What one is better? Benefits of both.
I'm looking at doing bolt-ons on my evo 8 and can't find any solid info. (tried searching)
Looking for most efficient and most power making bolt-ons. Any links or info will be apreciated.

Oh and things I decided on already are:
Ets fmic
Bigger pump/inj (e85)
Porting exhaust manifold.

Car has gsc s2 cams and tsudo exhaust.

Thanks for all the help

 

A dump will most likely yield the most power since it has more exhaust volume aka "less restriction" with the only downside beign noise due to the open dump,i used a Muse O2 dump which i think is a great value for the money,on the other hand if you go with a O2 housing it will be quieter since there is no dumping to atmosphere,however you'll be limited to a max of 3" on the biggest of housings,Lipp 3" comes to mind,but most of them are of the 2.5" to 2.9" versions including the Megan and Invidia housings,if you get a O2 dump make sure you get a fully divided housing gasket with it.

 

Im running stock turbo. Thinking of jmf dump or o2 eliminatIng downpipe.

 

i gained more hp on the dump,, and to be honest its really not annoying like some people say , on the wot u can hear it other than that u really cant ,,

 

I am running an Evo IX turbo with the FP antisurge cover, and a ported hotside. I have the JMF O2 Dump, and I have zero control over my boost. The least amount of boost I can run is 26psi. I have removed my boost contoller, I went back to the stock IX WGA. I adjusted the preload way out, and now the turbo is lazy, and still runs 26psi no matter what. I can only go up in boost.

For most people this is not a huge issue however for me I like to road race my car, and I need to get the boost down to about 20-21psi, to get the HP and TQ.

For a stock turbo I would recomend you stay with a standard O2 Housing. The dumps are cool as hell but you will have zero control of your boost.

 

^ how is the post turbo exhaust not letting you controll boost?

I have grimmspeed ewg (Vta) on my rsti, so I'm familiar with noise.


Anyone has hp number gained with o2 hosing vs stock and vs dump.?

 

They're both great choices imo,i've tuned cars with both and i preffer the dump for max power and the noise it's not really as bad as you might think,be aware if you buy the one piece housing and downpipe that it will be in the way for basically anything you work on under the engine since you can't remove the downpipe anymore.

 

^ how difficult is it to remove 1 piece unit? That might be a deciding factor.

 

The wastegate dump, cannot vent enough pressure. So that pressure will continue to increase boost, until the effencicy falls off enough.

I might try to port my even more and see if that helps, but for now I am either going to make my own o2 housing or switch to a titek.

 

I like the discussion here.

I have been battling creep issues with a ported Megan 02 housing with a ported BBK-Full on a 2.3l. I believe that there could be the possiblity of not enough restriction on the 02 side which could actually some weird turbulence/backflow or whatever it maybe. I wouldn't know unless some engineer type looked at it in CFD or something like that. I had to work around the creep by running more boost...weird how that works.

I know that some DSM owners ran into creep issues with 3" exhaust setups.

 

It is a pain in the *** since you would have to unbolt the piece right from the back of the turbo just like a housing,not a fun job,

 

I think your problem might actually be too much restriction and may be fixed with a true 3" housing or a dump,since the housing has only one outlet the individual exhaust and wg port sizes don't matter as much as overall main outlet size,specially running a 2.3 with a decently sized turbo as the BBK might be producing too much exhaust flow for your housing to expel efficiently creating boost creep.I've tuned cars with O2 dumps and never really had any creep issues specially if they were contoured properly on the wg side as the MAP and the Muse are.
http://www.maperformance.com/maperfo...2h-ss-evo.html

 

There are some threads saying anything from 25-80 hp gains from switching to a dump,like anything else take those with a grain of salt i've seen an average of 15-30 "real" hp increase in the cars i've had to deal with.

 

Thanks on all the info. Yeah I'm not looking for unrealistic power gains.

Does the dump help with spool up at all?

Now I'm on a hunt for jmf dump

 

My muse o2 dump runs low boost on my 71 hta. Its designed well

Megan racing o2 was horrible for boost control. Crept to 23+ psi even ported.

Spool no, depending how bad your current set up is holding you back it will clean up some power. I didn't gain much power just boost control.