Rear bag location...

[Spray-Bomb]

Hey guys, I am going to be building some new trailing arms for the rear of my truck & I was wondering how much have some of yall moved the bags forward ???

I need to build some cups under my bags in there current location as they dont collapse all the way & I need the extra travel, so I though that I could kill a few birds with one stone by moving the bags forward

Moving them forward would reduce the space between the trailing arms & the frame, thus making it un-necessary to make spacer cups (although I would need to weld a mount on the frame to level the bag out) would give me a smoother ride & more travel

So in short, how much did you move your bags forward ???

Thanks, Matt

[72hotrodder]

the ideal place for a bag on a control arm is a 2-1 ratio. so if the arm is 30in long you would want to put the bag 10in from the axle. (not exact measurements just for visual aid) if you go any farther away from the axle you get into a bouncy ride and more trouble than you want.

[Spray-Bomb]

Ok thanks

Anyone else ???

[Kontrol Phreaks]

On the short bed frames it's going to be tough to get the bag farther forward without running into fitment issues with the factory frame. You said you were building a new frame, so that's not going to really be an issue. Just remember that the further you move them forward, the more lift you're going to get, but it's also going to apply a larger force to lift the truck, as well as adding more stress to the chassis in that area.
I've move them forward a decent amount of a longbed truck without any problems. The truck actually got 13" of travel with a Slam Specialties RE6 airbag. I just remember moving them forward enough to the point where the bag would have plenty of room from the frame while leaving me enough clearance for my exhaust and driveshaft as well. I also didn't want them sticking up into the bed floor area. Here's an image of how I did them off the factory arm, factory frame, etc. The bed floor was cut for the center bridge design that I made along with the crossmember kick for driveline clearance as well. Truck laid out on 22's all around, no problem.



Good luck with your project

[Spray-Bomb]

Thanks Clint

Im actually not building a frame for the truck yet, but the rear is Z'd 6-3/16"

Im not really looking to get a ton of lift, but I do need more because of the Z
Right now I can air my bags up all the way & the truck is still down about an inch in the back compared to the front at ride height

On one of my other trucks that was a LWB, I had some RE-7s in the rear & I didnt like the fact that at close to ride height the pressure in them was so low that it bottomed out a lot
I know that a smaller bag would have prolly helped in that situation, but I am thinking that if I move the bag forward on my SWB to change the ratio that it will work better & maybe even be able to use the RE-7, so I dont have to buy RE-6s

Sorry if Im typing bowl of confusion soup here
Just trying to get it all worked out in my head

Also, what do yall think about running the trailing arms parallel to the frame instead of triangulated, I know that triangulated is stronger, but with a pan hard bar would I be ok with running them parallel ???

I have seen it done, but always wondered if it is strong enough
It would just make it a lot easier to move the bags forward & run exhaust with the trailing arms on the outside of the frame

Thanks, Matt

[69Rob]

sorry to jack your thread bomb but clint i was wondering if you have any more information on how you did your truck i think you have the setup im aiming for with the stock trails any info would helpful thank and sry again for the jack

[Kontrol Phreaks]

Let me send you a PM with descriptions on the what I did, and we wont jack this thread all up.

[Spray-Bomb]

So is 2:1 the most common non stock placement ???

[Kontrol Phreaks]

I think most people just move them to a spot where they fit, or look good, and don't really take the mechanical advantage into consideration. The 2.0 : 1 is a nice ratio but it's going to ride really soft down low unless you put a firm shock to compensate for that. By then you're going to be fighting the ride once there's more air in the bags. The bag will have med pressure because of the load applied at that ratio, but the bag is going to be relatively compressed still.
I'd take your driving desires, and style into consideration prior to placing the bags. If you were to move them back slighly, and decrease to a 1.5 : 1 ratio it might help you out as the bag would have more pressure and a taller height to improve / alter the ride. You're still going to get 10.5 inches of travel on a 7 inch bag at the 1.5 : 1 ratio which is awesome on the back of a C10.


Good luck and keep us informed.

[Spray-Bomb]

What about if I run my trailing arms parallel to the frame, then I can locate my mounts so that I have the bags at say 6" or 7" tall at ride height
So if the bag is at 6" or &" at ride height no matter where I mount them, then what do you think would be the best ratio ???