I was just examining the stock intake setup recently, how great it is that the stock X comes with a pretty SRI ram-air type of setup straight out of the factory. I thought it was something like this, with front flowing air flowing straight into the intake scoop and RAMMED solidly into the airbox, like so (red arrows):



ahh.. how great that was I thought to myself.

THEN I looked harder and realised once the bonnet was closed, there isnt any actual real space in front of the scoop for it to face oncoming air! WTF! the bonnet's front edge closes right in front of the opening of the air scoop! It seems to take a path like below ie. through the grille, hitting the top edge of the radiator straight on and having to flow upward vertically, and presumably gets guided by the underside of the closed bonnet (I'm guessing) into the scoop. (green arrows to illustrate my point)



seems like a RUBBISH way to make an intake from my layman point of view. no direct flow of air into the scoop, and instead the scoop only gets a whole bunch of "deflected" air. double deflection too - radiator/crash bar THEN top of bonnet before finally entering the scoop.

my dear friends, what're your thoughts on this?

 

which brings to the question: if you're using an aftermarket intake, ie. anything other than the stock airbox, do you leave the air scoop on or rip it off?

 

The intake will pull cool air easily through the channel that runs from the radiator cover. The reason that it isn't a straight in design is to prevent water from entering the system when it's raining, at least that's what I would assume. It's a good design that, with a simple drop in filter to increase flow, matches the power of pretty much any intake out there once tuning is done and unlike short ram open element intakes, the power delivery is a lot more consistent because the intake temps are a lot more consistent.

The only real gains in an intake, aside from the filter element, is from the maf housing being larger than stock to trick the MAF and cause the ecu to run a lower load cell, which will lean out the mixture and run more timing. There isn't really any more air entering the motor, there's just less velocity over the maf, which tricks the ecu. Once a reflash or any kind of tuning is done and the air fuel ratios are dialed in, everything pretty much equals out. Too many noobs don't understand how intakes make power so they think that if the intake gives 10 whp on a stock X, and a reflash gives 60 whp on a stock X, that if you have both on your car you'll make 70; it doesn't work that way.

Part of the 60 whp gain from the reflash is from leaning out the air fuel ratios, whereas most all of the gains from an intake is from the same. So, you can't lean the car out twice to make twice as much power. The end result of a car with a reflash and a drop in filter is almost always identical to the end result of a car with an intake and a reflash. Tying back in to the OP: the stock box is a good design. I would just do a drop in filter and maybe the turbo inlet pipe and call it a day.

 

thanks for the detailed reply. I will need to read that a few times to fully comprehend it. lol.

but one thing, you said:
on what basis are you saying this? or why do you think the air will reach the intake easily?

 

I believe this is the same way the 8s & 9s intake scoop operated. It's functional, but it's not as aggressive as it could be, probably due to Mitsubishi keeping it as streetable/safe as an earlier post suggested.

 

You think in the line of 'pushing' the air in .. try thinking in the line of 'pulling' the air in .. Airflow is always talked about in pressure differentials .. low and hi .. and direction of flow is always from high pressure to low pressure ..

The intake is always in a perpetual state of low pressure (sucking action of the engine) .. the front of the car when it's moving is always the highest pressure.. the higher the differential, the easier it is for the air to flow to the intake ..

The objective of the intake snorkel is not ram air as you suggested, but COOL air direct from the front .. though you are right in that it could be better designed .. but like STI2EVOX mentioned .. designers have other things to worry about ..

Ram air helps alot (contrary to what others think) on turbo cars too because you're increasing pumping efficiency of the engine (doesn't need to suck as hard ) ..

 

This post should win an award. Good job.

 

so you're saying the snorkel doesn't ram air, but simply facilitates the suction of air from the outside. that makes sense, but then, why have the snorkel at all? since without it cool air from the outside (highest pressure, as you mentioned) would already naturally flow to the filter (lowest pressure)!

which brings me back to my original question: what's the point of the snorkel? It seems almost redundant.

so guys, do you leave your stock scoop on with your "open pod" cone filter?

I'm starting a separate thread on the APR radiator cover. at least that looks like its channeling air better to the intake. ..

 

Air is always cooler from the outside .. once you pass through the radiator .. you're basically just sucking hot air .. which is the reason for the snorkel ..

While under normal conditions an open pod will still suck in air (obviously) .. but having a greater pressure gradient makes it easier for the engine to make power compared to it having to work to suck the air ..

anyway if you observe .. the opening is away / in front of any heat source ..
If you have the ability to log what goes on .. you'll find that if you're moving, the difference with or without snorkel is a few degrees ..

But once you slow down or get trapped in a jam .. it takes a very long time for the engine bay to cool to ambient, while the snorkel intake takes virtually no time to get back to ambient ..

Its really a good design within constraints .. all the more reasons the snorkel has its place in the engine bay ..

 

I disagree.
it should be like this:

the top part of the scoop should be more extended forward than the bottom like the above Gruppe/Coltspeed one.

and see the big hole at the bottom of this pic:


installed. see how the scoop covers the hole I was referring to above:

now THAT's an air scoop. the stock one scoops ****!

time to DIY something for that effect

 

The underside of the hood makes that same contour over the holes when it meets the stock scoop as the hood is closed. Sure, it may not look quite as cool, but it gets the job done just fine. In any case, read my earlier post if you're considering an intake, especially one like this. If you don't know what you are looking at, this is the Gruppe M/ Colt speed intake, and because it's JDM and all carbon fiber it costs like 1200 bucks. I guarantee that it doesn't make any power over the stock box once tuning is done, and certainly no more than any of the USDM aftermarket intakes out there that cost far less. Huge waste of money bro. Again, stop worrying about the stock box design man; it's actually very good.

 

Good stuff. I keep hearing bad cooments about the snorkle design, and I actually think it is pretty good. I went with the AEM intake just cause it uses the stock snorkle for all the reasons listed above, and its going to be awhile for me to get a tune. The other positive to the snorkle is it helps provide a linear air flow as opposed to hot tubulent air bouncing all over engine bay at idle causing the car to idle really crappy.

 

easy fix mate!.... Cut a hole in your "BONNET"

 

Dayumm.. stievox2 knows his shid... good post cause i was wondering the same thing but then i thought to myself.. these jap engineers have to know what they are doing.

 

i have an extra feeding tube for the STOCK intake box from the lover mesh from the bumper mesh
it is at least doubles the charging cold air in the box .
And always cold
I'm using the HKS drop in filter and the Cobb intake pipe.