What's that sitting on the trailer? Early '70's Corolla? My GTO is a similar color. Love the fender-mounted mirrors. Were they stock?

 

FYI, I had the Airlift 60824 air springs installed before starting an 11,700-mile trip around the US last summer. I kept them inflated to 35 psi and they definitely made a difference. My mechanic recommended joining the tubes to a single inflation valve. It makes inflation easier and they're always balanced. A single valve may not be best if you carry very heavy lopsided loads and need to have a different pressure on each side, but it's fine for towing.

They didn't eliminate the trailer sway completely but they kept the front wheels firmly planted so I never felt like it was out of control. One possible contributing factor to the swaying that I found is that the nose of the trailer is a little high, so I plan to lower the hitch before my next trip.

 

Awesome, thank you for the information! I have received my Airlift springs but have not installed them yet. I was planning to do the single valve for exactly the reasons you mention.

-Rod

 

i would be wary of having the two air springs on the same valve for one simple reason, body roll in corners, if the valves are linked without a check valve to stop air from flowing between the bags you can roll in a corner and as one spring shrinks the other will grow a proportional amount based on airflow. At the very least this would result in a different spring rate while cornering than while traveling straight and at the worst i could easily see it increasing body roll.

You do what you want, this is just an engineering perspective.

 

When I had a Buick Roadmaster with air adjustable shocks, the system was set up so that there was one line from the compressor going to the driver's side shock and a 2nd line going from the driver's side shock to the passenger side shock, however, to minimize air shifting from one shock to another, the line between the shocks was a much smaller ID. If I remember correctly, the line between the shocks was like 0.031" ID, while the line from the compressor to the shock was like 0.090" ID. When GM discontinued making the two different shocks, the replaced air shocks were the same type, but, I installed a "T" maintaining the line to the driver's side shock at 0.090" ID and to the passenger's side shock at 0.031" ID. I guess you could do the same when using one valve for both air bags - use two different ID lines to minimize air transfer between them when cornering.

 

Air Lift sells multiple versions of controllers and compressor systems that inflate both shocks from a single line, no indication of a check valve in those kits. Besides, a check valve versus an electronically controlled valve would prevent the user from being able to deflate the bags which would be an even bigger safety hazard as folks would be driving with inflated bags and no extra load.

I suspect if having a single line for both was a serious concern, their legal department would require them to provide check valves and have some form of preventing the installer from just teeing the two bags together. Instead though, the kit includes a tee.

-Rod

 

I'm not talking about a check valve the prevents air flow in one direction. What I said is a smaller ID line to reduce flow rate in both directions; the system will still balance itself out. At any rate, the DD comes with a rear stabilizer bar, whereas the Roadmaster I had didn't have a rear stabilizer bar, therefore, I believe this system they used helped reduce rear sway in turns.

Anyhow, the DD tow bar is mounted at the rear subframe. It would be better if they had a tow bar that distributed the load better over the rear wheels or even between the front and rear wheels - like 5th wheel trailers that are mounted on pick-up trucks beds.

Lifting the rear end up should help maintain the front end at its regular height. On the other hand, you could add a front end spoiler that would push the front end down and maintain better road contact (thus steering control) at speed - like the NASCAR cars have (well, maybe not to that extent).

 

Would you improve handling and front end steering of the DD if you would back-up the car on the trailer, thus putting the front end (engine) weight over the trailer's wheels?

 

Sorry, been out for a bit. The car is a 1970 Nissan Laurel I picked up from Japan, it's a project I hope to find time to pursue.

 

The angle of the photo doesn't help as it makes it look like the car was pulled more forward of the axles. I load it so the car is about centered over the trailer's axles. For how much the front of the DD lifts, it's actually pretty minor and the handling stability of the DD hasn't changed. I always error towards front loading a trailer because I've seen the aftermath of too many rear loaded trailers and the uncontrollable sway that can be encountered. This video is one of the best I've seen for illustrating the effect weight distribution can have on stability/sway: