[Sankar]

Originally Posted by VeyronSuperSprt

That is the resonator. The Swift uses a helmholtz resonator.

Yep i knew it was a resonator but was wondering which type. But why is it placed before the air filter?

In the Mazda manual page pic i posted above, there is a resonator before the filter and one after the filter. The one before the filter is referred to as a "silencer", to cut down intake noise, but the one after the filter is placed there for increased mid range torque.

So i'm wondering whether the resonator in the Swift VVT, the one before the filter, is provided there for silencing the intake sound.

And do you know why Swift uses a resonator and Ritz doesn't? The post i made earlier.

Found two nice links:
http://www.thunderproducts.com/AirboxesDynotech.htm
http://www.saltmine.org.uk/randy/airboxdesign.html

[Skyline GT-R]

Holy Molly. never knew this much technology rested in that rubber thing.

Slightly OT but relevant to the technological aspect i would like to share:-

Some years back i had modified my M800's air-filter box (resonator box?) by sealing the opening (which used to face the RHS fender inside portion) & making a similar hole on the side facing the radiator.

I had "procured" a funnel shaped 90 degree bent rubber hose from a totalled Honda City 1.3 (from Doha) and stuck it to the hole facing 45 degree down so that it sucks air coming in through the front grille.

Used to get FE of 18+ & car used to touch 135 kmph easily (with 155/70R12 tyres). @ 75K car still being used by FIL without any issues.

[gthang]

Originally Posted by VeyronSuperSprt

There are two types of resonators. The one that you are referring to is the in-line resonator. The other type referred to as side-branch resonators is being used here. Think the above link shows pics of resonators situated before the air box.

Yes, I was aware of the different types of resonators. To be fair, I did not mention any type in particular. Just said chamber. I believe there are also other means of achieving harmonic resonance by changing plenum and runner geometry as well. But the point I was trying to make is the location of the mechanism.

Like the link that Sankar has posted earlier stated, if before the filter, it only works to attenuate the acoustics, but does nothing to the volumetric efficiency. For VE, any type of resonance harmonizing must be done where it makes a difference to the pressure wave, i.e., after the filter, at the manifold.

So, coming back to the OP, I feel that the little mouthpiece does anything for VE, and unless accompanied by a chamber, does nothing for the acoustics either. But since it has varying ID in profile, it will affect the flow rate, which will in turn effect your FE, but not by resonance.

Cheers

[Sankar]

Another question hope someone could clear this as i have no idea why this kind of ridges are here inside an air box.




The airbox pictured here is of our i10 1.2 and the photos were taken many days ago an uploaded to team-bhp in another thread. I'm posting this here in this thread because i found the same ridges et al in the new Swift VVT airbox too. It was not present in the older Swift airbox. Can some one tell me why is like this?

[VeyronSuperSprt]

Originally Posted by Sankar

So i'm wondering whether the resonator in the Swift VVT, the one before the filter, is provided there for silencing the intake sound.

And do you know why Swift uses a resonator and Ritz doesn't? The post I made earlier..

Can't seem to find the time to view posts much less log in to tbhp! Let me respond quickly:

Yes, the Ritz does not have a resonator and as a result even though it is the same engine it makes only 85PS to the Swift which has 87 PS. There are other differences to the Ritz's engine too such as a different intake manifold, an additional TPS as compared to the older Swift's accelerator cable etc.

The new Swift has a resonator before the air filter and still delivers better VE through changes in design. Attenuation (Noise Reduction) is a very marginal spin off and is not worth the huge investment in R&D and the increase in car costs where every rupee is sought to be saved - case in point - you do not find the Ritz's engine noisy without a resonator before the air box or for that matter the old Swift which had the resonator after the air box.

The ridges in the air box help in marginally reducing vibration (NVH).

Originally Posted by gthang

So, coming back to the OP, I feel that the little mouthpiece does anything for VE, and unless accompanied by a chamber, does nothing for the acoustics either.

The rubber piece is connected to the larger dia inlet pipe which is connected to the resonator. It works in tandem with the larger dia inlet pipe and the resonator to increase FE / improve VE. As mentioned earlier the primary purpose of resonators in all Maruti Suzuki vehicles is fuel efficiency through VE and attenuation is an add on benefit and this is mentioned in their environment reports. Depending on the overall design resonators can improve FE/VE even when situated before the air box.

[gthang]

Originally Posted by VeyronSuperSprt

The ridges in the air box help in marginally reducing vibration (NVH).


The rubber piece is connected to the larger dia inlet pipe which is connected to the resonator. It works in tandem with the larger dia inlet pipe and the resonator to increase FE / improve VE. As mentioned earlier the primary purpose of resonators in all Maruti Suzuki vehicles is fuel efficiency through VE and attenuation is an add on benefit and this is mentioned in their environment reports. Depending on the overall design resonators can improve FE/VE even when situated before the air box.

Forgive me, I do not intend to start an argument, or be inflammatory, but taking the freedom of a free forum.

I cant help but notice a marketing bias in your technical replies. Which is fine and good, but, to say that every piece of the air box is a part of a resonator sounded a bit inaccurate.

Another example would be the ridges on the airbox. I would have said it was reinforcement ridges for the cover itself, but you say it reduces NVH. I guess we would be both right.

