? for people running air suspension??

[handy67]

so i finally got my truck to the point where it can drive. adjusted my four link and watts link and got my pinion angle where it needs to be for smooth driving. in the back im running a 4 link cantilever bag set up with 7" slam bags and in the front for now im running a stock control arm set up with the lower control arms boxed out for the 8" slam bags to set down inside of. this is my first air ride vehicle so forgive my ignorance, but i pulled it out and set it to what i thought looked like a good ride height. i was running roughly 55-60 psi in the front and somewhere around 45 psi in the rear. i am thinking that was to little air pressure because the first turn i tried to make almost didnt turn. the truck wanted to go straight. does this sound right? so after pulling over i bumped the pressure up to 80 psi in the front and that felt better. running 55 psi the truck felt spongey and very loose. the truck does not have a front sway bar so i though maybe that would help with the front. any info or advice you guys can give would be awesome. thanks.

[PGSigns]

Post some pictures of you front setup. Steering may need help. Are you running drop spindles? My truck at ride height is 75 psi but not the same bag so not a big help. Set your truck up at what you thought was a good ride height and look at your tie rods. Then pump it up to the second setting and take a look at the geometery.
Jimmy

[handy67]

thanks pgsigns, i will take some pics of the front set up when i get back over to the garage and post them up. when inflated what exactly should i be looking for? anything that looks like it would be binding or just looking out of whack?

[handy67]

oh and as for the drop spindles, no i am not running drop spindles yet. i am looking into getting a set unless that is a bad idea??

[PGSigns]

The drop spindles will get you 2 1/2" of drop with out running the tie rods up 2 1/2". What I am thinking is going on is your tie rods are running way up hill and it has the geometry out of wack. Also was the truck aligned at ride height? As the tie rods run through an arc the pull the toe in as the truck drops. The steeper the angle the more the change. All you need to do to see this change is to tale and draw an arc the same length as the tie rod. Draw a line through the center and and you will see that if the tie rod is level and then travels sum up or down the toe will change just a little. But if yo drop it 4 or 5 inches you will see the tie rod is running up hill a good bit and an inch or two of travel with it up there can change the toe a good bit.
Jimmy

[handy67]

Ok I see what you are saying for the most part. When the truck is fully aired out, yes the toe in is a lot. As I raise the truck the toe in reduces and the wheel and tire look much more straight up and down, as I would think they should while driving. No I have not got it to an alignment shop to have it done professionaly yet. Last night was the first night back together and with tags so it was the maiden voyage and we are getting slammed with rain so probably won't get it out tomorrow either unfortunately. But I am think 2.5 drop spindles will be a good direction. Any recommendations on which ones to go with?

[PGSigns]

I have CPP in mine. Google ackerman angle and do some reading. A bunch of toe really affects this.
Jimmy

[handy67]

Ok I'll definitely look that up and tomorrow when I'm at the garage I'll get some pics and post em up. Thanks a lot

[SCOTI]

Bags need to be run @ the mfr's recommended height/pressures for 'optimum' ride. Now optimum is subjective as one guys 'it rides great' can be completely different vs another.

Most 7-8" bags require a ride height of around 5-6" minimum. Whatever pressure it takes to yield that height will be what's required. A heavier nose (ex: full iron bbc w/brass 4-core radiator & a/c) will require more air pressure to achieve the same ride height as say an all alum LS drivetrain but both will have about an equal ride quality despite the diff pressures.

Another common mis-conception is that a bigger bag used w/a lower psi always yields better ride quality. It can/does if done within reason. Too little air pressure can yield too little spring rate & a bouncy ride (too much goes the opposite way as well). So installing an 8" bag in a truck arm application (rear) & running 25psi of air pressure to achieve the desired ride height will not yield as good of ride quality as a 6" bag @ 40psi yet both give you similar ride heights.

[handy67]

Scoti, thanks for that and that makes sense with different weights depending on your build with the front end. Mine shouldn't be to heavy as it's a small block 327 with a 3 core rad and no ac. But I will try airing my truck up to what I thought felt like a better ride (80 psi) and check to measure the bag and see how tall it is at that pressure.

[SCOTI]

Originally Posted by handy67

Scoti, thanks for that and that makes sense with different weights depending on your build with the front end. Mine shouldn't be to heavy as it's a small block 327 with a 3 core rad and no ac. But I will try airing my truck up to what I thought felt like a better ride (80 psi) and check to measure the bag and see how tall it is at that pressure.

That 80psi sounds about right on these trucks w/a sbc. If it rides better @ that pressure but needs to be lower, that's where spindles or other mods need to be considered.

[handy67]

It's not a bad looking height to ride at, but lower is always better haha so I'm thinking spindles are the next step. I was looking them up today but every spindle I looked at for 67 said disc brake swap needed. My truck already has disc brakes so I would think they should work.

[SCOTI]

Originally Posted by handy67

It's not a bad looking height to ride at, but lower is always better haha so I'm thinking spindles are the next step. I was looking them up today but every spindle I looked at for 67 said disc brake swap needed. My truck already has disc brakes so I would think they should work.

Correct.... drop spindles require disc brakes. Which spindle you need depends on how the disc swap was done....
http://67-72chevytrucks.com/vboard/s...d.php?t=444823

[handy67]

Yeah I'm not exactly sure how I'm gonna figure that out because they were on the truck when I got it