Does this look ported enough?

[blktalon3]

Hey guys, I have boost creep something awful. With the WG acuator disconnected I'm getting over 10 psi @ 6000rpms. So I went and bought an electric die grinder from Harbour Freight and went to town on my exhaust housing. I read the write up by Chadillac2000 and followed that. I was just wondering if you guys think I have WG entrance open enough? Oldman?

 

[97 4G63]

That's more than enough good job

 

[iwannagofast89]

Its a little wably but it looks good

 

[MrBoxx]

The wastegate entrance looks good. The flange entrance looks like it could be... how shall I say... "rounder"? Put a gasket up to it, scribe a line and try to port to match the gasket.

Follow up with a flap wheel for a smooth finish.

 

[turbo90gsx]

Looks good, now match that gasket.

 

[blcknspo0ln]

For some reason, I would think that particular housing is now larger than a 7cm gasket.

For future port jobs, try cleaning off the piece you are porting, put the gasket against the surface and use a sharpee to draw which parts you need to port. This way you can pretty much garauntee yourself from not going "past the lines".

 

[tkelly27]

Looks like you hit the flange. I normally put some axle grease on turbo to manifold mating surfaces for the seal, that might help if the gasket is crushed weird there.

 

[blktalon3]

I wasn't quite finished in this picture. I just wanted to make sure my WG inlet was big enough.
You're right it is a tad bigger than the gasket. Thanks for the tips though. This is my first port job and I definately want to do more.

 

[pitbull419]

Gasket match it an fix whats in red

 

[turbolover10]

^^+1, good eye!

 

[blktalon3]

I'm all over it. I just hope this helps my creep.

 

[turbolover10]

It should definitely help the creep, Is the divider in you manifold ported?

 

[pitbull419]

I'm all over it. I just hope this helps my creep.

How many miles are on that turbo?Hows the shaft play?
Kentucky huh? Im from the loui

 

[blktalon3]

I don't know how many miles are on it, it came on the car. It doesn't have any shaft play though. Ya, I'm originally from Missouri, I moved down here about 4 years ago. I love it down here.
The manifold divider is ported. It's not gone just thinned out.

 

[kenamond]

Is the manifold ported to the same size as the turbine housing inlet (which is a bit larger than a 7cm^2 gasket )?

Also, it's hard to tell in the picture, but did you smooth out the walls of the housing just after the WG entrance? It looks kinda rough and stepped where your porting stops and the cast finish starts. You want the walls to be smooth as air flows along them toward the turbine wheel.

Here are a couple pics of my port job (used a Harbor Freight electric die grinder, too!):

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[DsmDave95]

^wow real nice work right there^

 

[97 4G63]

Is the manifold ported to the same size as the turbine housing inlet (which is a bit larger than a 7cm^2 gasket )?

Also, it's hard to tell in the picture, but did you smooth out the walls of the housing just after the WG entrance? It looks kinda rough and stepped where your porting stops and the cast finish starts. You want the walls to be smooth as air flows along them toward the turbine wheel.

Here are a couple pics of my port job (used a Harbor Freight electric die grinder, too!):

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Damn this is real nice work the best so far props..

 

[Menacing talon]

Holy shit thats a really nice job

 

[blktalon3]

I worked on it some more after I took that picture. The WG inlet was my main concern. I went back cleaned the it up and sanded it smooth. Granted it doesn't look as good as yours Kenamond but I don't think that's possible. I thought mine looked halfway decent, but after seeing yours all I can say is, damn.

 

[turbo90gsx]

DAMN kenamond. That is very impressive!

 

[kenamond]

I worked on it some more after I took that picture. The WG inlet was my main concern. I went back cleaned the it up and sanded it smooth. Granted it doesn't look as good as yours Kenamond but I don't think that's possible. I thought mine looked halfway decent, but after seeing yours all I can say is, damn.

Thanks guys.

Another thing to keep in mind is that WOT under full boost, the WG is open a constant amount and a constant fraction of exhaust is split between the WG and turbine (this is all assuming constant RPM - that fraction will evolve as RPM changes). And this is where you care the most about the flow. Anyway, that means that the flow into the turbine housing needs to be smoothly split. When the turbo is still building boost, the WG is closed, and the shape of the turbine housing near the WG entrance is actually a disruption that probably slows spoolup a bit. But once you hit full boost, the housing should efficiently split the exhaust flow between the turbine and WG. That may not be obvious to a lot of people (I know I wasn't for a while). Full boost is where you care the most, and that's also when the WG is doing something.

I don't think anyone on a do-it-yourself budget knows what the ideal port job would be, so it's kind of a crap shoot there. You'd have to spend a lot of time trial-and-error testing or doing some flow bench analysis or computational fluid dynamics simulations to figure out what a good housing internal shape would be. So we do what we can.

I think the ideal WG would be one that provides a perfect shape while boosting and a different perfect shape when the WG is open. I think that the closest you could get to this would be an external wastegate. But I like many others am stuck with a housing that has the WG entrance ported out of it.