ok heres the deal i have a stock exhaust and around here the cops are kind of strict. i was wondering if haveing a o2 dump would be benifitial becuase i understand it dump's once the wastegate opens right? and waste gate opens at 12psi i think. so up untell 12 psi it would be stock sounding but once i hit the pedal to the flore it should open up giveing me some more power becuase less back pressure and be loud as f$#k.

There's a lot of debate on this, technically you are correct, but the debate is on whether or not it helps enough to improve performance noticeably, I would think that it would help more on a stock system than a system that already has a 3in downpipe back.

However I don't know of anyone makes external o2 housings with the stock flange size going into the downpipe, so you would have a 2.5-2.75" hole trying to feed into the 2.25" (I think) downpipe.

Your best bet if the cops are that strict might be to unbolt the cat from the downpipe and install a muffler right there for less exhaust restriction, that's what I'm doing and it's pretty nice, I did have to remove my heatshield though. Then you can leave the rest of the exhaust on and it will be stock appearing.

02 dump is a waste of time, IMHO. You will also attract every cop within a 1/2 mile radius.
A stealthy turboback exhaust with twin tips will attract much less attention with little restriction.

did you read the whole thread im doing this so the cops wont notice me so it will be quite up untell i get past 12 psi so it wont get cops and if i get pulled over he will notice i have stock exhaust and for the flange not hooking up couldnt i just port the flange on the down pipe and weld it or somthing

joey17 said:

and for the flange not hooking up couldnt i just port the flange on the down pipe and weld it or somthing

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You couldn't port the flange because the inside diameter of the downpipe would still be smaller than an aftermarket o2 housing, you could cut the downpipe and have a bigger piece of pipe and flange welded onto it to hook up to the o2 housing but that would be more work than I'd want to do. Just get a 3in downpipe and muffler it under the car, maybe add a resonator and, tuck it up high enough and it'll be quiet and still look stock.

yea but as low as 2g's are it would be kind of hard to put a muffler right under the car if thats what your talking about and im kinda going after that sleeper look i just want to no if it could be done and if it would help the power and if it will sound stock up untell the waste gate opens.

external dump is so dumb to me on a daily driven car, i had a ext, dump and it sound like trash when it opens cause it sounds like a big ass exhaust leak and it left a black film under my hood and engine so i switched back to internal.

how could it leave a film when the dump is pointing down?

really i cant tell ya all i know is i washed the underside of the hood and about a few weeks later pop the hood and black is everywere. but besides that a external dump is like venting you bov to me just trying to get everyones attention so they say dude did you here that whoa that thing is fast.

thats just me though, nothing against your goals.

i under stand what you mean i was just thinkn about doing it so i dont get as much atention as i would with a full exhaust and still have the power from one. and if the black film is somthing thats going to happen it would be cool to rout it out of the side of the pumper.

ilco187 said:

external dump is so dumb to me on a daily driven car, i had a ext, dump and it sound like trash when it opens cause it sounds like a big ass exhaust leak and it left a black film under my hood and engine so i switched back to internal.

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Mine is doing just fine, no black stuff anywhere, as for the sound some people like it some don't, I happen to like it, it sounds very nice from outside of the car.

if its not to much do ask could you maybe take a vid from out side the car sometime. i kinda dont care how it sounds i just want the performance of a full exhaust but most of the time the sound of a stocker becuase of cops dont get me wrong i love a good straight 3" but cops dont.

There's lots of videos on youtube of o2 dumps, my car is down with a clutch job right now and after that a 750mile break in period so it would be awhile before I could get you a video.

As for the performance of a full 3in, it's not going to happen without getting a full 3in. Do the cops pull people over for visual or just noise? Either one have ways around them, as stated a black 3" inlet muffler with duel tips, and a resonator or two throughout the exhaust and you should be very quiet.

ok but would the dump help at all or just make alot of noice

habitatguy187 said:

Mine is doing just fine, no black stuff anywhere, as for the sound some people like it some don't, I happen to like it, it sounds very nice from outside of the car.

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i was just looking at you mod list and pics i see you have the o2 internal gated to external dump, i had the tial and some other random mess thats why i had black problems i might try one of those type of externals next.

I guess you could extend the dump tube down..If the soot is really a problem..

i run a SS O2 housing from punishment racing w/ a tial 38mm&dump tube on my daily talon.
i did it because i hate having a loud TBE everywhere i go..and honestly, i would sacrifice spoolup time for tickets anyday. Plus, i love scaring annoying punks that cut me off

You can run the external dump but no it will not make a difference in power, it's pretty much all for the hearing please up until the point where you will really need it down the road.

Dsmj89 said:

You can run the external dump but no it will not make a difference in power, it's pretty much all for the hearing please up until the point where you will really need it down the road.

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He probably really needs it now since the rest of the exhaust is stock, he probably would feel a difference with it.

I hardly doubt the difference would be felt but if i were him i would just eliminate the cat and silencer which to me still sounds quiet but since he mentioned the noise problem then the o2 would be ok as long as he keeps the boost out.

joey17 said:

did you read the whole thread im doing this so the cops wont notice me so it will be quite up untell i get past 12 psi so it wont get cops and if i get pulled over he will notice i have stock exhaust and for the flange not hooking up couldnt i just port the flange on the down pipe and weld it or somthing

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Thats not 100% true. When I had my dumped o2 housing on you could hear it softly with boost, and then hear it completely at full boost. It got super annoying so i took it off.

robbo185 said:

Thats not 100% true. When I had my dumped o2 housing on you could hear it softly with boost, and then hear it completely at full boost. It got super annoying so i took it off.

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That would be a wastegate problem.

pboglio said:

02 dump is a waste of time, IMHO. You will also attract every cop within a 1/2 mile radius.
A stealthy turboback exhaust with twin tips will attract much less attention with little restriction.

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There is a simple solution when using an o2 dump; or an external wastegate dumping to the o2...

Don't get on it all the time or near where cops like to sit. It's that simple.

No, it's not that simple. You don't go out and buy a performance part so you can go slower more often. An 02 dump has that distinct disadvantage of attracting cops like honey to a bear. It is also a poor excuse for a turboback exhaust system and can't compete with it in terms of spoolup improvement, part throttle response, high rpm power increase. It also adds a crap load of heat to the engine compartment and the smell.

I have a neighbor who owns a sick looking EVO8 and he runs an open 02 dump. I asked him why and he said it was worth 25 w.h.p. I just looked at him and smiled cause I knew he bought it just to be loud and obnoxious, just like his catback exhaust. I can hear him 1/2 mile away. Makes me laugh but hey, that's what he wants to do with his car.

Why not just put on a electric exhaust cut-out. That would be your best bet. Quiet when you want to be and the flip of the switch and your running open downpipe.

An o2 dump will get very annoying on a mostly stock car. 12 PSI on a t-25, that dump will be opening all the time.