What's the outlet of the stock o2 housing? 2"?

I could see a 3" downpipe being beneficial if you got a recirculating o2 housing that has a 3" outlet. I know there are gains with a 3" downpipe with the stock o2 housing, but it would seem not near as much as 3" all the way through.

I still think the dump is the way to go. Someone who's about to upgrade and get tuned needs to do before and after. A tune with higher egt's such as a 93 octane tune will really pick apart the differences. E85 burns cooler which is all the more reason to convert.

 

An o2 dump, when you think about simple air flow, should work. no disturbance of flow after the turbo from recirculation, and it flows much more freely. Some people argue that the reason dumps make more power is because they tend to qutomatcially increase boost and that's where you see the power gain. Others swear by them.

I'm no tuner so I don't really know what I'm talking about, but I love my o2 dump. I put a JMFab o2 dump on my first Evo (5 hours labor on Christmas day in the cold, yay!), and then the new EVO, the previous owner had installed an EPM. I prefer the JMFab, I just don't want to go through that install again I like the sound. ALTHOUGH, there are times I drive my dad's bone stock MR where the quite exhaust is nice to accelerate with just a whisper

 

Exactly. In turbo theory, it should be better. Whether or not in real time testing it's better, is still to question.

 

^ IT IS BETTER! STOP ASSUMING ANYTHING. IT IS A LOT BETTER. I think it is worth 15hp on stock turbo and over 30hp on a Red or Black. If you don't believe me or take my word then do it yourself and tell me what you think!

The Shearer 02 dump gained 20hp over a Megan 02 housing. There are logs of that.

There should be no question!

Mikey

 

That's what I like to hear

 

^ I'm glad