I removed the muffler flapper door. Pain in the *** but I like it.
Sounds little bit louder. Can't really tell. I'd say I picked up about
1 hp.

 

How did you do it? Any pics?

 

i heard that this was rumor
i would also like to see pics
i am very interested on how you did it

 

BS that u picked up anything, they put it there for a reason, hell i bet u lost power in the low end if anything......

 

I did it,but like I said it is truly a pain in the ***. It is very possible to damage inside of muffler where the flap attaches to but I got lucky, no real damage. I air hammered that mother focker out. I have been meditating on the stock muffler for quite some time now and I thoght man it's a straight through muffler if you look from the outlet but I said to my self there has to be a catch here so I looked from the inside and holy **** big *** flapper door with a lot of spring tension that prevent straight shot out the pipe. I immediately wanted this piece out but looked impossible without cutting open the muffler.

 

Sorry no pic I don't have a digital camera. but it's about 2 inches in diameter. I spit on that **** and kicked it and I thought I lost it but I found it and torched it and cut it in half.

 

Hey EVO SPEC VIII are you upset or something. I just posted here cause I thought my fellow EVO owners might be interested.
Yes they put that for a reason and as far as I can tell I have to assume that it's for sound control as I mentioned in the beginng that it got little bit louder especially at idle and at low rpm and if you interpret 1hp gain as a real necksnapping g-force inducing horsepower then you misunderstood me. And no I don't think I lost any power. Do you know why I would lose power ( on a turbo car. Not a Sentra SE-R) if so please explain.

 

so thats what that flapping exhaust noise is coming from.
i need a turboback exhaust. damn trap door stocker!

 

less backpressure equals faster turbo spooling time my friend..meaning u get more power in lower rpms.

 

less back pressure means you gain on the higher RPMs you will loose on the lower rpms

 

that's the theory for N/A applications. with turbo it is the opposite, well close to it.

 

You're correct, however in this case I think the flapper would create more backpressure and increase spool up-time. The flapper is only there to keep the db level down. And maybe to help the cat light up faster.

Good job. Evo with RFL

 

i thought thats what i said i guess "faster spooling time" may sound a little odd. but u get what im saying

 

OOOOPS, Sorry about that.

I meant to address this.