I am curious to where everyone has placed their oscai intake tube. Mine is zip tied to the big steel engine cradle mount and draws air from the edge of the splash guard.

 

Mine just dangles down to the splash guard.

 

try to pull it down as far as you can and make the inlet pointing somewhat forward

 

mine is down as far as possible facing the front passenger corner of the car. It actually feels different in different possistions

Adam

 

I drilled a hole in the forward facing part of the plastic splash guard and placed the tube through it.

 

Same as PKO with a shop-vac rectangular end piece for a collector.

 

My inlet points to the driver side resting near the splash guard. It's near/under the silencer box.

 

Guys, question.. After removing the two sensors (punkdork's site), do you just place the oscai on the airbox and then put back together the sensors and front part of the stock intake? Does that K&N drop in filter just actually "drop" into the airbox? what is a "ram something"? Does actually removing the silencer make a big difference in noise? Sorry for the twenty question.. but I NEED TO KNOW.. THANKS!!

-RPNY

 

Yeah.. you only remove the sensors so you can have room to work with the scoop. the K&N replaces the stock air filter... fits right in the airbox. No real need to remove the silencer... I just had a personal vendetta against it.

 

Not sure where you got "ram something", but if you're asking what I think you're asking, ram air is when you make a collector of some sort (basically a funnel) collect air that's rushing past, over, under or around the car when you're driving down the road and force (hence "ram") it into the car's air intake. Same concept (basically) as other forced-induction setups like superchargers and turbos, only a lot less effective at increasing hp. Of course, NO hp gain is a BAD hp gain, right? Is that what you were asking?

 

If you have the end of your tube hanging straight down, it will cause a vacuum inside the tube. You don't want this. You will be sucking air out of the tube rather than in to the tube. If at all possible, point the end of the tube forward. Even if it is inside the splash guard, if it is pointintg forward, it is ok.

 

I'm not sure I'm following you, UMD_MaxSE. If the tube is laying inside the splash guard, you're not going to get a direct air flow no matter how it's oriented. If that's the case, does it really matter which direction the tube is pointing in so long as the airflow is unrestricted?

Also, isn't a vacuum in the tube exactly what you're looking for? No vacuum, no air rushing in toward the throttle body, right? Or am I missing something?

And while I'm at it, is this whole thing about putting a Ram Air scoop on the OSCAI really worth paying any attention to? I mean, how fast would you have to be moving to push enough air into the intake to really make a difference? And wouldn't the gains you'd get by installing a Ram Air scoop, if any, be more than offset by the buildup of road debris on the air filter and the risk of ingesting other foreign material?

 

If you have a tube that is pointing straight down perpendicular to the air flow, it will cause a vacuum inside the tube that will suck air out of the tube away from the throttle body. Take a straw in water and blow perpendicular to it. The water will be sucked up by the straw. The same thing applies here. If your tube is straight down perpendicular to the air flow, it will cause the air inside the tube to be sucked out. You still get some air inside the splash guard, just not a lot of it so it may end up hurting you either way

 

Air flowing directly across the mouth of a tube will cause a vacuum within the tube, pulling air out of it. For example, if you blow hard enough over the top of a straw when it's in a glass of water, water will actually rise within the tube. If air is passing directly across (perpendicular to the flow of the tube) the mouth of the OSCAI (i.e. when it is pointed directly down and wind is rushing past it while driving), it will pull air out of the airbox.

As far as the ram air question: I'm not sure if it helps all that much to position it as a ram air inductor, but it certainly can't hurt, can it? What better way to ensure you're getting the coldest, fastest moving air possible for $20?

 

OK, we've got a good exchange going here. The only problem I see with your thesis is that you've got one end of your straw stuck in water. I've got the end of my straw stuck in a combustion chamber. Water doesn't suck, combustion chambers do. And while I agree that orienting the tube perpendicular to the air flow might cause a tiny amount of vacuum to develop in the tube, that vacuum would be more than offset by the significantly greater vacuum created by the engine under load.

Does that make sense?

 

;¦1Ú4i!Âi]Originally posted by thorizeen [/i]
Air flowing directly across the mouth of a tube will cause a vacuum within the tube, pulling air out of it. For example, if you blow hard enough over the top of a straw when it's in a glass of water, water will actually rise within the tube. If air is passing directly across (perpendicular to the flow of the tube) the mouth of the OSCAI (i.e. when it is pointed directly down and wind is rushing past it while driving), it will pull air out of the airbox.
for $20? [/QUOTE]

hehehe.....read my mind while I was typing

 

And the widest, openest mouth available for sucking up road debris, newspapers, plastic bags, etc.

