J-Spec Intake Manifold

[twilightprotege]

hey...first of all sorry for going all over the place with this, but it's been bugging me for ages...

well I'd like to get some real answers on this because everything i've seen so far doesnt really explain it all to me.

I know the J-spec intake manifold is supposed to be dual runners.

now from the picture on the corksport website it looks the same, and i mean identical to my IM.

first quesion (might make this all much simpler and quicker) - does the J-spec IM have a marking stamped on it (like the camshafts etc)?????

2nd q - since the IM's look identical to me, and assuming the japanese make things in bulk to save costs...how does the VICS operate with the j-spec IM??? see the problem i have is that i'd be 99.999% sure the VICS mechanism works exactly the same as ours...and if that's the case...well...
see if i'm explaining the concept of VICS correctly....pls correct me if i'm wrong.
the idea of VICS is to have long runners at low rpm, short runners at high rpm. right? if that is the case, the VICS butterflys MUST be shut at high rpm (against popular belief i'm sure). if the VICS butterflys were open, air would be coming from as far away as the runner for cylinder 4 when no 1 is on the intake stroke. right? doesnt sound very good when the idea of VICS is to reduce runner length
now this is why i've got the 2nd q - that would mean on the j-spec IM VICS would be closed and...urrr...that would mean the air would be travelling along the longest runner.
maybe does the VICS work opposite on the j-spec IM to allow air to come through the shorter runner???

maybe i'm just confusing myself here, hell i dunno, but it would be good to get this all clarrified...hell maybe us aussies have the j-spec IM and that's why i'm getting confused??????

 

[TheMAN]

VICS operation is exactly the same as the US spec and Euro spec intake manifolds... the shutter is over the round short runners... normally closed... at high rpm, they open and allow a shorter path for air to reach the combustion chamber... this also allows for the oval long runners to be used at the same time to allow maximum inlet of air

there are no idenification markings on the j-spec manifold... there is no need to... the j-spec manifold has a resonator plumbed into the plenum chamber, allowing for resonance tuning that promotes better air flow at very low and very high rpm

 

[TheMAN]

more info here
http://www.clubprotege.com/forum/showthread.php?s=&threadid=2266

 

[twilightprotege]

see that's what doesnt make sense to me. if VICS was open at high rpm on non-dual runner IM's, the path of averages from the TB to the head would be longer. like i said, if no 1 cylinder is sucking in air, it would be drawing from the air from all runners.

am i understanding that correctly?

 

[TheMAN]

VICS only exist in the dual runner intake manifolds

long runners are ALWAYS open and go from the plenum, looping around towards the very back of the engine pay before going to the cylinder head

short runners are usually closed and are wrapped over in practically a fetal position by the long runners

 

[twilightprotege]

huh? VICS only exists in dual runner IM's?

yep i understand where the air goes....so let me see if i've got this right. the short runners (the ones with the butterfly plates for VICS), on the lower half of the IM they go no where - ie they dont link directly to the plenum?

 

[TheMAN]

ALL 1.8 & 2.0 BJ Proteges have VICS

 

[twilightprotege]

sorry bout this edwin, i'm getting all confused.

so appart from the black box resonator, is there any difference between the j-spec IM and the rest?

 

[TheMAN]

US intake manifolds have VTCS and have a step shaped runner end where the VTCS plates go... the MP3's does not have this but the rest of the casting design is the same... the 1.8 intake manifold is the same worldwide for all Proteges, no VTCS

Euro and Japanese FS-DE intake manifolds have a different casting design, the FS-ZE intake manifold is modified from that design


P.S. learn what a "plenum" is and how the air flow goes! there's no way in hell your short runner goes "no where"

 

[twilightprotege]

yeah i know what a plenum is...so, do the short runners connect to it? because on my IM they do not. the only opening it through the VICS butterflys

 

[twilightprotege]

attached is a picture of FS intake manifold. I have written on it. This is how I beleive the stock manifold works.

at low rpm.
air comes through the TB into the plenum. it then travels up numbers 1,2,3,4. it then connects to a,b,c,d and goes to the head. VICS butterflys are closed.

at high rpm
air comes through the TB into the plenum. it then travels up numbers 1,2,3,4. it then connects to a,b,c,d, but then goes through the open butterflys back into w,x,y,z. w,x,y,z is a "chamber" and has no air connections appart from the butterflys.

is this correct for any IM? (J-spec, E-spec, AU-spec or US-Spec)???

 

[TheMAN]

WTF? you have this all backwards... how can air flow backwards? air ALWAYS go from the lower intake manifold to the upper

short runners ALWAYS meet up at each end to whatever

 

[johnjay5]

(uhm)

 

[akhilleus]

twilight dont even waste your time. The j-spec Im has been shown to produce very little in terms of gains. ALso since yours has already been port matched there is no point. Now if u have some other scheme cookin let us know. And dont take theman's attitude too seriously...its hard being a protege genius.

 

[70]

twilight dont even waste your time. The j-spec Im has been shown to produce very little in terms of gains. ALso since yours has already been port matched there is no point. Now if u have some other scheme cookin let us know. And dont take theman's attitude too seriously...its hard being a protege genius.

The only person I have seen with the FS-ZE IM is TheMAN...And the car made decent torque gains where it counted, making a larger area under the curve overall.

Something that is very beneficial and worth while on the Protege. And something that would be more noticeable in a turbo application.

I understand what Edwin is saying, but I'm confused as to what twilight is getting at.

It seems like twilight is saying that his IM's short runners don't go from the plenum to the lower portion of the manifold. I think he is saying his short runners are just a little pocket thingy with no connection (holes) to plenum?

Wait, what?

 

[70]

I think twilight is saying the if you start at the TB in his picture, the only way to get to the w, x, y and z holes is through the butter-flies. So, effectively, the air travels through 1, 2, 3 and 4 into a, b, c and d and then loops back into the butterflies into a "pocket" through w, x, y and z.

However, what TheMAN is saying is that when the butterflies are closed, air goes from the TB through 1, 2, 3 and 4 into a, b, c and d then into the head.

When the butterflies are open, air goes from the TB into 1, 2, 3 and 4 as well as w, x, y and z and the into the corresponding holes on the other half of the IM and into the head.

IS THAT RIGHT?

 

[TheMAN]

right

 

[twilightprotege]

yep stuttersC, how you described what i'm trying to say is exactly how my IM works. the wxyz have NO, i repeat, NO holes going to the plenum. when i had the head and IM off i checked this. i didnt, but you could basically fill it up with water and it'll stay in that "chamber" i describe

hence you can see my issue...if VICS is open at high rpm on my IM, that woulc actually create a longer runner, but more air...and FARKING turbulant airflow

has anyone else taken their IM off and CHECKED this like what i have?

 

[Critter]

Have been reading this with much interest.

The bottom line is though, is the FS-ZE intake manifold worth getting?

 

[70]

Have been reading this with much interest.

The bottom line is though, is the FS-ZE intake manifold worth getting?

I think so...I plan on getting one. I don't have to worry about VTCS, all I have is VICS.

YAY MP3 IM!!!