Traction bars question

[ksnow]

I am working on the AMT Baldwin Motion 70 1/2 Camaro, and am having issues getting the trac bars to sit right. I am not that familiar with 1:1 trac bars, is the leading end supposed to touch the leaf spring? Or should there be a gap? Form dry fitting, it appears that the shock needs to be shortened slight for the trac bar to sit level side to side and have the front touching the spring. If I level the trac bar, the front would be dropped down, with a noticeable gap between the front and the spring.

Thanks in advance.

 

Oh, and if it matters, this is a circa 1998ish release.

[Rob Hall]

Pics I've seen of old cars with them, there is usually a gap between the rubber stop on the bar and the leaf spring.  I think they are supposed to prevent/reduce leaf spring windup under acceleration?

[Plowboy]

There should be a slight gap between the snubber and spring. 

[Muncie]

Generally, there should be a gap.  The gap can be adjusted by changing the height of the snubber to tune the rear suspension for harder or softer launch.

traction bars - 1971 CHEVROLET CAMARO Competition Engineering C2103 Competition Engineering Leaf Spring Traction Bar Kits | Summit Racing

instructions here for traction bar installation and tuning -    C2101C2103Bolt On.doc (summitracing.com)

[ksnow]

Thank you for the pics Rob. I knew their function, just wasn't sure on the geometry. Looks like I need to do a little detail painting first though.

[ksnow]

Thanks everyone. 

[Ace-Garageguy]

They're more correctly called "slapper bars" (though nobody much cares about word meanings anymore), and as said above, they don't necessarily touch the spring at the forward end.

Actual "traction bars" are a different animal and function somewhat differently.

 

 

 

Edited April 12, 2022 by Ace-Garageguy

[ksnow]

Thanks Ace. Thats the instruction sheet. Not real clear on alignment for someone not real familiar with trac bar setups. I'll get it sorted out now that I see the other pics and understand how they work.

[peteski]

31 minutes ago, Ace-Garageguy said:

They're more correctly called "slapper bars" (though nobody much cares about word meanings anymore), and as said above, they don't necessarily touch the spring at the forward end.

Actual "traction bars" are a different animal and function somewhat differently.

I have learned something new.  Until now I never heard of slapper bars.  But the misnomer is nothing new.  When I was a young guy, and into souping up cars (about 40 years ago), even then we all called those things "traction bars". 

[Plowboy]

16 minutes ago, peteski said:

I have learned something new.  Until now I never heard of slapper bars.  But the misnomer is nothing new.  When I was a young guy, and into souping up cars (about 40 years ago), even then we all called those things "traction bars". 

I've heard them called both. But, they're the same thing. I always called them traction bars.

[peteski]

4 minutes ago, Plowboy said:

I've heard them called both. But, they're the same thing. I always called them traction bars.

It might be a "regional thing" like many other phrases in the American English language.

[Ace-Garageguy]

1 hour ago, peteski said:

I have learned something new.  Until now I never heard of slapper bars.  But the misnomer is nothing new.  When I was a young guy, and into souping up cars (about 40 years ago), even then we all called those things "traction bars". 

"Slapper bars" were developed for street-strip dual-purpose cars because "traction bars", by virtue of their more solid mounting, with bushings at either end, could introduce a lot of ride harshness into a vehicle. Slapper bars only function during hard acceleration, when the rubber snubber at the forward end contacts the spring to limit spring "wrap-up". They can also be easily "tuned" for conditions.

The rest of the time, you can't tell they're there...other than an increase in unsprung weight that some sensitive drivers can actually feel.

"Traction bars" work differently. They bolt to the spring retainer on the axle like the slappers, but also are pivoted to a solidly mounted bracket at the forward end of the spring. They eliminate any spring-wrap-up, but as I noted, they often also introduce harshness during normal driving.

Edited April 12, 2022 by Ace-Garageguy

[Plowboy]

9 minutes ago, peteski said:

It might be a "regional thing" like many other phrases in the American English language.

May be. But, they're basically the same thing. Ladder bars, however, are different. 

Edited April 12, 2022 by Plowboy

[peteski]

Thanks Bill!  Like I mentioned, I learned something new.

