Has anyone removed or disabled The VTCS??

[thewrench]

Cool, now we are getting somewhere.

That optimism maybe a little premature. Geez, I hate to contradict myself, but I went back and took the damn thing apart again (to check how the lever was positioined when the flaps are closed) and upon further inspection saw that the butterflies really don't block any of the flow from the long runners. Obviously some air will get up there, and they'll surely create some turbulence, but I can't see how they would really affect the direction of the flow that much. It was a great idea though, huh? I still don't see that removing them and opening the plenum will help at all, and might just make things worse. Now I'm more than just idly curious, I'll definitely do some asking about it later. And I have to wonder just what benefit there is? to performance? emissions?

James

 

[twilightprotege]

yeah it's something we all have to live with, so we might as well understand it as best as we can.

are you going to talk to sunbelt?

 

[thewrench]

Yeah, but I don't want to pester them too much. They had said to expect cams around the middle of January, so I'll ask them some more about intakes then. I've got to do something about a racing seat and harnesses, too. Balanced Performance (next door to Sunbelt) has a seat ordered for me, so I'll be up there a good bit this month. It's funny about that bent butterfly, it shows no sign of being bent, scratches or anything. I don't think it effects anything, I was just wondering if it came from the factory that way and why.

 

[twilightprotege]

yeah it would be strange that it's bent from the factory, but i've heard of stranger things coming out of car factories...

 

[thewrench]

Well, FWIW, the butterflies are closed at idle with the engine warm, counterintuitive, huh? I'm really confused as to just what the VICS is. It seems like some sort of resonance chamber, I just don't understand how or what it is supposed to enhance/do. It definitely doesn't work like Edwin has in the FAQs (sorry edwin (peep) ) Maybe perf knows????

 

[twilightprotege]

yeah the whole thing has never made sense to me. the only reason i can see that it's open at high rpm is that all of the runners are connected to one another in that chamber, so i guess it goes more access to air (sucking from 4 runners instead of 1)...but longer runners. sounds all just weird to me.

i'd really like to see what can be done with the vics chamber...how possible is would be to open it up to make the runners shorter as they should be - ie connect them directly to the plenum and not have them joined to all other runners

 

[perfworks]

Couple things, First you can eliminate the rattle two ways (for the VTCS ONLY) Adjust the lever screw right below the actuator. Second just unplug the vacuum line and plug it with a screw or something and clamp it.
The rattle comes from the plates hitting the reversion lip inside the manifold.

Second the VICS. The plates are open when manifold vacuum is not present. It is supposed to provide more low end torque.
When the plates open it adds more "capacity" to the system like a shorty manifold would for top end breathing. How well does it work? Ok for economy vehicles but a nice 98 626 manifold that is of single runner design would be much better for FI applications.
BTW the TB (no wiring difference) is the same and all that would need to be done is rerunning the fuel lines. You could keep the stock 626 injectors in there.

 

[thewrench]

Thanks Perf, I was hoping you'd know. I would normally never question Edwin, but the faqs were talking about dual runners and such, so it just really didn't make sense compared to what I was seeing. Is there any advantage in to disabling or removing the VICS system for NA, or turbo for that matter? Wouldn't that just increase turbulence? This is assuming not going to the Probe mani. I remember greenmp3 gutted everything and had big problems with lowend, but that wasn't his only issue. Just fishing for ideas.

Thanks,
JamesT

 

[twilightprotege]

hang on, nick you're saying that the VICS butterflys are open at low rpm - james is saying they are closed.

 

[thewrench]

twilight, that's what he is saying, low vacuum=high rpm/load. The way he said it is kinda confusing, but I think that's right.

Low rpm=high vacuum=flaps closed=reduced intake volume
high rpm=low vacuum=flaps open=increased intake volume

 

[twilightprotege]

i c i c i c said the blind man.

 

[cdglowred5]

With the v6 probe and mx6 removing the flaps along with polishing gave alot of power.

I did the same with my 1.8L mazda bp motor found in the escort gt and it also added some power. The flaps just helped with warm ups.

 

[twilightprotege]

yeah me thinks extrude hone will work very very well.

i still would like a true dual runner setup

 

[perfworks]

hang on, nick you're saying that the VICS butterflys are open at low rpm - james is saying they are closed.

NONONO. I think i should clarify. The VICS are open when the engine is not running. THAT is why you see them open when you take it apart.
The control solenoid is energized by the ECU. It will control when the plates open up again. In theory at 4750 rpm
They are closed at idle until that rpm.
You will notice that on a dyno chart it will dip right in that speed range. Then it will bump right back up again.

 

[twilightprotege]

yeah - see my dyno chart

so, confirming they are closed from 0 to the designated rpm (mine is actually 5500 in oz). they open from there up

 

[thewrench]

Perf, Is that 4750 rpm set, or is it load related? Also have you seen any dynos with the VICS locked open? closed? moved around in the rpm range? I'm just interested in how/ how much it really affects performance.

 

[perfworks]

Perf, Is that 4750 rpm set, or is it load related? Also have you seen any dynos with the VICS locked open? closed? moved around in the rpm range? I'm just interested in how/ how much it really affects performance.

No its programmed into the stock ECU.
I have only seen the Dyno graphs from normal operation. I have though disconnected it before. For a while. It just KILLED acceleration. It never actually recovers, the turbulence is overwhelming. Low end is HORRIBLE

 

[thewrench]

But you never tried it with the VICS always closed, I wonder how that would effect top end?????? I guess I'll find out later when I install that mani.

 

[twilightprotege]

so perf can my ecu change the vics activation point?????????

 

[perfworks]

But you never tried it with the VICS always closed, I wonder how that would effect top end?????? I guess I'll find out later when I install that mani.

I think it will fall very slightly. Maybe not enough to notice but i'm not sure.