 

I respectfully disagree. Water in a glass on a table on a planet with gravity does suck to a certain degree, but only until it settles back into it's glass after it's been raised in the straw by the decreased pressure within the straw caused by the crosswind. (Whew!) This aside, as far as the intake is concerned, the suction will occur from the path of least resistance - not from the combustion chamber, but from the other mouth of the intake (the stock one), which means, not only are you not getting the benefit of the air from the OSCAI tube (because the air is being sucked out, not forced in), but you're getting less air from your stock intake mouth. Does that make sense?

 

Have you had this happen (newspapers & plastic bags)?! I was worried about that, so I thought about putting in some type of grill, but haven't gotten around to it yet. I haven't noticed an increase in debris in my airbox or my K&N. I attributed this to the fact that debris would have to travel directly up about 1 1/2 feet of ribbed shopvac tubing, which doesn't seem likely to me. Good thing is, if the mouth of the OSCAI is blocked by paper or plastic (I sound like a checkout girl I once dated ), you still have the stock intake as an alternate air passageway.

 

I wouldn't worry about sucking up something too bad. The air scoop acts like a bypass as you mentioned. Unless that is also sucking up bad stuff, you have nothing to worry about. As for the vacuum discussion, if you place the tube perpendicular it would end up sucking out air from the scoop since that would be the path of least resistance. This would result in getting less air into the engine.

 

Which is exactly what I tried to say, only I was far less understandable. Thanks for the simplification / clarification, UMD...

 

Jeez. Now I'm REALLY confused. But I think I know a way we can settle this once and for all.

Connect one end of the straw to a vacuum cleaner, turn the vacuum cleaner on, then blow as hard as you can in a perpendicular direction across the other end of the straw. Let me know how much of an impact blowing across the open end of the straw has on the amount of air that's sucked into the vacuum cleaner.

 

I guess it would depend on how light the material is that's being sucked into the OSCAI. If the material is very light, it could easily make it's way to the air filter. Plastic bags, for example, don't weigh very much. I see them floating in the air all the time when I'm driving on the freeways. And if a plastic bag actually made its way to the air filter, it could lead to some interesting results. Don't you think?

As far as sucking air out the scoop if the tube were perpendicular, I'd suggest that you'd probably be correct were it not for just one thing . . . a GIANT sucking sound heading toward the engine.

I think we're losing sight of the fact that an intake does not exist at normal barometric pressure when an engine is under load. An internal combustion engine is a HUGE air pump. It's going to substantially reduce the pressure inside the intake whenever it's drawing air and it will do so to a vastly greater degree than ANYTHING the environment can counteract.

But hey, I could be wrong.

 

hehe...I think the straw analogy may be a bit flawed in this case. In this case, you are hooking a vacuum cleaner up to the straw and only blowing on the other end. In the engine/tube situation, your engine is trying to suck in air, but the air that is flowing perpendicular to the tube may actually overcome the engine's force. At 60 or 70 mph, the air around the tube would be flowing quite fast....much faster than if you were to blow on the tube

 

Your point is well taken. It doesn't make good sense to to allow the tube opening to be oriented perpendicular to an unrestricted airflow. If the tube is placed inside the splash guard, however, it shouldn't make that much difference because the splash guard breaks up the airflow.

It would be interesting to find out if anyone has actually conducted a study of this phenomenon. You'd think such a study exists considering how long internal combustion engines have been around.

 

I think I've been unclear. As mentioned, the straw is just an analogy, and a limited piece of the puzzle at that - it merely shows that air directed across the collector of the OSCAI will cause a vacuum. It was meant to demonstrate nothing more than that.

Next...

Consider the following - the OSCAI is basically tubing shaped like a Y. Analogy time again.

To the top two sections of the Y tube, attach vacuums, one representing the engine suction, the other representing the vacuum created by the cross airflow. The amount (not velocity) of the air flowing in the bottom of the Y (representing the stock intake), is limited by the size of the opening. Given that this amount isn't unlimited, the second vacuum (OSCAI opening), no matter how strong or weak, is effectively "stealing" air that the first vacuum could be using, and therefore making it's job more difficult. The converse is also true: run the second vacuum in reverse (as a blower, representing ram air into the OSCAI collector), and it no longer steals air from the first vacuum, but provides air to it, making it's job less difficult, or, at the very least, simply no longer steals air from it.

You really think a plastic bag could wend its way all the way up the OSCAI tube and into the airbox? I guess I base my incredulity on the fact that I've yet to find anything out of the ordinary in my airbox or filter - not a bug or leaf, much less the NY Times or a Wal-Mart sack. Anyone with and OSCAI find more (or odd) things in their airboxes / filters?

 

I have also found nothing untoward in my airbox or filter since I installed the OSCAI. Nevertheless, I'm still more comfortable keeping the open end of the tube inside a protected area like the splash guard. Others may do as they please.