traction bars 101

I ran a real suspension for years on my gen 1 (a 4 link) and any suspension besides a 4 link has "bind" so lets clear that up.
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Where is the bind in the stock suspension? There is none. Why introduce it unnecessarily?
Also I said that bar type suspensions have bind but what you failed to say is that the longer the bar the less bind there is ($99 bars have way more bind that long bars).
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You said that the longer the bar the less bind. Wrong. There is an optimum length for a long bar – a length (and angle) whose arc would most closely replicate that of the leaf/axle assembly. What is that length? Without measuring I don’t know – but it wouldn’t be terribly difficult to find out.
Now you tried to explain "instant center" and "anti-squat" to all these guys and I think you just confused them even more. You stated that positive anti squat as the thing that will determine traction but you are wrong. Although it is a good contributer of that it is only 1/2 of the formula. The other half is the first item you talked about and that is the instant center. Now anti-squat should not be positive or negative it should be at 100%. if your vehicle is "squatting" or "separating" you are absorbing energy that should otherwise be moving you forward.
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You’re misquoting me. I never used the terms positive or negative (anti)squat. Anti-squat is expressed as a percentage. What percentage of anti-squat that is necessary is going to vary from application to application (not necessarily 100%) but in general - vehicles set up for drag racing run high percentages of anti-squat. As an example: a stock fox body Mustang has 39% anti-squat. Bolt on some Southside Traction Bars and that number goes to 109%. The point of my comic book illustrations was to demonstrate that Caltracs have a higher percentage of anti-squat than long bars. Or as I put it in my original post…

What this means from a practical perspective is that you can hit the tires harder with Caltracs than you ever could with long bars

The instant center being more forward for the long bar is much more important for our trucks then the anti-squat from the caltracs. If our trucks were shorter and had less weight on the nose the caltracs would work better with no doubt.
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You do know that these ‘trucks’ have a better weight distribution than a Mustang don’t you? I know you like to use the generic ‘truck excuse’ to explain away things that don’t jive – but the truck doesn’t know it’s a truck. It’s a vehicle that responds to the same physics as any vehicle. I know of an 83 full size Chevy running 10’s pulling 1.32’s @ 4200lbs on Caltracs. Do I need to tell him he can’t do that?

As for moving instant centers forward to provide lift: I’ve read it both ways but Bill Shope, retired Chrysler/GM engineer and one of the original Ramchargers, says it bull****.

The notion that a rear suspension instant center forward of the center of gravity will somehow aid in lifting the front of the car is simply not true. If it were, it would logically follow that an IC located an infinite distance forward...as with a parallel 4bar arrangement...would result in a violent blowover! Again, all that is important is the location of the IC relative to the rear tire patch, or, specifically, the tangent of the line passing through the IC and the rear tire patch.

What happens with the caltracs is that they "plant" the tires when you launch but the power to weight ration of most trucks can't maintain that pressure and then the suspension unloads and you spin the tires.
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You’re right… that scenario is entirely possible on a poorly set up truck. It’s a combination. Are you saying that you couldn’t tune all of that out with some double adjustable shocks front and rear? Throwing a set of Caltracs on a truck without any other changes and expecting instant hook is retarded.



I didn’t intend for my original post to be anything more than a very broad overview. Simplistic. You bet. I didn’t need to get bogged down in formulas and esoteric crap to make a point. But the principles I illustrated are valid. On reflection I would only rephrase two sentences for greater accuracy:

Anti-squat is a by-product of the geometry of the rear suspension where the axle ‘pushes’ away from the body of the car (via the lower link) under acceleration (this is called ‘separation’).

As you can see from the pictures the Caltrac’s geometry promotes a higher percentage of anti-squat than longbars.
 
Well I see that your looking to pick a fight but I'm not so I'll try and answer as best as possible

blownragtop said:
Where is the bind in the stock suspension? There is none. Why introduce it unnecessarily?

I wasn't referring to a stock suspension when I said that (you know that) were talking differences in traction devices and that is what I was referring to.


You said that the longer the bar the less bind. Wrong. There is an optimum length for a long bar – a length (and angle) whose arc would most closely replicate that of the leaf/axle assembly. What is that length? Without measuring I don’t know – but it wouldn’t be terribly difficult to find out.

Your right there is an ideal length but the $99 bars aren't it! It's the same as bump steer on the front of a vehicle!

You’re misquoting me. I never used the terms positive or negative (anti)squat. Anti-squat is expressed as a percentage. What percentage of anti-squat that is necessary is going to vary from application to application (not necessarily 100%) but in general - vehicles set up for drag racing run high percentages of anti-squat. As an example: a stock fox body Mustang has 39% anti-squat. Bolt on some Southside Traction Bars and that number goes to 109%. The point of my comic book illustrations was to demonstrate that Caltracs have a higher percentage of anti-squat than long bars. Or as I put it in my original post…

For the record there IS negative anti-squat and a mustang has a negative -40.4% and I attached a picture to prove it.

