rets

PeterUbers

iTrader: (1)

I can't wait to see this AEM CAI that'll produce 20whp/20tork supposedly...i'll be the FIRST to invest in this baby when it comes out...

Aegir... great thread, start to finish. Thank you for your contribution to the forum -- nothing beats the cold hard facts!

Road Rage

I put a AutoXray 6000 Scanner on my TL and the ambient air temps looked fine. I do not intend to waste my time just to get some "throat" in the intake. Plus, resonators can be designed to optimize mid-range power, and do not necessarily limit power at all - if the AEM provides any power at all, it will likely be up in the RPM range. Not useful for the street.

NightRider

Thanks Aegir for your time and effort.

PeterUbers

iTrader: (1)

well, per the .pdf from their site (yeah yeah, highly suspect, I know) they claim gains across the board ... see .pdf link above for yourself. Comptech's Icebox had it's own resonator .. and guess what, it had gains across the board as well ..

But I agree, the resonator is designed for two purposes -- contol the engine sounds, and low-mid range power.

Aegir

Thanks for the great feedback. I'd be interested in hearing about any IAT data you collect - such as if/how it changes with speed.

If anyone is still considering removing their intake resonator, please reread my first conclusion: "If you are looking for power, I do not think this is a good mod." Since my car produced basically 'stock' numbers on the dyno, I think it is fair to conclude that the resonator and factory ducting that I removed did not represent a restriction, or that any restriction removed was counteracted by altering the tuned length and volume of the intake system. At this point, I may try a CAI or I may reinstall the resonator. I won't leave it as is long term. More noise without a productive gain doesn't make sense to me.

NightRider

Maybe I am just over analyzing which tends to happen frequently, but does anyone know a defined pupose for the resonator/silencer on the intake? In the big Acura book about the TL (the one with all the pictures) , it claims that the low and mid-range power (in a nutshell) comes from VTEC of course, and also resonators supposedly within or attached to the manifold. If the power comes from these, then what does the box in the intake do? What does "resonating" the airflow do?

Also regarding that dyno.....40HP lost? Sorry if you specified, but is that the 6 or 5, because AT is probably even more power lost thru drivetrain than manual. That is ridiculous!

Aegir

Here is my layman's explanation of resonators. Intake airflow is not continuous. It is actually a series of pulses caused by opening of the intake valves and feedback pulses when the valves close, and this results in the resonance. The frequency of these pulses change with RPM. The resonator provides a volume with a size and opening tuned to counteract specific resonance ranges. If you look at the TL resonator, it has two volumes with two different sized opening, presumably to work in two different RPM ranges. Eliminating resonance results in a quieter engine, and the improved flow dynamics can improve torque and power.

A chassis dyno reports power at the wheels, not at the flywheel. About a 15% loss through a manual transmission is typical. 15% of 270 is 40.5, so 229 seems about right. My car is a 6MT. I've seen three other dyno's on stock 6MT's in the 220-230 whp range.

NightRider

Thank you for elaborating, sir. I already have a K&N filter which seems to warrant around 50 more miles a tank (or could it be the engine is coming to life after 6K miles?) and sounds throatier after 4700 RPM. I am going to try removing all the intake piping except for the one directly mounted to filter box. This looks like what you did - but mine is a 5AT and with the K&N and I will try and get a dyno going....

Road Rage

I hear ya - but wouldn't that be with a hi=po air filter as well? Hard to control the variables so it is an apples to apples comparo. BTW, nice to be back and see your name again - been a while. Swing over to WWW.S2KI.COM and see some of my work as Road Rage on the S2000 community. Lots of fun, pretty knowledgeable group.

Road Rage

The short point is this: there is absolutely no guarantee that removing a resonator, whether it be in the intake or the exhaust will necessarily result in better power or sound, or both.

