Kawi2strokes.com Forum

Unfortunately there is some belief among newcomers that stingers increase performance over silenced chambers. All the important stuff in chambers happens before the exit tube, which is just a pressure bleeder. If you cut off the straight stinger tubes from unsilenced chambers and replace them with silencers that have the same resistance to flow, a dynamometer should show the same engine power output.

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If it surges, that's normal, upshift.

When the AMA first required silencers to be fitted to GP bikes, they had no dB limit, and, EVERYBODY complained about the silencers costing power and ride-ability.

Come to find out that fitting Bassani silencers, the best of that day, actually added 4 horsepower in the power band on an H2R, and about 5 or so, on a TZ700. Never did get any results from the Suzuki guys,m but, their bikes seemed to run commensurately better as well, Out bikes, and Kel's actually ran a lot better all over the rev range, from "idle" to full run.

One 'barn' test I did on both an H2R, and TZ750 with a harmonic distortion read meter I borrowed from Bertea Corp, showed a loss in harmonic distortion in the main chambers of the exhaust pipes on those racers when the silencers were fitted, causing carburetion, and power output to be more easily controlled.

As has been noted, the "stinger" is literally a pressure drain. Go-Kart racers have had stingers and silencers exiting from the side of the center section for decades, with no significant loss in performance. I think some snowmobile systems do the same. Some testing was/has even been done with the "stinger" extending a short distance back into the area of the rear cone, with no adverse performance results, but, somewhat quieter noise output levels.

Nice try Jay, but it was the noise............

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Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........

Jim C. is currently experimenting with some tubes I sent him, that he welded to the Denco silencer cores, so that the silencers get the exhaust from the rear of the center chamber sections. He reports that they don't have the sharp, treble crackle, but he's holding off with dB measurements until the fiberglass packing gets the usual oily goo in it, so he can compare to his baseline measurements.

I have a set of reproduction Denco chambers I made with similar "internal stingers" before the silencers, and they are quite a bit quieter than the normal type.

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If it surges, that's normal, upshift.

So....... now that the stingers have been put back in the conversation from the original post some time ago, let me give you the prospective straight from the sneaky customer's mouth (pipe). To set the record straight for everyone. I put stingers on my bike because I knew I was going to be riding in traffic and wanted to make sure even with my own belief that every time I throw my leg over the seat my mind gets put into the constant never ending revolving words of "Every single person on the road today is trying to kill me" and they're damn good at it! Watch a few Utube videos and you'll be convinced. I am very, very, aware of my surrounding's every single second of my ride until I'm back home and off my bike and not a second sooner! My theory was that with even my constant attention to the road and my mind reminding me of the killer instinct that the car drivers have of laying me to rest. I thought "loud pipes could only help with my preservation, right". So I bought them NOT knowing that the triple's engine could melt a piston from wringing it out all the time. I don't race my bike on the street or get in a rush to go anywhere on it because of my paranoia of getting wiped out by some texting idiot. I do when the coast is clear in every direction, I will roll on the throttle and have some fun! In hindsight now, it might have changed me from buying the stingers because of the melting pistons. But, if you look around almost every Harley you see 98% of them you'll hear them loud and clear. So I don't feel to bad about the noise, do you think they care? And, there's a bunch of them and most are a bit on the older side like myself at 55. So the comment of "loud pipes will make people hate bikers more" begs the question, "Then why have Harley's numbers only gone up and up for a very long period of time"? I personally like the ding, ding, ding, not the thump, thump, thump, of the Milwaukee vibrator. To answer another question, "I'm on a roll now fella's", I don't get a headache from riding it because I'm wearing a helmet in case they make it past my noise and very paranoid mind force field. A helmet is good ear protection. I might put the cans on but, then again I might not. SO, that's the rest of the story. The triple RULES!! Thank you very much for reading!!

Stumpy

You make some valid points, Stumpy, but I don't think the general population likes loud Harleys or any other loud bikes. Harley sales are good partly because some people are impressed by loud, thumping, manly motorcycles. Those that aren't impressed are in the much larger group of non-motorcycle-owning drivers.

When I first put "silenced" chambers on my H2 in 1978, and rode it to the U of MD, I immediately noticed that cars on the DC Beltway quit changing lanes into me. The noise definitely made other drivers more aware of my presence. That doesn't mean they liked my presence, however. But it didn't take unsilenced chambers, just the "quiet" kind.

Now I'm of the belief that the less we do to irritate the masses, the longer it will take for motorcycles to be legislated out of existence.

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If it surges, that's normal, upshift.

Loud pipes do not save lives, it's been proven in studies many times over. What they do "do," is get the attention of people who want to regulate. California is clamping down even tighter with legislation to bad ANY aftermarket exhaust. (WE all know the rest of the country follows) It's because of the douche bags with loud pipes that will end up screwing us all.

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Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........

My own study that consisted of many hundreds of trips on the DC Beltway showed that it's safer for me to ride on a highway when the motorcycle makes enough noise to make its presence known to drivers around me. On single lane roads, it would not help at all, and it wouldn't help keep someone from turning left in front of me. But it's nonsense to say noise is of no safety benefit at all. And I don't mean open pipes, just enough noise to be heard by other nearby drivers.

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If it surges, that's normal, upshift.

I wrote "loud pipes"...................

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Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........

guys, didn't mean to start a heated debate about the pipes. I was just curious about moo's comment.

That being said, it doesn't matter what any of us do with our pipes or bikes. We ARE going to be regulated like it or not. Look how many weed wackers are 4 strokers now. have you heard a stock Harley? Doesn't sound like Harleys of past. The goal of all libtards/tree huggers and government is to get us in line and dictate what we can do and how we can do it. Make no mistake, it will happen. Bikes will eventually ALL sound like a Goldwing and if you modify it you will be made an example.