Throttle down air jack decent?

299sh, I just slowly pill out the valve to throttle how fast the car comes down.

@99sh - I had the same question, and took the approach that Charley took and was careful in how quickly I pulled the spool of the air fitting out after the lance itself had been disconnected.  This works... but I have help from  a number of different people at the track and it's hard to teach people how slowly it should be done when they only do it once in their lifetime... so I came up with another solution...

The fitting in this photo (the silver one on the left) is a factory supplied nipple that joins the air lance fitting that you can see on the bodywork, and the stainless steel braided hose fitting under the cockpit cowling.

I took it out and initially made a small aluminium plug that I pushed down inside the fitting.  The plug had a flat filed on the side so that it acted as a throttle to the air/nitrogen flow (in both directions) and this slowed the raise and lower of the car.  It worked OK but I decided I only wanted to restrict the flow when the car was lowering, so the car would raise pretty much like it would without this in the system, but could still control the speed when the car was being lowered.

That's where the brass fitting on the right hand side of this attached photo comes in.  This is a spool piece out of a plastic SMC pneumatic flow controller (I just busted the plastic surround that included the push in hose fitting off the outside - leaving just the brass assembly intact.) 

The fitting that remains included an adjustable flow restrictor (adjusted with the small knurled knob), but also includes a check valve that means the flow is pretty much unrestricted in one direction and throttled in the other...

 I then just machined/tapped out the internal bore of the silver factory fitting to allow the brass fitting to be screwed inside (see the second photo of the final 'assembly' below)... and then set the knurled knob to a position that mostly restricted the flow in one direction, then reassembled the original fitting with the brass fitting inside into the air jack circuit.... and bingo!.... normal raise speed, and restricted lowering speed... and it's adjustable (just need to take the fitting apart and turn the knob, then do it back up)  I have never had to re-adjust it, and it works great.

Car comes up as normal, and I've set the speed so that it goes down in around 6 seconds.... so now if someone just yanks it out, the car doesn't literally crash to the ground... I'm almost positive dropping the car doesn't hurt anything... but it still didn't feel great to watch it happen...

 I've just taken delivery of a new SR3-XX and will be making another one of these in the next month or so.  I would be happy to supply you the brass flow control part if you wanted... leaving you the only job to get the bore of the silver factory fitting drilled and tapped to suit....  let me know - no trouble. 

Here is what I did, works great!

@rjbender I love your idea. (my issue is dropping the car on my foot. I'm not so smart, as I've done it more than once. It's pretty easy to put one's foot directly under the front tire when lowering the car!!)

Any chance you could publish some part numbers? -- you're a bit far away to ship them up here to the 'States. 

Good info, thanks for the feedback. I've tried to pull the air release slowly but takes too much finesse and not always guaranteed. 

I'm running an AP Racing air jack connector. Let me try a manual ball valve first and see how that goes!