[VeyronSuperSprt]

Originally Posted by groom

Resonance always exists in the inlet and exhaust

Helmholtz wave resonators mentioned earlier are used only in the inlet area. They do not find application in the exhaust area.

Originally Posted by groom

Have you see a Carburetor?, its also on this principle,

Please refer:

Originally Posted by VeyronSuperSprt

Bernoulli's principle is used in fluid dynamics such as the constrictions found in venturis of carburetors. It is not applied in air intake systems.

[Sutripta]

Originally Posted by Sankar

Did a highway round trip of 460kms yesterday and i tested the car with and without rubber thing.

Hi,
Any change in the aural ambiance?

Regards
Sutripta

[gthang]

Originally Posted by VeyronSuperSprt

Helmholtz wave resonators mentioned earlier are used only in the inlet area.

Does resonance not happen in the air intake portion past the air filter, at the manifold?

This looks like a simple flow rate increasing device, based on Bernoulli's.

Cheers

[dhanushs]

Originally Posted by Sutripta

Hi,
Any change in the aural ambiance?

Probably no, considering most Maruti's and the damping its gone through.

Originally Posted by gthang

Does resonance not happen in the air intake portion past the air filter, at the manifold?

gthang, yes, resonance does happen in the air intake portion after air filter. Older IKON's had the resonator box where you mentioned.

This looks like a simple flow rate increasing device, based on Bernoulli's.

hmm... me thinks too.. And I think, the frontal portion of the engine bay has colder air and better circulation.

[VeyronSuperSprt]

Originally Posted by gthang

Does resonance not happen in the air intake portion past the air filter, at the manifold?

Yes, pressure wave reversion starts there.

Originally Posted by gthang

This looks like a simple flow rate increasing device, based on Bernoulli's.
Cheers

Yes, it looks like that and this creates the confusion.

[gthang]

Originally Posted by VeyronSuperSprt

Yes, pressure wave reversion starts there.
Yes, it looks like that and this creates the confusion.

Can you harmonize a pressure wave with an unknown variable such as air filter in the system? Unknown because the permeability will change with impurity.

I can see how the shape of the inlet adapter doohickey can make it appear like a Helmholtz chamber, but I cannot fathom how they can calculate the geometry with the air filter inline.

Can you explain?

Cheers

[Sankar]

Originally Posted by Sutripta

Hi,
Any change in the aural ambiance?

Regards
Sutripta

Yes there was but only very little.

Originally Posted by gthang

Does resonance not happen in the air intake portion past the air filter, at the manifold?

Not at the manifold but before the throttle body and after the airbox. I haven't so far come across a resonator box connected between the engine and the throttle body in a car engine. In two stroke bikes yes - Shogun, KB RTZ with Power Box, RXG onwards YEIS.

In the previous generation Swift 1.2K (non VVT) there is a resonator box between the airbox and the throttle body. You can see the resonator connected to the rubber pipe after the airbox and before the throttle body.

In the Ritz (the one i saw) which utilises the same engine and airbox, this resonator box is missing. (PS: That hose going into the rubber pipe is from the cam cover for PCV, not from the airbox).


In the AStar nee Alto exported to the Europe and Australia had this resonator box like in the Swift mentioned above. My old AStar (2010 March) which shared the same airbox like these export AStar/Altos didn't have this resonator. The engine is the same K10B unlike 1.2's case where they use K12B in markets outside India and k12M in our domestic market. (PS: Later model AStars have a different airbox design which is common to all K10 engines in India).

Why the absence or presence of resonator across the model range using the same airbox design and engine?

[VeyronSuperSprt]

Originally Posted by gthang

Can you harmonize a pressure wave with an unknown variable such as air filter in the system? Unknown because the permeability will change with impurity.

I can see how the shape of the inlet adapter doohickey can make it appear like a Helmholtz chamber, but I cannot fathom how they can calculate the geometry with the air filter inline.

Can you explain?

Cheers

You harmonize the pressure wave reversion in the same manner you harmonize the suction which is also affected by the same permeability. This is just the addition of an expansion chamber (the long tube) which further forces the pressure wave to slow down to fill the cavity, thus further expending it's energy and slowing the pressure wave reversion. This additional slowdown allows fresh air to flow more freely toward the engine.

[gthang]

Originally Posted by VeyronSuperSprt

You harmonize the pressure wave reversion in the same manner you harmonize the suction which is also affected by the same permeability. This is just the addition of an expansion chamber (the long tube) which further forces the pressure wave to slow down to fill the cavity, thus further expending it's energy and slowing the pressure wave reversion. This additional slowdown allows fresh air to flow more freely toward the engine.