Well, I will try to express this simply, as it deals with basic physics, and the properties of air in a enclosed space - it could be a room, or in our case, the airbox or air intake system. The basic principles stem from Helmholtz' pioneering work on the behavior of soundwaves in a space of known dimensions, actually eigentons, in such a confined space. http://www2.sfu.ca/sonic-studio/hand...Resonator.html

What Acura and other mfr's try to do with their resonators is twofold:
1) reduce unnecessary noise to comply with drive-by noise standards and customer preferences
2) "Tune" the airbox so that the eigentons work for you, not against you. By calculating the total air mass, and the dimensions, the characteristic frequency crests and troughs (remember that sound waves are analogous to ocean waves), and applying Helmholtz' equations, it is possible to have a terminal slot, or slots, which will cause the waves to build on one another, while cancelling at other frequencies. Properly done, this can allow more air to move through the space at a given frequency- actually a higher amplitude. Acura has a tuning mechanism already in the intake manifold, and by juggling the proper variables, they can actually provide a boost in mid-range power (or high RPM power if they wanted to), while reducing or eliminating intake "throat" noise. Note: this is a simplistic description of rather complex topics, and I have used loose language which would cause another engineer to cringe, but I have tried to make it conceptually accessible for the layman.

I have seen a graph from Volvo that shows how its resonator increased mid-band toreque, while an aftermarket "CAI tube" actually caused a loss, with a few HP at the very top of the powerband, which is useless for most drivers.

It does not surprise me that most sellers of CAI show only positive results, but this is very unlikely, since the same laws of physics apply to them as to the rest of us, and their engineers seldomly have the training, knowledge, or resources of the mfr. An exception is CompTech - look at their dynos for nearly any product, and they will show + and - gains vs. stock systems.

Aegir

Since this post has bumped up again, I'll again restate that I DO NOT think removing the intake resonator is a good move for this car. Removing it provided little or no power increase, and for the work involved it makes sense to follow through with a CAI install. Removing resonators has worked in the past on other older cars including previous gen TL/CL's, but Acura apparently did its homework on the '04. Technology marches on and I have no doubt that Acura and other companies are learning from what happens in the aftermarket.

As far as stated claims vs. reality, I give Injen credit for providing reasonably accurate dyno claims for the '04 TL. They publish actual WinPEP printouts of actual runs rather than presentation graphics. They were honest in their presentation of low/mid-range power drop (I didn't see this on mine) and my before/after dyno's looked very much like the dyno that they provided.

Bitium

maybe they learned that from here a-tl.com there is always excellent sharing between forums, but you almost never know who's idea was first. Hey, if it is a good idea why not share thanks, for the tip, thought I had that done over 4 years ago. :P

Swat Dude

Just one question, did you dyno your car before the mod???? You are assuming no increase by comparing your results with other posted stock results.

Aegir

Great question. No, a prior dyno was not done. I've kicked myself a few times for not doing one because it does make it difficult to draw more solid conclusions. A comparison was made to three other stock 6MT dyno's - which were all close and were averaged. They were done on different cars, at different times, on different dynos (all DynoJet 248's). I concluded that if there was anything gained it wasn't much to write home about. Also, the gains seen when I installed the Injen CAI seem to support that my TL was pretty much making stock power without the resonator.

Aegir

The continuation of the tale after the Injen install is here: http://www.acura-tl.com/forums/showthread.php?t=86423

It includes the post-Injen dyno and some of my speculation regarding dyno comparisons.

shawn744

wow dude ur filter looks dirty....lemme axe you...when you're idling your ride, do you hear a hum from the air box?...air vibrations?...anything? or is it as quiet as stock (at idle).

i ask cuz when i removed my silencer (03 SSM TL-S Nav) i got a loud hum from the box (air vibrations) so i got an injen CAI. if you don't have any extra humming at idle, ur lucky and enjoy your sweet intake.

T-Mobile

I love all the info. I wish I was a little more educated when it comes to my cars engine. It seems like you all are so I must ask some questions. They may seem lame, but I must ask.

I have the injen CAI. I am planning on installing it this weekend. I understand that I have to remove the bumper. IS this true? It's no problem, my neighbor is a body shop repair person. Also, IS there an ICEBOX available for this car? I heard they are much better all around. Is this true?

Am I going to notice anything BESIDES the sound? The car is so smooth already it seem s like it will be hard to feel the power diffrence.

PoochaKannInc

T-Mobile:

See Aegir's post above with the link to his Injen install. It is very informative. It also has a dyno of the increases that Aegir observed on his car. (Post # 56)

As far as I've read, bumper removal provides the most straight-forward way to install the Injen intake. If you do a search for Injen in this forum, you should come up with much more information.

Currently an ICEBOX is not available. The only intakes available are the Injen and the AEM (which is still "just" coming out).

