FL5 stock exhaust valve: Fuse pulled/always open - exterior sound clips

[Daniel Boffa]

I couldn't agree more with what @fredzy regarding this mod improving the sound and feel of the car and therefore helping set off. It was too quiet before which meant even though I may have been pushing the throttle I couldn't actually hear or feel it in the low RPM range which meant in order to let the clutch out id have to look down. I guess this is a biproduct of refinement! Regardless, with the valve open it increases NVH just the slightest amount which improves both feel and sound. I couldn't recommend this enough.

I'd also like to add my 2 cents on the issue brought up in this thread about the car stuttering/hesitating. This happens in my car when it is not fully warmed up both before I pulled the fuse, after I pulled the fuse, and again this morning when I tested it again with the fuse back in. So you are not alone in that feeling. In my opinion I don't think it is anything to worry but time will tell.

Ultimately lets recognize that the folks who mentioned this had good intentions in attempting to alert others in the community of a potential issue and should absolutely be appreciated. However, you have to exercise caution when stating things as fact that are not tested and proven, instead look to confirm with others and/or experts. I think we can agree that guessing at what the engineers may have intended is not a valid basis of argument. You could however, ask exhaust manufacturers what they are finding in their extensive testing of systems both with and without the valve, or even ask people who run those systems.

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[Imped]

I couldn't agree more with what @fredzy regarding this mod improving the sound and feel of the car and therefore helping set off. It was too quiet before which meant even though I may have been pushing the throttle I couldn't actually hear or feel it in the low RPM range which meant in order to let the clutch out id have to look down. I guess this is a biproduct of refinement! Regardless, with the valve open it increases NVH just the slightest amount which improves both feel and sound. I couldn't recommend this enough.

I recommend the PRL RMM for just a little more positive NVH. Combined with the open valve, you'll really enjoy things.

 

[fj80psi]

Thanks for the tip. This am I removed the small Resonator and opened the valve. The Exhaust is very controlled and deep. Sounds great for a daily driver!

 

[f22xclusive]

I put my fuse back in last night. I've noticed a few quirks during cold start driving that could be attributed to the valve being open. There has to be a reason Honda kept the valve closed at low RPM in +R mode since even with it open it's not that loud. On cold starts all of the exhaust is coming out of the center pipe which could change the flow and the car is trying to compensate.

This is all a theory and I'll report back after some more driving.

I plugged my fuse back in as well. I noticed the turbo took too long to spool up. Perhaps the two small ports are there to help build exhaust velocity for a faster turbo spool up

 

[f22xclusive]

I decided to put the fuse back in. I have followed this topic but I didn't think I had any issues to be honest.

I had moments every now and again where I felt hesitation. Twice I felt like... did I just drop my clutch?

Now that the fuse is back in... call me crazy but I feel like the car is happier for it. There is a smoothness that I didn't notice I lost but now that the fuse is back in, it feels like a welcome addition.

Could be all in my mind but I'm certainly convinced.

I had the exhaust valve fuse pulled for a few days and it felt to me like I had to give it more throttle to get off first gear. Putting the fuse back in felt much more responsive. I’d like to see a dunk run showing if the engine builds power sooner with the fuse in compared to without. It felt to me like the car took too long to build up boost while driving also.

 

[f22xclusive]

Sorry I did not mention the increased flow, my bad thought it was obvious. Its there for sound, simple as that. The previous gen did not have a valve so the increased flow was already there. I’m not trying to sound smart and neither am spewing BS. I guess the engineers forgot to put the valve on the FK8. Must have been an oversight on their part but they can’t be wrong because they are engineers. Not everything they make works just fyi.

Have it your way, its apparent that I struck some chords with some people and you are obviously upset. Do what works for you, I will live happily with a deleted valve and enjoy my warm weather without a shuddering car. Not going to waste my time on this anymore. I will just sit back and watch.

The FK8 had 3 tips but the center had no flow through it. Therefore it only ran exhaust out the 2 side ports.

 

[Jester04]

The FK8 had 3 tips but the center had no flow through it. Therefore it only ran exhaust out the 2 side ports.

I know the center section was not functional of the FK8, but either way it won’t affect anything. If not people would be having issues left and right with exhausts.

If you feel more comfortable running the valve run it like that. But it really does not make a difference in behavior.

 

[TypeRD]

@Jester04 knows best

After my initial excitement (placebo effect) running fuseless for several months, I put the fuse back in and neither felt nor heard any considerable difference. I just run it as-is (fuse in) now and enjoy less soot build-up on the center exhaust tip.

 

[TDC50]

Fuse out for several thousand miles and various weather conditions with no I’ll effects. I like the consistency in exhaust sound by just having the valve open all the time.

 

[f22xclusive]

I've had my AWE since October, and I can report zero issues.

It looks like AWE utilizes one port even though it has a triple tip. I can’t say because I’m on factory exhaust but from what I’ve seen, it looks like they’re built that way. That’s like the FK8 OEM exhaust. 3 tip exhaust but it’s not using the center exhaust at all.

 

[f22xclusive]

I know the center section was not functional of the FK8, but either way it won’t affect anything. If not people would be having issues left and right with exhausts.

If you feel more comfortable running the valve run it like that. But it really does not make a difference in behavior.

This is gonna be an ongoing battle with people saying “run it open” to “keep it OE” due to possible running issues. I want to see a dyno test with and without the valve open. That will determine if it makes a difference in performance or not. The dyno test will definitely show if there’s a loss in power or a delay in power on low RPMs or not.

 

[fredzy]

This is gonna be an ongoing battle with people saying “run it open” to “keep it OE” due to possible running issues. I want to see a dyno test with and without the valve open. That will determine if it makes a difference in performance or not. The dyno test will definitely show if there’s a loss in power or a delay in power on low RPMs or not.

If you mean typical power pulls on the dyno I don't think it will show anything because the the valve will be open through most of both pulls. I don't know that you could run a meaningful test on a dyno to capture possible subtle differences in low end/part throttle power.

 

[modern_sports_car]

And what is the process for re-activating it?

 

[Nothing]

And what is the process for re-activating it?

Plug the fuse back in the same spot and cycle the ignition.

 

[modern_sports_car]

Plug the fuse back in the same spot and cycle the ignition.

I’m not sure what the original instructions were—or if they even changed—but I think I pulled the fuse and maybe cycled ignition and put it back? It’s possible I did it wrong and it never worked to begin but I didn’t need to put it back because it was still plugged in. I feel like I’m being incredibly dense, here.

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