I was just a young kid with a 1976 Camaro, not a a high-performance expert.  And despite of agreeing that the world population has really dumbed down,  the improper usage of the phrase is nothing new.

[Ace-Garageguy]

1 minute ago, Plowboy said:

May be. But, they're the same thing. 

No, they're not. They are similar, but different.

[Muncie]

[Ace-Garageguy]

Prior to about '67, "traction bars" were as I noted above, i.e. Traction Masters brand.

https://www.npdlink.com/product/traction-bars-traction-master-style/202903

With the development of slapper-bars to give better ride under normal conditions, the nomenclature "slapper bars" was used to differentiate between the two designs.

Later, as is always the case, the definitions got cloudy...and many folks called everything that had a similar function "traction bars" (including ladder bars/lift bars, though they also function differently).

But y'all can call 'em cheese doodles for all I care. People will still argue endlessly about what "lakes pipes" are too.

https://www.jalopyjournal.com/forum/threads/slapper-bars.585811/page-2

Edited April 12, 2022 by Ace-Garageguy
TYPO

[1972coronet]

I, too, didn't realise there was a difference in not only nomenclature, but in functionality. Thanks for the new-to-me info, @Ace-Garageguy. 

I've heard both names employed, and have read the same. Like any colloquialism, one predominates the other, however in misnomers (e.g., "rear window" vs. "backlight". A fixed/stationary piece of glass is a "light"; a "window" can be repositioned/opened. That didn't stop the manufacturers from employing both terms in literature: "rear window defogger" and "backlight louvers", etc.).

Any time I see a torsion bar equipped car (Chryslers, i.e.) with slapper bars, I cringe. Even the factory race cars (typically, 426 Max Wedge / Ramcharger) had the 'bars affixed from the axle-rearward. Then there's the Cal-Tracs for MoPars... quite likely true traction bars as Bill has pointed out (please correct my info if it's incorrect).

[Bills72sj]

For correct positioning, the rubber snubber tips should be mounted right under the front leaf spring eye.

Here are some 3 printed ones I got on Shapeways.

[DRIPTROIT 71]

6 hours ago, Bills72sj said:

For correct positioning, the rubber snubber tips should be mounted right under the front leaf spring eye.

Here are some 3 printed ones I got on Shapeways.

There were a few different mounting designs. I ran a set on my 66 Satellite. They only had two u-bolts, one in front of the axle and one behind, and they were not nearly long enough for the snubber to reach the front eye on the leaf spring.

[Ace-Garageguy]

Just a note of clarification...it's really kinda OK to loosely refer to any of these things as "traction bars", as they're all "bars" that help increase traction...but only if you know the functional differences.

Sloppy terminology usually leads to erroneous assumptions that everything under the same general heading is the same, and works the same way...particularly among people with no first-hand knowledge.

Ladder-bars and lift-bars (once again, there are subtle differences in how those two work) are also routinely referred to as "traction bars" by a lot of folks...and again, the physics of operation is largely misunderstood or never even considered.

[Joe Handley]

1 hour ago, Ace-Garageguy said:

Just a note of clarification...it's really kinda OK to loosely refer to any of these things as "traction bars", as they're all "bars" that help increase traction...but only if you know the functional differences.

Sloppy terminology usually leads to erroneous assumptions that everything under the same general heading is the same, and works the same way...particularly among people with no first-hand knowledge.

Ladder-bars and lift-bars (once again, there are subtle differences in how those two work) are also routinely referred to as "traction bars" by a lot of folks...and again, the physics of operation is largely misunderstood or never even considered.

Now just to add a little confusion to things, I learned a few years back that FWD "Traction Bars" are a thing, at least for the Dodge Caliber SRT4 and 3.5l Altima, though I have see where people were putting the Caliber bars on the 3.6l Avenger and 200.  From what I understand, these keep the from arms front moving forward and back plus reduce wheel hop and torque steer on so equipped cars.

Here's one installed on a Caliber SRT4

 

Quick edit, looks like there is a Honda version as well!

Edited April 12, 2022 by Joe Handley

[4mula1fan]

Doing some research for my 1/12 Grumpy build, I noticed how long his traction bars are.