New PT6466BB turbo, does the exhaust WG hole need porting?

Huh.......am I missing sum'n here? I've been running a HD actuator for 5yrs along with a TE60 and up to 25-26 psi. Smooth a silk, never an issue.
No, the TE60 with the T-31 turbine will run at a higher exhaust pressure to boost pressure than these larger turbos. The HD actuator works well with the smaller turbines at high boost. I have no experience with the larger turbos, so cannot say.
 
So it's been a long time since I swapped turbos...back 15 years ago, I needed to port out the WG hole to near the same size as the Terry Houston downpipe oversized puck to control boost on the GT6131e turbo with .63 housing..back then the inside edge was not smoothed either which I smoothed out and ported out the hole to near the TH puck size.
Just got a new PT6466 with .63 exh housing, the inside edge of the WG hole is smoothed, but the hole is tiny.
I use the stock WG solenoid and a BstCommand controller and HD 18# accuator.

Do I still need to port this guy out or would that not be needed since the exhaust wheel is so much bigger?
Pics of the exhaust side attached
View attachment 304298

That hole on the 6131 looks like the puck wasn't even sealing.


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That hole on the 6131 looks like the puck wasn't even sealing.


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I noticed that when I took it off that there wasn't a clear wear spot. I originally ported it and it did have about 1/8" all the way around. I never had issues building boost, could easily hit 15# on the foot brake with a 3k stall convertor.

I've been using the HD controller for 15 yrs with a stock WG solenoid and BstCommander...but yes, the smaller exhaust wheel was more restrictive and created alot of exhaust side pressure...so I at least have to see if it works with this combo, I have a few 13# stock WG actuators laying around new somewhere.
 
I did a 1.05" port on my 6262 and pegged my 3 bar map sensor with the wastegate flapper completely disconnected. 1.3 egg shaped got it into the teens.
 
I just ported my 7168 and I need more . I have a 4lb spring in there and it's making 10lbs and climbing . I just have way to much back pressure and need to go to a 4 bolt or vee band .
 

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No idea what size mine is ported to, but egg-shaped. Not sure if I can port it anymore
 
There are plates you can get to fix it if the hole is too big or won't seal.


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could you give more info on this or a link? I took the housing I have now to get ported more and the guy told me the that because of the previous port job this one (for a larger puck) couldn't be done. he then told me I needed a new exhaust housing. so I'd like to avoid getting a new one if I don't have to


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could you give more info on this or a link? I took the housing I have now to get ported more and the guy told me the that because of the previous port job this one (for a larger puck) couldn't be done. he then told me I needed a new exhaust housing. so I'd like to avoid getting a new one if I don't have to


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Hit up Bison. He has them


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Good info on here, thanks for all of the feedback! Still waiting on other parts to come in before I can run it. Probably be at least another week.
 
You can get these plates blank with no wastegate hole from Bison and put it where it needs to be and the size you want . I needed one for a misaligned puck but then made it too big ( 1.20" ) and couldn't make over 24 psi , so got a new one , made the hole .91" and now 30 psi.
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good to know thanks guys.. do you need new hardware to account for the thickness?


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The plate is .125" (1/8") thick stainless, I didn't need new bolts but mine are not the original ones .
 
Yep, I need to port mine more, it instantly goes to 25# super fast. Will also put the 13# stock actuator back on...will port it all the way out to the max size now...if that don't help, guess I will have to go to an external WG whihc I didn't really want to do.
 
Yep, I need to port mine more, it instantly goes to 25# super fast. Will also put the 13# stock actuator back on...will port it all the way out to the max size now...if that don't help, guess I will have to go to an external WG whihc I didn't really want to do.

What's the problem with it going to 25# super fast? I would think that would be what you want. No?


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Is it set to 25#? or is it overboosting? If it is overboosting then, you should really think about possibly an external gate. If it is not overboosting, it is working as designed.
 
Is it set to 25#? or is it overboosting? If it is overboosting then, you should really think about possibly an external gate. If it is not overboosting, it is working as designed.
My controller is turned all the way down and the WG rod is set with some slack in it, that was 25# and not even full throttle yet. Yeah, already thought about going external if I can't get it down some. Also putting the stock 13# actuator back on...just need some cooler weather before I work on it some more. Like to get it down to 20-22# is the goal.
 
My controller is turned all the way down and the WG rod is set with some slack in it, that was 25# and not even full throttle yet. Yeah, already thought about going external if I can't get it down some. Also putting the stock 13# actuator back on...just need some cooler weather before I work on it some more. Like to get it down to 20-22# is the goal.

That turbo works better with a .85 exhaust housing and low pressure WG actuator- the boost can be controlled better with properly porting exhaust puck hole. It really need a lot of radius done on the inside of the housing- shaped like a mushroom or intake/exhaust valve where the radius is larger on the inside of the housing so the air flow will exit smoother and faster- the turbo will make high boost even if the WG rod is loose or if its a low pressure WG actuator rod if the exhaust housing is not properly port on the inside.

Haulz A
 
Good luck controlling boost with a .77 housing on a PTE 6466. Your wg hole is under .9 ? Trying to control boost with the turbo that is "King of back pressure" with 20-22mm wg hole? Exhaust gas already has to make a narley turn out of the buick exhaust housing ... Then out 20-22mm eg hole.lol

You need an external gate. The plate is an option or you can just wire the gate shut with some auto mechanic wire... spindle to maybe your actuator bracket. Or weld a rod and the end piece of your actuator (part that connects to the spindle of the downpipe) and bolt it too actuator bracket.
I wouldn't weld the gate shut just in case you want to get rid of it someday.

Good luck.
 
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