Ideas for beating noise meter | Page 4 | GTAMotorcycle.com

Ideas for beating noise meter

Can I get this straight please? You say that you don't know the procedure, I link to a video OF the procedure, and ask only if your unshared idea will beat the test, and you're treating me like i'm the one with comprehension difficulties?

Would that be a correct summation?

You might want to search for some of inreb's other posts ...

When I had my bike tested, the person doing the testing had a tachometer that he could attach to determine your RPM in case your bike wasn't equipped with one.

Was that the acoustic analyzer?

There is no guaranteeing that your bike's primary sound frequency (that this thing would be analyzing) would correlate properly to the RPM. It could conceptually show half, equal, or double pretty easily. For example, a very well balanced inline four would have exhaust pulses at twice the crank rotation frequency and if the carbs/throttle bodies were well balanced and the exhaust system was a symmetrical 4 into 1, there would be no occurrence of a half-crank-rotation frequency. A single will have exhaust pulses at half crank rotation speed. An inline-four with slightly out-of-balance carbs would have a half-crank-rotation pattern imposed on top of the double-crank-rotation pattern. And so forth ... It's easy for someone who knows a thing or two about engines to shoot holes in how that thing works.

Mechanical tach? No dice. My bikes all require fairing removal to get to the crank end covers, and most of them are "wet" (oil pumped/splashing/circulating) under those covers.

Ignition pick-up? Lots of newer models are coil-on-plug; there is no accessible high-voltage signal that an inductive pick-up could access. In some cases (and I own one example), gaining access to the spark plugs and re-assembling the bike afterwards is an 8 hour job, and you cannot run the engine in the condition that allows access to the spark plugs (you have to take the throttle body assembly off ...)

OEM tach? Lots of them are inaccurate. Of course, they generally read high, which actually is in the bike owner's favor since 5000 rpm on the tach would be something less in reality, but still, it's not a certified instrument.

Of course, a lot of the primary noise offenders have a separate exhaust pipe for each cylinder, an uneven firing pattern, and readily accessible high-voltage leads to the spark plugs ...
 
Can I get this straight please? You say that you don't know the procedure, I link to a video OF the procedure, and ask only if your unshared idea will beat the test, and you're treating me like i'm the one with comprehension difficulties?

Would that be a correct summation?

From the tone of your assault I thought you were taunting me with my quote. We'd already moved along to the point where my engine won't start. Apology accepted in advance.
 
I have been on a few OFTR rides, they sound test all bikes before your are permitted to ride. Even if you have a stock pipe on a bike like a DRZ400.

Most dual sport bikes don't have a tach, they put a gauge of some sort on the seat, it looks like a compass, and they rev up your bike. Not sure how it works, but it does give an RPM reading. The forest service in the US use them as well when testing atv's on public trails.

So there is no need for them to rip apart your bike.
 
I have been on a few OFTR rides, they sound test all bikes before your are permitted to ride. Even if you have a stock pipe on a bike like a DRZ400.

Most dual sport bikes don't have a tach, they put a gauge of some sort on the seat, it looks like a compass, and they rev up your bike. Not sure how it works, but it does give an RPM reading. The forest service in the US use them as well when testing atv's on public trails.

So there is no need for them to rip apart your bike.

That gauge is probably a sirometer. As discusssed by Brian above, it measures the dominant frequency of a vibrating object, but as a bike is a collection of objects, it's not guaranteed that it is providing RPM.
 
I have been on a few OFTR rides, they sound test all bikes before your are permitted to ride. Even if you have a stock pipe on a bike like a DRZ400.

Most dual sport bikes don't have a tach, they put a gauge of some sort on the seat, it looks like a compass, and they rev up your bike. Not sure how it works, but it does give an RPM reading. The forest service in the US use them as well when testing atv's on public trails.

So there is no need for them to rip apart your bike.

