Whats the exaust flap do?

[Farmer_dave]

I just noticed after owning the car 18 months, that the crappy standard twin exit muffler on my gt-t has a flap in one of the tips that is operated by a cable what does it do? what operates it?????????

[Ebola_One]

It's probably there to close off one of the tips to keep low down response up, and then at Xrpm it opens up to allow the higher flow rates thorugh.

The new Integra Type R's have a similar "flap" but instead of blocking a tip off, it opens a shorter route from inlet of muffler to exit. The Type R one is activated when there's a certain amount of pressure in the muffler.

It'll probably help to keep noise down a little too.

[AceSniper]

AE111 20v's have a flap system in there (what iv seen on diagrams) sorta working the same as the twins on AE101's opening up in higher revs

[Farmer_dave]

So no advantage in making it open all the time then oh well.
Well at least I know kinda what it does now still dont understand how restricting the exaust helps but oh well.
Thanks for the help guys.