Incidence of Stock Muffler and CAN Flap on Overall Sound

[user2688]

Hey guys, I'm currently running a completely stock exhaust except for catless downpipes. My goal is to be able to switch from a low profile exhaust note to something ridiculously loud with the push of a button. I've thought about doing a cutout but I don't want to get surgical with the car and add components that could possibly fail.

I guess I'd go with N55 midpipes and keep everything else stock, that way I could have the flap on auto when daily driving and keep it open when i feel like it.

Question is... is that flap really that effective at masking sound? With catless downpipes and N55 midpipes It's pretty much a straight pipe setup until you hit the muffler so it doesn't get any louder than that(unless you install cutouts after the downpipes!).
In theory, should sound like an N55 with catless downpipes... or close? See:
http://www.1addicts.com/forums/showthread.php?t=559978


I remember seeing a thread a long time ago with either a diagram or an actual picture of how the stock muffler works (with the CAN flap). Link anyone?

I don't know which way I want to go... I want more sound but at the same time I love the flap concept + coppers will be giving me tickets all summer for the swapped muffler.

Could a custom setup be made that would use the CANflap actuator to open up a cutout at the 2-1 collector? I guess that's wishful thinking...

[str8shot]

Originally Posted by user2688

Hey guys, I'm currently running a completely stock exhaust except for catless downpipes. My goal is to be able to switch from a low profile exhaust note to something ridiculously loud with the push of a button. I've thought about doing a cutout but I don't want to get surgical with the car and add components that could possibly fail.

I guess I'd go with N55 midpipes and keep everything else stock, that way I could have the flap on auto when daily driving and keep it open when i feel like it.

Question is... is that flap really that effective at masking sound? With catless downpipes and N55 midpipes It's pretty much a straight pipe setup until you hit the muffler so it doesn't get any louder than that(unless you install cutouts after the downpipes!).
In theory, should sound like an N55 with catless downpipes... or close? See:
http://www.1addicts.com/forums/showthread.php?t=559978


I remember seeing a thread a long time ago with either a diagram or an actual picture of how the stock muffler works (with the CAN flap). Link anyone?

I don't know which way I want to go... I want more sound but at the same time I love the flap concept + coppers will be giving me tickets all summer for the swapped muffler.

Could a custom setup be made that would use the CANflap actuator to open up a cutout at the 2-1 collector? I guess that's wishful thinking...

I believe the can-flap is only activated on cold starts. I think it's open all the time otherwise.

[Freon]

I'd just go the cutout route in your shoes. I don't think a catless and N55 midpipe car is really all that loud with the factor muffler.

[Dackelone]

Originally Posted by str8shot

I believe the can-flap is only activated on cold starts. I think it's open all the time otherwise.

No. The flap is controlled via vacuum at the rear muffler. Its OPEN on cold start AND when you go WOT full throttle. Do a search on "golf tee mod" to open the flap all the time.

You might want to look into a PE(Performance Exhaust) system from BMW. It really sounds great! And its quiet enough at part throttle cruising, but LOUD MUSIC to my ears at WOT!

[darkrom]

If you have JB4 it can leave the flap open all the time via software. I love that on my N54.

You can also just unplug a connector in the trunk for the cable.

IMO the performance exhaust is a HUGE ripoff (sorry Dack, just honest opinion). Its not very different from the stock exhaust at all once you have the flap open all the time.

[edisapimp]

Originally Posted by darkrom

Its not very different from the stock exhaust at all once you have the flap open all the time.

Lay off the crack!!

[darkrom]

Originally Posted by edisapimp

Lay off the crack!!

What is different about it? I can't seem to see what the differences really are, other than no stupid flapper valve. I could be mistaken, but no one is able to explain what else changes.

Either way for the price it seems crazy to me, but maybe there is more to it than just the axleback without flapper?

[Stvee]

Originally Posted by darkrom

What is different about it? I can't seem to see what the differences really are, other than no stupid flapper valve. I could be mistaken, but no one is able to explain what else changes.

Either way for the price it seems crazy to me, but maybe there is more to it than just the axleback without flapper?

One of the pipes in the muffler is solid rather than having holes inside the muffler. That pipe is the one with the flapper on the stock exhausts.

The other change is that it gets rid of the Y-pipe resonator.

But yeah, I agree. It seems like a waste of money for not much difference in sound.

[chris82]

the flap does nothing in sound. I've disabled it and then enabled it again a few times and don't notice anything at all. All I hear when it is enabled is that stupid clanking noise of it opening when I blip the throttle on downshifts

[Stvee]

Originally Posted by Chrisar82

the flap does nothing in sound. I've disabled it and then enabled it again a few times and don't notice anything at all. All I hear when it is enabled is that stupid clanking noise of it opening when I blip the throttle on downshifts

It does make a noticeable difference. I could definitely tell that there was more volume under 3k rpms when I did the golf-tee mod originally.

If you want to hear the difference directly, enable it, then unplug the vacuum line while the car is idling. It won't throw any codes and the difference will be very noticeable since you're right there by the pipes.

[darkrom]

Originally Posted by Stvee

It does make a noticeable difference. I could definitely tell that there was more volume under 3k rpms when I did the golf-tee mod originally.

If you want to hear the difference directly, enable it, then unplug the vacuum line while the car is idling. It won't throw any codes and the difference will be very noticeable since you're right there by the pipes.

Yeah I notice quite the difference. I can enable and disable it with my JB4...so like seconds. Its very easy to hear for me. Exhaust is practically silent until 3400 RPM or so with the flapper enabled. With it off I hear my exhaust all through the power band, and it sounds quite nice.