Flowing The Intake Manifold

[soulstylee]

My head is being built up. The shop is now inquiring about the VICS. They're toying with the idea of removing the VICS, and flowing the manifold. Would there be any negative aspects of removing the VICS, or should the manifold not be flowed and leave them in there?

[TheMAN]

you'll lose low end power... leave it there... you can try porting it if you want, but you'll have to have custom oversized butterflies machined

[Little Beavis]

The VICS has some merit, but the VTCS can be removed. . .

Right? (Well not sure if you have those or not, but if you do, I think there has been plenty of talk about removing them.)

[flat_black]

Hmm... Yeah, if you have VICS, keep the setup... But if you have VTCS, like that in a P5, get rid of the thing... It's blocking flow. Generally, if you're porting out the intake manifold, you'll lose torque, and could lose gas vaporization; One trick to removing the gas problem is having the manifold ported out almost all the way, with only a thin layer of material beyond where the edge of the porting 'should be' and where it is, then get it acid etched where the walls get contacted by the gas... That gives it enough grooves and bumps to properly vaporize.

That is, if they can do that, or if you can afford it. =)

[Turbo Matty P]

Id be interested in some pictures of that Flat_black. Last intake manifold I had ported was on my 2.5L SVO motor and we just walled it out as far as it would go. It was also running 26psi of boost so I dont think I really lost much low end!

Which would be better: mildly porting the us P5 stock manifold or buying the J-spec manifold??

[soulstylee]

My bad, the engine I'm building came out of a P5, so I assume it has VTCS then.

[flat_black]

I've never ported an intake manifold this way, but saw it on a Volvo, back when I still had mine... It was ported out almost all the way, and had hatch patterns acid-etched on the bottom of the intake runners, where the fuel squirted. The dyno showed a distinct loss in torque on the low end, and once he did this, it went up a tiny bit. =) I'll see if I can find the guy's address to see if I can get pictures, but it's been a long time. But if you're going for pure power, and don't much care about low end torque or anything, port the hell out of the intake manifold. =) Just keep the revs high!

[Turbo Matty P]

well, the low end torque on the P5 is pretty high already. It feels just as torquey as the MSP does, but the MSP pulls harder on the topend. I plan on adding the mazdaspeed cams and MP3 ECU. With a good port-jopb on the intake manifold I should be pretty well off. I'm holding off on the exhaust until I go turbo. No sense in paying for headers and midpipe now and then replacing them in a year.

[soulstylee]

Sounds like I'm ditching the VTCS. Hope everything works.

[Equinox]

ditch the VTCS, only thing bad is you wont be ULEV while the engine is cold.... and you will have a check engine light, unless you run a mp3 ECU, then no more CEL

[perfworks]

Originally posted by Equinox
ditch the VTCS, only thing bad is you wont be ULEV while the engine is cold.... and you will have a check engine light, unless you run a mp3 ECU, then no more CEL
This is partially true.
You WONT get a check engine light if you just leave the solenoid plug connected. Just plug the vaccum actuator line so you dont have a leak.That in itself will allow the plates to remain open constantly. You dont even have to rmove them unless you plan on taking the manifold off and doing some porting and polishing

[twilightprotege]

you cant just remove the VICS pure and simple. if you remove it (even if there were no problems with a CEL) you'll loose high end power. see VICS is not quite what everyone thinks. below the set RPM it's fully open. it allows air to move into a little chamber giving it the effect of a longer runner. at high rpm it closes right up giving the shorter runner length.

an idea i had was to reverse the VICS. you could drill holes to open up the chamber of the VICS and then reverse the little butterfly plates. so at low rpm you'd be running like you were at high rpm before - the plates would be closed and you'll still get the effect of longer runners as the bottom of the VICS chamber is open. then at high rpm you'll have the VICS open. it wont give the effect of a shorter runner, but it will give the effect of more air because you'll have the rear runners open (as usual) plus the air going through the VICS chamber.

does anyone have any thoughts on this?