I thought the idea of resonance harmonizing was to direct the air to the cylinder with the maximum velocity without getting bounced back to increase volumetric efficiency with a "spring" like effect rather than just increasing travel and slowing down the wave. Even then, how would a longer intake length slow down your reversion wave?

Is not the suction and pressure wave reversion a function of cylinder capacity and rpm, and as such independent of air filter permeability?

I just dont see how you can affect the pressure wave in any way with the air filter in the way. Is the wave passing through the filter in both directions? If not, how would changing the flow prior to filter give the desired effect? And will the change be uniform in the wave reversion and suction wave with a clogged filter? i.e, will the clog be the same in both directions?

Used to think most resonance chambers was in the air intake manifold area where one has the capability to affect the pressure wave.


Cheers.

[Sankar]

@veyronsupersprt, does the airbox of the new Swift use a quarter wavelength resonator? Like the one mentioned in the article below. I'm asking since i don't see a small bottle or box like structure like the one that can be seen in the older 1.2's airbox, but the new one has a long rectangular box that runs almost the length of the intake pipe and a bit more. What is that?

AutoSpeed Blog » Blog Archive » Those funny things tee’d into intakes…



My experience with intake resonators on my ported RX135 5 speed is a little strange. The bike was ported and chambered by Chinoy and jetted by me. With the Yamaha's YEIS on it was easier to jet the bike, the engine was more forgiving in terms of jetting meaning it would run good even if it wasn't too perfect, and the power delivery was linear and the FE is good too. Now when i remove the intake resonator from this setup, the jetting goes bad especially at the lower end of the RPM, the power delivery is erratic and the FE went down a bit. Now when i got the jetting near perfect without the resonator the bike was really fun to ride, the throttle response was crisp and the power when the engine got onto its power band was crisp and sharp, the FE was still lower than what i got with the resonator. Now put the resonator back on with this jetting the bike becomes mellow. In the end i retained the non resonator setup. The bike was producing more power without the resonator but FE was low. I have a fair understanding of how the resonator works in the 2 stroke setup when its between the carb and the engine, but the one on the airbox of the car, especially when its before the air filter i don't understand much.

What does the long rectangular box do in this setup? Is it for helping air filling or could it be put there to silence the intake sound? I'm going to see if i can separate the long box from the airbox and see if there's any difference.

Edit: Anyone know...

Why the absence or presence of resonator across the model range using the same airbox design and engine?

And why does the Ritz and Non VVT 1.2 Swift have the same power output according to the tech specs when their air intake setup is slightly different? When the engine is tested on the engine dyno do the manufacturer install the road going airbox and exhaust systems?

[VeyronSuperSprt]

Hey guys, am currently traveling and most of the responses on this thread have been out of an iphone which is a real pain. Will respond in more detail later. Thanks.

[Sankar]

Originally Posted by VeyronSuperSprt

Hey guys, am currently traveling and most of the responses on this thread have been out of an iphone which is a real pain. Will respond in more detail later. Thanks.

Sure, much appreciated! looking forward to read your inputs.

[hellraiser_yank]

me not being from a science educational background cannot comment on most of the discussion, but my experience with the 2 strokes(RD/RZ) explains the need for the resonator (boost bottle or whatever) as a supplement to the carb when sudden supply of charge is required. as someone here pointed out that their RX had erratic throttle response without the resonator on a ported setup, while maintaining the same jets. that is something every 2stroker has faced or will face while tinkering around. especially on a ported setup the resonator can be used to replace a bigger carb till a point.

Back to the case of the swift, the assumption of the engine running lean can be easily judged by gauging the change in regular running temperature, if there is a noticable difference in the temp gauge(most probably not) then i believe there is big trouble for the engine, otherwise it would be better to take readings from the OBD2 port to judge minute changes in operation.

HOTTER ENGINE in this case = Lean Charge.

PS- as i said im not from a science background and all the information in the above post is just my opinion based on experience and what little logic i have.

Cheers to us geeks, pondering around for questions to be answered.

[Sankar]

Found this on the Internet. But this uses Helmholtz resonator after the filter, unlike the one in my Swift. Still trying to understand the long box on the Swifts airbox.

Its from Mazda. Prolly MX6.

[VeyronSuperSprt]

Originally Posted by gthang

Used to think most resonance chambers was in the air intake manifold area where one has the capability to affect the pressure wave.

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.

Originally Posted by Sankar

the new one has a long rectangular box that runs almost the length of the intake pipe and a bit more. What is that?

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