Sorry about that, here is the original post:
1/4 turn ball valves are just as effective as motion control units....
Here is a quick summary of today's activities using a Freightliner chassis.
Friend has a 2012 Phaeton 40 foot QKH and was convinced 150 psi 1/4 turn ball valves would work the same as the motion control units. It was just a matter of experimenting with the valves. So he bought a pair and added push to connect connectors on each end of the ball valve. We decided to put them on the front air bags first because the front is easier to work on and there are 2 ride height control valves on the front axle and only one ride height control valve in the rear. Front ride height valves use 1/2" air lines, rear uses 1/4".
Before any changes I drove his Phaeton (with Road King shocks by the way) and we both observed a lot of side to side " wallow". The Road King shocks were helping in the turns, but by themselves it wasn't enough. We also observed that just sitting at a stop sign and lift off the brake then stomp on the brake, the nose dive was very severe. We attributed this to the air bags. Then he drove my Bus on the same route ( I have Koni shocks and motion control units) and observed a significant difference, no wallowing. We tried the stomping on the brakes while sitting in traffic and very little nose movement.
He installed the 1/4 turn ball valves with both 3/4 open on the Phaeton then test drove it, no difference. Crawled under front axle and turned both ball valves so they were 1/2 open, drove it on the same roads as before and noticed very little wallow ( side to side rolling), drove on interstate as we did before without ball valves and very little roll with ball valves 1/2 open. Trucks that passed us were no longer an issue as they were before.
So he left it as is for now, to me it seems like an ideal trade off for handling versus ride. He is going to drive it some more with just the 2 ball valves on the front and leave the 1/4" rear airlines ( which are tied to just one ride height control valve) alone. It was not obvious that he needs ball valves on the rear. I expect he will continue to experiment with adjusting the front ball valves as well as adding the ball valves to the rear to see if the rear valves are really needed since there is just one ride height control valve and the air line is 1/4".
We did a manual dump of the air bags and the front air bags continue to dump faster than the rear just the same as before the ball valves were added. The rear axle with one ride height control valve and using 1/4" air lines continue to dump slower than the front air bags just like they did before the change.
To be continued with more experiments.
Griff & Debbie
All Electric 2010 425hp 40 QXP with Vorad (Collision Warning, Smartcruise, Side Object Detection)
Previously 2005 38DP from June 2007 to July 2012
2011 Ford Edge Limited