^It really is terrible. I remember inspecting an airbox and maf that had used the HKS for no more than 10k miles and it was very sludgy. Apex dry filters are the best and a LIGHTLY oiled K&N would be my second choice.

 

I wish there was a definative answer to this conundrum, but I've been on this board for two years and this age old debate rages on. This is what I have taken from years of discussion:

- Cone filters ala Buschur/HKS flow more air BUT the position slightly behind the radiator makes it prone to sucking in hotter air.

- Panel filter replacements flow slightly less because of the restrictions inherit on the plastic intake runner BUT the air is cooler AT SPEED because it is fed directly from the outside, isolated from the radiator.

Which is better I have no freakin idea...

 

I think your caps button is permanently glued down, but anyway most "project" cars are not daily driven and are tuned through AEM standalone. These cars are usually 1/4 monsters and are just meant for the drag strip. The settings are tweaked while a good chunk of evom.net owners stick with reflashes or custom tunes thru piggybacks.

Can you provide some data backing up your intake claims?

I would imagine turbo motors provide extreme amounts of heat and the cold air being sucked in from an intake would be extremely hot air (once the hood is closed), potentially making it less benefical than the factory airbox.

 

The thing is tuner cars are meant to run on the track. At WOT, high speeds, and no traffic. I use my car as a daily dirver, as probably most people in this board also do.

Would having a cone style intake be better then using the airbox for real world driving? I think that is the real question here.

 

I love my Helix intake! I made great power with it as well! After 30k miles the filter still looks brand new!

 

I had the same talk with Shiv on my dyno day, and it's the reason why I still have my stock airbox/filter on the car today. I have seen people with the same mods as me plus and intake and not even get the same results. On the stock turbo the stock intake flows perfectly from what i've heard, and it's not worth messing with/spending money on.

Honestly dude, i'd say the most ROOKIE thing in this whole thread is your above statement. Not everyone modifies their evo based on car magazines and watching tuner car shootouts. There is actually some research to be done here, and i'm not saying i've done it..but people in the know HAVE, and do you see VISHNU's 400 hp evos with an aftermarket intake? case in point.

 

An air filter can determine the flow and air intake in a car dramatically. Do this: place a plastic bag just over the a cone air filter and don't tie it up, attemp to crank the engine and your engine will not even start.

That is just an extreme example but I had done it when cleaning my engine bay.

The myth about the "cold air intakes" they are busted for Turbo cars for the simple fact that no matter how "cold" your air is being suck, as soon as it passes though the turbo it heats up again. Also the intercooler will cahnge the temps again and finally the upper intercooler pipes will heat it up again.


As far is the flow, indeed there is no doubth that a good aftermarket filter can do miracles, the type of material used on the air filter can determine directly how the turbo breaths and how the turbo spools.

More over the design of the air filter itself can give not only flow but also velocity to the incoming air. Even the piping leading to the turbo intake can be influencial

So, sumarizing:

location of the filter
design of the filter
material of the filter


all of the above can change the performance of your car. Put a drop in and your blow off valve hardly makes noise, put a cone filter and the BOV makes a a lot of noise.

my .2c

 

on my 03, i had the hks rsi, made a big difference, turbo seemed to spool much quicker. in my ix i am going with the drop in so as to not go to far from stock so mitsu wont be a bunch of penises ... my buddy has an 05 with a few mods and the k & n drop in and his is running low 12's ... thank god for al and his flashes

 

Here is a thought. If the volume of air enters 1 degree colder, and passes through the whole system of turbo, intercooler, intercooler pipes and such... wont it be 1 degree colder as it exits. How about 10 degrees? How about 100 degrees?

Perhaps though the difference is negligible especially in the single digit temperatures.

 

Agreed, but wouldn't the net temperature increase still be less if the incoming ambient temp of the air is cooler?

For instance if the incoming air is 60 degrees and increases by 100 after being compressed by the turbo, wouldn't it be 20 degrees hotter if the the ambient intake air temp started at 80?

I know the thermodynamics of this situation are not that simple, but just throwing it out there...

 

I'm not sure if you have really thought about why that is. I'm willing to bet that a BOV will make the same noise regardless. Now the DV in the Evo makes a louder noise with a cone intake because it purges air into the intake pipe directly behind the filter, if there is no air box then there it nothing to muffle the noise. As for which is better, I like the stock look.

 

Is it quite a bit louder than the stock airbox ie more intake/turbo noise?

 

I was a huge Stock Airbox follower for a long time. But after a while I realized I had the parts sitting in my garage to make my own intake. So I did. My intake ended up being extremely similar to the Buschur Racing unit... and it rules.

No idle problems, no flat spots in the tune, no problems. Just more airflow and more power. Plus it really cleans up the engine compartment. There is no reason not to use a good intake. I would go with the Buschur stuff. The combination of the intake and intercooler pipes is pretty sweet.

I boxed off my filter and made sure it gets cold air with a 4 inch duct from the front bumper

 

I know exactly where you are coming from. I am aware that colder air has more oxigen molecules and more oxigen in a mixture has more potencial to make more power in the combustion chamber and yari ari ari etc.

I know what you mean about the external temp but again I must reiterate that when the air passes through the turbo, then to the LICP, then to the intercooler then to the UICP then to the TB the air is changed from cold to hot to cold to hot .

In a non turbo car the air goes straight to the throtle body from the air filter and a short or sometimes long pipe but basicly it is a more realistic temp. Whatever temp you get in a non turbo car air filter there is not much variation from the air filter to the Throtle body therefore the Cold air intakes are more eficient.

In a Turbo car the air filter acts more for flow and velocity more than cooling down the air regardless on how cold the air is outside. On the turbo car you have to worry about the intercooler to be efficient.

The pics of the guys building the box is not a bad idea, somehow yes you are dropping a bit more the temp on the turbo intake and perhaps the overall temp might be reduce but you actually have to have temp sensors to really determine the difference and so far not many people has done it. The aluminum flexible piping he built is a great idea to aid the air filter to suck more air.

 

Simply put, by just using a "bolt-on" cone filter, this really screws with the MAS readings. I had a long discussion with Pete from WORKS the other night about this very topic.

The evo uses a pretty "dated" design when it comes to its mass. It is very sensitive to the way that the air actually enters its reading zone. Typically using a stock air box, the air has a predictable path to follow. The air enters the MAS straight though, and the readings dont have the ability to fluctuate as drastically.

By using a cone filter, the air enters the MAS very unpredictably, in many cases cases spinoffs (ever seen a tornado?) these vortices fool the MAS into thinking its getting more air that it actaully is, thus dumping in more fuel, basically a domino effect.

To EVIL EVO 8, you sir are RETARDED. Just because "all the shops use it", theres no way in hell you know if its the best application for your car. Doogie Howser brought up a very good point that the guys running cone-type intakes have spent considerably more time correcting the effects of an intake of such type. There is no way in hell a "bolt-on" modded evo needs a cone filter.