When did Imprezas lose that boxer rumble and start sounding like civics?

[Georgethefierce]

i like hondas.

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[boxered]

Originally Posted by plunk10

no. I'm just wondering why Subaru chose to install unequal length headers on the car, if they are known to be inferior. Furthermore, if equal length = better, I'm surprised everyone didn't mod their subies to be equal length. Perhaps the performance difference is minimal?

Because Subaru isn't superior about superior performance parts.

[Dizmal]

header runs to lengths that are both equal

[WRX Shenanigans]

Originally Posted by teh Phil

Srsly, I'm curious, why is that an inferior design? Does it create a misfire of sorts?

Well, in reality there are pluses and minuses to both designs.:

http://members.rennlist.com/pirtle/zexh_science.txt

"Unequal length headers are by definition not tuned at a specific rpm; rather each pipe is tuned for a different speed. They tend to perform better than the stock manifold and may increase performance over a broad speed range. Because of their unequal length, each pipe will utilize wave scavenging at a
different speed, thus reducing the effect at any single or narrow band of
speeds. They often have sub-optimal merge collectors and so, do not make
the best use of inertial scavenging. Equal length headers can be
excellent wave scavengers, but often have inferior collectors, so inertial
scavenging is not optimized."

What this paragraph is saying actually is that the wave pulses are spaced for each cylinder differently allowing exhaust to escape faster because there is less of a bottle-neck. However, they do not make the best use of "inertial scavenging" which ironically is not beneficial to turbo-charged vehicles. So the irony is that the model with the turbocharger (WRX) has the less turbocharge efficient design, while the model with the better inertial scavenging has no turbo to take advantage of it...

[moshter11]

Originally Posted by Georgethefierce

i like hondas.

i like turtles

[ardevas09]

Originally Posted by Mr.Sparkle

NO, equal length is SUPERIOR.

your mom is superior







in bed

[97whitesi]

Originally Posted by Brad Pittiful

equal length armbard

you're really running that into the ground.

[WRX Shenanigans]

Originally Posted by plunk10

no. I'm just wondering why Subaru chose to install unequal length headers on the car, if they are known to be inferior. Furthermore, if equal length = better, I'm surprised everyone didn't mod their subies to be equal length. Perhaps the performance difference is minimal?

actually, the funny part is, I think most people don't mod their car with equal length headers is because they want to retain the "boxer rumble"

[ScubaruImpreza05]

Originally Posted by WRX Shenanigans

Well, in reality there are pluses and minuses to both designs.:

http://members.rennlist.com/pirtle/zexh_science.txt

"Unequal length headers are by definition not tuned at a specific rpm; rather each pipe is tuned for a different speed. They tend to perform better than the stock manifold and may increase performance over a broad speed range. Because of their unequal length, each pipe will utilize wave scavenging at a
different speed, thus reducing the effect at any single or narrow band of
speeds. They often have sub-optimal merge collectors and so, do not make
the best use of inertial scavenging. Equal length headers can be
excellent wave scavengers, but often have inferior collectors, so inertial
scavenging is not optimized."

What this paragraph is saying actually is that the wave pulses are spaced for each cylinder differently allowing exhaust to escape faster because there is less of a bottle-neck. However, they do not make the best use of "inertial scavenging" which ironically is not beneficial to turbo-charged vehicles. So the irony is that the model with the turbocharger (WRX) has the less turbocharge efficient design, while the model with the better inertial scavenging has no turbo to take advantage of it...

I'm fairly certain only the NA cars got the Equal length, the turbo cars still retain the UEL design for said reasons. Unless the newest models have EL which i hadn't heard.

[RLRaven]

I have unequal length headers and a busted baffle in the muffler and my car sounds the same. It's embarassing. I dislike Hondas.

[97whitesi]

^ I'd rumble her box.

wait wut?

[WRX Shenanigans]

Originally Posted by ScubaruImpreza05

I'm fairly certain only the NA cars got the Equal length, the turbo cars still retain the UEL design for said reasons. Unless the newest models have EL which i hadn't heard.

Yes, you are correct. I wasn't disputing that. Only the non-turbo charged 2.5i has the equal length headers and the WRX has non-equal length headers. If you read the paragraph above, this is back-asswards and should be the other way around for optimal performance in both circumstances...

[ScubaruImpreza05]

Originally Posted by WRX Shenanigans

Yes, you are correct. I wasn't disputing that. Only the non-turbo charged 2.5i has the equal length headers and the WRX has non-equal length headers. If you read the paragraph above, this is back-asswards and should be the other way around for optimal performance in both circumstances...

Ohhh, I was under the impression that the EL headers were most beneficial to NA applications, versus UEL which was best for turbocharged applications.

[RLRaven]

Originally Posted by 97whitesi

^ I'd rumble her box.

wait wut?

[subySerb]

wrong forum.

2.5i gained something like 8hp vs. the RS when they switched headers in 06.

[Georgethefierce]

Originally Posted by moshter11

i like turtles

i like your mom's warm touch and her soft lips caressing my unit....I'll PM you with pics.

[Kiel]

I have a UEL header on my car and IT GOES BRUM BRUM

[WRXbrian]

im here for the ELH discussion

[Brad Pittiful]

Originally Posted by 97whitesi

you're really running that into the ground.

armb...uh i mean what

[hedwagon]

are we arguing about how good 4bangers sound, or what ones just sound worse than the other?

[Harv]

= length

[Matt K]

i talked to an australian guy with a phd in automotive exhaust engineering about headers. His phd thesis was all about tuning the header length ratios to make any anemic little engine sound good. It was nothing all that complicated (well, there was some nasty math behind it all, but you didn't have to grasp all of it to get the jist), but it was very interesting nonetheless. I had a lot to do with 2nd and 3rd order harmonics, iirc.

[SureGrap]

Originally Posted by 97whitesi

^ I'd rumble her box.

wait wut?

Bust her baffle too? *nudge nudge, wink-wink*

[brendan_mac]

Originally Posted by Matt K

i talked to an australian guy with a phd in automotive exhaust engineering about headers.

Had he consumed more than 24 beers? If not, don't believe him.

[Kiel]

Considering what we consider to be pleasing sounds are all based on math anyway, that makes utter sense.