Exhaust rapping (old school bus)

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Hi everyone.

Have you heard and old school bus rapping when the driver release the throttle? Any tips on how to boost this sound on a Norton? I just love this sound.

Thanks in advance
 

maylar

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Tach it up to 5K in first and let go of the throttle. Lovely, isn't it?
 
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Mine did that 20 years ago when i released the throttle when I had a big rust hole thru the bottom of the right hand exhaust :)
 

MichaelB

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Hi everyone.

Have you heard and old school bus rapping when the driver release the throttle? Any tips on how to boost this sound on a Norton? I just love this sound.

Thanks in advance
Yes I have and no, quite frankly I never wanted to sound like an Old School bus..
 
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Just record the sound , then fit a megawatt speaker to your bike and play it back.......... o_O
 
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Press kill button for 5 seconds while going down the road in gear. Then release! No, probably not the best idea but it was fun when I was in my early 20s.
 

lazyeye6

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Jamb a screw driver between the carb and the manifold so you get a nice air leak.
 

RoadScholar

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I am of the opinion that the resonance that produces the subject noise greatly impacts exhaust scavenging which in turn diminishes cylinder packing of the intake charge reducing power output. On an old school bus with a 35 foot exhaust pipe who cares?

I hear the noise mostly coming from GM/GMC pickup trucks where some dumbass installed a 3" or 4" set of dual exhausts on a small block..the price of vanity.

Best.
 
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Option 1. Remove the mufflers altogether.
Option 2. Remove the exhaust system altogether. I did it this year just to hear it run.
Option 3 . Create trumpet style short exhaust header pipes.
Option 4. Wire up amplifier and speaker and microphone. Check polarity , may need an older British make.
 
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Being on the other side of the pond, I don't know how your school buses sounded.o_O
But in my young and dumb days, before switching to Norton, I rode a 1930 flathead Harley w/o silencer.
Simultaneously rolling back both throttle and ignition handles, produced a lot of noise.
 

concours

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I’m quite sure the OP is referring to the popping noise of fuel firing off in the pipe on the overrun, closed throttle. Which is definitely not resonance.
My bike does it well, light throttle up to 4-5k in first, back off throttle (but don’t chop it completely)
Perhaps the OP has a richer (Idle) mixture?
 
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maylar

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My bike does it well, light throttle up to 4-5k in first, back off throttle (but don’t chop it completely)
Mine does it too, when backing off throttle for the 1st to 2nd gear shift. I kinda like it.
 
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You mean the sound like one might get between 3500 RPM shifts in a GM Gen 1 V8 powered vehicle with dual exhaust and glass packs?

I get off throttle joy between shifts, but my exhaust is an obnoxiously loud and long 2 into 1 megaphone. I do like the sound, and it lets cars know I'm close. I really doubt the holier than thou sensitive types, of which there are thousands, in Seattle care much for it though. Sometimes I get a thumbs up, and sometimes they cover their sensitive ears.
 

Derek Wilson

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I personally get a great deal of enjoyment from listening to the wastegate open and the turbo spool down through a 4" straight pipe between gear changes with my Cummins, but I will never get my Commando to make sounds like that... LOL!

But kicking down a gear and honking on it in tunnels is quite appealing - both the Norton and the Cummins!! :cool:
 
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Conrad

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Not sure I can hear that sound from my memory, but maybe a pair of old supertrapps?
 
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