Originally Posted by rets

Pics??

Originally Posted by Aegir

I spent some time last night checking out the stock TL CAI. I found some interesting things and would like to share them. I didn’t compare it to other cars, find any rattle, or polish anything, so those looking for that please go to the next thread.

Let’s start at the filter box. The inlet is at the bottom of the box, and a baffle directs incoming airflow up through the filter towards the outlet. Subsequent pictures of the air filter show that this baffle is definitely doing its job.





Check out the next picture of the air filter. With 3500 miles on it, the dirt pattern clearly shows the preferred path for airflow. I had previously knocked the K&N because it had less than half the surface area of the stock filter, so how could it flow more? Seeing this airflow pattern has me considering a K&N for several reasons. 1) Despite the large filter area, the majority of the airflow is clearly occurring through a relatively small area. Since much of the filter is relatively unused, the filter D/P won’t change, but the air flow path and efficiency will change. I am taking the simplistic approach that any deviation from the path of least resistance reduces efficiency. 2) The stock filter pleats are oriented in a direction that would seem to obstruct airflow. The K&N pleats, according to their website, are oriented in the opposite direction. 3) As the preferred path through the stock filter is restricted, airflow through the filter box will change and become less efficient. Whatever element I went with, I would want to replace/clean it often. The K&N would save me a lot of money…



Next I found the intake silencer. Many cars have these and they serve the noble purpose of quieting down the rush of air into the intake. Many people like hearing that rush of air. Noise may not equal power, but disrupting airflow to quiet it generally does reduce efficiency. Intake silencers are widely known to steal a few horsepower in many applications. The silencer in the TL is pretty big so it may be better than others. It’s also pretty well hidden. At the inlet to the filter box is a rubber sleeve that connects the filter box to the silencer piping. Someone wishing to remove the silencer could disconnect it there. I suspect the incoming air charge at that location is just as cool as where the current inlet is…more on that later.



So, where is the air inlet? Good question, and the answer surprised me. Check out the shrouding around the battery in the next picture. This helps separate the CAI area from the ‘hot’ air around the engine. Check out that little triangular shroud in front of the battery.



Pull off the triangular shroud, and there it is!



When the car is in motion, air is forced up into this area by an opening in the front fascia.



There is clearly nothing cold about this CAI when the car is stationary. With the shroud in place it is pulling air through a restrictive path that is heated by the radiator. Acura claims a 15F drop when the car is in motion. How could you simulate this on a dyno? Just pull the triangular shroud and allow the intake to draw air directly from above. Could be wrong, but I’ll bet the colder air provides a nice bump on the dyno. I don’t think it makes sense to do this outside of testing, however. Removing the shroud would reduce the cold air benefits in a moving car (no real world power increase) and increase the chances of dropping something down the inlet that you might want back.

Conclusions - I'm going to get a K&N. I'll consider an aftermarket CAI, but I'd like to see a fair comparison to stock first. Because of it's inlet location, the stock CAI is at a huge disadvantage when stationary.

Originally Posted by JDM5lugHatch

Just finished a DIY CAI. I would have taken pictures but I let my friend borrow my camera and didn't remember until I was already underway. I have included diagrams though. The image was originally provided by another member on this board.

Fairly easy but very time consuming.

1. Remove fender liner and joined pieces
2. Remove the 3 bolts holding the Resonator box in. The one bolt closest to the front of the bumper is a PITA to get to. It took forever!
3. You will need to drill 2 rivets on the resonator that hold the tube that #1 is attached to.
4. #1 will pull right off of the tube as it is just a pressure fit.
5. Deliver the baby! (remove the resonator box from the fender)
5. You will need to cut #2 off of the resonator box. There is a line going around it to act as a guide. It does not just come out, cutting is a must.
6. Once you have removed #2 from the box attach #1 to it. They should fit together nice and tight.
7. Wrap some electrical tape around the 2 pieces just to make sure they don't come apart.
8. Cut a little bit of the plastic out on the lower duct (where the grill work is) in the front bumper so that it is practically even for direct air flow to the intake.
9. Drill a hole in the end of #1 and zip tie it in place for support.
10. Reassemble, clean up, and test drive!
11. Enjoy
12. ????
13. Profit

No loud really noticable noise. I thought it would really growl when it hit vtec but it's still very mild and quiet. Seems like power delivery is much smoother as is idle or so it seems. Might just be my mind playing tricks on me. Also, it seems to be a bit torquier upon dead stop acceleration. Just an added note I do have a K&N panel filter in place.

Originally Posted by Repecat

One more little caveat: Placing the battery in the stream of cooler air certainly helps in the ultimate life of the battery. Hot engine compartment environments are the enemy of batteries.

Originally Posted by wildchild_8635

All of that sounds nice if you wanna shred your emissions reading. In some cities/states like Houston Texas, wehre they are tougher on emissions testing, your reading will be too high with your intake bypassed like that. And what the guy was saying earlier about the intake not being cold because its by the radiator, that's partially true but you dont need cold intake while you're sitting still. It was made like that for a purpose. And those boxes that you are calling resonators, those things cool off the air. Thats why you have them there. They make the air travel through more windings and pathways before reaching the final destination. A Good way to think about it is like this, I put my food in the microwave, heat it up and go straight into the living room, my food is still hot. But if I heat it up and walk around the block and back, then my food is cold. Those resonators work the same way. They dissapate the heat from the air by 'stalling it' for lack of better words. Besides, it adds a few more points on the dyno, but its at the expense of fooling your computer. It will catch up with you one day.

Originally Posted by ayethetiense

uhhhh, not really true....

think of it this way....

the more that the air travels and bounces off plastic, the quieter it is. thats it, period

think of it this way too....

if you heated up something(air) in the microwave, and you put your hands in the oven (engine bay) and it was there long enough that it was hot, even hotter then the air. then your hands would heat up that something that you just put in the microwave walking to your living room.

get it? the plastic, being in the engine bay, will actually warm quite a bit, the air moving through the plastic will not necessarily cool down touching the plastic. in fact, it may even draw heat from the plastic parts themselves