Please critique my Aux port/VDI activation method.
 

I've been gathering the parts to properly activate my VDI and Aux. ports using a lumbar pump and some MSD RPM switches. I already have the pump, relays, and should have the switches shortly so I drew up a diagram to see what you guys think (and because I've always wanted to learn Visio ;).)

I plan on building two boxes, each with a RPM switch, variable resistor (instead of the pills so I can change activation RPM), and LED (to let you know when each switch activates.) The aux. pump switch will activate the airpump itself, and the VDI switch will activate one of the vacuum solinoids I have left-over from emissions removal to send pressure to the VDI actuator.


So what do you guys think? This is the pump I grabbed: clicky. I think it should be able to put out enough PSI to handle both actuators.

my only concern would the pump operation. Lumbar pumps by design are only momentary pumps not designed to be used for long periods of time. Also looking at the diagram is the ramp up time for the pump fast enough.

So I see that pump as the fail point.

But other than that I see nothing wrong with your diagram/set up

Hmmm, maybe I should run out and grab my vac/pressure guage and see how long it takes for the pump to get up to speed. I'm not too worried about the pump burning out either. It's only going to be active for two seconds tops during accelleration and these things are dirt cheap ($10+shipping off of eBay new.)

Looks like I forgot the fuse in the diagram too, I'll have to update that. I was planning on putting one on the relay and just going off my stereo wiring for the switch power (they're grounding switches so the only juice they need is for the RPM circuitry.)

yeah you will want a fuse within 12 inches of the power source for the circuit.

You probably don't want the main power for the pump or switches tied into the radio power though... too much chance of the voltage dropping with the radio on the same circuit.

Good point. It's not like there isn't a ton of available accessory lines available. Maybe I pull one off the logicon since it's not going to see much use (don't drive it during the winter, no AC.)

There's no need to do any wiring in the cabin. Instead of using the ACC circuit you should get switched power from one of the many ignition-switched circuits in the engine bay.

I want to keep the switches in teh cabin though, I'm thinking glove compartment, so I can easily adjust the triggered RPM. The only wires I'd have to run through the firewall would be from the coil for the RPM reading, and two wires for the solinoid/relay.

I had some time today and it was above freezing, so I wired up the relay and pump, then gave the thing a test sans the RPM switch (still haven't grabbed one yet.)

All the wiring works out great, the pump kicks in and doesn't get warm to the touch running for 20-30 seconds straight, so I don't think it'll burn out.

The bad news is that it will not actuate both the VDI and 6pi, it just doesn't have the juice. The VDI opens pretty quickly (doesn't snap open but takes maybe a half second.)

For now I'm going to leave the 6pi running off the split air tube and just clean out the passages so it'll be a little quicker to open then it is now (the sleeves are probably pretty dirty after 100k of use.)

any progress on getting the pump to run both switches?