Has anyone removed or disabled The VTCS??

[Walker]

Has anyone done this ? It seems to hender performance and improve fuel. But it seem it would help sence it is absent from the MP3 and the mazdaspeed. It only works on cold days to improve the heating up and lighting of the CAT. In normal operation it is an obstruction of the intake. I would like to see a dyno of before and after. Anyone??

For those who want to know what it is the VTCS is a variable tumble swirl valve control system. The valves shut off 2/4 of the incoming air at each cylinder and it tumbles the incoming air into the cyclinder on a cold day to create a rich condition and increase in heat so the CAT lights of quicker and It is the reason for the 2500-2800 Rattle in the intake.

[uclap5]

i believe one member did something to set it at open all the time, i cant remember how though somethign with a zip tie maybe? hehe :p

If you buy the mp3/ msp/ japanese intake manifold without the VTCS then you will need the ECU from the mp3 to not cause a CEL.

[cyomega]

Just get a turbo, you won't even notice the VTCS rattle...

[twilightprotege]

it can be removed fine, just dont diconnect the controler for it. you'll throw a cel

[P-Funk!]

...but what kind of performance improvement?

I don't need dyno - just butt-o-meter estimates...

Was It Worth The Effort?

[Little Beavis]

It is fairly easy to remove, but you have to remove the whole manifold first.

I have an "extra" manifold with the VCTS removed and ported and polished by perfworks that I would sell for $200 if you want an extra or what to do this. The combination of removal, port, and polished has been stated to have made big gains I ended up with two manifolds (talked to two different people about doing this). So, one is up for sale. It will help!

You will need to leave the solenoid there to make sure you don't throw a cell, but you can do this without changing your ECU!

[twilightprotege]

beavis, can you do me a favour with the spare manifold...take pictures of the lower half of it and confirm if the VICS runners only go to a chamber and in no way connect to the plenum???

[thewrench]

hey Beavis, I'll take that manifold, you have pm

James T

[Installshield 2]

Damn it James T...I wanted it...but you better buy it because it will just cause further debt for me...:D

[P-Funk!]

So.
'Is it Worth It'? I don't want to messa round with it for little/no improvement...

Thanks!

[twilightprotege]

let's just say race protege's were using ported STOCK intake manifolds up until recently...

[StuttersC]

Originally posted by twilightprotege
beavis, can you do me a favour with the spare manifold...take pictures of the lower half of it and confirm if the VICS runners only go to a chamber and in no way connect to the plenum???

Still trying to figure this one out twilight?

[ELEmental59437]

Originally posted by Walker
It is the reason for the 2500-2800 Rattle in the intake.


Can you describe the rattle? latley I have been hearing a random rattle at that RPM but it sounds like its coming from behind the dash on the inside and only while in gear. If its the same sort of thing because of VTCS please let me know.

[twilightprotege]

stuttersc - well no body can help me. edwin just stops replying to threads when someone questions him, so i need to find someone who can take a picture of their IM and really look at it properly. i know that mine is like, but i need to confirm what everyone else has

[thewrench]

Once I get this intake from beavis I'll help you out twilight. I got a pm from him today, so I'm not sure how long it'll take to get it.

JT

[twilightprotege]

sweet!

hey i think once you get that IM, cams and cam gears, you'll prob have the most powerful na p5 out there!

[thewrench]

hehe, shhhhh, don't tell :)

[twilightprotege]

hehehe...i'll just have to spend more money now wont I!!!! ;)

[thewrench]

Gawd, don't do that, my credit cards are high enough now, quad webers, yeesh!

[twilightprotege]

hehehehehehe...yeah that just an idea, mind you a very good but expensive idea...

[thewrench]

Thought of another joke


Originally posted by twilightprotege
you'll prob have the most powerful na p5 out there!


Which still isn't saying much! :D

EDIT: Oh man! Major threadjack, so sorry, back to your regularly scheduled topic!

JT

[twilightprotege]

(lol)

[Equinox]

aww I thought I was one of the most powerful n/a p5s before nitrous :D

[twilightprotege]

does anyone who has the most powerful NA P5???

[Equinox]

Originally posted by twilightprotege
does anyone who has the most powerful NA P5???

it would come down to posting dynos really. Unfortunately my scanner/printer is broke and I don't know how to fix it

[thewrench]

Actually Equinox I think you probably are. But there's going to be a bunch of people stepping up shortly I think. It seems a bunch of us auto guys are going na. We'll just have to see what develops. Have you got a pre-nitrous dyno?

Twilight-intake mani hit UPS today.

