I just bought a firestone kit. Bottom of the bag straddles the spring plate with a bracket, top of bag mounts to the side of the frame rail with another bracket. Easy job, drill 8 holes, bolt it all down, run the lines and you're done.
CK5
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4 Link rear tech
- Thread starter ryoken
- Start date
yeah, the only thing I would have is, it needing to be under the frame, cuz the spring will be under the frame.. but with a flip, I bet you would have the space to run it on the spring plate to a plate under the rail..
here's a pic of Kert's setup.. would definitely be room in there for a bag...
For what you're doing, it sounds to me that a truck arm conversion would be a simple easier way to get what you want. What I'm talking about is what is used on the '60-'72 2wd trucks. With these the bags would go between the arms and the frame. There is someone that makes a conversion kit for the squarebodies. I think it might be Hot Rods to hell. I know they make them for cars.
I'm sure you could find some more info and some pics over at http://www.67-72chevytrucks.com/vboard
Just throwing another idea out there.......
I'm sure you could find some more info and some pics over at http://www.67-72chevytrucks.com/vboard
Just throwing another idea out there.......
ooo, yeah, I know what your talking about.. I'll go read up on the pro's/con's of that setup too and see if it seems feasible.. thanks!
Just a little FYI should you go that route. The C20's have added support on the trailing arms.
I found this while searching around, its a fourlink air bag setup...
http://www.airbagit.com/v/vspfiles/pages/TowKits_PAGE.html
http://www.airbagit.com/v/vspfiles/pages/TowKits_PAGE.html
I saw that kit on the site, but didn't see the installed pics, cool...
now, my assumption at this point is that a double triangulated setup is superior cuz you wouldn't need that panhard bar...
now, my assumption at this point is that a double triangulated setup is superior cuz you wouldn't need that panhard bar...
Yes I think a double triangulated setup would be superior and I can't wait to see ya get started on it and the finished product, thought about doing this to my K20.
I'm not sure how well the double triangulated design will do with cornering and side loads from the weight of a trailer n built k5 behind it. I would think any design with a soild mount point parralel to the axle would be more stable. I have absolutely NO experience with 4 links though, Its just my own theory that makes the most sense to me.
Where's the link theory experts when we need em? 
If it were me, I would stick with the springs and air bags, or if you want, tomorrow I will take a pic of my big rig air suspension, if it can take 80k lbs, I think it's good enough.
I am kinda leaning towards basically Kert's setup with bags... and actually iirc, I think he said his is bagged now...
the main reason is the down time involved with doing a link setup, whereas I could bang out a whole new back leaf/bag suspension in a weekend... than do an anti-wrap on another weekend, etc...
the main reason is the down time involved with doing a link setup, whereas I could bang out a whole new back leaf/bag suspension in a weekend... than do an anti-wrap on another weekend, etc...
I hate to say it but leaf springs are terrible compared to links, the only thing that can be said about them is they are simple which they are.
So different types of links, I saw a watts link mentioned, this would be the ideal setup for towing I think, it allows the rear axle to travel more vertically than a panhard or then a double or single triangulated. More than likely the most stable type, also very tune able. Probably the hardest to fabricate.
Now typical panhard, probably the way I would go easy tuning of the roll center, in its simplest terms getting the roll center height as close the the height of the center mass of the car will make the car overall "roll" less than taking the RCH lower and further away from the center mass.
RCH of course can be changed with a double triangulated link too but it is a little more complex and tends to change things througout.
So in all honesty I wouldn't even consider a triangulated 4 link at all, just do a panhard.
I saw truck arms mentioned, they are basically the same as a radius arms, if you go back through and read some of my posts you will realize these are not my favorite suspensions at all, they work but lack some adjustability.
The links that go from the frame to the axle are actually pretty simple, they need to clear your bags and tires not run into anything and IMHO be at 100% AS or less, you don't need to be terribly concerned with where your pinion angle is going to be. Its not being built for suspension travel
In a rear suspension looking for ride quality the angle on those arms needs to be as level with the ground as possible, the ride hence is the same with compression and droop as the arms are getting shorter for both. Since this is not practical and sometimes looks stupid on a lifted truck its a compromise. Adding length to the arms can minimize this effect to a point.
Now bear in mind some of the things you read about suspensions are going to be not what you need to read. Pirate is a good source to learn alot but those are definitely geared towards suspension travel and articulation. The stuff you will read about sports cars I think applies a little more than off road stuff ( race cars and quite a few hot rods use watts links) because they are more concerned with handling.
The fact that you are going to be running a larger tires points to the fact that you should ignore alot of whats out there. I bet if you put a guy in a rig that has ( lets use a simple one here) 110% AS vs one that has 90% AS he wouldn't be able to tell much of a difference. So numbers are a big deal but not a huge deal.
Now before anyone gets in a huff over me saying numbers aren't a huge deal, on a rig like this plenty of adjustment can be built in to the suspension. 3 holes on each end of the panhard, a couple on the upper and lower mounts at both the axle end and frame end can let you get the suspension dialed in just right, you can rock the math all day long but if the numbers add up and it just doesn't feel right to you then the numbers mean nothing, they are a starting point on a custom suspension like this.