Anyways, interesting conversation. Thanks.

Cheers.

[Mpower]

The ridges in the airbox are stiffening ribs and are not intended to influence airflow.

[VeyronSuperSprt]

Originally Posted by gthang

to say that every piece of the air box is a part of a resonator sounded a bit inaccurate.

I would certainly like to be corrected on this one. Could you let me know where I've said it? Thanks.

[gthang]

Originally Posted by VeyronSuperSprt

I would certainly like to be corrected on this one. Could you let me know where I've said it? Thanks.

I apologize. I must have misunderstood. I retract my statement.

Mods, please delete my previous post.

Thanks

Cheers

[VeyronSuperSprt]

Originally Posted by gthang

I must have misunderstood.

No worries mate. Happens to me all the time.

Was a good discussion. Thanks

[Sankar]

Originally Posted by VeyronSuperSprt

Yes, the Ritz does not have a resonator and as a result even though it is the same engine it makes only 85PS to the Swift which has 87 PS. There are other differences to the Ritz's engine too such as a different intake manifold, an additional TPS as compared to the older Swift's accelerator cable etc.

VeyronSuperSprt, i think you got confused between Ritz 1.2 and Swift 1.3G13B. I was referring to Ritz 1.2 K12M and Swift 1.2 K12M (non VVT 2010-11), both make same power and same amount of torque at the same RPM as per the tech specs. The engine manifold, TPS, drive by wire etc is common between these two. The resonator is the difference between these two engines' intake setup, even airbox is the same. Why so?

The new Swift has a resonator before the air filter and still delivers better VE through changes in design. Attenuation (Noise Reduction) is a very marginal spin off and is not worth the huge investment in R&D and the increase in car costs where every rupee is sought to be saved - case in point - you do not find the Ritz's engine noisy without a resonator before the air box or for that matter the old Swift which had the resonator after the air box.

Both engines (K12M) in the 2010-11 Swift and the Ritz sound the same, and they make the same power and torque figures according to tech specs. Then why the additional resonator in the Swift? Thats what i'm trying to figure out.

The ridges in the air box help in marginally reducing vibration (NVH).

Suppose i don't mind the additional vibration and if the ridges are smoothened out? Will it flow better or worse?

The rubber piece is connected to the larger dia inlet pipe which is connected to the resonator. It works in tandem with the larger dia inlet pipe and the resonator to increase FE / improve VE. As mentioned earlier the primary purpose of resonators in all Maruti Suzuki vehicles is fuel efficiency through VE and attenuation is an add on benefit and this is mentioned in their environment reports. Depending on the overall design resonators can improve FE/VE even when situated before the air box.

Undesrstood. Resonators are IN

Originally Posted by Mpower

The ridges in the airbox are stiffening ribs and are not intended to influence airflow.

Why does it need to be stiffened from the inside? This airbox has ribs on the outside which should provide enough stiffening(?). The old airbox didn't have stiffening ribs inside it only had them on the outside, and that too even fewer ridges than the new one.

[Sutripta]

Anyone any ideas on how to model this. I mean cavity - porous plug - cavity - stepped pipe. Then we can see what we get if we remove the step in the pipe.

Regards
Sutripta

[VeyronSuperSprt]

Originally Posted by Sankar

VeyronSuperSprt, i think you got confused between Ritz 1.2 and Swift 1.3G13B. I was referring to Ritz 1.2 K12M and Swift 1.2 K12M (non VVT 2010-11), both make same power and same amount of torque at the same RPM as per the tech specs. The engine manifold, TPS, drive by wire etc is common between these two. The resonator is the difference between these two engines' intake setup, even airbox is the same. Why so?

You're right Sankar. The only reason I can attribute is that with the resonator the Swift would have a marginally better (flatter) torque curve than the Ritz in keeping with it's positioning as a sporty car in comparison with the Ritz. The peak torque would remain the same.

Originally Posted by Sankar

Suppose i don't mind the additional vibration and if the ridges are smoothened out? Will it flow better or worse?

You wouldn't notice any difference as it would be too small to make any impact.

Originally Posted by Sankar

Why does it need to be stiffened from the inside? This airbox has ribs on the outside which should provide enough stiffening(?). The old airbox didn't have stiffening ribs inside it only had them on the outside, and that too even fewer ridges than the new one.

Marginally improved NVH - one of the reasons that contribute to making the new car marginally smoother.

[Mpower]

Originally Posted by Sankar

Why does it need to be stiffened from the inside? This airbox has ribs on the outside which should provide enough stiffening(?). The old airbox didn't have stiffening ribs inside it only had them on the outside, and that too even fewer ridges than the new one.

Its just more mass efficient to add ribs (gussets rather) on the inside of a curved surface rather than outside.

[Sankar]

I made some changes to the stock airbox today since i didn't have anything better to do today. I found that i could take off the tube and the resonator along with it without damaging the airbox. So i did take out the long tube and the resonator but retained the rubber funnel end.

Went for a test drive in the evening and noticed some changes, 1) The torque curve shifted down, i expected the opposite, and it is very evident 2) throttle response is quicker and 3) the intake noise increased as expected.