James T

[mp3moose]

Any chance I can get a manifold like that for 200? =)
Moose

[Equinox]

Originally posted by thewrench
Actually Equinox I think you probably are. But there's going to be a bunch of people stepping up shortly I think. It seems a bunch of us auto guys are going na. We'll just have to see what develops. Have you got a pre-nitrous dyno?

Twilight-intake mani hit UPS today.

James T

pre-nitrous dyno hit 132whp, 145wtq, just before I dropped on the port and polished heads.

[thewrench]

Did you do any work on the intake mani, sorry if you've covered this before. If I've seen it I can't remember.

JT

[mp3moose]

Damn you wrench! I wanted that manifold! =) Its cool, but let me know how it all turns out as I am all about the NA power.
Moose

[thewrench]

Hehe, I'm trying to figure out what order I'm going to do all of this, header's firrst, but I could do intake->cams->cam gears or vice versa. I'll let all know what happens. There was someone selling a new jspec mani on the forum somewhere for $400, look around for it if you can afford that because it was a decent deal. But I'd rather have what I got, sometimes it pays to not have a life outside of this forum. :D

JT

[tritonheat1]

I think (MacProtege5) Is one of the Quickest n/a P5's on the net. He beat few RSX-Type S's, MSP's...;)

[twilightprotege]

I look forward to seeing what the IM brings you james! i just wish i knew exactly what i want to do next to my car!!!!

[thewrench]

OK Twilight, I cracked the intake open today, and you are absolutely right, the VICS butterflies just lead to an open chamber. Makes you wonder just what exactly it does. I'll ask when I go to discuss cams, hopefully in a couple of weeks, to see what "they" did to the intakes. And in looking at the pics on Corksports website, I can't see how the Jspec mani would be any different. I can't see where removing the VICS butterflies would help. It would basically just add intake volume, but not flow, and may actually increase turbulence. You could remove the butterflies and open the upper chamber to the plenum to shorten the runners, but you would have to work hard to smooth it all out, and the runners would effectively be so huge you would kill any bottom end. One question, on your intake, are all of the butterflies flat? On this one, one butterfly is slightly bent.

Hope I helped you some,
James T

[twilightprotege]

yeah coll james! finally i'm right with something!!!!

that's exactly what i thought. it would increase turbulance. it just doesnt sound nor look like an ideal setup to me.

the butterflys...i honestly cant remember. but i'm guessing they should be straight as butterflys usually are

[thewrench]

You know I just thought of something, when the butterflies are open they block the main runners cuasing the airflow to run all the way up through the chamber and back around down the main runner, thus greatly increasing runner length. So with that in mind, would the butterflies be normally open, and close under high load , thus shortening the runner length. So it would be better to disable the butterflies, closed position, but leave them in place, giving shorter runners all of the time, right?

[twilightprotege]

that was the arguement i had with theman 1 time. the butterflys should be closed at high rpm not open as he claimed because having them open increases the runner length. you can see why the whole IM topic has been quite confusing and strange...

[thewrench]

Yeah, the more I think about it, the more that has to be true. If I can get to it to see, I'll try to take a look at the lever to see what position it's in at idle. I can see now where having the ability to control that would be helpful now.

[twilightprotege]

good idea. would be good to know the truth behind this...

[StuttersC]

Cool, now we are getting somewhere.

[thewrench]

Originally posted by StuttersC
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]

Originally posted by twilightprotege
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]

Originally posted by 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.
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????????? :D

[perfworks]

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

[perfworks]

Originally posted by twilightprotege
so perf can my ecu change the vics activation point????????? :D
Anything can be changed. It is in the software so if its reprogrammed then it will be OK. Once we have our PNP out I'll let you know ;)

[Little Beavis]

Hey, that's odd about the bent butterfly. Sorry, I had no idea. Basically I pulled the thing out of the box, took pictures and put it back in. Heck, I sent it to you in the same box I got it from perf in.

Sorry though. . .I feel bad, but I didn't know.

As for the VICS you could control it with some of the piggybacks out there. I know the MPI has an output that you could set based upon RPM, temp, MAP/MAF, or deflection (or any combination thereof), thus you could control the VICS as you ask. It would be very interesting to try that (maybe if I ever find some free time I could mess around with it), but that won't be for a long time.

Sorry I missed the thread over the past few weeks (forgot what thread it was). Oh well.

[thewrench]

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

I would hope so for Mazda's sake, that's a helluva lot of engineering to do if there's NO gain, unless it's emissions oriented.

