I just had a revelation, and switched my traction bar plans.

My main concern was bind. So that means compliance in twist (suspension articulation) and in push-pull (axle moving up and down, with TBs and axle on different arcs).

I looked for 3/4-16 threaded rubber bushings, and couldn't find them anywhere. So I was going to use urethane bushings on the front and Johnny joints on the rear for twist compliance. To solve the push-pull compliance, I was going to use a circle track "biscuit bar." The parts would push $400.

Then it occurred to me as I was re-reading some literature on the Blackwood traction bars ("torque arms"): "Two anti-windup bars provide additional resistance to axle windup or wheel hop. The bars are mounted with relatively soft bushings, so they transmit less harshness from road irregularities."



Just buy the damn Blackwood bars! They aren't real sexy, but guaranteed to fit in the Blackwood front mounts that I already bought as my front mounts, the soft (rubber?) bushings should eliminate bind in all directions, and my parts count goes down from about 20 to 2. They may well end up weighing a bit less as a bonus.

I've learned over the years that outthinking the OEM engineers is a difficult task indeed. AFAIK, the only two F150 traction bars ever to come from Ford on a production vehicle are the Gen 1 slappers and the Blackwood bars.

I just ordered a pair for $220 delivered. The only hitch I see is that the Blackwood leafs could have the axle positioned slightly fore or aft of the Hotchkis, especially considering that my axle is several inches lower than stock. Oh well, worst-case scenario, I'll add another couple of parts to my growing heap of crap I'll never use but can't bring myself to trash.

 

Wouldn't the Metco lowers or uppers do the same job, weigh about the same and provide some adjustability? And you already have them.

 

Tim at least you are testing these and offering real world experience

I'm gonna keep watching this thread until I decide...

using these "blackwoods" with the soft bushings might suffice for me on the street, I won't be autocrossing my supercab but I like to carve canyon roads

 

TB: I sold the Metcos a while ago. The wouldn't play nice with the X-Factor, and I was ready for a change anyway. They were close, but I still don't like the differing arcs (the Metcos mount below the axle in the rear) and a lot of heavy hardware. The Metcos were 42 lbs. The Blackwood front mounts are barely a pound apiece, and the rear mounts are weld-on axle tabs that can't weigh a pound total. Add in a pound for hardware, and the BW bars would need to weigh over 15 lbs apiece to not be lighter.

I never adjusted the Metcos after the install. The BW front mounts are slotted, so they can accomodate some minor changes in static ride height and such.

tarajerame: Traction bars are only to stop pinion rotation (and hopefully just disappear from the picture otherwise). Loose traction bars do not mean loose handling. My final suspension will have urethane spring eyes and a full-length panhard. With or without any traction bars at all, the suspension will stay just where it's supposed to be.

 

Tim,
Those blackwoods look pretty cool.I did a search for blackwood traction bars and only found this crazy guys website
http://www.timskelton.com/lightning/mods.htm Whered you get em from?
Seriously tho,only problem I see w/ those is when you weld them in,you'd better be sure your rear axle is aligned perfectly.The only way to make it perfect is to have it on an alignment rack w/ centered steering to make sure the distance from the drivers side front center axle(spindle) to rear axle center is equal to the passenger side measurement,and then weld it in.

From the pic you posted it seems to me that the position of those bars (centered on the axle) would allow some axle wrap that would squat the rear momentarily under heavy load(launch).The metco lowers seem to have better leverage based on the lower rear mounting to prevent axle wrap.Is one better than the other?? I guess it depends on what your using the vehicle for.
The above paragraph is mere speculation based on my interpretation.And I reserve the right to change my mind at any time

 

The front mounts for the BW bars are slotted, so there is a little room to adjust them. But I did have a 4-wheel alignment check done recently, and the axle is squared.

I buy my parts online from Bob Utter Ford out of Texas.

My problem is that the Lighting community is just about singularly focused on drag racing. The aftermarket parts, like the available traction bar choices, reflect that focus. But straight line acceleration from a dead stop is almost completely irrelevant to me. And when I do mash it from a stop, I'm almost always looking for the opposite of traction.

It is because the BW bars mount at about 4:00 on the axle that I decided to replicate them. All of the other traction bars mount at 6:00 (below the axle). I understand that the 6:00 position, as away from the axle as possible, is best for minimizing wrap. But Ford could have placed them anywhere on the axle, but chose 4:00. That tells me that the Ford engineers modeled/tested the suspension (a leaf spring suspension, despite its simplicity, is much harder to model than a link suspension), and rejected the 6:00 position. Although it could have been simply to avoid having something below the axle to snag on the terrain, based on the BW's complete inability to go offroad, and the fact that the shock mounting tabs are below the axle, I have to assume that the 6:00 position was rejected because of bind.

Remember, because the springs are tilted (lower in the front than the rear), the axle moves a little forward as it travels up. Then add in the dynamic forces acting on the spring in the real word . . .

I want my bars to do one thing, and one thing only -- stop potentially destructive axle wrap/wheel hop. And that's what Ford engineered these bars to do.

My remaining concern is that Ford kept the staggered shocks for the BW, whereas I am flipping the passenger shock around. I don't think that cost had anything to do with this decision, because the frame is already capable of handling staggered or same-side shock mounting.

Again, we'll just have to wait and see. I've burned the boats by buying the parts.

"The Blackwood adds staggered acceleration-sensing shocks plus a hybrid combination of monoleaf parabolic and air springs in the rear. The Blackwood's rear suspension's pressurized air springs instantly adapt to additional passengers or cargo, providing automatic load leveling, while the monoleaf rear springs reduce the harsher spring rates found in the SuperCrew's conventional leaf spring designs. Anti-windup bars further dampen any spring windup when the cargo box is unloaded creating a very sticky truck with good rear axle control."

 

wow, I might just just try a panhard bar then if that doesn't work I'll add the blackwood bars and some good shocks

 

????

PHB and traction bars are completely different animals. Please re-read post #4. A PHB would be the very last thing I would add to the truck. For the most part, it's a 10/10ths device. I've taken mine off at the track for before-and-after testing, and the difference is very subtle, and I suspect mostly due to changing the rear roll center rather than preventing axle movement.

Look, none of these parts are necessary. Without drag tires and trying to do a dead hook, there is very little chance of driveline breakage.

And don't be put off by my overanalysis. Like Pitstain, I've been obsessing over the Lightning suspension for several years. Other than a rough ride, there wasn't a damn thing wrong with version 1.0 of my suspension -- Hotchkis springs and sways, and then later Metco bars and QA1s. It handled great.

I'm just trying to get the best compromise between handling and ride quality. One of the tactics to achieve this is to free the suspension of as much bind as possible. My ramblings are more theoretical than practical. Chances are you would be happy with any of the traction bars.

 

ok thanks