[TheMAN]

uhh no

VICS butterflies are CLOSED when it is NOT engaged... air goes to the narrow LONG runners at low RPM... at high RPM, the VICS butterflies open and allow the short runners to be opened up... BOTH runners are used at high RPM... it does NOT work like a "switch to that pipe" thing

[perfworks]

Originally posted by TheMAN
uhh no

VICS butterflies are CLOSED when it is NOT engaged... air goes to the narrow LONG runners at low RPM... at high RPM, the VICS butterflies open and allow the short runners to be opened up... BOTH runners are used at high RPM... it does NOT work like a "switch to that pipe" thing
Damn Edwin you beat me to it!;)
Good post

The VICS is only operative during 4550 rpms and up. At that point the plates are opened allowing a larger "capacity" of air into the manifold plenum.

[Little Beavis]

You can get the VTCS out easily. Just drill off the screw head that hold the plates in there, then pull the rod out through the side. Then drill, tap, and plug the hole in the side. That's it. Very easy.

[flat_black]

Meh... Be done with it! have someone fabricate you a whole new tubular intake manifold. ;) Hehee.

Don't listen to me, 'cause I don't know how much that'd cost. =)

[PaulMP3]

come jan. we will have a tubular intake mani.

[flat_black]

We who? o.o I want one! Hehee. Any details, or you gonna leave me hanging? ;)

[perfworks]

Paul if anyone can make it, he will do a great job. Andy knows his shit.;)

[PaulMP3]

Originally posted by flat_black
We who? o.o I want one! Hehee. Any details, or you gonna leave me hanging? ;)

Andy Wagner from www.wagnermotorsports.net said he is gonna start the project in january :) It will be going on my car when it is done and ready.

[Equinox]

Originally posted by paulmp3
Andy Wagner from www.wagnermotorsports.net said he is gonna start the project in january :) It will be going on my car when it is done and ready. sounds good, I was gonna get it done custom but if he is gonna do the research I'll be willing to buy the second one.



Also how come all these guys are talking about the VICS system and not the VTCS system, cause they are two different things.

[Installshield 2]

I was wondering the same thing...

[Little Beavis]

Originally posted by Equinox
sounds good, I was gonna get it done custom but if he is gonna do the research I'll be willing to buy the second one.


What makes you think you've got dibs on the second one? :D

[Turbo Matty P]

would these only benefit turbo cars? I thought this discussion was about porting a stock manifold??

[Little Beavis]

It would benefit any car. . .

[Turbo Matty P]

wow, I've not seen many tubular manifolds that improve both top end and bottom end on NA cars. This would be a first for me. I thought that was the point of having the design we have already. To increase bottom and top end through switchable runner lengths. I know this works because at 3900rpms on my taurus the secondaries open up and the tires break loose again. On my tubular civic manifold it seems to have a good topend pull but nothing in the bottom.

[Installshield 2]

Originally posted by Little Beavis
It would benefit any car. . .

Not always...I can almost garuantee with a tubular manifold on an NA car you will loose lowend (at least on protege's), unless the stock manifold was shorter to begin with...

a built NA protege would probably significantly gain a peak hp with a tubular intake manifold, but it won't gain lowend....So you are right that it would probably benefit any car overall, but not lowend torque...

[twilightprotege]

Originally posted by TheMAN
uhh no

VICS butterflies are CLOSED when it is NOT engaged... air goes to the narrow LONG runners at low RPM... at high RPM, the VICS butterflies open and allow the short runners to be opened up... BOTH runners are used at high RPM... it does NOT work like a "switch to that pipe" thing

are you sure??? have you taken the intake mani off and had a look??

maybe i have a different version of the manifold but i do not have two runners. it is exactly like how i explained it. i have a single runner with what i like to call the VICS chamber (you could almost call it a resonator...it's that sort of a design)

edwin, are there different manifolds around the world??? dont tell me i've got another j-spec item....

[Installshield 2]

Originally posted by twilightprotege
are you sure??? have you taken the intake mani off and had a look??

maybe i have a different version of the manifold but i do not have two runners. it is exactly like how i explained it. i have a single runner with what i like to call the VICS chamber (you could almost call it a resonator...it's that sort of a design)

edwin, are there different manifolds around the world??? dont tell me i've got another j-spec item....

Is this chamber on the top of the intake manifold, possibly with a black box on it? North American manifold don't have anything mounted on top chamber wise...You just see the runners folding back under itself...The J-spec ones have a rectangular box on the top of the runners...I haven't looked inside of either though, so my info stops there....

