Custom dump worth trouble?

[LumpyVR4]

So I've been doing a little reading and noted that if the wastegate exhaust dumps back into the main feed close to the turbine outlet it will screw up the flow out of the turbine. This effect is worst as full boost is reached under full throttle in the 'lower' RPM ranges. The effect would decrease as the revs rose and the max boost out of the turbo started to fall near your desired boost level.

I have a full 3 inch system, but a stock o2 housing. I'm toying with the idea of getting an o2 housing with external dump on the waste gate. Then I'll lop off the 2.5 inch flange and extend the main pipe to match the wastegate pipe and blend the two together into the 3 inch flange, giving me a longer than normal seperation of the main and waste feeds off the turbo, then trim a bit off my exhaust to match.

What do you think? Worth the effort?

 

[captainTeeBag]

I had a divorce dump on mine and noticed a huge difference.if your not familiar with them its just a dump with the merge down near the flexi. No flow interruption helped spool turbo up quicker and boost was far more stable. Very good upgrade and you can keep internal wastegate

 

[captainTeeBag]

So yes definitely worth the effort!

 

[JayRome]

 

[Marc]

An easier way to fend off any change of flow interuption, wouldn't it be best dumping gate to atmosphere? (yes i know it's not legal, but what isn't these days) :lol:

 

[4piknup]

An easier way to fend off any change of flow interuption, wouldn't it be best dumping gate to atmosphere? (yes i know it's not legal, but what isn't these days) :lol:

I hope thats a joke. There has to be 6 better reasons than its illegal to not run a screamer.
1. Sounds so crap
2. Too loud
3. Attracts unwanted attention
4.
5.
6.

 

[DOUGMO]

/\/\ old man shouting at clouds? /\/\

 

[Marc]

/\/\ old man shouting at clouds? /\/\

Vapour trails.... :lol: I think him and Billzilla would get along.

I hope thats a joke. There has to be 6 better reasons than its illegal to not run a screamer.
1. Sounds so crap <---Everyone has an option, that is yours, that's cool
2. Too loud <---When it's open Hand in your man card if you havent already....too loud..
3. Attracts unwanted attention <-- Yeah when you're boostin like a C$NT, if you're worried about unwanted attention i.e the cops, you wouldn't be giving it arseholes in front of them anyway.
4.
5.
6.

What's the other three??

 

[DOUGMO]

as above, split or screamer do make a difference.

it also depends on how much boost you run as to how anti social a screamer is.

my s13 and evo run screamers, the s13 is loud as it runs bugger all boost, the evo isn't too bad

 

[Marc]

Well naturally the lower the boost the more obnoxious the screamer will be as it's trying to bypass more gas if that's correct.

I have noticed on the flange plate i have, the hole for the wastegate side, is easily over double the diameter of the actual hole in the exhaust housing, seeing as tho something will only flow as much as its smallest point, if you were to reduce the pipe diameter from the size of the hole in the flange to something inbetween that and the hole in the housing, would that be detrimental??

I only ask because the smaller the diameter that should create a higher velocity rate than a larger diameter pipe, and in theory make for more annoying, attention grabbing, anti-social, baby killing, ozone burning, vapour trail creating screamer pipe??

Thoughts Dougmo??

 

[DOUGMO]

the bigger the better as it will relieve the pressure around the wastegate plate, also radius in and out of the wastegate port, the little things all count

 

[VR42LT]

Screamer +1

 

[ENGINR]

Screamer FTMFW :drool:

 

[DOUGMO]

this is my old split dump (non screamer)

 

[Marc]

Screamer FTMFW :drool:

Now i'm just torn, do i get out a hole saw and attack my bonnet, or the side of my bumper and have it coming out in front of the tyre.....

 

[ENGINR]

Now i'm just torn, do i get out a hole saw and attack my bonnet, or the side of my bumper and have it coming out in front of the tyre.....

Yes. Yes you do.

 

[Marc]

Yes. Yes you do.

Yeah that's a given, but which one, if i do the bonnet then i have to worry about driving in the rain, or have it come out PAST the bonnet so i can put on one of those flapper things on top

 

[ENGINR]

Have it sticking through the bonnet but put a 90deg bend on the end of it, (make sure the hole in the bonnet is big enough to clear the bend). You could have it pointing backwards so that the onrushing air won't go into the screamer (but the vented air could possibly shatter your windscreen....)

 

[Marc]

Nah, in a perfect world would like to have it cut flush with bonnet, like so.

 

[4piknup]

2. Again, too noisy as in too much louder than the normal exhaust note. Run straight out the dump onto the road and a screamer is fine. Its about balance.
4. There is no point or benefit from them
5. They show you are lazy and cant be bothered/ not skilled enough at designing a proper operational exhaust.
6. Point 1 again. Sounds crap. But let me explain. You have a sporty exhaust with a fat note and a great burble. Then when the gate opens, the noise overpowers the muffler note and all you can hear is a jet sound.


If its a track car its fine as the exhaust is louder anyway.
If you are going to vent it out the bumper then run the exhaust out there too. Shotgun style ftw.