I have got my car running really good and I have dynoed it but I am still tuning the haltech e8. One problem is that vdi has no way to open and I was going to use a walmart airpump but I didn't like the idea.

So I just purchased some 12vdc push solenoids with spring return kits(I had to buy 2 sets -__-" just because)
part numbers
solenoid a422-064104-04( masterDpart# tp12x19-c-12d)
spring a490-367460-09

http://www.guardian-electric.com that is where I found them but I ordered them from Master distributors. It's gonna be 4 to 6 weeks till I get them -_-.

Now I am gonna use to haltech to operate it but you could use a summit racing rpm switch.

what do you guys think?

 

You do have the S5 intake on it right? S4 has no VDI, only 6 ports actuators.


SPec.

 

I don't mean to jack another's thread, though this topic is quite useful and perhaps not as informed as others. Now, I have searched this topic and find there to be those that use an air source (be it the stock s4 air pump or other, such as lumbar pump and an rpm switch) or the use of an electic solenoid and rpm switch. Now, one can't use air pump if removed; also, heard of problems like outsourced airpump not being powerful or strong enough, etc. I have also read that perhaps electric solenoid too quick, and defeats some gains. Sorry so long- just thought I'd save others the time. Which of these is most effective? Solenoid sounds good to me, but unsure about "quickness thing."

 

Spectator - I do have a s5 intake on my s4 and rats nest and airpump is gone.

chuckrx - I am going electronic because It to me seems to be to most reliable esp with the solenoid that I have chosen.
I have no idea about your "quickness thing" I just know that my car makes more hp if the vdi is opened at 5k by a human hand while I'm on the dyno.