There’s a Reason Honda Made Active Exhaust, Don’t Disable

[Jester04]

You would know better than me but it was my understanding the valve functions the same in all engine modes and is based on load, RPM, and throttle position only. I think it was AWE that stated they found this in their exhaust testing.

Check my post above, posted a bunch of data. The valve is controlled by throttle position and rpm. But each mode has a different requested command for the valve. Load is not taken as a factor that is why the valve will open on revving the car on standstill.

Value 0 valve closed
Value 100 is 50% open
Value 200 is 100% open.

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[CTR]

Ah I understand the different images in your post now. Thank you!

Is the engine calibration that much different in +R engine mode vs. Comfort? I hate the throttle response in Comfort engine mode but I use it frequently when the roads are wet to make the car easier to drive.

I know there are a lot of theories but could the valve function have more to do with how well it performs in that particular calibration? Can you confirm if the ITS keeps the valve open 100% of the time in Sport+ mode?

 

[GJPEN]

Ah I understand the different images in your post now. Thank you!

Is the engine calibration that much different in +R engine mode vs. Comfort? I hate the throttle response in Comfort engine mode but I use it frequently when the roads are wet to make the car easier to drive.

I know there are a lot of theories but could the valve function have more to do with how well it performs in that particular calibration? Can you confirm if the ITS keeps the valve open 100% of the time in Sport+ mode?

Ah I understand the different images in your post now. Thank you!

Is the engine calibration that much different in +R engine mode vs. Comfort? I hate the throttle response in Comfort engine mode but I use it frequently when the roads are wet to make the car easier to drive.

I know there are a lot of theories but could the valve function have more to do with how well it performs in that particular calibration? Can you confirm if the ITS keeps the valve open 100% of the time in Sport+ mode?

 

[Jester04]

Ah I understand the different images in your post now. Thank you!

Is the engine calibration that much different in +R engine mode vs. Comfort? I hate the throttle response in Comfort engine mode but I use it frequently when the roads are wet to make the car easier to drive.

I know there are a lot of theories but could the valve function have more to do with how well it performs in that particular calibration? Can you confirm if the ITS keeps the valve open 100% of the time in Sport+ mode?

Yes the torque target requests change on drive mode so the throttle will feel more vague or slower responding in comfort compared to sport or R+.

The valve is closed for longer in comfort that is for sure so that would have to be tested to confirm 100%

With tuning you can get the throttle response to be snappier in comfort.

I can check for you tomorrow for the Type S

 

[GJPEN]

I really no nothing about this to make any particular argument about what it is or is not. I know I’m not crazy and the car Behaves differently with the active exhaust outside of sound. I don’t know if a dyno is the right way to measure this or another way to.

May there is another tool: It kind of grinds my gears people saying it’s placebo or your imagining it. I’m glad some people confirm my feelings that something is different with throttle behavior. Maybe your car didn’t do it? Maybe you didn’t feel or notice it? Doesn’t make either of us better or worse.

This argument reminds me of audiophile groups I used run around with. Solid State guys would sayIf I can’t measure it in frequency response a certain way it doesn’t happen. Tube guys would say bullshit you’re not measuring the right thing., ie distortion.

 

[thatonedaveguy]

A dyno is probably the best way to tell. It's definitely possible that the primary reason Honda did it was to try bridge the gap for the car needing to be quiet in certain scenarios and sporty(louder) in others- and the car needed to fit requirements across a wide range of markets.

Big open exhausts can definitely have an impact on engine feel vs a more restrictive one but I'm not qualified to say what the difference between the middle pipe being opened vs closed will be. It's possible in some scenarios a difference would be noticed but I doubt it will cause any damage or issues of any kind what people choose to run. It probably will all boil down to a preference of sound.

Dyno is best way to get a scientific result.

 

[Jester04]

I really no nothing about this to make any particular argument about what it is or is not. I know I’m not crazy and the car Behaves differently with the active exhaust outside of sound. I don’t know if a dyno is the right way to measure this or another way to.

May there is another tool: It kind of grinds my gears people saying it’s placebo or your imagining it. I’m glad some people confirm my feelings that something is different with throttle behavior. Maybe your car didn’t do it? Maybe you didn’t feel or notice it? Doesn’t make either of us better or worse.