In that environment, when the outcome of the instrument's reading isn't going to be used in court, and when basically all of the bikes have an engine of the same general type (4-stroke single!), it's appropriate. If the device does happen to read half or double in that environment, it's relatively apparent to anyone who has any experience with engines. But that doesn't fly in a courtroom. The device has to be right all the time, or it's wrong.
 
I've visited a few J2825 testing clinics recently and imo if a bike fails the test it isn't just loud, it's obnoxiously loud.

My bike is loud and it passes the J2825 noise test and limits. IMO, a sportbike v-twin has a bit of an advantage in the test with only an idle and 2000 rpm check. FWIW, the bike exhaust is 60mm diameter inlet/outlet, with basic straight through race-style baffles.

J2825 test parameters can be found with a simple google search. One can always get an inexpensive sound meter and have a check. I myself have an inexpensive noise meter and it measured 3 dB less than the expensive sound meter that will be used in enforcement. For those that try, use A weighted. Slow or fast response did not change my measurements, but J2825 supposedly uses slow response.
 
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I'm telling you, I tested with a $800 meter. and the DB meter app on my phone read almost exactly the same.
 
I'm telling you, I tested with a $800 meter. and the DB meter app on my phone read almost exactly the same.

On my iphone (using the internal mic), the reading from the app was quite accurate from 70-90 dBA. Above or below that, things got worse (above 100, the readings don't change with increasing volume). Phone app should get you close here, but don't be surprised it there is a difference from a quality SLM.
 
If you have a Yamaha R6 2006-2014 or a 07/08 R1 I can wire a switch up to the ECU that'll keep the EXUP valve closed even when you rev it for the noise test. Works sweet for Calabogie ;)
 
If you have a Yamaha R6 2006-2014 or a 07/08 R1 I can wire a switch up to the ECU that'll keep the EXUP valve closed even when you rev it for the noise test. Works sweet for Calabogie ;)

Can you make that condition based on the existing neutral switch? Then there's nothing non-OEM to break :)
 
Can you make that condition based on the existing neutral switch? Then there's nothing non-OEM to break :)
Ohhhhhh nice idea :) I know I can probably do it off the clutch lever sensor if yours is still connected. 1 sec while I check the neutral position sensor.
 
Can you make that condition based on the existing neutral switch? Then there's nothing non-OEM to break :)
Yep, works :)

exup_noise_trick.png
 
One problem that I have with this standard is the requirement for a 3 cylinder engine to rev to 5,000rpm. For a bike like the Triumph Daytona 675 that is nothing but for my bike which has a 2300cc engine that is getting close to redline and I'll be damned if I'll let a copper run it in a no load situation like that.
 
What's Unrestricted TAFB edition?
Usually dyno tuned fuel and ignition maps from Champion Cycle (available for 06/07 R6, 2008-2014 R6, 07/08 R1 and 2009-2014 R1, all bikes MUST have removed catalytic converter due to possible melting of the cat), For smoother on/off throttle transitions: Less engine braking via no injector shut off on deceleration plus ignition advance at zero throttle, disabled O2 sensor and disabled fuel economy map (both of which also help for much cooler running in traffic and low throttle loads) as well as my own totally from scratch fly by wire throttle maps, super smooth, no snap in of power at 9000 rpm, brings it in much lower and smoother.

Oh yeah, every TAFB edition map also has a custom written idle program for a silky smooth idle (especially on R6) no matter how much you've messed with the exhaust and air filter (tested on bike running open headers and pantyhose for an air filter, don't ask).

The rest of the map is just out of the box flash tune maps, speedo correction for changed ratio sprockets, lower fan kick on and off temps, disable immobilizer for easy/cheap cutting of duplicate keys or to make keyless track bike, disable AIS (smog) pump, etc.

Just had a guy ask me today if I could make his 08 R1 idle on three cylinders so it would sound like a crossplane?! Wonder if that would be hard on the engine at all, having one cylinder's fuel injector always be shut off at idle??? freaky.
 

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