[M-827]

Hello! :cheesy:

216RIDER got me thinking about ride heights the other day :angry: :biggrin: !

Because I can't use a bolt on kit for my car I'm going to have to estimate the height for my air spring mountings. My car is a full size 1967 Oldsmobile, so I'm guessing that the suspension, although not identical, will be similar in its geometry etc to a 1960s Impala.

What I'd like to find out is how much drop from standard ride height do you get before the car is on its bump stops (or hitting metal if bump stops are removed)? This would give me an idea for a starting point for mounting spacer heights because I don't want to be wasting any of the springs' capacity if I start in the wrong place.

Originally I was going to try and get the air springs at their design height when my car was at its original ride height, but now I'm wondering if I should start a little lower.

Has anyone with a 1960s Impala (mentioning no names ) worked out their air springs' actual height at 100psi on the car, compared with the 100psi figure given by the manufacturers? I expect it will be a bit shorter with a car sitting on it .



Last edited by M-827 at Nov 7 2003, 04:31 PM

 

[SIXONEFORLIFE]

Originally posted by M-827@Nov 7 2003, 06:31 PM
Hello!  :cheesy:

216RIDER got me thinking about ride heights the other day  :angry:  :biggrin: !

Because I can't use a bolt on kit for my car I'm going to have to estimate the height for my air spring mountings.  My car is a full size 1967 Oldsmobile, so I'm guessing that the suspension, although not identical, will be similar in its geometry etc to a 1960s Impala.

What I'd like to find out is how much drop from standard ride height do you get before the car is on its bump stops (or hitting metal if bump stops are removed)?  This would give me an idea for a starting point for mounting spacer heights because I don't want to be wasting any of the springs' capacity if I start in the wrong place.

Originally I was going to try and get the air springs at their design height when my car was at its original ride height, but now I'm wondering if I should start a little lower.

Has anyone with a 1960s Impala (mentioning no names   ) worked out their air springs' actual height at 100psi on the car, compared with the 100psi figure given by the manufacturers?  I expect it will be a bit shorter with a car sitting on it   .

5 to 6 inches



Last edited by SIXONEFORLIFE at Nov 7 2003, 07:42 PM

 

[Rusto67]

Dude... use a tape measure. Measure from the bumpstop, to the spot where it hits the frame.

 

[M-827]

Thanks for your replies :cheesy:!

SIXONEFORLIFE, which of my questions were you referring to? Is the 5-6" inches the amount of drop to the bump stops (I think this is the one you were answering ) or the difference in height on and off the car at 100psi?

Rusto67, I've been under the car and got some measurements already but I didn't take account of the leverage ratio for the front suspension (I looks about 2:1, but I can't imagine that it would be in reality). The rear is 1:1 because the spring is on top of the axle.

Thanks :cheesy:

-----------------------------------------

The critical point with my mounting spacer dimensions is that I don't want to be crushing the deflated air spring before the car is on its bump stops. Ideally I want the car on its bump stops just before the air spring is at its minimum dimension (2.8" for my chosen air spring). If I go too far in the other direction, i.e. the air spring is noticeably inflated, then I will be losing stroke and therefore losing raising capability.



Last edited by M-827 at Nov 8 2003, 11:33 AM

 

[Swingin80Lincoln]

its not hard to make the adapters for the air bags, if you have a torch and a welded. youll have to take the spindle off and get the coil out of there, i would make a plate and either bolt it or weld it to the lower arm, preferably welded. then figure out what bumpstops you want to use, and put them in. measure idside the coil pocket where the coil sits to the lower a-arm. the airbag is like 3" when compressed all the way, plus you need the plate on the cup which should be 3/16 to 1/4 " thick. so take away 3 1/2 to 4" from your measurement and thats how tall the cups should be. you may need to make the upper cut at an angle to line eveything up right. the pipe should slip over the litle fingers in the spring pocket. i think the diameter is 5" but im not sure. when you get the cup all welded up you need to get a long bolt and weld it in so it goes thru the original upper shock hole and bolts the upper cup in place. figure out how you want the airline. i think if you use 90 degreee fittings you can make a hole in the side of the cup and run the line thru the frame rails.

 

[M-827]

Thanks DusterNut :cheesy:

That's very helpful advice .

My front coil springs are about (I haven't got my piece of paper with me at the moment!) 5.5" in width, and my rear coil springs are about 6.5" in width. I will need to be exact with the tube diameter for the front, because the spring seats (at least the bottom one anyway) are defined with a circular pressing in the A-arm. I'm hoping I can then use the same diameter tubing for the rear mounting spacers (despite the wider coil springs) because the rear spring seats are flatter and I think I can get away with it :cheesy: .

 

[Swingin80Lincoln]

the same tubing should work in the rear. i think the coils are pigtailed.(larger, but with regular diameter ends) my brother has a 65 olds and thats how it is. on the bottom arms you shouldnt use any tubing just a flat plate, less things to go wrong and get cocked at an angle.

 

[M-827]

Thanks again DusterNut :cheesy:

I've just got in from the workshop and have been under my car. You are right, the rear coils are much smaller at the mountings - they twist inwards to about half their full diameter. There will be no problem with the mounting tubes. The bottom coil seat looks okay too - it sits on top of the axle and there looks to be plenty of opportunities to mount an air spring there :cheesy: .

I hadn't thought of using a flat plate for the bottom arms. I had seen it used for other set-ups, but it hadn't occurred to me to use the same idea for my car :uh: .