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Discussion Starter #1
i like subarus. we've been loyal owners for 20+ years. nevertheless, i've always thought their engines sounded pretty nasty. today i saw a old 911 drive by. it had the same kind of sound. then one of the press reports (thanks clone!) remarked about how all boxer engines have a "growl". i read this as a euphemism. :) so what is it? you increase the V to 180 degrees and suddenly you got this rattly, ugly sounding engine? any ideas??

cool animations from howstuffworks.com, which show the difference, but is that all that accounts for the "growl"?

v-6


inline-4


boxer- 4
 

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I think the engine layout and the turbo account for the growl. I remember reading somewhere that on the new JDM STi, the one with the twin-scroll turbo, that the STi lost its familiar growl. So that's all I know on the subject.

P.S. I don't think they were using a Euphemism to describe the growl. From what I understand, the press, particularly the British automotive press, sees the growl as one of the scoobies "quirky and lovable" characteristics. But then again, mabye not. :p
 

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Discussion Starter #3
chawklit said:
I think the engine layout and the turbo account for the growl.
but we have the "growl" on our unturbo'd outback, my old '82 hatchback gl, etc. <shrug>

chawklit said:
P.S. I don't think they were using a Euphemism to describe the growl....the British automotive press, sees the growl as one of the scoobies "quirky and lovable" characteristics. But then again, mabye not. :p
:D oh man, that's a euphemism if i ever saw one. like donald rumsfeld being a "cozy cuddly teddy bear". :)

eh, just conversation to pass the time. i can't wait to hear it in person. i should ask one of the fortunate hawaiians on nasioc to compare the sound of the sti with the wrx.
 

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The way the engine is setup, it actually runs like 2-2 cylinder engines. Ever noticed the WRX sounds a lot like a 500cc sport bike, like a Ninja 500R? V-twin.....engine not 'firing' as often.

I believe the reason for the 'hardly running' sound of the boxer is because the cylinders fire at the same time, instead 1-4-3-2 it's 1 and 4, 2 and 3.

Just what I read somewhere........
 

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it also has to do with the unequal-length headers. makes the exhaust note a bit lumpy. some people who put equal length parts complain of a loss of "that boxer sound."
 

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I LOVE the way my RS sounds and I hope my STi sounds better. What do you mean by "rattly". ;)

Be proud man, only two manufacturers install such "ugly" sounding engines, Subaru and Porsche. :) ;)
 

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Discussion Starter #8
CloNeGTS said:
I believe the reason for the 'hardly running' sound of the boxer is because the cylinders fire at the same time, instead 1-4-3-2 it's 1 and 4, 2 and 3.
ah, i see it now! this explanation works for me. however, the inline-4 above should sound the same also; i wonder if that animation is correct? anyway, thanks guys for indulging me.
 

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4MLA1FN said:
CloNeGTS said:
I believe the reason for the 'hardly running' sound of the boxer is because the cylinders fire at the same time, instead 1-4-3-2 it's 1 and 4, 2 and 3.
ah, i see it now! this explanation works for me. however, the inline-4 above should sound the same also; i wonder if that animation is correct? anyway, thanks guys for indulging me.
If the cycles of the engine are staggered then the inline-4 from above could be igniting one cylinder while it is on the exhaust cycle on the other cylinder. Remember in a 4 stroke engine ignition of the fuel and air happens every other cycle of the piston in the cylinder. Actually I'm pretty sure this is how most if not all inline-4's work.

So in the boxer engine the opposing cylinders are on the same cycle?
 

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Discussion Starter #10
darwood said:
If the cycles of the engine are staggered then the inline-4 from above could be igniting one cylinder while it is on the exhaust cycle on the other cylinder.
doh! of course. these are 4cycle engines. thanks.

darwood said:
So in the boxer engine the opposing cylinders are on the same cycle?
http://www.cars101.com/subaru/impreza/wrxsti2004.html

the firing order for the wrx is 1-3-2-4. so i think this implies they're on different cycles. (he says cautiously.)
 

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Hmm......maybe it is just like a regular 4 (which I KNOW only fire one cylinder at a time), but the header makes all the sound difference. I do know the uneven lengths add to the lumpy sound.

That really makes more sense. It would be too hard to make an engine try to run as if it had half the cylinders.

It didn't sound right, but I thought I'd throw it out there. I'd admitily know jack about boxer engines.
 

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heres another question, is the boxer motor cylinder labled similar to the regular inline 4? the reson why i ask is both the crank is a sigle plane 4 cylinder (the Journals are 180 apart from each other) and its labled with the cylinder closes to the crank being number 1 cylinder, because if its labled so then the firing order dont sound too strange even its got two banks. just my thought.....

Billy
 

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While the one cylinder on the left in intake mode the opposite cylinder on the right is in exhaust mode. It's called a boxer only because the pistons are in sync. What the valves are doing is the opposite cycle of the other. Most of the boxer sound does come from the unequal length headers. The pistons are in sync to prevent vibration that would occur if they weren't. The cylinders are opposed to create a lower profile weight mass which can also be mounted lower that most engines. Hope all this is clear and helps. :D
 
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