I've been doing alot of reading on Caltracs, pinion snubbers and suspension in general. I'm leaning towards Caltracs at the moment because you can adjust them to help the car launch straight, but I wanted to hear from the people I trust, my fellow slant 6 maniacs. I've also been finding less info on stick cars than autos

Current setup: 13.0@110 2.0 60ft on that run
Front shocks single adjustable strange engineering
Rear shocks single adjustable strange engineering
SS leaf springs
275 60 /r15 mickey thompson drag radials
3.73 rear gear t5 tranny first gear is pretty steep don't recal ratio maybe 2.94??
The adjustable shocks got me down to 1.9 60fts without 2 stepping but it will spin if i 2 step. before the shocks could barely get a 2.0 without really launching. Other than 1st gear the duster doesn't spin in any other gears except into 2nd gear on a very hard shift once in a blue moon

Kev

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I would say Slantzilla and Seymour are the resident experts here on those devices, maybe Covalts and madmax/6 too.

Lou

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Home of Slant6-powered fun machines since 1988

Only my opinion, but I wouldn't have a pinion snubber if you gave it to me.

One problem with Cal-Tracs is they are so adjustable you can get yourself in trouble if you play with them too much. Keep really good records of what you do and it's effect.

I also had real good luck with just a pair of clamp on slapper bars. You can make shims and adjust them too. I went a 1.57 60' with them on my '66 on ET Streets.

Do you have any video of your car? That will be invaluable when trying to sort out launch issues. Spin issues can be caused by the front suspension just as much as rear, especially if it is not lifting the nose.

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Official Cookie and Mater Tormentor.

Boy, does that question has been debated by multiple internet pundits in multiple forums.

The first question that you need to ask yourself, is my car, a street car that I occasionally race or a race car that you occasionally drive on the street. Once that question is answered, you can make a realistic choice.

A leaf spring has a tendency to turn into a "S" shaped pretzel when torque is applied. It also flex and elongates during normal usage. Leaf springs have two sections. Chrysler designed theirs to have a shorter front section. This has a tendency to restrict the "S" shaped pretzel and to some people give magical properties to them. But, this was only good enough to allow your Dad to outrun the the other guys Fairlane from the stop light, with his Cornet.

Most leaf spring traction aids, restrict this natural motion in some way or fashion. Those traction aids can be broken down into four categories.

Category one is all about stiffing the front segment of the spring. This can be done by changing out those 50 year old 4 leaf springs to 5 or 6 leaf springs. For most /6 people this will be good enough.

If that doesn't work you can always try adding spring clamps. This clamps the front segment of the spring together and hopefully eliminates the "S" pretzel. Another variation on the theme is the South Side Machine Bars. These are a set of bars that replace the shock plates and extend to the front of the spring where they are clamped on. They will eliminate the "S" pretzel at the cost of spring elongation. Both should be considered a race only modification, as they will eventually wear out the springs.

Category two is what I would call single pivot traction aids. This includes the SS springs with pinion snubbers, slapper bars and ladder bars with spring sliders.

SS springs and slapper bars work in a similar fashion, SS springs have a stiffer front segment to eliminate the "S" pretzel and the pinion snubber forces the tire into the ground when it contacts the floor pan. The slapper bar bolts to the leaf spring and has a fixed bar the eliminates the "S" pretzel when the front pinion "slaps" against the front spring eyelet while also forcing the tire into the ground as it does so. Both were designed in the early to mid '60s to fit within NHRA rules for specific classes. Slapper bars can be preloaded with the usage of shims under shock plates and/or the front rubber pinions. SS springs have a higher arch so you can run a taller tire without modifying sheet metal.

I would consider SS springs and pinion snubber a race only modification.

Ladder bars with spring sliders are a race only modification. They have one end welded to the axle housing. A plate that "slides" on the leaf spring and the other end welded to the chassis. They work by lifting the chassis and forcing the tires into the ground. They basically reduce the leaf springs to only supporting the weight of the car.