What this means from a practical perspective is that you can hit the tires harder with Caltracs than you ever could with long bars



You do know that these ‘trucks’ have a better weight distribution than a Mustang don’t you? I know you like to use the generic ‘truck excuse’ to explain away things that don’t jive – but the truck doesn’t know it’s a truck. It’s a vehicle that responds to the same physics as any vehicle. I know of an 83 full size Chevy running 10’s pulling 1.32’s @ 4200lbs on Caltracs. Do I need to tell him he can’t do that?

First off I never said that you can't make caltracs work. Second off trucks do behave different because of weight and height compared to a car. If they have so much better weight distribution then a mustang then why do we see guys using trucks instead of mustangs? The might transfer weight better (I still don't agree with that) but they can't maintain that weight transfer (well at least not in the average power level that we see) JLP has gone 9.50's pulling consistent 1.40's @ 4400lbs on his long bars. Do I tell him that he can't do that?

As for moving instant centers forward to provide lift: I’ve read it both ways but Bill Shope, retired Chrysler/GM engineer and one of the original Ramchargers, says it bull****.

The notion that a rear suspension instant center forward of the center of gravity will somehow aid in lifting the front of the car is simply not true. If it were, it would logically follow that an IC located an infinite distance forward...as with a parallel 4bar arrangement...would result in a violent blowover! Again, all that is important is the location of the IC relative to the rear tire patch, or, specifically, the tangent of the line passing through the IC and the rear tire patch.

There is a limit to everything as I and everyone else knows but the instant center DOES make a difference. I'm not sure how many gen 1 guys you know or not but here is an example. My good buddy Jody has a gen 1 that runs 10.0's his truck has gone 1.4X 60' times. His truck picks the wheels up 2+ feet all the time. My buddy Keith has a gen 1 that runs 10.0's his truck has gone 1.4X 60' times but picks the wheels up only a couple inches. What is the difference??? Keith has 36" long ladder bars and Jody has 54" long ladder bars. Jody's instant center is also 6"-8" higher then Keith's, and to top it off Jody's truck is WAY more front end heavy. The instant center makes a big difference. My truck when it had the 4 link would run run 10.0's and go 1.32-1.35 60' times with the wheels up 4"-6". It had a instant center similar to Jody's length but lower like Keith's. It's about length and height (and proper ones for a combo)

You’re right… that scenario is entirely possible on a poorly set up truck. It’s a combination. Are you saying that you couldn’t tune all of that out with some double adjustable shocks front and rear? Throwing a set of Caltracs on a truck without any other changes and expecting instant hook is retarded.



I didn’t intend for my original post to be anything more than a very broad overview. Simplistic. You bet. I didn’t need to get bogged down in formulas and esoteric crap to make a point. But the principles I illustrated are valid. On reflection I would only rephrase two sentences for greater accuracy:

Anti-squat is a by-product of the geometry of the rear suspension where the axle ‘pushes’ away from the body of the car (via the lower link) under acceleration (this is called ‘separation’).

As you can see from the pictures the Caltrac’s geometry promotes a higher percentage of anti-squat than longbars.
But that doesen't mean that is what will work better!
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I'm not going to argue here back and forth. This is stupid. I don't know how much you actually know or how much you know in "theory" I have had over 10 gen 1 lightnings. I have had leaf springs, ladder bars, and a 4 link. I have use stock slapper bars, long bars, and caltracs. I talk from Gen 1 experiance. Could you make caltracs work? Apsolutly! Thats why I wrote that they "were" a traction aiding device unlike those $99 bars, but for the average guy they are too complicated and are too noisy. For that average guy the long bars when just bolted on will help to hook better then the caltrac's that are just bolted on. These guys don't want to buy the long bars because they are too much money. Do you think they are going to buy adjustable shocks? :blink: I will say that the long bars are the best "bolt on" traction devices for a gen 1 and whether you agree or not that is the 100% truth! I have see way to many guys take caltracs off and put long bars on and pick up 60' times. :eek:ldtu:
 
Wow.. This is confusing!

If I could afford long bars I would get them. But I cant so Im just getting duff bars to stop wheel hop. My truck is my DD also.
 
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Well Jamie… whatever works for you. I still don’t “get” long bars but I at least understand your reasoning. I just don’t see any science to support it. Shope addresses weight transfer and the next to last sentence of that page condenses this discussion nicely.

Note that, in determining the value of the weight transfer, no consideration is given to the "internal" workings of the suspension. Suspension design parameters affect weight transfer only when they affect CG height and tractive force.

