as for the Caltrac bar design (and similar designs) I think it's been proven many times on these two 460 forums that these bar's violent(ish) design usually work great on lower launch-torque (and/or) small block applications. But they can at times be nothing but massive headaches on big torque applications because of the added torque induced suspension at-launch speed/violence & extra wasted motion (even with the high dollar shocks).


If it has to be a leafspring application, and it's 100% strip use only, I still feel that either a ladder bar or 4-link (and adjustable valving shocks) with spring floaters is the best option, even if the spring floaters are a pain to keep greased/clean.

And if it's going to be mostly a street/street rod/pro street application with leafsprings, I still feel that (A) some kind of a ladder bar setup (or even the NASCAR style traction bars) that are made/modified to "float" at the front pivot mount (either using big super spongy rubber front bushings, or some kind of a shackle pivot mount at the front) could be made to work, or (B) a 4-link with rubber/urethane bushed rod-ends.

Another possible option for a street(ish) application is some kind of a single bar torque arm setup with some kind of a floating front mount. But because of their super long length (& since they do allow body roll) they are probably best left mostly for street use.

Could you show me the part I will need for the ladder bar / leaf spring setup? I think I have seen one before but I,m not 100%

jones wrote:Could you show me the part I will need for the ladder bar / leaf spring setup? I think I have seen one before but I,m not 100%

If your referring to a leafspring floater/slider/pivot setup, there are a few designs out there.


This design is one of the oldest, it's been around forever. It's truly a "floater/slider/pivot" since it allows the housing to both rotate/pivot (on the housing tube's centerline axis) and slide/float forward & back on the leafspring. It's bad points are that it's big & bulky and can wear grooves the housing tubes if you don't keep everything clean & greased.




These three designs below are more "modern".......

This design allows housing rotation/pivot (but it happens at the leafspring instead of at the housing C/L axis). But I don't think you can truly call it a "slider" if you tighten the base assembly U-bolt clamps solid to the leafspring. If you do that it's not going to slide back & forth because the pivot point is a round hole.




This design is similar, but if I remember correctly it's truly a "floater/slider/pivot" since it allows both housing pivot/rotation & foward/back movement. I think this is because the pivot point is a slot instead of a round hole (again....if I remember correctly ).




Another modern design that's kinda similar (and different) to the two above does allow the housing to pivot/rotate & also slide back & forth. It uses similar housing brackets, but instead of the leafspring being "captured" by a bracket & U-bolt clamps, there are two roller tubes (with bearings/bushings inside) above & below the leafspring to hold the leafspring in place (couldn't find a pic).

[Edit] I got to thinking that if you use a floater you will have to flip the housing above the spring cuz I don't think they will work with the housing under the spring (but I'm not sure).

Do you know if someone imports those from Mcdonald bros racing?

Of course if I do this I want to have the proper floater. Might just go with the first one.

Do you know about this type?

jones wrote:Do you know about this type?

Those are what I plan on using on mine you trim the bolt sleeves to allow enough space for them to slide on the leaf pack and the suspension height is adjustble with the multiple mounting holes. Of all the designs I like them the best and Jegs markets them for a good price.

How much do these setup move along the leaf springs? I have decided that is the way I am going to go with the suspension on my truck. The local 275 class requires stock suspension.

jones wrote:Do you know about this type?

That is another design that allows the housing to both rotate & also float/slide.

Jones...I've got a few extra pairs of the laser cut front and rear cal trac style mounts if you're interested. Same as I put on mine. It's all about the geometry. Pm me if you're interested and I can fill ya in on how I got mine to working.
Mike

jones wrote:How much do these setup move along the leaf springs? I have decided that is the way I am going to go with the suspension on my truck. The local 275 class requires stock suspension.

I think the slot is the limiting factor which the center pin of the leaf pack will ride in, I would imagine if you need more travel you could simply chuck them up in a Bridgeport and lengthen the slot.