[twilightprotege]

there is nothing on top of the manifold i'll draw a crappy version of what my intake mani looks like from the side on paint...hang on

[twilightprotege]

good thing i'm not a graphic designer....

i hope that explains what i have. the vics chamber is not open anywhere but where the VICS butterfly (in red) is

[TheMAN]

:rolleyes:

http://www.corksport.com/content/00/01/06/61/73/shop/products/images/480809.jpg

[twilightprotege]

on the bottom half of the intake manifold - the one of the left. the round holes. they go no where on my intake mani. they are not open to anything at all, hence why i call it the VICS chamber.

pls explain, is this what everyone has or do i have something different?????

[flat_black]

Maybe the 323 Astina has a different intake manifold than the Protege5. Huh. We don't have VICS over here, we have VTCS... The MP3 had VICS, though.

[StuttersC]

The current North American Protege has both VICS and VTCS. The MP3 does not have VTCS.

[twilightprotege]

yeah i dont have VCTS, only VICS - just like the mp3

[Little Beavis]

Originally posted by Installshield 2
Not always...I can almost garuantee with a tubular manifold on an NA car you will loose lowend (at least on protege's), unless the stock manifold was shorter to begin with...

a built NA protege would probably significantly gain a peak hp with a tubular intake manifold, but it won't gain lowend....So you are right that it would probably benefit any car overall, but not lowend torque...

I agree 100% but I was trying to keep it (really) short. :D

Also, since we all have VICS, what's to say we don't make a manifold that uses that system too! Best of both worlds. . .I'm already whipping out the crack pipe. . .I'll have an idea by dawn!

As for our manifold the VICS chamber is nothing more than a way to have longer runner by allowing cylinder 1 to steal air from the other cylinders during the intake stroke by sucking air out of the VICS chamber. So, at the moment #1 is on the intake stroke it can draw air from all four runners essentially.

[twilightprotege]

i didnt think of it that way.... sounds like a messy way to get more air

[KzA]

bumpppy bump....its february...

[TXMazdaSpeeder]

someone wanna tell the noob (me) what vcis is?

[Equinox]

someone wanna tell the noob (me) what vcis is?
about half this thread has been explaining what VICS is to people.

[TXMazdaSpeeder]

about half this thread has been explaining what VICS is to people.

i was half asleep when i asked that, i'll go back and read it again.

[twilightprotege]

VICS - variable inertia charge system. it's a system which allows the intake runners to hold more volume at high rpm - the effect is like a shorter runner (but it's actually longer)

[TXMazdaSpeeder]

ok i got it, helps to be awake

[PR5Matt]

Hmm... Yeah, if you have VICS, keep the setup... But if you have VTCS, like that in a P5, get rid of the thing... It's blocking flow. Generally, if you're porting out the intake manifold, you'll lose torque, and could lose gas vaporization; One trick to removing the gas problem is having the manifold ported out almost all the way, with only a thin layer of material beyond where the edge of the porting 'should be' and where it is, then get it acid etched where the walls get contacted by the gas... That gives it enough grooves and bumps to properly vaporize.

That is, if they can do that, or if you can afford it. =)
Just don't polish the shit out of it.

[PR5Matt]

Id be interested in some pictures of that Flat_black. Last intake manifold I had ported was on my 2.5L SVO motor and we just walled it out as far as it would go. It was also running 26psi of boost so I dont think I really lost much low end!

Which would be better: mildly porting the us P5 stock manifold or buying the J-spec manifold??
Hey I just built my old Merkur for my brother in-law. I cut, turned, and welded the intake as well as a full porting jub. 65mm t-body etc. He is set up for 400+ whp, but He still has to get his big turbo. We are going wiht a Precision unit this summer.

Check out my website. I am going to try and get some new engine pics soon.

[twilightprotege]

yes, definately dont polish it to a mirror. it still needs to be roughish (like you've sanded it with 200grit sandpaper) so the air gets a very very slight turbulance through it so it mixes better with the fuel

[ebmp5]

what the heck is vics means

[ebmp5]

or vtcs what is that too

[twilightprotege]

variable inertia charge system

variable tumble control system

[peepsalot]

lol

[SpicyMchaggis]

From the ashes it rises.

VTCS = death.