rear bags which ones?

[rtinniste]

Okay so here's the run down s10 swapped 51. I'm now finishing up the rear end and don't want to do the step notch or anything until I have the bags I'm going to use.

Front: speedway uppers, dehumped lowers, thorbros bag cups with airlift d2500 bags, belltech drop spindles, spring pockets cut and flared, little shop no toe steering.

Rear: thorbros 4 link with a bolt in c notch.

misc info: running boards hang 2" below the s10 frame and is the lowest point on the truck, I'm running a 350/th350.

With everything listed above my truck lays the running boards flat. Now I'm not 100% happy with the bolt in notch I couldn't get it to land exactly where I wanted, I feel like its a potential weak spot, and I cant fit a bump stop.

So now I'm planning on scraping the c-notch and building a small step notch/bridge. I want to run bag over axle keep everything in one clean simple package. Since I plan on running a gas tank behind the axle between the frame, exhaust dumped before the axle out the fender. And I've ordered the brackets already.

I was thinking d2500 to match my fronts so I can keep a extra bag in the truck. But I read d2500 will ride like garbage on the rear and give almost no lift and I should run a f9000 sleeve bag or at least a d2600.

My ride height is going to be low running boards 2 inches off the ground at most, I just need to be able to clear speed bumps with out getting hung up so maybe 6" lift total. So a d2500 with 7.7" of stroke at a 1:1 ratio seems right but maybe there's something I'm missing.

What bags would you suggest and why?

[rtinniste]

pictures of the bucket im asking questions about

before dehump, c notch, lower link arms, and with the old bondo filled cab



how it sits as of now

[joedoh]

I have had about 25 bagged cars and trucks, which sounds like a lot (and if you ask my wife it is a lot) and I have had every kind of rear suspension setup possible. from two link (bought like that, changed to 4 link), triangulated with heim and with bushing, parallel with heim and with bushing, monoleaf, long bars, short bars, bolt in bars from thorbeckes, kp, air ride technologies, IRS, torsion. every kind of lift setup from over axle, behind axle, in front of axle, bag on bar, small bags, big bags, semi bags, sleeve bags, shockwaves, air cans, air shocks, hydraulics, hydraulics with accumulators, everything. I never used it but I even rode in a civic my friend built with the hybrid setup, bags that push on hydraulic cylinders that are connected by lines to more hydraulic cylinders. it needed shocks. badly.


the very best ride was with bags was sleeves, and you get more lift (7.5 inches) than with a regular double convoluted bag installed behind/above/in front of axle. You will need shocks with a LOT of travel, I used shocks from a jeep that had 10.5 inches of travel and set them up to limit the lift, sleeve bags will tear themselves apart when overinflated. also, limit the down travel, they dont have an internal bumpstop.

I tried the bag on bar thing, it is hard on the bushings unless perfectly centered and it takes barely any pressure (5-10psi) to get drive height, which sounds like a dream until you drive it and the spring rate is so low the shocks foam and soon you are banging more axle than the chicken ranch. no one needs or uses 13 inches of lift anyway.

I mention this because spring rate is the first most important thing related to ride, shocks being second. most people use bigger bags in the rear than the front, I dont understand it, there is 1/2 the weight and even if you carried a load the smaller bag will handle it. most of the reason is because a double convoluted bag only lifts about 5 inches, and while that sounds like a lot the front (with the geometry of the arms) lifts about 8 inches, so it has that gangster lean if you lift to the ride height. its more attractive to lift evenly, so people overinflate the rear bags and that gives a poor ride, and the poor reputation. a larger bag has more volume, so the spring rate is lower even when overinflated. a 2500# bag over axle will ride very nice when not overinflated, but you will have the lean.

a sleeve bag is a great compromise, normal pressures (60 psi or so instead of 20-30 at ride height) and decent lift (to center of travel is about 4 inches, a good respectable ride height). mount them behind the axle, nice and low. they have small ports so jumping around or super fast fill is impossible, but they sure ride nice.

the absolute best ride I ever had was hydraulics with accumulators. literally rode like a strut because that is the operation principle.

[rtinniste]

Originally Posted by joedoh

I have had about 25 bagged cars and trucks, which sounds like a lot (and if you ask my wife it is a lot) and I have had every kind of rear suspension setup possible. from two link (bought like that, changed to 4 link), triangulated with heim and with bushing, parallel with heim and with bushing, monoleaf, long bars, short bars, bolt in bars from thorbeckes, kp, air ride technologies, IRS, torsion. every kind of lift setup from over axle, behind axle, in front of axle, bag on bar, small bags, big bags, semi bags, sleeve bags, shockwaves, air cans, air shocks, hydraulics, hydraulics with accumulators, everything. I never used it but I even rode in a civic my friend built with the hybrid setup, bags that push on hydraulic cylinders that are connected by lines to more hydraulic cylinders. it needed shocks. badly.


the very best ride was with bags was sleeves, and you get more lift (7.5 inches) than with a regular double convoluted bag installed behind/above/in front of axle. You will need shocks with a LOT of travel, I used shocks from a jeep that had 10.5 inches of travel and set them up to limit the lift, sleeve bags will tear themselves apart when overinflated. also, limit the down travel, they dont have an internal bumpstop.

