I figured this out a while back, then made a header for my car lengthening 2 of the cylinders. And boy did it work! I have since turbocharged my car and made the manifold utilizing the same principle and now it sounds just like a wrx. The rumble, the wirring, and the woosh. It’s great!
Does that make the turbo run weirdly? Cause the air hit the hot part of the compressor in a unequal way
No, there is always pressure in exhaust manifold created by turbo resistance (spoling needs force)
It gets smoothed out a bit so it’s not so harsh but yeah it dose. You would never notice it though
I wish Subaru would keep the unequal length headers just for the iconic sound and to be different. You can never mistake the WRX or STi for another turbo 4 on the streets.
If they used two headers, that connected to two parallel pipes, it would proabably sound the same. Take cyl1 and cyl four as one header, and cyl2 and cyl3 as another header, 1&2 would have a longer way to get to the piping, than 3&4, given the pulse rate of a 1-4-2-3 , it would probably have even more of a burble.
Do boxer engines number their cylinders from the back of the engine? I thought normally engines number them from the front, right? If they do number them from the back: “oh Subaru, stop being so quirky” :P
Front right is 1, front left is 2 Rear right is 3, rear left is 4
I don’t quite buy the idea of the exhaust with uneven headers vs the equal length being what causes the rumble, so to speak. I actually believe that the VW boxer has a much more pleasant note and find that true whether it uses the peashooter exhaust or a header. The only difference between the motors is the firing order. VW uses a 1-4-3-2 order. The Subaru sounds to me like its misfiring all the time. I do not like it whatsoever!
You can’t really compare an air-cooled beetle engine developed in the 1930’s to a turbocharged subaru engine, the only similarity between the two engines is the piston layout
oke so, you save weight on headers 2 and 4 of the left hand drawing. but you gain weight by the length of headers 1 and 3. It look equally heavy. I looove the sound but i don’t see any advantage.
The drawing is deiceiving in this case. The runners on 2 and 4 cannot be shortened so basically you end up just making 1and 3 longer on an actual Subaru. The issue with the picture is that the turbo moved from the right side of the engine to the center. This isn’t actually accurate as Subarus actually have their turbo on the right side (there’s a transmission in the center lol). He moved the turbo to the center for the second picture to make the drawing simpler. Real subaru equal length headers are very complicated in design and he couldn’t draw them as easily or clearly.
Why eneven headers? Weight reduction.
So, if we use 2 pipes instead of one… we can shorten the length of the 1 and 3 headers… and then this way we do not lose out the heat and pressure on the turbo… is this how the twin scroll turbos work?
Unequal length headers, hence why the sti sounds savage and the brz sounds awful.
Talking about uneven exhaust pulses…even an old fiat 127 can sound decent with it…2 pistons removed due to seized crankshaft bearing so the engine only fires at 180/540.
Comments
I figured this out a while back, then made a header for my car lengthening 2 of the cylinders. And boy did it work! I have since turbocharged my car and made the manifold utilizing the same principle and now it sounds just like a wrx. The rumble, the wirring, and the woosh. It’s great!
Does that make the turbo run weirdly? Cause the air hit the hot part of the compressor in a unequal way
No, there is always pressure in exhaust manifold created by turbo resistance (spoling needs force)
It gets smoothed out a bit so it’s not so harsh but yeah it dose. You would never notice it though
I wish Subaru would keep the unequal length headers just for the iconic sound and to be different. You can never mistake the WRX or STi for another turbo 4 on the streets.
If they used two headers, that connected to two parallel pipes, it would proabably sound the same. Take cyl1 and cyl four as one header, and cyl2 and cyl3 as another header, 1&2 would have a longer way to get to the piping, than 3&4, given the pulse rate of a 1-4-2-3 , it would probably have even more of a burble.
Do boxer engines number their cylinders from the back of the engine? I thought normally engines number them from the front, right? If they do number them from the back: “oh Subaru, stop being so quirky” :P
Front right is 1, front left is 2
Rear right is 3, rear left is 4
I don’t quite buy the idea of the exhaust with uneven headers vs the equal length being what causes the rumble, so to speak. I actually believe that the VW boxer has a much more pleasant note and find that true whether it uses the peashooter exhaust or a header. The only difference between the motors is the firing order. VW uses a 1-4-3-2 order. The Subaru sounds to me like its misfiring all the time. I do not like it whatsoever!
https://youtu.be/PGykinGlPno
You can’t really compare an air-cooled beetle engine developed in the 1930’s to a turbocharged subaru engine, the only similarity between the two engines is the piston layout
oke so, you save weight on headers 2 and 4 of the left hand drawing. but you gain weight by the length of headers 1 and 3. It look equally heavy. I looove the sound but i don’t see any advantage.
The drawing is deiceiving in this case. The runners on 2 and 4 cannot be shortened so basically you end up just making 1and 3 longer on an actual Subaru. The issue with the picture is that the turbo moved from the right side of the engine to the center. This isn’t actually accurate as Subarus actually have their turbo on the right side (there’s a transmission in the center lol). He moved the turbo to the center for the second picture to make the drawing simpler. Real subaru equal length headers are very complicated in design and he couldn’t draw them as easily or clearly.
Why eneven headers? Weight reduction.
So, if we use 2 pipes instead of one… we can shorten the length of the 1 and 3 headers… and then this way we do not lose out the heat and pressure on the turbo… is this how the twin scroll turbos work?
Unequal length headers, hence why the sti sounds savage and the brz sounds awful.
Talking about uneven exhaust pulses…even an old fiat 127 can sound decent with it…2 pistons removed due to seized crankshaft bearing so the engine only fires at 180/540.
https://youtu.be/GcKNt6QxEYE?t=80