Little Beavis- No prob,man, I've looked at it pretty close and I can't see any evidence of it being ...ummm...."manipulated". either purposely or accidentally, no scratches or marks on the butterfly or screws. That's why I was wondering if for some reason it's like that from the factory, you know, different breathing needs on different cylinders, but the change would be so negligible I can't see why that would be. It's no biggie to pop it off and straighten, or if I get industrious I could take one off my mani when I swap them out.

[igdrasil]

i still dont get it...

what are vics and what is vtcs.

perfworks removed the butterflies that are placed in the end of the intake...which are those?

Because, let me tell you something...I dont know if its the vics or vtcs, because when my car hits 4750rpms, the pull is like fucking badass, even harder than my friends' GTS or CivicSI.

I may take a video...im sure it will be noticed.

could it be the open loop?

[thewrench]

VTCS- the butterflies across the runners right at the head, they are closed to 3000rpm when the car is closed, basically act like a choke on a carburetor.

VICS- the butterflies are not across the actual intake runners, but close off a chamber that is seperate but next to the plenum and below the runners. They are located about midway down the runner, they open at 4750rpm and basically induce an extra charge of air, and open up some volume, to help top end.

That clear it up some?

[twilightprotege]

vtcs - variable tumble control system
vics - variable inertia charging system

gee mazda thought long and hard about those names!

[shinzen]

Ok, so as someone that is going all n/a, I just re-confused myself with a part of this thread- wrench, you mentioned the probe IM swap- does that go to single runner design? And would we pickup some power? Or did I just comepletely miss something?

[twilightprotege]

just spend whatever you would spend on another IM and P&P the stock IM. much easier and will yield very good benefits

[shinzen]

yeah, I totally agree, but an an intake from an older probe is pretty cheap compared to a good P&P job- that's why I got a bit confused.... If it's a direct bolt on and adds more than a few whp it might be a worthwhile mod...

[StuttersC]

yeah, I totally agree, but an an intake from an older probe is pretty cheap compared to a good P&P job- that's why I got a bit confused.... If it's a direct bolt on and adds more than a few whp it might be a worthwhile mod...

It's old technology and more thna likely will not give you more power.

Like twilight said, keep what you have stock, maybe remove the VTCS and go from there.

VICS technology is actually good...

Or get the FS-ZE intake mani, which is a proven power increase.

[shinzen]

on an off note, did anyone else notice how the wording on essential speed's site changed from saying a 25% increase in hp to a 25% increase in airflow? It really doesn't sound like it's much more than a p&p job

[twilightprotege]

yes vics is a good system, just carried out poorly.

and yes, a good p&p will yield 25% increase in air flow. just think of a cylinder. say the stock is 30mm in diameter. that's a cross area of 706.55mm2. and that's rough. increase the diameter to 35mm (not much of an increase really) and you get 961.63mm2 area and that's smoother. just the area is a 27% increase....then you start talking about decrease in turbulance and flow....50% increase in flow isnt that difficult to get

[thewrench]

wrench, you mentioned the probe IM swap- does that go to single runner design? And would we pickup some power? Or did I just comepletely miss something?
That actually comes from perfworks, from what I understand, it is single runner, no VICS, I like the idea of extrude honing it, or maybe a mild port and just smoothing, but I think I'm going in a little different direction from twilight now, I'm looking at smoothing airflow and increasing velocity to try to build torque. A single runner without any obstructions would suit me, but right now I've got a ported stock P5 mani and an MP3 mani to play with. I'm going to see what they can do first, well, after I get some cams, if Sunbelt would ever get them released, grrrrr.... I would think there are also some concerns with the probe, or is it 626?, mani just "bolting up". Stuff like the EGR valve, fuel rail, throttle cable, cruise (if you want to keep it). But they are cheap.

[shinzen]

yes vics is a good system, just carried out poorly.

and yes, a good p&p will yield 25% increase in air flow. just think of a cylinder. say the stock is 30mm in diameter. that's a cross area of 706.55mm2. and that's rough. increase the diameter to 35mm (not much of an increase really) and you get 961.63mm2 area and that's smoother. just the area is a 27% increase....then you start talking about decrease in turbulance and flow....50% increase in flow isnt that difficult to get
Did you ever find out how much of an increase you got off of your IM p&p job? or I guess more appropriately, did we find out what the cfm is stock for us??

[Equinox]

VICS open up the plenum(intake manifold air chamber) and give the chamber more displacement. Normally your plenum displacement must be 50-70% larger than your engine displacement. I suppose when the VICS opens up it makes the plenum go from something like 50% bigger than displacement, to 70% displacement when open.