Category three is what I call dual pivot traction aids. These include "under riders", "Shelby bars" and Ansen Ground Grappers. They all work with a one pivot point under the axle, a bar extending to the front of the axle and another pivot point attached close to the front spring eyelet. "Under rider" and "Shelby bars" have the pivot point welded to the chassis in of the front spring eyelet and the Ansen Ground Grappers have the front pivot point bolted to front spring segment. They all do a good job of eliminating the "S" pretzel at the cost of restricting the elongation of the springs. The "under riders" and "Shelby bars" do nothing to force the tires into the ground. The Ansen Ground Grappers have a unique twist in that the lower bar extends past the axle pivot point some inches and provides a bolt hole that basically converts them into a fancy version of the South Side Machine Bars when a bolt is inserted. They may force the tires into the ground.

Category four is what I call multi-pivot traction aids. This includes the Calvert setup, CE Slide-a-Links, the Assassins and Chrysler's Leaf-Link. They all work in a similar fashion. They all try to convert the front segment of the spring into one half of a four bar setup. They were all developed to get around some NHRA rules about modifying the leaf spring suspensions in some racing class. The Calvert, CE and Assassins have a one pivot point under the axle, a bar that extends to another pivot point on a bell crank. The bell crank pivot point is then attached to the spring eyelet bolt or the front segment of the sprint. The other end of other the bell crank applies force against something. This something eliminates the "S" pretzel and forces the tires into the ground.

The Leaf-Link was Chrysler's attempt to emulate a 4 link. It works with a pivot point under the shock plate with a bracket welded to the bottom of axle. A upper link is attached to the top of the axle with a heim joint and extend to the chassis where is was attached to another heim joint. This setup had limited adjustability and is described in the late '70s DC chassis manual. It is race only and obsolete.

I feel that the Calvert s and Assassins are not good street setups, well the CE bars have limited usage. When you install the aluminum bushing, you remove the flex from the spring. They also limit the elongation of the spring. The CE bars do slide and thus solve that problem.

Which one should you use? That depends on your answer to the first question and how much money you want to spend.

My '65 Dart suffers from excessive wheel spin, and it may even hop a little bit when I do get traction. But then I have 40 year old 5 leaf springs. My problem may be solved by installing new springs, but I won't know until I try that. If that doesn't work, I would then install a set of used slapper bars and go from there.

The reality is that any traction aid for a leaf spring car is a band-aid. The only good solution is to bite the bullet and convert to a 4 link. But that is a three to five thousand dollar solution.

Of the bolt-on bars Cal-Tracs are the most streetable, but Calvert will probably tell you they do NOT recommend using them with SS springs. I do not know why, but that is what they told me.

What is the weight distribution on the car? If it is nose heavy by a bunch you will play hell ever hooking it up without slicks and some traction aid. You want to be as close as possible to 50-50 front to rear.

How much burnout do you do? Are your burnouts consistent? Line loc?

What torsion bars and are the shocks set loose on extension in front?

While I agree that anything you do to a leaf spring car is technically a band aid, you can do a lot of patching before you get to the point of needing a ladder bar/coil-over or 4 link, especially with an 11-13 second car.

Once again, get video of the car to confirm what it is actually doing. Seat of the pants feel does not always tell the truth.

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Official Cookie and Mater Tormentor.

As has been said before. S.S. Springs will wrap up too and it ain't pretty! Ryan's Dart is a fully street driven, 3300# car and with slicks and the snubber up close it will launch fine, but it will totally destroy the floor pan. It just isn't strong enough for the hit of the rear end on slicks.

When I go to the stick in my car I will have to run something more substantial like the Cal tracks ...etc

Like Dennis said a decent set of slapper bars will go pretty far for a lot less money. I hope to run some 12.90's next season!

Rick

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

My duster is daily driven to work, school and back home from Tallahassee to Tampa bay area on a regular basis. I'll have to get better video of the car launching and post it this link is with the adjustable shocks but before the line lock or 2 step hence the weak burnout. I'll dig through some videos I believe I have some practice 2 step launches somewhere.

The floor crushing thing is the only thing that concerns me about the pinion snubber because I'm looking to turn the boost up still and start being able to really launch this thing eventually.

https://www.youtube.com/watch?v=iaCw3v39dYE

Thanks for the info guys i'll get some more info and videos

Kev

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