This argument reminds me of audiophile groups I used run around with. Solid State guys would sayIf I can’t measure it in frequency response a certain way it doesn’t happen. Tube guys would say bullshit you’re not measuring the right thing., ie distortion.

Well don’t let it grind your gears. Just run what makes you happy. I’m just posting the data, also you never mentioned which mode you were running. Anything on R+ after 2300rpms starts opening the valve. So it is essentially open before even building boost.

So there is literally no way it can make a difference in that mode. Now on the other ones you do have valve closure for longer.

Also nobody here is better or worse either. Nobody has said that.

The only thing I can think of is that if the valve was closed and was actually hurting power and then it opens it would make more power and thus give a feeling of surge. But like I said a dyno would be needed.

 

[spectre186]

Not attacking you at all. I’m just trying to make sure people are informed correctly.
People could see your post and then immediately be turned off to trying their exhaust with the valve open, or be hesitant to buy an aftermarket exhaust.

If the car feels better a certain way to you, that’s cool man, that’s your personal opinion.

But, your thread title is literally telling other people what they should be doing…That’s the only reason I popped in here.

 

[Noize]

Early FL5s using Hondata had a tuning issue that made the car run like total crap from cold start at low/mid RPM for a couple minutes due to excessive intake cam advance.

This was obvious, however, and hard to miss.

I believe it has since been rectified, but sold my 23 and haven’t jailbroken my 24 yet. Love Hondata, but want to make sure it’s fixed before I consider tuning this one.

 

[Jester04]

Early FL5s using Hondata had a tuning issue that made the car run like total crap from cold start at low/mid RPM for a couple minutes due to excessive intake cam advance.

This was obvious, however, and hard to miss.

I believe it has since been rectified, but sold my 23 and haven’t jailbroken my 24 yet. Love Hondata, but want to make sure it’s fixed before I consider tuning this one.

The software has been constantly improving, lots of new features as well.

 

[Jester04]

Ah I understand the different images in your post now. Thank you!

Is the engine calibration that much different in +R engine mode vs. Comfort? I hate the throttle response in Comfort engine mode but I use it frequently when the roads are wet to make the car easier to drive.

I know there are a lot of theories but could the valve function have more to do with how well it performs in that particular calibration? Can you confirm if the ITS keeps the valve open 100% of the time in Sport+ mode?

Here are the factory Integra type S settings.
They are even more aggressive than the type R.

 

[GIChoe]

I've been running with the fuse removed and valve open for about two weeks, and while I don't have any hard numbers since I never dyno'd the car under these two different states, I can definitely say it feels worse. When I'm in 1st or 2nd gear and going from about 3k to 4.5k RPM, the engine just feels rougher; I can feel it through my pedals and wheel. When I put the fuse back, it feels as smooth as I'm used to.

 

[Jester04]

I've been running with the fuse removed and valve open for about two weeks, and while I don't have any hard numbers since I never dyno'd the car under these two different states, I can definitely say it feels worse. When I'm in 1st or 2nd gear and going from about 3k to 4.5k RPM, the engine just feels rougher; I can feel it through my pedals and wheel. When I put the fuse back, it feels as smooth as I'm used to.

Any information on the drive mode?

 

[GIChoe]

I'm always running in Individual mode: engine set to sport, suspension/steering/engine noise set to comfort.

 

[type r fanatic]

Sorry forgot to post about it.

Stock exhaust valve values respectively for
Comfort
Sport
R+

Dyno testing on my stock car with just an intercooler and valve completely open showed peak torque at around 3,300-3600 rpms starting the pulls at around 2,200 rpms. The valve opens half way at 2300rpms in R+ and shortly after it opens up completely.

So there is literally no way the valve is closed during spool up unless you are lugging the engine in 6th gear at like 1500rpms.

I will gladly give a discounted tuning price for whoever has a stock turbo car that is willing to dyno the car. To test this theory out, I can no longer try it out since I don’t have a stock turbo anymore.

I will close your valve on a pull and then one with fully open.

Here is the log for the dyno on my car on stock turbo with no mods aside from intercooler. The valve is already halfway open already in the programming and it still has not built boost. Even though I had my valve open it still applies that the valve is already bypassing most of the exhaust gas through the center section.

Thanks for the charts. Do these correlate to the "Engine" setting or the "Engine Sound" setting? I haven't found a definitive answer on which setting changes the valve behavior

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