Wonderin about something!

[cbxer55]

Was in a large empty parking lot today, and did some burnouts for the heck of it. Every time, left two long black tracks on the dry ground. Truck has a 3.73 standard 7.5 axle. Always thought standard axles didn't leave two tracks. Thought one tire spun, while the other hooked.

1998 3.0 auto with a custom catback, no muffler, on stock manifolds and a MAC intake. Two large 255/60-15 Cooper Cobra GT's out back. Also has tightly adjusted Lakewood traction bars. Spins like crazy and does nice burnouts with 155,000 miles on the clock.

Just wondering about the axle. I expect my Lightning to lay two tracks, it has a 3.73 12 bolt 9.75 posi rear. Didn't expect it with the Ranger.

Burnouts done with no brake use, just slamming the petal to the floor with the shifter in first gear from a standing start.

 

[adsm08]

If traction is roughly equal between both wheels it is possible to get both broken free.

I've done 11s with an open rear and some crappy tires. I have also done a 1 wheel peel with a Torsen LSD unit. Mine doesn't like to do the lock up thing in a straight line, but sure will hop the rear if I punch it in a turn.

 

[alwaysFlOoReD]

I suspect the traction bars are having a lot to do with it. In a stock system the right wheel brakes loose because the right wheel is lifted from torque on the axle. Once the tire breaks loose all the power goes to that wheel, as is inherent in the design of the rear end [all the power goes to the wheel with least traction]. With the tight traction bars the axle won't move up nearly as much and both wheels will get an equal amount of power...until one gets more traction than the other.

 

[cbxer55]

Thought the traction bars might be partially to blame. I know, before I put them on, many moons ago, it would hop really bad with a full throttle application from a standing start. Doesn't anymore.

By tight, I mean I have about one inch of gap between the bars and the spring. Have them set so the bar hits right behind the eye, not directly on it. This was debated on the Lightning forum I frequent, and it was said the best for slapper bars is for the snubber to hit the spring behind the eye, not the eye itself.

My Lightning has Johnny Lightning Performance long bars on it. They attach to the axle using the u-bolts that join the axle to the spring, and a hard mount on the frame 58 inches forward. Junior ladder bars?

 

[alwaysFlOoReD]

it was said the best for slapper bars is for the snubber to hit the spring behind the eye, not the eye itself.

I would disagree. Hitting the spring behind the eye sets up reverberations in the spring. All the energy of the engine should be used for forward motion, not making the spring move. A personal example; when I first used slapper bars over 30 years ago the stock length of the slapper hit about 10 inches behind the eye. I got wheel hop. I used some square tube and made the rubber bumper hit on the eye and problem solved. This is total anecdotal but it's what I believe with the knowledge I have.

 

[rangerenthiusiast]

I know this is cbxer’s thread, but if anyone is bored, could you enlighten me about the benefits & costs of traction bars? I’ve never gotten that deep into the suspension on any of my rides, which were all DDs. If not, it’s cool.

 

[pjtoledo]

2 pro's to traction bars, for leaf springs

(condensed version)

reduce wheel hop, increase traction

to reduce wheel hop they basically take the flex out of the spring.

for increasing traction, view them as levers. the bars are fixed to the axle and extend forward to the end of the spring. as the axle housing attempts to rotate up the end of the traction bars puts the force farther forward instead of just over the rear axle. that takes advantage of the center of mass, and the car "pushes back harder" against the traction bars, thus forcing the axle down which increases traction. this also helps wheel hop.

without traction bars, the axle pushes up on the front of the spring while simultaneously pulling down on the rear., you don't get as much leverage effect to push the axle down for more traction.




con's

solid steel bars snugged up against the car in race mode make for almost no suspension articulation. translation: it will ride like a 1937 Dodge truck.

 

[alwaysFlOoReD]

^^^ I'll add to this. Traction bars are for straight line acceleration, think drag race. Not good for off road or road races.

 

[pjtoledo]

^^^ I'll add to this. Traction bars are for straight line acceleration, think drag race. Not good for off road or road races.

see his picture?

 

[fastpakr]

So there is a significant flex and ride quality penalty from a set of traction bars like James Duff offers for our trucks?

 

[alwaysFlOoReD]

see his picture?

Nope. I've been having problems on TRS.

So there is a significant flex and ride quality penalty from a set of traction bars like James Duff offers for our trucks?

I haven't seen the JD traction bars. I'll take a look.

 

[pjtoledo]

I was mostly speaking of drag racing. I'm not familiar with the JD bars.

 

[alwaysFlOoReD]

I took a look. They mount on top of the axle and would definitely prevent wheel hop. With the bushings I would guess that they would be a lot better than a true slapper bar in offroad use and wouldn't act like a sway bar either. But I don't think they would help with weight transfer like slapper bars do in a straight line acceleration. But I have no real world experience with them.
I've seen mentioned using a chain in the same mounting points as a JD bar. That might give more flex while still preventing wheel hop...but again no real world experience.
In my race truck I made a single slapper bar that mounted on the dif and hits a crossmember. It works good. But it tuned itself after taking a few jumps...the gap is larger than what I set it at.

 

[cbxer55]

^^^ I'll add to this. Traction bars are for straight line acceleration, think drag race. Not good for off road or road races.

I don't know about that. I'm posting a link to a guy who uses a Lightning for road courses. He uses long bars on his Lightning for this purpose.

https://web.archive.org/web/2016040...htning/race_prep/suspension/traction_bars.htm

Also posted are pics of my Lightning's rear suspension, which includes parallel QA-1 shocks, long bars (traction bars) and a panhard bar. And further forward a custom made tubular transmission cross member and a very firm drive shaft safety loop, both of which firmed up the frame readily.

 

[cbxer55]

I know this is cbxer’s thread, but if anyone is bored, could you enlighten me about the benefits & costs of traction bars? I’ve never gotten that deep into the suspension on any of my rides, which were all DDs. If not, it’s cool.

It's not my thread per se. I just started it. Anyone can participate. I've got no problems with that at all.

Traction bars, such as the Lakewood's I have on my Ranger definitely make the ride harsher. Since they clamp the leaf springs together, there is less "give" in them for bumps. Like it or hate it.

Even the long bars on my Lightning, take some getting used to. And they have urethane bushings at the front and rear mounts. Some out there, such as Stiffler's, use heim joints on the ends, so don't even have bushings.

Everything's a trade off. There are not a lot of curvy roads where I live, so road course handling is not an issue. Straight line is where it's at.

Basically I started the thread because I thought an OPEN differential wouldn't let both tires spin during a burnout. And both my rears spin quite nicely, being a 3.0 and all. And fairly large rear tires for that.