With the Injen most members have responded they have "felt" an increase in power and sound. Aegir's Injen install thread also shows (more empirically) the results of the Injen install.

vtechbrain

The improvements in power will be marginal at best but your vroom feel is increased. Bad idea in wet climes, wet will quickly foul your filter. Any improvement in air flow will be negated by sucking in the hot engine air. Don't foget that convoluted tube is actually a CAI.

Willhoit Inc

No doubt thanks for the great write up on your experiment!!!!

gumby430

iTrader: (2)

I pulled this one off today. I went through the wheel well because it was just me and I did not want to take off the bumper alone for the first time. I will add one note to this. When you get the resonator out you will be left eith just the short hose coming off the bottom of the filter box. You can use the tube that you pull out near the battery to extend the intake about 6 inches lower. Use the part of the tube that was on top near the battery and work it into the rubber gasket below the filter box. This should help pull cooler air. Its a pretty tight fit to.

EcKoHeD72

^^ Whoa... way to revive an OLD thread! LoL

Friss04TL

well screw the "remove resonator" mod then

Copperbottoms

as long as we're bumping this antique thread...

Has anybody done this mod and then put a CAI in? I'm wondering what kind of difference there is in sound quality between a CAI or nothing at all. I just pulled my silencer out last night (what a bitch it was to get that riveted bit apart) and it sounds really nice

maddsiick

i used to have an AEM CAI but i had to remove it for waranty purposes. I also removed the silencer from my best friends 04 TL so ive had experience with both. The sound with the AEM is alot more aggressive and can be heard at LOW RPM, removing the silencer is only heard throughout MID range RPM. removing the silencer does give a nice growl and an alernative to spending money but if you really want a nice sound and some added power, the AEM CAI is the way to go, or any other CAI. The AEM CAI has a really aggressive growl compared to just removing the silencer though to answer your question.

1fsthatch

you failed

Copperbottoms

?

maddsiick: sweet, thanks man. I figured the CAI would be louder, thanks for lending your experience I'm thinking I might just put in a high-flow filter and forget the CAI for now. My stock one's pretty dirty and a K&N would make a nice sound w/out the silencer I bet.

Red Voodoo

On the contrary, you failed to provide an explanation to why anyone failed here. So, touché!

Copperbottoms

lol indeed

maddsiick

no problem. glad to help. i had to take mine out cuz my car is still under waranty and i didnt want to hear the dealership make any remarks or blame anything on the intake.

robocam

So has anyone done a before and after dyno for this mod? Is the conclusion still that this mod is only for sound?

Copperbottoms

I think there's nothing but butt-dyno at work here.. If anything I've noticed a slight decrease in power.. I'm actually noticing less wheel spin off the line than I used to (though that could be for any number of reasons).

Still glad I did it though, it sounds great and is totally free

Freshjive360

quick question...what year TL was this dyno run performed on? just trying to see if the wheel hp that was generated from the dyno is for the 270 hp or the 258 hp engine

robocam

The first couple of years it was rated using a different standard. The engines are the same. The one rated at 270 isn't more powerful than the one rated at 258.

Freshjive360

Thanks for the insight! I've seen the different numbers for the '06-'08 and wondered why the change in power.

AcuraVic

I did this mod last year, same results. More 'sound', same power.

Great write up Aegir.

Izzy-Type-S

iTrader: (1)

There is only one 3.2L engine for the 3rd gen [quote=robocam;11050844]

What about the 3rd gen Type-S with a 3.5?

ironlung1948

Hey buddy what are the advantages of removing your air box silencer and what is 'dyno'd" ( new to this mod mumbo) tx

D's Up

I did this mod about 2months after I first got my car, my conclusion is that it's mainly for noise.

Pros of Intake resonator removal:
- more aggressive sound as opposed to stock
- you become familiar with your car (a pro to every DIY)

Cons of Intake Resonator removal:
- The sound is only in the mid-high RPM range (pro/con depending on the individual. Con to me)
- No power gain, if anything I feel a loss in torque. Maybe it's mental, but my car seemed to be pulling harder off the line when I had the resonator in.
- Hard to work with the riveted parts. lol

My conclusion, this is only worth doing if you want some extra noise at mid-high RPM range. No true power gain, at least for me.