The Civic Type R Exhaust

[JDhonda]

That middle exhaust pipe has a function that might surprise you

A detail of the Type R’s design many have picked up on is the unusual exhaust layout. Gone is the quad exit of the FK2, replaced with three centre-mounted pipes, with a smaller one in the middle of the trio. So is it just an aesthetic thing? Were the designers massive Ferrari F40 fanboys? Well no, actually. To explain what it does, let’s hand over to Kakinuma-san:

“The three tail pipes each have a function. At low RPM exhaust gas is streaming out of all three pipes in order to create a very dynamic, ‘roaring’ sound. At mid and high RPM, the middle pipe creates a certain negative pressure, which reduces the booming noise in the cabin. We can amplify the exhaust sound, but by controlling the exhaust flow we can also reduce the noise we want to avoid in certain operational conditions.”

This is jolly good news. The outgoing Type R didn’t have a particularly exciting exhaust note, and on long motorway journeys, the booming of the pipework did get particularly irksome. So if it’s been reduced, it’s another sign - along with the much improved trip computer system found on the standard Civic hatch and the new comfort driving mode - that the new Type R will be much, much easier to live with than the old one.

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[the1dynasty]

Just saw this posted a bit ago...

 

[17CivicTypeR_Brian]

We all know the 20'' wheels serve no purpose other than show. Honda can say whatever marketing BS they want lol.

It will affect steering feel...
I don't think it will be as much of a problem as most people think.

 

[bobafettm]

It's more so about tire costs and options that limit us with the 20s...

I'm excited to hear more of this exhaust!! The FK2 was so disappointing to me through youtube videos... Even with aftermarket exhausts.

 

[ayau]

It's more so about tire costs and options that limit us with the 20s...

I'm excited to hear more of this exhaust!! The FK2 was so disappointing to me through youtube videos... Even with aftermarket exhausts.

Correct. Look at tire options for 20" then look at tire options for 18". It's night and day. There aren't any extreme summer performance tires in 20", which is what this car is made to run.

 

[Browncoat3000]

Just saw this posted a bit ago...

We need a whole new thread about this!

"Honda hinted at a faster Type-R... a 'club-sport' version with 330hp."

Whaaaat?

 

[bobafettm]

We need a whole new thread about this!

"Honda hinted at a faster Type-R... a 'club-sport' version with 330hp."

Whaaaat?

Which is a good thing because it means Hondata will be able to do this for us with no mods other than an ECU flash

Imagine what this car would be capable of with removing USA regulation exhaust plus a tune!

 

[Phosky]

Geez, that's like 50-60lbs worth of dead weight that can be replaced by a straight pipe right off the turbo.

 

[Browncoat3000]

Don't over think the exhaust. It's very clever, and like most very clever things, it's quite simple.

It's using a bit of old school aerodynamics, or in this case a more accurate description is a wind instrument like an trumpet. Actually the most accurate analogy would be a bagpipe since it's 3 sound makers supplied by a single source.

The object you see in the middle pipe is a baffle, or a restictor, that turns the middle pipe into a Venturi to use the technical name. In this case it makes the middle pipe function like a passive valve.

At low pressure (low power) the middle pipe's restriction makes it harder for the gas to go through that pipe, thus more gas takes the easier path through the other two ducts. That extra airflow makes the car sound louder at low rpm.

When pressures build (at higher RPM), the gas flow overcomes the restriction, and this is the counter intuitive part, the center pipe begins to create a Venturi effect; a negative pressure or vacuum, that sucks off gas flow from the two larger pipes, thus reducing the sound levels at high power.

If you've played a wind instrument you've experienced this; it takes an initial surge of pressure to get the instrument to sound, but once it does start, it requires a lower pressure to keep it going.

For the math inclined, lets make a number analogy. These are totally made up by me strictly for illustration:
At low RPM, 0-50%, exhaust air would be something like 95%through the 2 large pipes, 5% through the center. However at 100% RPM, you'd see closer 30% through the center and 70% through the mains.

As I mentioned, this is old tech. Early pressurized airplanes used a version of this idea to regulate cabin pressure. In fact, it's still in use on light pressurized piston aircraft. If you follow the musical instrument analogy, bagpipes go back at least 5000 years.

The whole thing would have been quite fiddly to get set up, actually more art than science at some point, which would explain the sloppy tig-weld in the video. But once you got it all tuned up, easily reproduced and 100% reliable as long as the components don't rust.

 

[17CivicTypeR_Brian]

Which is a good thing because it means Hondata will be able to do this for us with no mods other than an ECU flash

Imagine what this car would be capable of with removing USA regulation exhaust plus a tune!

I think I saw a video of a white TypeR in France (previous generation) doing like 360 on a dyno. Modded/flashed I'm sure but still on gasoline I'm guessing. E85 is typically good for a 30-40% bump on top of whatever the gas is able to make...

 

[17CivicTypeR_Brian]

BTW I'd love to be able to get an electronic external wastegate on this buggy... basically a dual wastegate setup for different situations.

 

[pie]

Don't over think the exhaust. It's very clever, and like most very clever things, it's quite simple.

It's using a bit of old school aerodynamics, or in this case a more accurate description is a wind instrument like an trumpet. Actually the most accurate analogy would be a bagpipe since it's 3 sound makers supplied by a single source.

The object you see in the middle pipe is a baffle, or a restictor, that turns the middle pipe into a Venturi to use the technical name. In this case it makes the middle pipe function like a passive valve.

At low pressure (low power) the middle pipe's restriction makes it harder for the gas to go through that pipe, thus more gas takes the easier path through the other two ducts. That extra airflow makes the car sound louder at low rpm.

When pressures build (at higher RPM), the gas flow overcomes the restriction, and this is the counter intuitive part, the center pipe begins to create a Venturi effect; a negative pressure or vacuum, that sucks off gas flow from the two larger pipes, thus reducing the sound levels at high power.

If you've played a wind instrument you've experienced this; it takes an initial surge of pressure to get the instrument to sound, but once it does start, it requires a lower pressure to keep it going.

For the math inclined, lets make a number analogy. These are totally made up by me strictly for illustration:
At low RPM, 0-50%, exhaust air would be something like 95%through the 2 large pipes, 5% through the center. However at 100% RPM, you'd see closer 30% through the center and 70% through the mains.

As I mentioned, this is old tech. Early pressurized airplanes used a version of this idea to regulate cabin pressure. In fact, it's still in use on light pressurized piston aircraft. If you follow the musical instrument analogy, bagpipes go back at least 5000 years.

The whole thing would have been quite fiddly to get set up, actually more art than science at some point, which would explain the sloppy tig-weld in the video. But once you got it all tuned up, easily reproduced and 100% reliable as long as the components don't rust.

Millennium falcon driver indeed. Appreciate the info from someone who knows what they're talking about! The new nür footage on the other thread still makes it seem pretty loud when pushing it

 

[Evo]

The Lancer evolution has a huge issue with a boomy exhaust and the STI sort of did, refreshing not to have to deal with that

 

[the1dynasty]

good info @Browncoat3000 now only if we had some exhaust video samples

 

[NoelPR]

Correct. Look at tire options for 20" then look at tire options for 18". It's night and day. There aren't any extreme summer performance tires in 20", which is what this car is made to run.

Correct. I made a similar statement on the Type R reveal thread and I got flamed. Glad that people are starting to get it now.
Is non-sense. Lets see how this ends for the USDM version.

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