Lung Fu Mo Shi

Damn that's a lot of plastic for an intake. I probably removed a good 8 pounds of tubing and boxen in the process.

I won't go through the removal steps, others have done a bettwe job of documentation.

My impressions:

1) At under 4500 rpm it all sounds normal. A bit more bass.

2) Unless you're over 2/3rds throttle it still sounds the same.

3) Hell bent = f*cking awesome sounds. Before the engine sounded like all the other whiny 4-cylinders I've heard before...although it had a little bit more throaty bass due to the exhaust. It now sounds be damn good. That said, it's not overly loud either. I'd say volume-wise I went up by about 15%-20% but then it was screaming at that point anyway.

My only question is then...will a true CAI sound similar?

buffalo-tsx

yea i did the same thing after awhile u will be like how did i ever live with out this bad motha foka noise i love the way mine sounds evenbougt three diffrent cones to try out i found out the cyclone is the best overall

AKay

do you notice any more pep at all?? in higher or lower rpms?
How about more or less lag in take offs?
AKay

Lung Fu Mo Shi

Couldn't really tell you.

Seems to be a bit better taking off, but then it might be the sound. It SOUNDS faster, but I don't know if it is.

I've got a firned of a friend who runs a Mustang/Ford upgrade shop with a dyno. He should have his "dyno-days" coming up.

I'd like to see stock, no resonator, intake, short intake.

buffalo-tsx

what kinda intake u have home made or actual cold air or short

Lung Fu Mo Shi

Read the first post again. No intake, just the stock airfox/filter and snorkel with the resonator removed.

BDI

Did you remove the bumper to get to the resonator or did you go thru the wheel well??

Lung Fu Mo Shi

I removed the bumper.

97AcuraCL

okay so where are the 'WELL DOCUMENTED' directions on how to do this?? :wink:

moda_way

Find my instructions in:

http://www.acura-tsx.com/forums/show...ight=resonator

If you search on my name, you'll also find some pics. The same pics are in my linked sig.

buffalo-tsx

did u put an air filter back on or just having it run with out one

moda_way

Resonator and air box are two spearate pieces. I show the air box and resonator together on the ground so you can see the assembly. I would never run a car without the filter.

I just took a look at the Comptech installation on the Accord V6, previous Gen, and they put the filter in a box in the engine compartment and then snorkel down where the resonator exists. Basically, I can't see any different with a Comptech IceBox with my setup other than a cone filter.

My air box still has the snorkel to the resonator, just no resonator.

fdl

So moda...where do you feel the most improvement. Does the car have more pull on the top end? On your website you say the car seems more responsive and peppy...just wondering if you have more to add to this now.

moda_way

I would say low end responsiveness is the biggest improvement and it is moderately better. There is also a much more noticeable jump prior to each engagement of the 2nd and 3rd lobes on the cams. 00Prelude00 has noticed this as well on his 00 Prelude w/out its resonator.

Overall, it is a minimal difference, but worth not having the resonator on. It is worth the time b/c it didn't cost me any money.

FYI, the 00 Prelude and my TSX are EXACTLY the same in acceleration and speed. My buddy's Prelude can only out handle me now and I think a set of ES100 Yoko's would solve that minor difference.

fdl

Not sure exactly what you mean by this. 2nd and 3rd lobes? There are only 2 sets of lobes...with the second set coming in just after 6000 rpm. Are you saying you feel a more pronouced change after 6000?

Quote:

FYI, the 00 Prelude and my TSX are EXACTLY the same in acceleration and speed. My buddy's Prelude can only out handle me now and I think a set of ES100 Yoko's would solve that minor difference.

Nice! Is your friend on stock rubber? I think these 2 cars are very comparible in accel and handling.

TinkySD

If taking the resonator gives any semblance of the gains that the cai companies are showing you should feel quite a bit more pull in the vtec range as it should give you a noticeable jump in toque...5lbft or so.
Also when you talk about low end reponsiveness do you mean below 3k or like midrange 3-5 where the CAIs also show the largest gains?

fdl

ya...cuz low end (<2500) should actually suffer from thiis type of mod.

Lung Fu Mo Shi

Actually I find it a bit more responsive all the way around.

The shifts seem to come a bit easier with less lag. But then it might just be my perception.

moda_way

Lots of questions... cool. Let me answer since I just was racing with my buddy on the way to work this morning.

FDL:
1. The cams have 3 lobes.... 1 is < 4.5k rpm, 2 is 4.5k to ~6k rpm, and 3 ~6k to redline.... 3 lobes on the cam. So I think the greatest gain seems to be just prior to the 2nd and prior to the 3rd lobes being engaged, as in, there is more air entering into the system and max the fuel/air mix at the most desireable points.

