Engine/Exhaust noise 2t and 4t

P.addy · Red Rocket Joined: 14 Feb 2008 Karma :

Call me stupid but..
Why is it 2 strokes are very whiney and noisy, where as a 4 stroke sounds alot deeper?

Again, maybe im an idiot..but its the same petrol goes in, spark, gas goes out?
Both use a piston...both explode petrol and air... so why the different noise?

I could just be a total idiot and miss the point completely, i know a 2t fires 2 times more than the 4t, but why such a different exhaust/engine noise?

btw im tired and pretty much confused Embarassed

ms51ves3 · Super Spammer Joined: 08 Jun 2007 Karma :

P.addy · Red Rocket Joined: 14 Feb 2008 Karma :

is that really it...thats bugged me for a while now..

Alexio · World Chat Champion Joined: 27 Aug 2009 Karma :

If you can understand the concept of measuring a frequency / pitch (a unit measuring the number of vibrations per second) then I'm sure you can figure this one out Thumbs Up

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will never give up his CG. I look at my fuel gauge more as a progress bar than a fuel gauge.
G: With my GSXR I do often effectively use it as a scooter with a clutch in town.
ms51ves3: why does it need 500 miles? Are you teaching it how to be a piston?

Mystery · World Chat Champion Joined: 23 Jul 2009 Karma :

it all depends on the exhausts as well i know a few fourstrokes thats louder than 2 strokes i love small 2strokes but i love the sound of 1000's more
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Carbon knuckles assure you maximum protect against debris and unfortunate accidents or if someone cuts you off, their side mirror.Mopeds are like chubby chicks.. they are really fun to ride until you're friends catch you on one

5v3d3b0 · World Chat Champion Joined: 24 Sep 2006 Karma :

It's not quite as simple as more explosions per second make a whiny noise... If that was the case a 4t at twice the revs would sound the same as the 2t

Alexio · World Chat Champion Joined: 27 Aug 2009 Karma :

yeah yeah... I know. It's to do with the size of the explosion as well most likely, which affects which exhaust is used etc. and also how the sound reverberates within the size of different chambers no doubt.

I still call 2 strokes 'hair dryers' though.
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will never give up his CG. I look at my fuel gauge more as a progress bar than a fuel gauge.
G: With my GSXR I do often effectively use it as a scooter with a clutch in town.
ms51ves3: why does it need 500 miles? Are you teaching it how to be a piston?

P.addy · Red Rocket Joined: 14 Feb 2008 Karma :

buddy · Trackday Trickster Joined: 07 Mar 2009 Karma :

i reckon its because on a four stroke the smaller exhaust valves open pretty gradually and smoothly, whereas a two stroke, suddenley has a massive port is (in comparison) quickly revealed giving more of a "pop" sound

basically a two stroke lets out the exhaust instantly giving a "pop"

and a four stroke smoothly pumps the exhaust out

also 101 other stupid reasons why i think a two stroke gives a different noise
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When this baby hits 88 miles per hour... you're gonna see some serious shit.