rear suspension help

[djracer]

Here's why you want trailing arms. So you can leave like the ole farm truck.


http://yellowbullet.com/forum/showthread.php?t=143943

[Outlaw72]

Originally Posted by djracer

Here's why you want trailing arms. So you can leave like the ole farm truck.


http://yellowbullet.com/forum/showthread.php?t=143943

Trailing Arms are not his only trick, but he does have them and he has made them work with his setup as a whole. That truck is crazy sick....you should see it in person.

[Super73]

Originally Posted by SCOTI

Basic physics would suggest an airbag acts very much like a spring when compressed to a certain extent: the bag (spring) will want to return to its uncompressed state or size (squish a ballon & it distorts, unsquish it & returns to its original form immediately).

I agree with what you are saying but, and this is a big but...

A bags spring rate is dependant on the weight applied and the PSI in the bag right? So, let's make a hypothetical situation here..

Bag situation
1500lb unsprung weight
Leverage ratio of 1.5
10" bag at full length and 7" at ride height
Effective spring rate would be 375lbs

Spring situation
1500lb unsprung weight
Leverage ratio of 1.5
13" spring at full length and 7" at ride height
Effective spring rate would be 187.5lbs

Most bags I have seen don't allow you to compress them as far as a spring. For istance, my front springs at free height stand 17 3/8" and were at 9" at ride height. That's 8 3/8" of compression and I still had a good 2.5" of travel before coil bind. I believe coil bind was 6 7/8". Talking 10 1/2" of travel the spring has. If there are bags on the market that will allow you to do that, then I could see it being done effectively.

[SCOTI]

That's sounds about right. The nature of airbags translates into a progressive spring rate on compression vs. a coil that can possibly be set-up for a linear rate.