2. My buddy's Prelude is actually on Bridgestone Potenza Pole Position S-03, I'm stock.

TinkySD:
1. I do think there is a recognizable gain and especially after 2.5k to 3k RPMs. What I've also seen, as mentioned above, is that there is a slight improvement before each vtec lobe is engaged, so the transition is even smoother and stronger. If you aren't used to feeling the torque in the steering wheel while busting through the gears, it would be unnoticeable.

FDL (second response):
1. I don't feel anything suffering below 2.5k, but then I hardly remember much about that range since I rarely have the RPMs that low.

My overall opinion remains... there is a difference and without a dyno at my disposal to test it, I can only rely on what I felt during break-in and then a short period after. I've had my resonator off for quite a while now and my insider at Acura who drives them daily (stock) says that mine is definitely better than stock and wouldn't see anything better out of a CAI that could warrant spending the money for it, meaning, spending an additional $150 for a CAI wouldn't give me that much more than what I have right now.

fdl

I think you are wrong about this. Just like the old vtec...there are 3 lobes, but you are using the first 2 as lower rpm lobes. Then when vtec kicks in the 3rd lobe comes into play. So vtec is really ON, or OFF, ... there are not the 3 vtec stages you mention. With ivtec however...before the vtec lobes comes in there are minor adjustments made to increase effeciency, power, torque, etc. Check out the link below.



How does vtec work?

moda_way

The picture you are showing is in fact a 2-stage VTEC motor. The K series motors all employ a 3-stage i-VTEC motor in which both advance/retard is done at the VTC mechanism on the shaft AND there are 3 distinct lobes or stages, thereby flattening the torque curve and making power more seemless.

This is why you feel a jump at 4.5k RPMs and ~6k RPMs. Also, our motors spin in the opposite direction as previous motors. i-VTEC is primarily concerned with low RPM engine efficiencies.

fdl

Are you 100% sure about this? Even by looking at the dynos you can see only one vtec engagement..at just past 6000 rpm. Got a link documenting these "3 stages"?

moda_way

Here is a link that explains it all.

EDIT****
So the picture is correct, the guy's explanation is wrong. He negated the middle engagment.


3-Stage VTEC

fdl

Yes, that explains how a 3stage vtec works, but it doesnt show that the new ivtec engines employ this technology. The whole idea of ivtec would eliminate the need for lower stage vtecs anyways wouldnt it?

I am not trying to argue with you, I just have not seen anything to lead me to beleive that the TSX has 3 stages of vtec. And the dynos I have seen support the idea that there is only 1, at around 6200 rpm.

majormojo

The explanation of the iVTEC is a few pages along (follow the Continue... links)

http://autozine.kyul.net/technical_s...ine/vvt_31.htm

According to that article, iVTEC is a two-stage setup. fdl wins.

moda_way

I will consult the manual when I get out of work, plus I have a call into an Acura mechanic. Also, I'm not finding 3 stage on i-VTEC either other than it was first used on 1995 Civic SOHC and assumptions as to its use aren't mention afterwards. It is very possible that I am wrong.

Thanks for the clarification.

Back to the point of the thread, I feel that the removal of the resonator has definitely improved the overall engine responsiveness.

EDIT**********

This article puts the debate to rest, it is a 2-stage and not a 3.

Canadian Driver

TinkySD

Colin had an explanation a while back about how while the rsx-s and tsx user 3 lobe vtec systems there are still only two came profiles. I was under the wrong impression for along time as well.

moda_way

I consulted the manual and the camshaft shares the same profile on the primary and secondary lobes and the mid lobe is the vtec. The misleading piece to the diagram comes with the test on the lock for the rocker arms. The test has you move the secondary arm independently and then has a move the primary arm independently. My confusion was and still is, why would both move independently unless it has to do with the fact that each move independently thus making it a three stage. After reading further, you see the lock mechanism lock down all three rocker arms making the VTEC lobe the one controlling both values.

Ultimately, untill you hit VTEC, we are driving a 4 cylindler 8 valve car. Does this sound correct? It would have to be unless we have a 3 stage.

moda_way

Or is it simply that the engine works on 16 valves at a minimal extrusion and then with vtec it works with a maximum extrusion? This would to be the least complex of the two thoughts as I've seen both scenarios played out in explanations on the web.

Bear Trap

Back to the resonator topic...
When I installed my fogs a couple months ago, I too took off the resonator. I found it was not restrictive (the resonator is just a side piece to the air intake without an air diverter - I was able to take my drop light cord and drop in one side and out the other - straight though!!!) Although removing the snorkel will make the intake a little more free, it doesn't make a big difference as far as I could tell. I didn't like the sound and I didn't note any better response than with the K&N filter alone. I put mine back so I wouldn't have to worry about it when it came time to trade-in. Just my $.0.02. However, I would like to see Comptech dynos for an icebox - if there are significant gains, then it may be more restictive than I thought.

fdl

Very interesting....and I think this may be the case. This is a quote from the Canadian Driver article on i-VTEC...

