I just thought I'd give everyone a rundown on my electronic 5/6th-port & VDI method, which can only be done on a S5 N/A (sorry S4 guys). W/ this method, the pump will spend most of it's time OFF rather than switching on every time you pass 3200RPM.

Here's what you'd need...

(1) Cadillac Air-Ride Compressor
(1) Air Pressure Differential Switch (which I have sourced for under $20)
(1) 30A Auto Relay
(1) 3/8" Barded Fitting
(1) 3/16" Barbed Fitting
(1) 3/8" to 1/2" flared Fitting
(2) 3/16" Plastic "T"

...also, you'll need some lengths of 3/8" hose (compressor to adapter), 3/16" hose (adapter to solinoids), and some zip-ties and small screw clamps (to keep the hoses secure).

Now, just as Dave from www.FC3S.org did, I'm going to mount the air compressor in the same area as the charcoal cannister (which I plan to completely remove). Next take the Fittings, and make a reducer. The cadilliac air compressor uses British fittings (which I couldn't find locally) so instead, I used a screw clamp, and attached a short length of 3/8" hose to, attaching the end to the larger side of the reducer. Using one of the plastic "T's", add a short peice of 3/16" hose from the reducer, to one of the legs of a "T" (this will go to the switch) then, the other leg will go to the 5/6th & VDI solinoids (using another "T" to split the line for each solinoid). Run a line from the 1st "T" to the switch, and the pressure system is done. Wire the switch up for the normally open to go to the "switching" terminal on the relay, and the normally closed switch can be grounded out. Whereas the Constant goes to a fused 12v+ accessory source (to only operate the pump when the car is on). Wire the rest of the relay to their respective locations (the pump, the 12v+ on the battery, and a good ground).

I'll probably revise this a few times, but that should give you the just of it. I'll have pictures and info (part#'s) for the switches in a few days. Any questions or comments? Post here.

 

Thank you for the w/u. I'll be following your procedure and try this myself. Can you expand a little more as to how the compressor will work build pressure, power the actuators (know when to open/close) etc etc...

I'm not familiar with air pressure diff switches - so can you expand on those also?
Thanks L.A.

 

how is it that the pump runs less this way?seems to me,unless you have a storage tank,the pump will still run whenever the aux. ports have to be open...

 

Ok, I'm in class right now, so I'll keep it short.

The system I'm using keeps the stock solinoids. Whenever they're closed, it's a closed system. Whenever they open (to actuate one of the systems) the solinoid opens, making the line and the actuator pressurized as well. After it drops to below the actuation point, the solinoid switches the other way, vents the pressure in the actuator and the line, and it's like it never happened.

My only concern is the PSI it will take to pop an actuator. Seeing as Dave is running them off the pump (+40PSI) I don't think 7½ will be a problem.

 

Can we get an update on this? How has the system been working? Can you tell us more about this "pressure diff switch" for those of us who don't know what that is (me).
Thanks,
-a

 

Liquid - you out there?

 

well, my engine has blown up, due to mishandling of the front housing... but, I have my setup pretty much finished.



You can see the bracket holding the air compressor in the passanger corner near the firewall. I bought a pressure switch from www.worldmagnetics.com that I'll tee into the hose going from the compressor to the vacuum rack (as I'm using the metal rack to distribute the air, rather than running silicon lines between the engine and the manifold).

It's really pretty self-explanitory if you think about it.

 

wow dug up from the grave