Open dump is awesome. I love mine.

 

im going with a fpred (trying to upgrade to black) set-up and my goal is to hit atleast 470+ on pump gas with the red... or 490+ pump gas with the black...

 

Out of Car:
http://www.youtube.com/watch?v=jtSInSunjTw

In Car:
http://www.youtube.com/watch?v=rMuOwkZ_yYs

2005 OEM Turbo, EPM O2 Dump, DC Sports DP/Apexi GT-Spec Catback.

 

dump doesnt sound as bad as most people make it seem... =\

 

Its echoing off all the things around that speedway. Make no doubt. It is loud. But only at WOT.

 

i love seeing wrx's open gate at 2000rpm. kinda screams yes my car is slow. but if you hear a car get on it, then seconds later a gate open.... well thats a whole other bag of worms.

 

Open dump external typical has a loud "hollow" sound to it...

Dyno tests have proven that external dump beats internal by several HP everytime though. Usually by around 5whp at least too...

 

Read this post from Buschur. He tested the Shearer dump.

https://www.evolutionm.net/forums/7373636-post55.html

 

OEM O2 v. EPM O2 on my car:


Made a difference.

 

There are some dyno test on diff o2 housing in the dyno section. I don't mind the noise I drove a 70mm single exhuast js racing s2k for a while

 

OPEN is FTW!

You only hear it when you want to anyhow!

I have no problem driving around town and even getting on the freeway without it opening and this is with fast spooling stock turbo.

 

Were those graphs with no other changes than o2 housing smike? Seems rather..drastic for such a minor mod.

 

Our blue shop car isn't that loud at all in comparison to the recirculated o2. Just like an aftermarket catback, it's only loud when you get on it. If you already have an aftermarket exhaust system then the added sound is minimal in comparison.

It may not be for the guy running a stock exhaust but for most other people I think the noise isn't bad at all.

 

Same PSI and adjusted my timing/fuel maps.

 

By chance, does anyone know if an open dump would exceed 100db? It obviously depends on a lot of factors, but I'm specifically getting at the impact on AutoX sound restrictions.