Would a larger intake filter/tube help? For example, if I wanted to run a 4" inlet air filter and have it reduced to the stock, 2.75" throttle body. Would that work? Would it improve performance?

The only reason why I ask is that theoretically, IF there is a larger opening to suck in the air through the intake system, and it is compressed to a smaller diameter (ie. 4" --> 2.75") IT SHOULD increase the velocity of air entering the throttle body because the larger amount of air has to be compressed to be sucked in through the smaller diameter, thus forcing it to go through faster, increasing the power. Does that make sense at all to anyone?

EDIT:

Going with a modified HAI. Check few posts below to see what i mean!

 

You haven't changed the sucking force or the actual inlet diameter, so I wouldn't think it wouldn't change at all. Of course, I haven't done any calculations to figure it out either.

 

I don't see how it could hurt if the transition from 4" down was smooth

 

More velocity but lower volume than the 4" so the actual amount of air will not change dramatically. Smoothing the path would gain a higher benefit.

 

its the same with exhaust. all that matters is the narrowest point. no matter how big your tube is all the air has to go through the 2.75" TB. thats why manderal bends are so good, the crush benders at most exhaust shops will turn your 3 inch pipes into 2.25"ish at the bend.

 

Using the OP's logic, a 24 inch intake would give some terrific performance!!
Serious...then the tube transitions to a smaller diameter....and remember it is getting SUCKED in, there will be little change....
The theeroy you are using is the Venturi theory...it says as a fixed of air passes through a smaller opening (like a carburetor) you will create an area of low preasure (great to evoprate gas)....but nothing is free...the engine is sucking, like you sucking on a straw, and the smallest opening will be the restriction....opening up anything else will do little....once you have a smooth intake tube, and a good filter, next blockage is that 2.75 inch intake...one company once sold a machined on that was a bit bigger...

 

Zippy there is no sucking in physics. Air is being pushed in (since we are pressurized at about one atm), when there is a low pressure environment in the engine (like when a piston is moving down and the intake valves are open). Same happens when you "suck" on a straw. Atmospheric pressure is pushing on the liquid as your diaphragm creates the low pressure environment.
To shum, you want to have the least amount of restriction prior to the TB. 4" sounds like overkill but will not hurt anything. More airflow at the TB? Not unless the original piping is more restrictive than the TB. I'm not sure if a velocity stack could be fitted at the TB (or if it already has one for that matter) but that would help smooth the air flow. Also, air is not being compressed as it goes through the TB, it's just accelerating.

 

Sure...but think about it this way....the sucking is limited by the smallest hole...just like pushing...blowing...the lower pressure does nothing for you...unless you are trying to evaporate fuel....
Basic Physics....you are thinking of venturi's (and more importantly this opening is not shaped as one!!)....but what is different here id the diameter of the tube..pre and post restriction, and the SHAPE of the restriction.
From a physical standpoint, if what you say is 100% true, an infinite amount of air could pass through that intake if you had NO INTAKE TUBE....we both know that is not happening...so more is acting here than pure theory...it is APPLIED....a theory is good for guidance, but applied, which is governed by a few different laws come into play..to use a SINGLE theory in a design IS A VAST OVERSIMPLIFICATION....an engineer learns that a scale model ROUGHLY replicates an item, or event, but not 100%....since variables like gravity, molecule sizes, etc cannot be scaled.
Here what you MAY gain by a larger tube is perhaps reducing turblance, and possible increasing airflow, the same idea as porting....so just sticking a bigger tube won't help so much....it would need some sculpting of the narrowest point...but is is nearly 90 angles....with flat surfaces....so the way to get more air is usually to increase the diameter of the opening...
Maybe I described why just putting a bigger tube will have a minimal effect wrong, but as previously said, it is the smallest opening that will determine the flow rate...and you have tons of small openings further along!!

 

The lower pressure inside the engine IS what actually drives the air to flow into the combustion chamber.
The TB acts as an orifice. If it is the smallest hole, it will control the flow. However, if the intake pipe is smaller than the TB or very irregularly shaped, rough, etc., it will control the flow (at least prior to the TB).
I also said that I didn't think he would see any gains from a larger tube, unless what he has now is more restrictive than the TB.

 

HAI

 

Decided to try something a little different that involves a HAI as R53_MCS stated:

I have a 3" opening UNI filter, stretching about 9" in length. What I also have is a 2.75" to 3" silicone reducer-coupler. I also purchased a Spectre 90 degree 3" intake tube elbow thing. What I will be attempting to do is this:

Connect the reducer coupler to the TB, then attach the elbow to the coupler then the filter to the elbow. Having it face to the right outward position (having the filter point to the driver side. The setup SHOULD be short enough to fit under the hood so that should be fine. I also purchased a couple of sheets of aluminum and a ebay air filter heat shield. I'm planning on attaching the heat shield onto the filter then adding the aluminum piece it and connect it to the plastic piece that attaches to the radiator. This way, blocking off the heat from the intake horn/ engine area as well as directing the air flow from the hole on the plastic radiator piece.

Hope that makes sense :D

 

Can't wait to see the pictures when you finish ... then it will make sense

 

I had a system on one of the race cars that was short, smooth , and 1 bend with a big filter where the drivers Headlight would be .
That was one of many different things we played with .
Some helped the SC sound really good . others made me THING it helped .
BUT .. in measuring HP made no recordable difference. The gains are so minute that other factors would be more significant.
Barametric pressure, temp, IC temp ...
Will post a photo

 

Here it is ...

 

PLEASE DO! As for HP gain, that was really the direction I was going. Just hoping to make something more effective I suppose. The original Intake design just didn't seem too effective so to speak. Please post a pic!!

 

OOO very cool, I mean of course I'm doing this for DaytoDay driving too. So that's why I thought behind the plastic radiator piece would be the best place and still incognito I suppose LOL. But that looks pretty kick ***

 

I did have a filter right on the TB for a while...
The eventual system was a modified K&N Thyphon system with ducting to the inlet area.
With a heat shield to the "airside area"
For some reason that had the best #s and perhaps the least heat drawn to the IC.

 

Yea, I am going to have a modified heat shield too so that should help. Also I'm going to make another whole on the plastic radiator piece right next to the intake vent hose, that and the modded heat shield should direct a solid amount of cool air to the filter

 

cor blmy do you have any under the hood pictures of that system? Also did you anything special with the breather to the crankcase?

 

I will look for them.

Take a look at your grill and you will see that the side 4" left and right are blocked ..this is to have air only go to the radiator.
I opened up the drivers side of the grill and had the funnel system to the inlet snorkel.
When reading temps at the filter area this really helped lower them at speed / moving

 

When I get a chance to setup my intake ill post a pic asap! But yea, did you have anything done to the breather hose to the crankcase? I was thinking about using a breather filter and connecting it right to the crankcase when the vacuum line would go. Either that or drill a hole on the intake 90 degree tube I had and placing a pcv valve there and connecting the breather hose.

But I was talking about the space where (on the typhoon kit) the other red hose, not the one with the filter on it, but the other one thats connected to the radiator shield, taking that out and adding another hole to the right of it. Did you mean that area is restricted?