Long Travel BS Thread

Are you using a kit to start or making all brackets yourself?

 

What direction and magnitude for the forces acting on the links in that model? I’m trying to see how those figures are being derived. I’ll try to play around with the calculator and see how it’s written.

 

It might be haha. No clue how things work out there especially this week. Back door might have to be for another time when it’s a little less crazy out there

But it has been a long time coming that I get out there and try it

 

It’ll take a lot more beef than what’s in my picture haha I just had to get something tacked up in the empty space to get a better feel for what’s going on. I’ve been looking at Motobilt’s four link kits and I like how they brace them to the frame. I’ll likely copy a lot of that over. I’m trying to figure a way to have a big belly skid while I’m at it and ditch my current trans skid.

 

links themselves are a two force member. net force acts along the direct line that contains the two end points

 

What’s causing 2g on the links is maybe a better question

 

combination of making my own and ordering prefabed brackets from Ballistic Fab, artec, TMR, etc.. depending on the design I like the best for the application.

Primarily push and pull.

 

Where are the forces coming from ? the weight of the entire truck and the forces from the axle etc. Think about it - you hit the gas pedal and your rear axle is trying to rip off the back of the truck...you slam on the brakes and the rear axle is trying to join you in the cab. You hit a big bump...same thing. Yes, they are pivot points but they are pivots connected to a motorized 5k lb chunk of Japanese perfection that you are completely ruining. It is not weightless cycling of the components, you've got the inertia etc of the entire vehicle applying stress in every direction.

 

Lol I’m talking about his calculation specifically. I understand where the stresses are coming from. You can get paralysis by analysis real quick. Unless we include acceleration, torque, tire size, psi, shock tuning, coil size, weight etc etc it’s all . I’m not building a race truck. The bar is even lower for slow crawl links. Tons and tons of people link their trucks, it’s really not that complicated. Just because there’s not a lot of Tacomas specifically doesn’t make the math any different. Run the numbers, fit the space, beef it up. Reassess if shit breaks. Rinse repeat.

 

Yes but when links break or mounts shear off... that's very expensive parts and loss of control, brakes, and wrecks. Over-build it and never worry about it. Are the link mounts I make over kill for the application? absolutely, I also know that I can send a truck out the door and never worry about the work I did failing and killing someone.

 

That’s the most important. I’m not arguing that point at all. I’m right there with you. People get caught up in too many specifics. Build it strong and don’t worry. We aren’t trying to shave pennies off production and man hours. A little more steel and time spent is worth the peace of mind. I was honestly curious where the 2g figure came from and what that would most accurately depict in a real world scenario. Like is that hitting a six inch 30 degree rock at 50mph with one wheel or something like that. I can’t use numbers if I don’t know the context. I’m not smart enough.

 

I don't care how much you gusset or brace that tube this point of connection is going to fail. That oe cross member is thin and weak, any flex at all and it is going to break right off. If you removed that oe cross member and held it in your hands you could twist and squeeze it with your bare hands. Even just the constant twist from frame flex from daily driving and it's going to break.


You should build more of an X brace tied into frame plates before and after that oe cross member

 

I had mentioned doing something similar to that a few posts back. I’m aware how weak that crossmember is. No sense in building it until everything is cycled and I’m happy with those bracket locations.

 

Could also just reinforce that crossmember and gusset and plate it if you wanted to keep that location. Would wanna chop it out and weld it back in to do that though likely

 

I’d talked about doing that, too. I’ve got to see where my exhaust fits into this equation before getting too silly with the space. Still kinda scratching my head on that

 

Unless you completely box in the entire thing that's a bad idea, you'll run into the same prob I had where you are just going to move the weak point ie: mixing rigid and flexible is bad. It would seriously be easier to fab a new carrier bearing cross member from scratch than it would be to box / plate / gusset / support the oe one.

re exhaust - this is how I did mine, there is a Magnaflow oval muffler ( 4" x 9" i think ) right where this text is tucked above the bottom of the frame rail under the cab. Mine is just a 3 link so I was able to follow the frame rail with a tail pipe and dump before the axle but with your double tri 4 link and where you have located you pivots I think you are going to be SOL on a tail pipe. You might have to dump under the cab and figure out a resonator set up to knock down the drone. I dumped mine after the muffler at first...sounded great...outside the truck...but the truck was not drivable on the highway...craziest loudest drone I've ever heard it was actually disorienting. If you move your lower pivots to the bottom of the frame rails you could follow the frame rail ?

 

I'm mean come on really how stupid are we for mod'ing these pieces of engineering perfection ? the aero dynamics, the gas mileage...I won't even mention the warranty problems

 

Not to mention the resell value of a stock truck right now!

 

Yea, experience with that speaks more than just my heresy so you're probably right there.

After doing a shock relocation on my truck and doing an exhaust turndown right after the muffler under the bed, I was surprised at how much more I could hear the exhaust and drone in the cab. Didn't think it would have been much of a difference given how far back it is.
Makes me wonder if a dirtskum side dump out of the bedside would even make that much of a difference compared to how it is now