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Ok, Then what makes the induction noise?

There was brief statement that the holes in the separation plate (called because dirty air /filtered air either side) were located at the top side to direct the induction noise towards the Rider (escaping any noise test).
So, those like P Paul who jettisoned the plate, is that plate able to slightly move back and forth, like in a rubber gasket, to allow it to resonate like a speaker cone to make noise?

Rob.
NO, the plate is rigidly fixed in place with a number of screws - definitely louder without (Suzuki mention that its there for noise reasons as well)
 

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still trying to figure out the numbers above and how they relate to the letters. You are saying with plate the air intake area is 120 cq.cm, and we should have at least 206?
What I was trying to say is that K&N filters have a formula to calculate the minimum size of the airfilter for a given air flow (Engine size * rpm)

When I removed my stock air filter, i also removed the restrictor plate and I noticed that the only dirty area of the air filter correlated directly with the size and location of the hole in the restrictor/separator plate.

Now why would Suzuki fit such a large air filter (big enough using K&Ns formula) when only a small part of it is being used (not large enough for max power) - I'm sure that some air will go through other areas of the filter but insignificant with what's flowing through the small area opposite the restrictor hole.

Now Suzuki say it improves efficiency (which I take with a pinch of salt, just like the SET Valve) AND reduces noise

 

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Ok, Then what makes the induction noise?
Air rushing into the air box must be hammering against something to make noise. If it was just air going though those 2 small hole's, it would whistle at a pitch like a turbo pop off valve.
Induction noise is a result of the acoustically tuned length of the individual intake manifold runners (you have 4 runners, or air tunnels, one for each cylinder). Think of them as trumpet horns. For any given cylinder, the intake runner is simply resonating to the whooshing of the air charge being sucked thru it every time the intake valve opens.

A trumpet has no moving parts (at least not any parts that are intended to make sounds by moving). The sound emanating from a trumpet is merely a horn-amplified rendition of the "brrraaaappp" sound of air moving past the musician's flapping lips. In a similar fashion, the induction sound from your bike is merely the result of the regularly-spaced (but very fast) repeated intake air "gulps" of each cylinder.
 

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Changed my air filter for the first time the other day, and did notice the dirty area concentrated towards the middle of the filter. So I attempted to remove the restrictor plate by removing the 4 corner screws, but the thing wouldn’t budge! Didn’t want to force it. I did not see more than the 4 screws securing the plate. What did I miss to get it out?
 

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Changed my air filter for the first time the other day, and did notice the dirty area concentrated towards the middle of the filter. So I attempted to remove the restrictor plate by removing the 4 corner screws, but the thing wouldn’t budge! Didn’t want to force it. I did not see more than the 4 screws securing the plate. What did I miss to get it out?
There are 6 screws, two more closer to the center.
 

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can removing the restrictor mess with our tune? if it runs good now, if it gets more airflow, will the ecu just compensate and make it run better/worst?
 

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can removing the restrictor mess with our tune? if it runs good now, if it gets more airflow, will the ecu just compensate and make it run better/worst?
The experts here will tell you it's only for noise reduction.
I think that that oversimplifies that as the air box is a part of a tuned enclosure system. The aim of the tuning is two fold.
Firstly, noise reduction or enhancement
Secondly, it can be used to peak up the torque curve up to compensate for the HP curve dip at the for the noise range dB test.
Manufacturers put a lot of effort in getting the best compromise, so it depends on what those aim's other than legal noise were.

Unfortunately, Jap designs are for all the World, so we all get the lowest (quietest) design.
Just follow the advice previously given by the seat of the pants dyno crowd, that you can safely remove the plate and go for it.
Just keep it safe for later refitting if needed to return it to stock.

Rob.
 

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Changed my air filter for the first time the other day, and did notice the dirty area concentrated towards the middle of the filter. So I attempted to remove the restrictor plate by removing the 4 corner screws, but the thing wouldn’t budge! Didn’t want to force it. I did not see more than the 4 screws securing the plate. What did I miss to get it out?
You can see the six screw holes in this pic

 

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Seems you could check the TB synch before and after removal of the plate. That should show you if there really is a change in airflow.
 

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No offense but I call this the Dust and hearing killer mod! Cause that’s all it does! 🤦🏼‍♂️ If this bike has one thing it’s to much air we are having to tune it rich because of it with all the factory stuff In place! Now if you was gonna be making huge gains, say turbo, nos, where you need to burn tons of fuel really fast then yes a new air system would be best! But for a cat removal and being richened up a little factory box is to much already!
 

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No offense but I call this the Dust and hearing killer mod! Cause that’s all it does! If this bike has one thing it’s to much air we are having to tune it rich because of it with all the factory stuff In place! Now if you was gonna be making huge gains, say turbo, nos, where you need to burn tons of fuel really fast then yes a new air system would be best! But for a cat removal and being richened up a little factory box is to much already!
The gsxs 1000 is not lean over the whole fuel map or in general, it unfortunately is mostly lean on low throttle inputs and obviously closed loop.
I have an 02 delete and use a pcv5 with autotune set to 13 afr and the majority of the map (roughly 65%) is trying to reduce fuel, it varies from -1% right the way to -23%, the same can be said where it adds fuel but overall it's reduced fuel across the map. The numbers are hard to calculate as I have several maps from stock all the way to where it is now, this means opening each one up (10+ maps) and adding them to gain the total.

The baffle doesn't make much noticeable difference to induction roar tbh, well not with my arrow pipes anyway

Sent from my POCOPHONE F1 using Tapatalk
 

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Having worked in engineering and design for a couple of decades you are projecting a level of coordination between directives that I think is unlikely. Usually it goes something like: make this work as best as possible for maximum performance, then neuter it as needed to meet regulatory requirements. So I expect the plate is all about noise regulations, not laminar flow. That is the purpose of the velocity stacks on each throttle body. Engines are ultimately just elaborate pumps, anything you do to reduce flow restriction is generally good if it doesn't hurt scavenging, which most modern engines don't have hardly any of because of emissions.

JT
 
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