"Variable valve lift is accomplished by opening the valves with two different rocker arms and camshaft lobes. In the past, Honda operated VTEC engines with three rocker arms: two to open the two intake valves and a third that could be locked to the other two causing them to follow a different camshaft profile. With the new "two rocker" design, only one valve is opened at lower engine speeds. This causes the intake air fuel mixture to swirl, optimizing combustion at lower engine speeds. At a rpm programmed into the engine computer, oil pressure is used to lock the two rocker arms together. Now both valves open together but follow the higher camshaft profile the second rocker arm follows."

TinkySD

here is an excerpt from a tech article about the tsx on acuranews.com
VTEC is an innovative system that adjusts the lift and opening duration of the valves to help the engine produce strong low-rpm torque and excellent high-rpm power. At low rpm, VTEC automatically adjusts valve timing and lift for optimum cylinder filling. In this low rpm mode, the timing of the intake valves is staggered and their lift is asymmetric, which creates a swirl effect within the combustion chambers. With better mixing in the cylinders, burn speed and combustion stability are improved. As engine rpm builds, VTEC transitions to a high-lift, long-duration cam profile for improved high-rpm engine output.

The TSX uses a variation of this technology that is very similar to that of the NSX. With three rockers operating each pair of intake and exhaust valves in each cylinder, the TSX powerplant varies the opening lift and duration of the intake and exhaust valves. At low rpm, the valves follow low-lift, short duration camshaft profiles to help boost low-end torque. Above 6000 rpm, the intake and exhaust valves are operated by high-lift, long-duration cam profiles, for maximum high rpm horsepower.

moda_way

I think we are understanding why I had some confusion now. The service manual seems to suggest what TinkySD is saying that both valves operate staggard because of the constantly adjusting via the VTC.

Also, back to BearTrap's question. If you look at the comptech installation instructions for the Integra, since the RSX instructions aren't there, you have to remove the resonator anyway... back to my point of saying, if the IceBox is nothing more than a cone filter in a box, then what differs from my OEM filter in the OEM box without the resonator.

The resonator, if you look at the pics in my sig, has a tube that attaches to the box itself. This tube has unequal length connections and unequal widths, so that air at different frequencies (e.g. vacuum speeds) will be more quiet. Is it as restrictive as some might believe, yeah. In that box there is a series of baffles and passages which air is not going to flow as efficiently. However, I have a hard time believing gains of +5hp will be possible, but that is just my take.

Thinking the IceBox is going to be more quiet than running OEM but without the resonator is a mistake in my mind.

Bear Trap

Yes, I agree there shouldn't be much difference except in that the icebox will have a tube routed to take in cold air. I think if you leave the tube upstream of the OEM filter box such that it takes air from the cavity that used to hold the resonator, then there shouldn't be much difference. That is why I want to see the dynos from Comptech.

Yes there are baffles in the box, but there is nothing in the main tube that redirects air flow into the box and the main tube is straight through with the resonator on the side. Thus, the resonator itself does not restrict air flow (just all the tubing) and it only changes the sound.

There probably won't be much of a difference in sound unless their tubing to take in cold air is significantly different.

Lung Fu Mo Shi

My reply from a different thread:

LINK

See, I think it is restrictive in my own little theory. You intake from a 3" to 2" funnel. Then eventually down to a 1.5" to 1" pipe into the resonator. Out of the resonator is a fat 3" pipe into the airbox, filter, 3" to intake manifold.

In the process, you go through five 90 degree bends and one 180. Each bend slows down the air velocity and/or increases backpressure.

ALSO, with a CAI/no resontaor sitting just behind the driver's side chin air vent, you start getting ram-air-like effects the faster you go. Either way you do get a high pressure zone right before the CAI filter.

You're not going to get massive gains from a CAI, but I would believe the posted dynos are within reason.

moda_way

Out of everything you said, this in my mind is the most important and really the most valid. I can't speak to the idea of a pressure increase in the area of the resonator (after it is removed), but I have to believe that if the resonator is limiting noise it is also creating less ability to get air. Hence, my reason for removing the resonator and dislike for spending extra $$ for a CAI. Just no need in my opinion other than looks.

Bear Trap

True, if I were going to do a CAI, this would be the way to go. The potential gains are not significant enough for me to endure the noise. I guess I'm just getting old.

Bear Trap

Yea, I replied to that one too. We've got two threads going on the same topic. Maybe we should just pick one and keep it going.

TinkySD

Here is the other question. The cavity where the resonator/open element filter resides is more or less enclosed. Is there a way it is getting cold fresh air or is it sucking in hot engine air? The stock resonator is connected to an intake port near the headlight that you don't get with the resonator removed. Yes there is still a tube from that port to the resonator cavity...but i'm wondering if you would also get soem hot engine air sucked in.

Bear Trap

Good point, that's why I'd like to see where the Icebox draws air from.