P.S. I never said that anti-squat couldn’t be negative; and since negative values aren’t relevant to the discussion there’s no need to muddy the waters. The values that I listed for a Mustang are lifted straight from Mathis’ book. The numbers aren’t really important – just the principle that bolt on traction devices (other than long bars) are designed to increase anti-squat. (And for what it’s worth Ford revised the Mustang’s rear suspension mid year 84 by lowering the control arms pivot points. Mathis based his calculations on those revised locations. Any guesses as to what lowering the lower control arm axle mount would accomplish? ;))
 
blownragtop said:
Well Jamie… whatever works for you. I still don’t “get” long bars but I at least understand your reasoning. I just don’t see any science to support it. Shope addresses weight transfer and the next to last sentence of that page condenses this discussion nicely.

Note that, in determining the value of the weight transfer, no consideration is given to the "internal" workings of the suspension. Suspension design parameters affect weight transfer only when they affect CG height and tractive force.

P.S. I never said that anti-squat couldn’t be negative; and since negative values aren’t relevant to the discussion there’s no need to muddy the waters. The values that I listed for a Mustang are lifted straight from Mathis’ book. The numbers aren’t really important – just the principle that bolt on traction devices (other than long bars) are designed to increase anti-squat. (And for what it’s worth Ford revised the Mustang’s rear suspension mid year 84 by lowering the control arms pivot points. Mathis based his calculations on those revised locations. Any guesses as to what lowering the lower control arm axle mount would accomplish? ;))
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lowered the front or rear mounting points? Just curious
 
blownragtop said:
Well Jamie… whatever works for you. I still don’t “get” long bars but I at least understand your reasoning.
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Well at least we can just agree to disagree!:eek:ldtu:

Non of us "lightning" guys though the long bars would work 10 year ago either. We all gave the same reasoning you gave for the caltracs and such. Thats why a bunch of us use to use them. but after some guys started running long bars and having better success some of the caltrac owners started to switch and also saw better results. I don't know "why" they work better???? Possibly not enough power for the weight? Possibly not enough time spent in adjusting them? (but we sure worked on that?)

all I know is I went right to a 4 link and loved it. I have since switched to a "custom" ladder bar for a class regulation. and I hope it works as good for me as the 4 link did.

My last main point for the long bar is this. There are so many factors to racing (as most know) and having guys wondering if they have their caltracs adjusted right just adds one more. With the long bars, guys put them on and they are what they are. Noting to think about or worry about. Most guys just want something to "bolt on".

I hope guys can read this thread and learn that they have to make up their own minds on what is best for them. If a guy has no money just get the $99 bars to prevent breaking the rear end. If a guy wants the "no adjustment" factor and wants what has worked for years for most others then go with the long bars. If a guy want to have "adjustability" and wants to try and squeeze every last ounce out of his stock suspension. and isn't afraid to adjust on things then try the caltracs.

Good luck to everyone with their decision! :thumbup:
 
after reading the entire thrad, getting confused a few times, reading some more ... seeing some arguing ... i have just one question:

What should a guy do (a guy like me) who has 2 trucks with axle flips do for a traction control/wheelhop device??
 
Bootleggers DLX said:
after reading the entire thrad, getting confused a few times, reading some more ... seeing some arguing ... i have just one question:

What should a guy do (a guy like me) who has 2 trucks with axle flips do for a traction control/wheelhop device??
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My red truck had an axle flip with cal-tracs, i didnt read this post. But I know i didnt have traction problems.
 
As much as I hated my cal tracs,...I would use them on your truck just for the ground clearence.
 
they made the truck ride rough,rattled terribly....but the worked.and yes i towed with them on.
 
I'd build one on top of the springs if I was in your shoes, but I can weld/fab. It won't work as good, but in your situation I believe it's the best compromise.
 
Am I understanding correctly that the brackets that bolt to the rear end are stock on a ranger? If so then a set of stock bars from an explorer could be adapted to the lightning with just a little drilling of the frame to mount the other end. Brackets could be made easily to mount them at the springs if necessary too.
 
blakshukvw said:
Am I understanding correctly that the brackets that bolt to the rear end are stock on a ranger? If so then a set of stock bars from an explorer could be adapted to the lightning with just a little drilling of the frame to mount the other end. Brackets could be made easily to mount them at the springs if necessary too.
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No, the traction long bars we use are nothing like anything that came factory on a ranger or exploder. They are all aftermarket.
 
After reading this whole thread my mind is a bit boggled but very good information and loved the back and forth :) . Shows passion.

But either way i am looking at doing long bars, I have a 2" shackle drop in the back and 1" spring drop in the front. Everything else is stock but with the new shift kit and bigger injectors, intake, etc i am noticing some wheel hop and i plan on turbo or s/c in the future and would rather get it right now.

Is there a link to a kit for the long bars and if so do i sill have to fab anything when i put them on? Any write ups on how to do it?
 
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