Ported Garrett turbo project

[jefo]

Hey Guys,

I am porting my NOS garrett turbo to replace the mitsu turbo I ported as shown in this thread.
http://www.turbo-mopar.com/forums/sh...tsubishi-Turbo


I have only done the compressor housing so far:
http://www.pinkbike.com/photo/10957170/
http://www.pinkbike.com/photo/10957168/
http://www.pinkbike.com/photo/10957166/

Couple of questions:
I have an adjustable wastegate actuator. How much preload should it be at?
Do you guys think I will need to port the wastegate hole? 2.5 turbo van 3" intake and 3" dp dumped.

And of course, share questions/comments.

[wallace]

I had creep issues with my van using a .60/.63 garrett. It started when I went to a 3" exhaust so I would recommend porting it.

[supercrackerbox]

Be very careful about opening up the wastegate hole; you don't want to cause sealing issues with the puck. Been there, done that, and had to have TU install a larger puck in my swingvalve to fix my screw-up. If anything, simply smooth out the passage inside to better direct the airflow, and call it good.

Tons of info in this thread, and with pictures!

http://www.turbo-mopar.com/forums/sh...=turbo+porting

[jefo]

Here is the swing valve ported out to 2.8". A little uneven but it'll do. I put loctite on the bolt inside the sv, and ground it down flush with the inside of the swingvalve.

http://www.pinkbike.com/photo/11086002/

http://www.pinkbike.com/photo/11086001/

I didn't port the turbine inlet much, as it matched up with my ported exhaust manifold. I opened up the waste-gate hole slightly also.

[jefo]

Well installed it and I have boost creep. bummer.

[supercrackerbox]

I hope you didn't overdo the wastegate hole. I made that mistake and fried a turbo from overspinning.

[GLHNSLHT2]

how does an opened up WG hole cause the turbo to overspin?

[jefo]

The puck still sealed completely. So the turbo's max boost is 15psi until it creeps... then it will creep up to ~20psi.

[GLHNSLHT2]

it's not that bad to pull the turbo while leaving the head on if you have had it off recently and have braided oil/water lines too it. Could take it off and open that hole up some more. I ported the S60 turbo .63 housing out to 1" with the turbonetics 2.5" SV. did 1.125" with the TU 3" SV. All these new turbo cars run small turbos and huge WG's So opening up yours isn't going to hurt anything.

[wallace]

Another option would be a stage II wheel.

[supercrackerbox]

how does an opened up WG hole cause the turbo to overspin?

By the puck not sealing forcing the turbo to work that much harder to reach the ~17psi I was pushing. I'd have to look but I might have some pics of the scorch marks on the housing where the puck was leaking.

[GLHNSLHT2]

I'm not sure I buy in on that. The turbo is going to spin the same rpm to make 17psi on the intake side wether the puck is leaking or not. The only thing a leaking puck will do is cause slower spool up. Now if you had a leak on the compressor side then yes you'll overspin the turbo.

[supercrackerbox]

I do see your point.

[jefo]

How's this for boost creep? haha

https://www.youtube.com/watch?v=RRTfIHxH2dA

[cordes]

That is some pretty serious boost creep. Are you sure you're WG can is good? It's almost like it has enough to knock it down to 15PSI at the start, but somehow can't sustain. That's just so violent it's almost hard to believe that an investigation of the mechanical side isn't in order.

[Vigo]

Seems like classic boost creep to me.

I would just take the turbo back off and port the wastegate orifice. As said, it's actually not super hard to take the turbo off with the head on the engine (especially on a van!) if its been off recently and everything isn't still rusted together.

[5DIGITS]

Hey Guys,

I am porting my NOS garrett turbo to replace the mitsu turbo I ported as shown in this thread.
http://www.turbo-mopar.com/forums/sh...tsubishi-Turbo


I have only done the compressor housing so far:
http://www.pinkbike.com/photo/10957170/
http://www.pinkbike.com/photo/10957168/
http://www.pinkbike.com/photo/10957166/

Couple of questions:
I have an adjustable wastegate actuator. How much preload should it be at?
Do you guys think I will need to port the wastegate hole? 2.5 turbo van 3" intake and 3" dp dumped.

And of course, share questions/comments.

Please consider that turbine housings with stock turbine wheels require more porting the housings machined for larger wheels.
In stock turbo 'wheeled' applications the flow demand on the WG increases, especially when other components are modified to improve flow.
Likewise, turbine housings machined for larger wheels widens the scroll passage and therefore excessive WG porting in these cases can cause boost oscillation due to rapid loss of turbine wheel exhaust gas velocity.

[jefo]

It holds boost fine with the exhaust cutout closed. I'm using a grainger valve to control boost. My wastegate can is adjustable, so I may try and reduce the preload.

[Vigo]

If it's controlling boost at low rpm it has to be opening so i dont think it's possible for it to have too much preload. That would just give you too high of a minimum boost setting.

The fact that it gets worse with the cutout open sounds pretty normal. By reducing backpressure behind the turbine you're making it more efficient, so the wastegate would need to bypass even more flow at the target boost level.

You have to take it apart to fix this.

[jefo]

Or get a 3 bar tune