View Full Version : Benifits of porting exhaust housing.
03-09-2007, 12:01 AM
So, is there a real benefit to porting the exhaust housing. If so, what is it? Porting the head makes perfect sense, but the housing??? Would one not have to port the exhaust manifold to make the most of it? Input from those who have done this would be great!
I don't know if we're referring to gasket-matching as porting, but that's what I did to my 16cm before installation. I noticed the thing was nowhere near (almost 1/8" off one side) matching the manifold, so I got the dremel tool going and cut out quite a bit of material to get the thing matched up to where it would have the best flow with no obstruction. Is that what you're talking about?
Porting heads is a whole different ballgame.
03-09-2007, 12:49 AM
Gasket matching is always good, but I see alot of guys going to town on the intake of the exhaust housings with the die grinder, seems vain to me.
03-09-2007, 07:06 AM
I read, and it makes some sense to me, that porting and polishing aids in no and low boost conditions. After the turbo spools up the advantage is reduced.
03-09-2007, 07:14 AM
I hogged my 12cm based on what member got...diesel? did with his to enlarge the wastegate when going to twins. He ended up being able to use a 35/12 hybrid very effectively without an external wastegate, which is my end goal as well. All things being the same, my 12cm will presently hold the engine to a comfortable 30psi whereas before the hogging (which included enlarging the wastgate hole to nearly the size of the flapper itself) I could easily overcome the wastegate and push nearly 40psi. Definitely a worthwhile BOMB for me:)
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