In all honesty, I would suggest keeping the stock IM in all applications and just port it out, and get rid of the VTCS.

VTCS is only for emissions and only chokes the car while under 3000rpm. Although I think it only chokes the car while it is cold, or while NOT at wide open throttle. Mainly it's to keep cold starting the engine from poluting the atmosphere too much.

So, to make your IM the best it can be, take it off, take out the VTCS butterflies near the head portion of the IM, and weld up the holes where the rod ran through. Then put the intake gasket on the manifold and port match it to the gasket, as well as port match the head to it. Then polish the casting of the intake manifold down to a nice smooth surface, and tada, you have one nice intake manifold at minimal cost, depending on if you do the work. To not get a check engine light when removing the VTCS system, just keep the little solenoid that turns the butterflies, plugged in, but not manually controlling anything anymore. The engine will think it's doing good. Just when having your emissions checked on your car, make sure the car is already warmed up. You will avoid failing.



BTW, Twighlight, if you remove too much turbulence from the IM after the injectors, the air and fuel wont mix well.

[shinzen]

Anybody wanna do a how to with pics? I have always gone to a shop for stuff like this in the past, but you are making it sound a little too easy- the polishing I wouldn't have an issue with, but I am a bit concerned with the port matching- got a dremel but..... isn't there a pretty big chance of screwing things up royally?

[PR5Matt]

it can be removed fine, just dont diconnect the controler for it. you'll throw a cel
I am going to be lazy and ask. How did you remove it? If you disable the actuator with out taking the intake off to try and remove the flappers, which way do you zip tie the actuator lever?

[PR5Matt]

beavis, can you do me a favour with the spare manifold...take pictures of the lower half of it and confirm if the VICS runners only go to a chamber and in no way connect to the plenum???
Porting is no problem for me, but I too would like to have pics of the mods needed to completely eliminate these flappers/valves. (uhm)
Again, I am lazy...

[PR5Matt]

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.;)(uhm)
Just one HUGE problem with that explanation: At WOT there is low/no vacuum. Also you need short runners then, not l-o-n-g ones...

Low-end torque= low RPM= high vacuum (long runners needed not shorter ones)

Top-end power= high RPM= low vacuum (short runners needed not longer ones)

Are you sure you are not screwed up, or are Mazda engineers smoking Crack?

[Turbo Matty P]

I'm investing my money that they smoke crack.

[shinzen]

I am thinking they are hitting the hard stuff as well, but who knows maybe we all are the ones that are messed up

[twilightprotege]

shinzen - i got about a 20% increase in cfm flow out of my p&p of the head from memory...with my full exhaust system i'm hoping it'll help me reach 150whp.

pr5matt - i dont have vcts stock (us aussies dont get it)....and as thewrench proved, the vics butterflys are close at low rpm, they open at high rpm

[StuttersC]

(uhm)
Just one HUGE problem with that explanation: At WOT there is low/no vacuum. Also you need short runners then, not l-o-n-g ones...

Low-end torque= low RPM= high vacuum (long runners needed not shorter ones)

Top-end power= high RPM= low vacuum (short runners needed not longer ones)

Are you sure you are not screwed up, or are Mazda engineers smoking Crack?
To simulate shorter runners in the IM, VICS opens thus creating more intake volume at higher RPM. More intake volume is like having shorter runners.

It works...

The 626 was a dog up high becuase of the single length long runners. Everyone I have talked to who have driven both the protege with the 2.0-liter motor and the 626 with the similar motor have said the 626 was not has good.

626 IM = old crappy technology.
Protege IM w/ VICS = Better flowing and new technology.
FS-ZE IM = Best...

But, that's just MHO.

[thewrench]

Quote:
<TABLE cellSpacing=0 cellPadding=6 width="100%" border=0><TBODY><TR><TD class=alt2 style="BORDER-RIGHT: 1px inset; BORDER-TOP: 1px inset; BORDER-LEFT: 1px inset; BORDER-BOTTOM: 1px inset">Originally Posted by PR5Matt
(uhm)
Just one HUGE problem with that explanation: At WOT there is low/no vacuum. Also you need short runners then, not l-o-n-g ones...

Low-end torque= low RPM= high vacuum (long runners needed not shorter ones)

Top-end power= high RPM= low vacuum (short runners needed not longer ones)

Are you sure you are not screwed up, or are Mazda engineers smoking Crack? </TD></TR></TBODY></TABLE>

That's what Perfworks said, he just said it in kind of a back-ass-wards way