Onto the whole thing of of a weekend project. Paul you aren't going to be rockin a bed for a bit right? Pretty easy to use off the shelf brackets and make brackets so everything is ready to go for a weekend long weld fest.
Using off the shelf brackets ( not made for the truck) me and a buddy linked his 02 duramax in one day. Now we spent some time before that messing around with this that and the other had all the links built and the brackets ( those that could be) had been test fitted.
He messed with air bag lines and a couple other things later, but it was driveable the same day.
So preparation is key if you can't be down for a long time.
As far as air bags go, well I have a big truck wrecking yard close to me and if you are going to be lifting it then I say use big truck air bags, we used triple convoluted firestones from a cement truck on a 78 crew cab I did. Don't know the part number but man the back of that truck rides nice.
Research and more research is the best thing, if you have specific questions just ask on here, there are some engineer types that can offer opinions too and have in the past corrected me on misstated stuff, but for the most part I feel pretty confident in my skills building links suspensions.
So different types of links, I saw a watts link mentioned, this would be the ideal setup for towing I think, it allows the rear axle to travel more vertically than a panhard or then a double or single triangulated. More than likely the most stable type, also very tune able. Probably the hardest to fabricate.
Now typical panhard, probably the way I would go easy tuning of the roll center, in its simplest terms getting the roll center height as close the the height of the center mass of the car will make the car overall "roll" less than taking the RCH lower and further away from the center mass.
RCH of course can be changed with a double triangulated link too but it is a little more complex and tends to change things througout.
So in all honesty I wouldn't even consider a triangulated 4 link at all, just do a panhard.
I saw truck arms mentioned, they are basically the same as a radius arms, if you go back through and read some of my posts you will realize these are not my favorite suspensions at all, they work but lack some adjustability.
The links that go from the frame to the axle are actually pretty simple, they need to clear your bags and tires not run into anything and IMHO be at 100% AS or less, you don't need to be terribly concerned with where your pinion angle is going to be. Its not being built for suspension travel
In a rear suspension looking for ride quality the angle on those arms needs to be as level with the ground as possible, the ride hence is the same with compression and droop as the arms are getting shorter for both. Since this is not practical and sometimes looks stupid on a lifted truck its a compromise. Adding length to the arms can minimize this effect to a point.
Now bear in mind some of the things you read about suspensions are going to be not what you need to read. Pirate is a good source to learn alot but those are definitely geared towards suspension travel and articulation. The stuff you will read about sports cars I think applies a little more than off road stuff ( race cars and quite a few hot rods use watts links) because they are more concerned with handling.
The fact that you are going to be running a larger tires points to the fact that you should ignore alot of whats out there. I bet if you put a guy in a rig that has ( lets use a simple one here) 110% AS vs one that has 90% AS he wouldn't be able to tell much of a difference. So numbers are a big deal but not a huge deal.
Now before anyone gets in a huff over me saying numbers aren't a huge deal, on a rig like this plenty of adjustment can be built in to the suspension. 3 holes on each end of the panhard, a couple on the upper and lower mounts at both the axle end and frame end can let you get the suspension dialed in just right, you can rock the math all day long but if the numbers add up and it just doesn't feel right to you then the numbers mean nothing, they are a starting point on a custom suspension like this.
Onto the whole thing of of a weekend project. Paul you aren't going to be rockin a bed for a bit right? Pretty easy to use off the shelf brackets and make brackets so everything is ready to go for a weekend long weld fest.
Using off the shelf brackets ( not made for the truck) me and a buddy linked his 02 duramax in one day. Now we spent some time before that messing around with this that and the other had all the links built and the brackets ( those that could be) had been test fitted.
He messed with air bag lines and a couple other things later, but it was driveable the same day.
So preparation is key if you can't be down for a long time.
As far as air bags go, well I have a big truck wrecking yard close to me and if you are going to be lifting it then I say use big truck air bags, we used triple convoluted firestones from a cement truck on a 78 crew cab I did. Don't know the part number but man the back of that truck rides nice.
Research and more research is the best thing, if you have specific questions just ask on here, there are some engineer types that can offer opinions too and have in the past corrected me on misstated stuff, but for the most part I feel pretty confident in my skills building links suspensions.
so if not doing a watts, something like that red one pictured, with an adjustable pan, and maybe adjustable uppers would be a good way to go then? the only issue I would have is the links being outside the rails, I'd have to move them inboard...
I'll do some more reading when I get out of work... thanks for the post Eric...
I'll do some more reading when I get out of work... thanks for the post Eric...
wayne
3/4 ton status
And you don't need any 4 link calculator. I didn't bother with it when I linked mine, I just built what fit and worked. I ran coil springs for a year and they were ok. I am now running air shocks, they work good but I am still tuning them and I might be going to 16's instead of the 14's I run now. My neighbor is running a watts link on his bagged and linked rat rod and it works well and is very stable.
Here are a few more pics for you to look at. This guy is local to me. He does use heavy truck bags on his kits.
http://www.trex-tech.com/trexairlift.html
http://www.trex-tech.com/trexairlift.html
yes, that was the original thought... links, bags and shocks... tho i guess that does put the bags into that "fail factor" category... maybe a coil/bag combo would be better...
did you end up adding bags to the CC after those pics?
did you end up adding bags to the CC after those pics?
