External wastegate location

[matress]

hey guys,

I'm just wondering how much of a part the location of the wastegate plays in its performance?

Would a wastegate mounted on the dump pipe perform aswell as one mounted on the manifold?

Mat

 

[EVO-00X]

External wastegate placement is crucial!! Some do it to 90 degrees off the manifold, some do it 180 degrees from the top of the stock manifold, some do it off the turbine housing. Basically you need the external wastegate as close as possible to the turbine wheel but BEFORE the turbine wheel to vent the gasses which spin the turbine i.e. The place for it is either coming off the manifold or welded onto the turbine housing (both before the turbine wheel). If you put it past the turbine wheel on the dump pipe it isnt going to rid gasses before the wheel now is it? :wink:

 

[GSRSOL]

this may be a stupid question, but is it possible to remove the internal wastegate and replace it with an external feeding from the same spot? (does that even make sense :?? )

 

[3zercrowd]

I have seen external wastegates/flanges on the exhaust housing itself, just cant find the pictures

 

[matress]

forced performance turbos have flanges for a wastegate on the turbine housing.

dan, the wastegate on the dump pipe uses the internal wastegate with flap removed (i think) and the waste gate port acts as a port to the external.

this picture might help:
http://www.slowboyracing.com/more.php?id=1355&

 

[ZedEx]

dan, the wastegate on the dump pipe uses the internal wastegate with flap removed (i think) and the waste gate port acts as a port to the external.

I'd say thats exactly how it works... though you would prolly port out the hole a bit aswell once you removed the flap.

 

[GSRSOL]

forced performance turbos have flanges for a wastegate on the turbine housing.

dan, the wastegate on the dump pipe uses the internal wastegate with flap removed (i think) and the waste gate port acts as a port to the external.

this picture might help:
http://www.slowboyracing.com/more.php?id=1355&

yes

thats what i meant 8)


only thing is, like zedex said, you would have to get the wastegate port enalrged, other wise you would still essentially be using a 31/34mm wastegate. (with a big 16g anyway)

 

[EVO-00X]

Here's the other alternative off the turbine housing:

 

[matress]

off the turbine housing would be good, but how easy is it to port out and weld to cast iron and keep the structural integrity of the original housing?

 

[tharaka]

off the turbine housing would be good, but how easy is it to port out and weld to cast iron and keep the structural integrity of the original housing?

all you need is a die grinder


and a dump pipe like this

or

i wouldnt bother welding onto cast iron

 

[matress]

check this out -
agent orange (mmc.org.nz) discussing how he welded a wastegate pipe to a turbine housing
http://www.mmc.org.nz/forum/viewtopic.php?t=42782&highlight=wastegate

 

[GSRSOL]

Agent oranges one is a better way to do it, the ones above are detrimental to exhaust flow, where the reentry of the plumbback is at right angles to the exhaust gas in the main pipe.

same goes for dump pipes from an internally gated turbo.

 

[EVO-00X]

Dirk (Agent Orange) is my guru and has helped me out heaps The guy knows his stuff :wink:

 

[matress]

Yeah, he's no silly ****! :lol:

Forget about Dirk's way for a minute because its unfeasible for me...

How much work needs to be done to the turbine housing to be able to use a wastegate on the dump pipe?

 

[EVO-00X]

I think you've missed the point - off the dump pipe is not the best place for it. Remember that its gotta vent "before" the turbine wheel dude. You want it either 90 degree's off the side a custom manifold's merge collector, 180 degrees off the top of the stock manifold, or coming off the turbine housing as Agent Orange's setup. These 3 positions offer the most even amount of venting from all 4 cylinders at once "before" the turbine wheel.