IceY2K1

iTrader: (3)

CREDIT: krismax

Stock DEK throttle-body to intake manifold inlet restrictor:




Here is withOUT the restrictor and opened up to ~71-73mm:



I think this would be a MUST DO for FI guys, but should benefit NA guys also. According to krismax the "restrictor plate" top-to-bottom is 56mm and left-to-right is 53-56mm, however withOUT the restrictor top-to-bottom is 65mm and left-to-right is 61-62mm.

Larrio

iTrader: (10)

hmm.... any links to a bigger pic? This is interesting.

the benefits are obvious, but how about any potential drawbacks? It must have been there for a reason

IceY2K1

iTrader: (3)

Nope...those are it for pics.

Guesses could be an EGR crap shield to keep oily residue from TB, sealing surface for TB, neck down TB maybe, 5hp less then AE.

Just random guesses though. Need to see one up close maybe.

HondaKilLR

Possibly has something to do with triggering the VI? Looks like there is a sensor directly behind it. Maybe it connects to the 'black box'? I can't tell with those pics. Doesnt air turbulance trigger it along with RPM's? I would think the restrictor plate would help monitor that turbulance. Peace_

IceY2K1

iTrader: (3)

Actually, here's one more of just the restrictor. The backside that goes INside the intake manifold looks like a water slide, ie half circle on the bottom half.

IceY2K1

iTrader: (3)

No, the power valve isn't that far forward. This is on the neck part before all that.

The power valve is activated by vacuum and rpm(via ECU), not resonance like the MEVI.

IceY2K1

iTrader: (3)

I have a PDF of the VIAS w/IM if somebody can host it?

IceY2K1

iTrader: (3)

Damn...I figured more of you would have been excited about this.

Also, back to the possible reasons it's there, it's made out of metal, so any ideas on the sealing surface for the metal throttle body to a composite manifold vs. a simple gasket reasoning?

Kiosk

I am interested, what was it like when u took it off?
I'll host the PDF if u send....thx

HondaKilLR

I'd be interested in seeing the backside of the metal plate. Looks like the 'wide' opening has an egg shape to it. Im curious to see how the 2 seal/match up on the backside--> Looks funky.

IceY2K1

iTrader: (3)

Kiosk - PM me your email address.

HondaKilLR - I see what you're saying, but it just "hangs off" inside the inlet neck part of the IM. The restrictor part face plate is just like a gasket inbetween the IM/TB, so it seals fine. It appears the "bottom half circle" is just there directing airflow over the void below or shielding the EGR tube inlet.

NewLoveI30

Wow, I dont want to sound stupid, but I didnt know the 2k/2k1 had a VI. If so Im excited that I have something else to brag about.

I guess I just havent seen the two sets of runners. Are the shorties coverd by the long, low RPM runners that are visible at the top of the engine.

Where is the valve? I am very intrested in this. Does anyone have a diagram?

About the little plate: Maybe you should take it off and see if there is any difference.

HondaKilLR

Yeah, you're right. I didnt look at the 'plate' pic hard enuff Oh well.......but those pics are inside a 4th gen, correct? I'll take a look inside my hood and see if I notice anything different.

IceY2K1

iTrader: (3)

Okay, small pics were replaced in first post with bigger ones.

Here is the cardomain where all this is coming from:
http://www.cardomain.com/memberpage/500673/2

Larrio

iTrader: (10)

i can host it also if you want ice

superlario@aol.com

IceY2K1

iTrader: (3)

Got email larry...thanks~!

Kiosk

here it is

iriol@yahoo.com

Larrio

iTrader: (10)

http://larrio.maximaclubca.com/VIAS_1.PDF

theMax

Perhaps the plate is to smooth the airflow? Causing better flow?

Would it do anything with the stock MAF? How big is that opening?

IceY2K1

iTrader: (3)

That's what I thought, but why only on the bottom side? IF that was the case, I'd think it would be a transition cutoff like those civic V2 or whatever intakes where it's basically a smaller pipe into a larger pipe to increase flow volume without too much turbulance.

I'll look at the TB to restrictor to IM diameters TONIGHT. Don't have a digicam though, but I'll see if I can get some measurements.

Jeff92se

iTrader: (82)

Wanksta. Flow velocity? Not flow volume because a smaller opening would not flow more. But the venturi effect of a smaller opening would affect flow velocities.

IceY2K1

iTrader: (3)

Smaller opening lowers volume, but increases velocity, especially with a venturi, right?

When you go from small pipe to large volume, you don't want an abrupt transition or you'll cause lots of turbulance and decrease velocity kind of like the punched out OE cat.

Anyways, not what I think it's used for here.

sloppymax

iTrader: (8)

if you find it to be smaller than the TB, then ill pull mine out this weekend (if i stay in town) and get some pics and hopefully a positive impression.

IceY2K1

iTrader: (3)

Sweet...I'll let you know in a couple hours what I find.

IceY2K1

iTrader: (3)

Actually, ignore the V2 civic comment, it's the otherway around, ie large pipe into small pipe.

Kiosk

I dont know anymore but used to be that bigger wasnt always better....getting bigger intakes and pipes will cut down low end torque, which is already short on small CI engines. This the same problem back in the carburator days I used to see countless people install huge carbs like 750cfm double pump holleys only to run worse when a 650cfm would do.

