Okay, I'm working on removing all the emmisions related equipment off of my S5 and I'm looking at the UIM and there's a barrel shaped gadget inside it that rotates and connects the two shorter runners pretty much...didn't have a lot of time to investigate it so I don't know for certain. It's vacuum operated and I sure it has to do with a variable intake runner mechanism but I don't know:

what it's called.
how important it is.
whether I can live without it or not.
what happens if I remove it and block the hole off.
what happens if I wire it to the open position.

Any help will be appreciated.

 

I believe that's the VDI sleeve. Removing that will reduce your torque or high-end HP (I can't remember which.) I'm sure someone more knowledgable in S5 N/A's will chime in, but for right now, I'd leave that thing in its place.

 

That's the Variable Dynamic Intake (VDI) system, and it's not emissions related. It a big part of the reason S5's have 14hp more than S4's. Do a search and you will find plenty of info.

I wish people would stop assuming they can just rip everything off their engines...

 

this is the VDI system...It helps out power in upper RPM range...Kicks in around 5200RPM...If you remove it then it will most likely hurt you performance...it won't work though because you are removing you emissions stuff...the system works off the air pump...There are peolpe on here trying to devise a way to make it work without the emissions crap on the car...search for 5th and 6th port fixes or something along those lines!!

 

Believe me if I were just ripping things off my car I wouldn't have asked...

so if it kicks in at over 5K then if it were wired open then I would still have the top end it attains only I would lose low-end power? I would really like to ditch the air pump but if it's necessary for this particular device then I may reconsider. Thanks for the help guys...

 

okay...did some research and it's staying...found another way to get what I want done.

 

what would be the results if the VDI were wired open indefinitely? I don't want to do it this way but I may not have a choice with the route I'm taking.

 

...great, now I'm as curious as hell how badly an RX-7 would run if a VDI block-off plate was made? Anyone tried it?

 

You'll find out in a few days prolly...that or I'm going to wire it open...I'm trying to mix too much **** up to make one working car and some of this stuff just isn't fitting together.

 

Wiring it open would have a completely different effect than taking it out, and making a block-off plate. People have wired it to the "high" setting before, but I don't know of ANYONE who has used a block-off plate.

 

what were the results of wiring it open?

I'll cut a plate and try that first. May do both and run a quarter on each and see if either changes.

 

I'm pretty sure doing so would have a very undesirable effect.

 

which would? wiring it open or using a block off plate?

 

He he thats what i did, hell i even cut off all the aluminum so now it just looks tubular!

I ****** rock!

-Chris

p.s. mine is turbo though, sorry

 

This guy swapped an s5 intake to an s4 engine.
He explains how it works & why..
http://homepage.mac.com/carldavis/intake/intro.html

 

Thank yo for that link Sureshot...that's very helpful beings it's an S4 block I'm having to utilize.


But...let me clearify my situation a lil. This car is not my driver. I have a much more dependable car for that. This car will be my semi-race project car. Another big reason for me doing this is that I do not have a decent air pump to use...my good one will go on the rebuilt car, not the toy. I am not worried at all about low-end drivabillity. I want top end only. I want everything at the top. So, beings this gadget only opens after around 4800rpm then I'm considering wiring it open. The port sleeves I am also considering removing or wiring open, beings there will be no air-pump nothing will be operating them either. So, does anyone have any results of wiring the VDI open? Or removing it and blocking it off all together?

 

Just wire it open.

Just like everything else you mentioned, the bottom end will suffer, and there will be no change in top-end; as compared to a working, stock system.

 

Get a TII and you won't have such silly things

 

Below 5000rpm is not "low-end", it's most of the rev range! There are no gains from doing this, only losses. I thought you weren't just ripping stuff off...
Why do you need to loose the air pump so badly? Why don't you just leave it and have properly working VDI and 6PI systems. The air pump draws hardly any power and weighs little compared to the weight of the car. It'll require a lot of stuffing around to rig other ways to make these systems work properly without the air pump, and at the end of the day you won't be any faster.

 

I didn't think anyone would take the seriously...

 

lol...not trying to just rip stuff off...I'm short of parts and I want my toy working. I've got a pump and all the stuff to do it propperly but I can only have one car put together propperly with the parts that I have...and as it stands the propper parts will be going into my extremely clean '91 as soon as I got my rebuild.