Intake Tube - Is the resonator necessary? Perrin, Mishimoto, et al....
 

I've been researching the intake tube and its seems like only AVO and Mishimoto have decided to keep the resonator.

Mishimoto shows specific methodical testing proving that the resonator is critical for power.

Perrin's blog shows extensive testing and the resonator is not critical.

Most manufacturers are in Perrin's camp, but the only well documented development is coming from Perrin and Mishimoto and they contradict each other.

I'd love to get Mishimoto's and Perrin's take on this. Along with any other manufacturer who would like to chime in.

Got a link? I really cannot comprehend how the resonator could contribute to power.

I'd guess a resonator will affect the flow differently depending on intake design.

most of the case, resonator doesn't do much beside flows the air better on the design of the intake.

I don't think it really makes one bit of difference. The aftermarket intake tube a cosmetic item in my opinion.

The findings from Mishimoto indicated that removing the resonator lost power... this is not uncommon for NA vehicles were removing something OEM in the intake system can cause an issue which reduces power.

i'll simplify it as best as i understand;

Throttle body opens
Air gets sucked in through intake
Throttle body closes
air moving at speed toward throttle body is stopped
Velocity is then reversed back toward filter as it has no where to go
air then gets compressed into resonator due to low pressure (path of least resistance)
Throttle opens
air is still moving forward from tube toward resonator
think of it as a dampener of the velocity of the intake air.



Dyno numbers gonna change much, probably not
throttle response going to change much.. probably enough to some

my concern would lie in those split moments when the computer is expecting X amount of air and its not there due to the velocity of the air needing to be reversed back into the intake

there is more to intake design then flowing as much air as possible... Sound, throttle response, EPA ... those are just SOME factors

Looking over Mishimoto's post, they were using the factory intake with their inlet hose. it looks like from their research that they recommended keeping the factory resonator that's connected to the the factory intake, but deleting the sound generator connection in the intake to make the most power when using their inlet hose. We never tested this specifically, since our inlet hose doesn't have the sound generator tube connection.

We decided to remove the sound generator connection completely to clean up the engine bay, and to make the intake tract smoother to make the most power.

I don't know if you're talking about the resonator on the intake box, or the sound generator. If you're talking about the resonator, I'd assume the loss of power is from pressure wave intake charging. Mazda did it through a really long intake manifold and ridiculously complicated valves in the NA FC's. They called it dynamic intake charging. On a cold winter night at sea level the NA FC Rx-7 can see up to 2 lbs of boost in the manifold. They use the reflective sound waves to keep the intake manifold pressurized when the valve closes(in the Rx7's case once the rotor closes the port). I would guess that removing the resonator changes the pressure wave tuning and thus the loss of power.

Thanks for checking out our data OP! As mentioned, we conducted extensive testing during the development of our induction hose. A full write-up of our development and testing process can be found at the build-thread below.

http://www.ft86club.com/forums/showthread.php?t=65891

For those not interested in the long read, we found that removing the resonator reduced power. Although not substantial numbers, it is certainly something to consider if you are trying to squeak out every last bit of power. The explanation of the resonators function is explained in this writeup, also noted by Fear above.

Our numbers showed maximum power output (Mishimoto induction hose) with the resonator installed and the noise amplifier removed. After surveying the market we found that most customers were not interested in retaining their noise amplifier, so we removed the port from our hose.

Feel free to follow-up with any questions regarding our testing or induction hose. :cheers:

All of your testing was performed with the OEM tune correct? -I'd be curious to see if the opposite result is found when tuning for the different characteristics of an intake without this resonator. It would make sense to me that the OEM tune, expecting behavior similar to the OEM intake would benefit from a resonator still being in place.

This thread is a bit all over the place...OP is comparing stock airbox/snorkle/aftermarket filter/aftermarket inlet hose (apples) with a cold air intake that throws everything stock away (potatoes). They're going to act very different. Perrin and Mishimoto were working toward different goals in their respective designs.

I don't think that you're going to arrive at any valid conclusions from this type of comparison. And then start throwing in the variable of tuning...good luck.

I will say though, I have a Mishimoto hose and aFe panel filter coming in the mail... :clap:

That's exactly my point. People are claiming having the resonator is critical for power which has only been verified for a computer tuned to run with a resonator. Most real power gains with intake/exhaust are only really seen when properly tuned for the changes. Often times systems that mimic the OEM design are slightly improved when running the OEM tune but fail to perform at the level that a different design, properly tuned can.

It's very unfair to say a resonator is critical for power until we see more testing.

This is correct. All of our testing (Both our induction hose and intake) was completed using the factory tune. Unfortunately we did not investigate the effects of additional tuning on the removal of these additional intake components. That would certainly be an interesting test. :)

Thanks for checking in Chris. I think your design is really well thought out, I wonder if it would make more power everything else the same, but adding the resonator back in...

Acura did something similar with the CL. My guess in this case it that resonator eliminates a power robbing frequency or impulse, rather than actually creates any positive pressure

Not at all, we're talking about tube vs. tube. This has absolutely nothing to do with cold air intakes. I'm not sure where you came up with that idea. Also OEM tune only for this discussion.

Thanks for checking in Mishimoto! I really appreciate the way you document your builds. I've only had turbo cars for the last 15 years, and I determined to see what's the best I can do with N/A and not ripping into the engine, so optimizing every mod is definitely critical for me.

That's a really important point, and it would only be fair to say the resonator is critical for making power with an OEM tune...not in general.

It is important to keep in mind that most people will only bolt on and not get a tune, so OEM response is important. For people that are getting tunes, it's definitely important to know what parts provide the most power potential with tuning, but you also need to break it down between custom tunes and OTS tuning.... People who bolt on and get custom tuning probably represent the smallest percentage of all the people that modify (i.e. most are bolt on only, OTS tune only or both)

I'm not sure, at this point we probably aren't planning on changing the design. Spending time to redo it will cost us a lot of money, for something that we don't believe will net much or any gain. Sorry to be a downer!

I know some like to obsess about the max power number...and that's OK..

however here is some food for thought ....If the power gains using the resonator were across the board that would be one thing, and I would be opening my wallet make no mistake about it....however per Mishimoto ( I read the PDF download) it is only in the last 500 rpm that any power gains were noted with the resonator installed . So for me at least..I'm keeping my Perrin.

Not a problem, thank you for the kind words. :cheers:

Sorry to bring this back to life but now that everyone has had these for a while does anyone know if keeping the resonator is beneficial to performance or not?

Mishimoto (keeps res) v.s. Perrin (no res)

Who wins?

I'd say, you should look at it as a whole. If in mishimoto's dyno runs their intake tube shown better results with sound tube delete but keeping resonator - run this way. If perrin decided to design their way with deleting it too - fine. Imho perrin is company that takes required steps in product design/preproduction samples testing too. Evaluate/compare sets (this time intake with or without resonator) and their relative performance for them as a whole. And if one chosen one way that differs from others' it doesn't say that this or that is only one wrong or right. In rare cases same recipes work same way everywhere and are universal enough.

So basically both ways res or no res could both work well either way. But perrin is a more reputable and trustworthy brand that i should go with them? Lol thats what i got out of it :lol:

No. I was more saying along the lines - depending on which from these intake tubes you buy/install, follow recommendations of vendor that made it, instead of blindly assuming that they should be identical regarding that resonator. In my eyes both of these brands make fine products.