Now if we were NOS or blower it would be different story, or if you were adding CI's with a stroker kit or something or unless you planned on running the engine on the high rpm band consistently.....

I dont know this used to be basic rulz back in the days, maybe they have changed but, hey, they still reciprocating gas engines!

krismax

iTrader: (15)

I think the altima and max now have 70-75 mm TB, what the 3.0 has stock is undersized and small

kwd2kSE

I can't remember, what is the size of the TB on the 2k and 2k1's? ie, does the opening on the TB match the size of the restrictor or the intake manifold?

Mike

IceY2K1

iTrader: (3)

Okay, very interesting.

This is definitely a restriction, ie it's smaller then the throttle-body opening. It's a piece of cake to remove(4-bolts) from the IM, however I didn't have to get the TB loose from all the vacuum lines, 2-coolant lines, electrical connectors, etc., because I'm using Dixits spare. Also, I *THINK* it might not require any other gasket, since the IM side has a rubber "crush" gasket that's reuseable, but don't quote me on that.

I believe the purpose is to force the bypass air from the Idle Air Control Valve(large opening infront to behind throttle plate) over the large EGR port or shield the EGR from IACV outlet. Why I'm not sure, however I doubt it would have an effect on idle. Maybe it's to prevent EGR gas from entering the IACV valve easily or to mix better for emissions or to prevent turbulance, I can only guess.

This restrictor *IS* smaller then the TB outlet and *IS* smaller then the IM inlet, so it needs to be removed or be modified. WithOUT the restrictor, the throttle-body outlet is very close to being the size of the IM inlet for the most part, however it has a few areas that could easily by opened up to match the IM inlet.

MaximaVQ97

iTrader: (4)

I Took the TB Resistor thing off today... heres what i noticed.. 1st thing the actual peice in my car was painted black... although alot of the "black" had chipped off into the manifold, so that was no good.... (luckly..i guess) not much of the paint got past the EGR tube (i hope) so i cleaned it up with TB Cleaner... 2nd i noticed the car accelerated smoother and didnt have to try do hard (DAMN Auto) so i guess it helped acceleration..to bad i couldnt do a before and after dyno


I do have a question for those of you guys who know the intake system.. i was noticing alot of the GM LS1 guys cut the EGR Tube to allow better airflow.. do you guys think this can be done on the maxima?? because it does kind of stick up..

Any Input is Appricated

-Anthony

IceY2K1

iTrader: (3)

Hmmmn...that's one thing I forgot about, since I don't have the EGR tube, just the manifold.

How would you cut it withOUT removing the manifold?

MaximaVQ97

iTrader: (4)

Well... the EGR Tube is pretty close to the opening to where the TB and the manifold meet... i think if i just shove a shirt or a towel in the manifold and cut it with the dremrel it will be ok, i can just clean up with TB cleaner, but i will look further into tomarrow morning since i will be doing my plugs!!



im kinda just baseing it off this

http://www.ls1.com/link_egr.html


Let Me know if anyone else has any suggestions
-Anthony

MrGone

iTrader: (30)

I took that off when I installed the Injen on my dads car (maybe a year ago?). I wasn't thinking about the differences in sound and performance at the time, otherwise i would have installed the intake, drove it, then remove the the plate and drove it. If I can get ahold of the car tommarrow I'll play around with it (I threw the restrictor thing inside the stock airbox ).

I didn't think about it much at the time, just figured it was another worthless thing they put on the car (like the 3rd gen, there is a tube that goes into the inner fender that does absolutely nothing).

edit: oops, forgot to mention, its a 2000 SE 5spd, if that matters, lol.

sloppymax

iTrader: (8)

any issues with idling and any gaskets you would see fit replacing?

krismax

iTrader: (15)

The manifold does not have to be removed to take that EGR guide tube out. Just unbolt the large egr tube then the small. I was thinking about cutting it level to.

spirilis

iTrader: (2)

Huh, I wanna try this out, actually I wanna remove my manifold and inspect the whole thing (VIAS and all), but if this is an easy trick then I'd do this first.

You don't have to undo everything from the throttle body to do this? you just gotta remove the bolts holding the TB on, back the TB off a little, remove this plate and bolt it all back on?

sloppymax

iTrader: (8)

also, if someone has theirs removed, see if you can identify a part number. check it through nissan's fast catalog and get a name on it.

IceY2K1

iTrader: (3)

You don't want to remove the intake manifold, it doesn't look like fun. What are you hoping to see? I've pretty much got it all figured out now, pretty interesting really. The "power valve" could be modified to enhance air flow after switchover and the long runner(low RPM torque) ports could be easily opened up a little to give a more direct path. However, it's probably minor and without flowbench testing, not worthwhile.

You'd need to drop the TB down out of the way and then the restrictor just slides out. I *THINK* it's possible without disconnecting too much, maybe just slip off the throttle/cruise cables and a couple vacuum lines. All this is once the stock airbox/intake tract are removed of course.

IceY2K1

iTrader: (3)

I didn't see one, but I'll look again tonight.

redstradic

just checkin in.