I'm building a 4 bar air ride rear suspension for my truck.
Its very tight fitting everything in. There is about 11.5 inches between the frame and the wheel with 265 tires to fit the air bag. When pressurized to 100 PSI the bag is 9 inches in diameter.
I plan to mount the center of the bag 5 inches away from the frame to leave 1/2" clearance between it and the frame and 2 inches of clearance between the tire.
Its not possible to mount the bag between the frame and the axle without lifting the truck. There is only 8 inches of clearance between the frame and the axle with the bump stop removed. About 6 inches with the bump stop in place. The shortest bags with any travel have a safe minimum height of 4" so that wouldn't leave much travel.
There is 10 inches of clearance between the frame and the perch on the back of my axle mount. One could get a shorter bag and mount it under the frame to the perch, but the bag volume would be so low that you'd have to run a ping tank in order to get the bag air volume up to get the ride quality up. Bags with 3/4" fittings suitable for use with ping tanks are more expensive and harder to get.
I've chosen a bag that has a low natural frequency for good ride quality. Its 13.5" high and that means it must go between the frame and the tire.
Bear with me... this is getting some where.
So... because things are tight between the frame and the wheel, I can't just bolt a plate with a bag mount onto the frame. I don't want there to be any material between the bag and the frame. And because the bag is tall, there isn't room for a bunch of bracing on top of the mount.
The bag mount has to be to the sides of the bag and down.
And this is all fine except that to mount the bag in this manner I pretty much had to move the axle back about 1.25 inches. The frame sides aren't perfectly flat and there are rivets and stuff and parts of the frame already look like swiss cheese so I don't want to be drilling a bunch more holes.
Like I said, I can make everything work if I move the axle back. I've posted pictures in my gallery so that everyone can see what I am talking about.
What does everyone think of doing this ?
The stock fenderwell space in front of the wheel and after it is about 4 and 5". I have about 5+ and 3.5+. There isn't going to be a clearance issue with these tires... but someday I might want to run 20s...
I haven't thoroughly checked my driveshaft yet. At first glance it seems OK. How much spline travel does the stock driveshaft setup have and how far out can one run them before they give trouble ?
I could shorten my bars and make a mount that would move the bag forward... but it would be a lot of work. What does everyone think of moving the axle back like I have ?
Thanks
Picture in my gallery here:
Air ride suspension pics - Me2000s Photo Gallery
Its very tight fitting everything in. There is about 11.5 inches between the frame and the wheel with 265 tires to fit the air bag. When pressurized to 100 PSI the bag is 9 inches in diameter.
I plan to mount the center of the bag 5 inches away from the frame to leave 1/2" clearance between it and the frame and 2 inches of clearance between the tire.
Its not possible to mount the bag between the frame and the axle without lifting the truck. There is only 8 inches of clearance between the frame and the axle with the bump stop removed. About 6 inches with the bump stop in place. The shortest bags with any travel have a safe minimum height of 4" so that wouldn't leave much travel.
There is 10 inches of clearance between the frame and the perch on the back of my axle mount. One could get a shorter bag and mount it under the frame to the perch, but the bag volume would be so low that you'd have to run a ping tank in order to get the bag air volume up to get the ride quality up. Bags with 3/4" fittings suitable for use with ping tanks are more expensive and harder to get.
I've chosen a bag that has a low natural frequency for good ride quality. Its 13.5" high and that means it must go between the frame and the tire.
Bear with me... this is getting some where.
So... because things are tight between the frame and the wheel, I can't just bolt a plate with a bag mount onto the frame. I don't want there to be any material between the bag and the frame. And because the bag is tall, there isn't room for a bunch of bracing on top of the mount.
The bag mount has to be to the sides of the bag and down.
And this is all fine except that to mount the bag in this manner I pretty much had to move the axle back about 1.25 inches. The frame sides aren't perfectly flat and there are rivets and stuff and parts of the frame already look like swiss cheese so I don't want to be drilling a bunch more holes.
Like I said, I can make everything work if I move the axle back. I've posted pictures in my gallery so that everyone can see what I am talking about.
What does everyone think of doing this ?
The stock fenderwell space in front of the wheel and after it is about 4 and 5". I have about 5+ and 3.5+. There isn't going to be a clearance issue with these tires... but someday I might want to run 20s...
I haven't thoroughly checked my driveshaft yet. At first glance it seems OK. How much spline travel does the stock driveshaft setup have and how far out can one run them before they give trouble ?
I could shorten my bars and make a mount that would move the bag forward... but it would be a lot of work. What does everyone think of moving the axle back like I have ?
Thanks
Picture in my gallery here:
Air ride suspension pics - Me2000s Photo Gallery