I tried the bag on bar thing, it is hard on the bushings unless perfectly centered and it takes barely any pressure (5-10psi) to get drive height, which sounds like a dream until you drive it and the spring rate is so low the shocks foam and soon you are banging more axle than the chicken ranch. no one needs or uses 13 inches of lift anyway.

I mention this because spring rate is the first most important thing related to ride, shocks being second. most people use bigger bags in the rear than the front, I dont understand it, there is 1/2 the weight and even if you carried a load the smaller bag will handle it. most of the reason is because a double convoluted bag only lifts about 5 inches, and while that sounds like a lot the front (with the geometry of the arms) lifts about 8 inches, so it has that gangster lean if you lift to the ride height. its more attractive to lift evenly, so people overinflate the rear bags and that gives a poor ride, and the poor reputation. a larger bag has more volume, so the spring rate is lower even when overinflated. a 2500# bag over axle will ride very nice when not overinflated, but you will have the lean.

a sleeve bag is a great compromise, normal pressures (60 psi or so instead of 20-30 at ride height) and decent lift (to center of travel is about 4 inches, a good respectable ride height). mount them behind the axle, nice and low. they have small ports so jumping around or super fast fill is impossible, but they sure ride nice.

the absolute best ride I ever had was hydraulics with accumulators. literally rode like a strut because that is the operation principle.

Nice this is the first 4 link I've done, I bagged my g35 coupe with Uas doughnut type bags on 32 way adjustable coilovers and airlift autopilot digital managment.
I've done at least a dozen of the same type of install's on lexus, nissan, infiniti, acuras but being the coilover is completely adjustable you can fine tune your dampening preload on the bag and over all height of the coilover. And there's only 2 or 3 of these types of bags so it makes selection easier.
End of the day they all rode amazing and still handled just as well as a decent coilover would still.

Funny you say the hybrid setup because I tried a air/static setup with mine I wanted to beable to roll low around town with out destroying my lip or my rim lips destroying my fender (carbon fiber lip less then a inch off the ground aired out the fender sat between the rim lip and tire stretch) so I machined derlin sliders ran the bag on top with a 30kg spring under the bag so the air bag worked a tender spring (like a dual rate king or fox coilover) that used most of the travel last inch of travel was for the spring since the spring was so stiff it was impossible to ever bottom out.
It worked good around town I was static and low enough that my frame was ripping road reflectors off the ground my rim lips never hit my fenders with less then 1/4" clearance, then driveways speedbumps or freeway I can just air up. Only downside was the rear of a G35/350z you can't run a bag on the coilover it wont fit so you have to run it in the stock spring bucket on the toe link and my spring was on the damper (true type coilover) so when I aired up the spring was loose and would rattle. Then I had the car painted and buckled a fender backing into a parking space so I was over riding around slammed and went back to the normal bag setup.

But anyways I talked to Jason form thorbros and what I've come to understand on the rear bag setup is you run a bigger bag to get more lift at a lower psi to get a softer ride. I don't know why that wasn't clicking with me earlier must have been half asleep earlier. I'm not sure why I thought a 2600 was to carry more load or for something heavier. I'll probably put a order in today for airlift d2600's

[HUSSEY]

sorry if this is a hyjack but I have statement / question related to this topic....

I would like to bag my truck in the future...realistically probably a year or more down the road...but I've been thinking about it.

The way I would select my bags is first determine the spring rate I want. From there, identify a bag that gives me that spring rate at a manufactures specified pressure and height. Then, set my mounts up for that specified bag height, then run it at the specified pressure. Of course you would need to include the available travel up and down from ride height into that equation.

The only problem is I can never find this information from bag manufactures. On one rare occasion I found a graph on Contitechs website that plotted multiple curves on a chart to give you the relationship between pressure, ride height, and spring rate. Anyone else seen such a thing?

[HUSSEY]

Ok...Google search and I found this:

http://pdf.directindustry.com/pdf/it...68-263935.html

I'd see if you can get your hands on some similar charts of bags you're looking at. You would also need to know the weight of the rear of your truck.

I think you're going about it the right way by thinking it out first. I definitely prefer thinking things out rather than trial by error...it actually fits my schedule better in that I can "work" on my truck while I'm away from home.

[joedoh]

that chart is a good example of what I was talking about, ride height is usually best at about 1/2 stroke, and using a large volume bag will do 1/2 stroke at a much lower pressure, but your spring rate related to pressure is really low. being at ride height at 15psi sounds great, but it slams around pretty good and gives the shocks a workout.

rtinniste the dominators have a lot of stroke, good luck!

[neverfinished94]

joedoh is right. F9000 or a similar sleeve bag is the correct bag for the rear unless you are mounting the bags on the bars. A 2500 or 2600 on/in front/behind the axle will not ride as well as the F9000

[rtinniste]

Originally Posted by neverfinished94

joedoh is right. F9000 or a similar sleeve bag is the correct bag for the rear unless you are mounting the bags on the bars. A 2500 or 2600 on/in front/behind the axle will not ride as well as the F9000

I've come to realize that after ordering 2600's lol, but I'll go with it for now. I can always use the 2600's on the front of my dads c10 and put f9000's on mine.