Porting internal wastegate hole

[inmyshadow]

Wondering how much material I should take off.

My current setup with the Super60 suffered from major boost creep. Basically with boost set to 6lbs, I would see 22lbs by redline. Made for a fun ride, but I'm wasting power down low and risking the motor up high.

While I have everything apart, I was going to use an external wastegate setup. I have all the parts and images to make one. My friend doesn't have the time to help me out this time around.

My next step would to port my .63 housing. I was just looking over the housing and swingvalve. There is a perfect template to port that whole. Love carbon build up making my life easier. Just wonder if I should port out the hole to the exact size, or just under?

later

[Tony Hanna]

Just under. You want to leave a little overlap to give the puck something to seal itself against.
Another option would be to find a larger wastegate puck. The turbo on the 16 valve cars has one that's considerably bigger. I replaced the tiny puck in my Holset with one, and that allowed me to really open the hole up. If you do that, you just want to be sure and mount the new puck so that it can wobble like the original or there's a good chance that it won't seal up right.

[inmyshadow]

how do you swap the flapper? Where do I even look to buy a bigger one?

[Tony Hanna]

I don't know where you could buy one individually. I had the original turbo off of my R/T and cannibalized the one off of it. I guess maybe you could start a thread looking for a cracked R/T housing. The puck from the R/T turbo had sort of a stepped center stud with a washer staked to it. This allowed it to wobble in the arm. To get it off the original arm, I just ground the staked part off and popped the washer off with a screwdriver. To re attach it, I put it in the new arm, put the washer back on the stud, and then tack welded the washer to the stud with an arc welder running stainless rod.

[johnl]

Doesn't the greater surface area of the puck that is presented to the pressure in the SV, overcome the spring of the wastegate can at a lower boost level?

[Tony Hanna]

Makes sense that it would I guess. Come to think of it that could explain why the Spirit would always drop a little boost in the upper rpms too. I guess a strong spring in the w/g can or maybe an external spring would compensate.

[inmyshadow]

I won't have to worry about this problem. I can't weld or find parts to use a larger puck on the swingvalve.

So I'll just port out the whole abit and hope it elimates my boost creep.


Doesn't the greater surface area of the puck that is presented to the pressure in the SV, overcome the spring of the wastegate can at a lower boost level?

[Tony Hanna]

There used to be a website with instructions and pics for the porting. The process is pretty straight forward obviously, but there was a really good pic of how much meat to leave around the edge so it seals ok. I wish I could find it. Maybe somebody knows and can post the link.

[t3rse]

Doesn't the greater surface area of the puck that is presented to the pressure in the SV, overcome the spring of the wastegate can at a lower boost level?

no, the opposite: you are distributing the pressure over a larger area, therefore less force with more area.

[tryingbe]

Have you try to adjust the adjustable wastegate arm first?
Something else other than the size of the wastegate bypass hole is wrong if you can't even hold 6psi.

[inmyshadow]

I can't adjust the wastegate arm other then shimming it.

It will hold 6lbs at low rpms. When I reach around 4000, it shots to 14lbs. Then by 6000rpm, boost rapidily increased to 22lbs. The boost hits so hard after 14lbs of boost, that it breaks the wheels lose.

later

[tryingbe]

What are you using to control boost?

[contraption22]

The TU 3" swing valves have huge pucks in them. Wouldn't be a bad investment.

[minigts]

Yes and it would help us attain the 40 pre-orders we need. :D

[tvanlant]

Yeah, it sounds like you've got actuator issues. I doubt porting the hole will cure something as drastic as you are experiencing.
On both of my .63 housings, I left the hole the stock diameter, and have had no boost creep issues at all. The "short turn" is pretty much a 90* turn. Take that 90 down and make it a nice radius from the direction the exhaust is coming from to the hole. You can also radius the "sides" of the hole as well. Leave the far side (part farthest from where the exhaust is coming from) of the hole just like it is.

If you do open up the hole, do it just a small amount. The puck doesn't sit exactly over the hole, so don't open up the hole evenly all the way around. Bolt your swingvalve on, then reach a marker in there and outline the puck. This will show you where the puck sits relative to the hole.
An old way of doing it was to bolt the swingvalve on, and spray paint the inside. Then remove the sv and the area the puck covered would be unpainted. This is more work, though.

[t3rse]

I've got an actuator that held 28# (min is 18#) that you can have if you need it. You can thread it out and lower the min if needed.

[inmyshadow]

The only reason why I didn't go with a 3in swing valve was because I didn't have the time to wait. Over the weekend, I found out my friend didn't have the time to assist me in swapping motors nor build a 3in external wastegate O2 housing. That created the time I needed to wait.

I did put a deposit down over the weekend. Thanks to a error, I'll have a 3in swingvalve next week instead. So I won't port out the wastegate hole until I have the 3in swingvalve.

Not wanting to waste my vacation on nothing to do. I pulled the head so I can replace the bad turbo and thread repair the head. This is the perfect time to fix my boost control issues. I know the plunger doesn't cover the hole perfectly round. I noticed that on the housing when I pulled the swing valve off.

I might get the parts needed to thread my wastegate can. I have two large cans to play with. Both have pretty much the same pull strength on the rod.

Boost control is a HKS something EZ electronic boost controller with large wastegate can. Simple stepper motor, on/off button and dial to adjust boost. It was free and I was starting to get lazy with my graniger valve. I was also thinking the boost controller wasn't fast enough to control the wastegate. This boost controller worked great with the small can and stock TII turbo and 18lbs of boost.

[badandy]

no, the opposite: you are distributing the pressure over a larger area, therefore less force with more area.

True for the surface area of the puck itself but the wastegate diaphram is the actual lever/fulcrum which will still see the same amount of pressure acting against it no matter what the size of the orifice and puck (everything else staying the same).

Two different principles

[tryingbe]

Boost control is a HKS something EZ electronic boost controller with large wastegate can. Simple stepper motor, on/off button and dial to adjust boost. It was free and I was starting to get lazy with my graniger valve. I was also thinking the boost controller wasn't fast enough to control the wastegate. This boost controller worked great with the small can and stock TII turbo and 18lbs of boost.


Have you try to take out the boost controller and run straight vacuum to the wastegate actuator and see what happens?

[inmyshadow]

I didn't do any diagnoses before I stopped driving the car in march. I was too upset to work on the car. So now I never ran start vacuum wastegate can.

[t3rse]

True for the surface area of the puck itself but the wastegate diaphram is the actual lever/fulcrum which will still see the same amount of pressure acting against it no matter what the size of the orifice and puck (everything else staying the same).

Two different principles

edit: I read his comment differently. Yes, the size of the puck has no impact on when the gate opens assuming everything is functioning.

[Tony Hanna]

I didn't do any diagnoses before I stopped driving the car in march. I was too upset to work on the car. So now I never ran start vacuum wastegate can.

Another good way to test would have been to simply unhook the wastegate rod and test drive it. With the puck hanging loose, any boost creep at that point would definitely point to the hole being too small. If there wasn't any creep, then it would be time to look at the wastegate can and boost controller for the source of the problem. Since you've already got it apart, I really don't see any harm in porting the hole as long as you don't go overboard with it and leave enough meat for the puck to seal against.:thumb:

[inmyshadow]

Alright, got my 3in swingvalve today. The swingvalve puck is huge.

how much should I port the wastegate hole?

[Tony Hanna]

It says to leave a 1/8" margin for the puck to seal against here:
http://www.allpar.com/fix/holler/turbo-rebirth.html

So I'm guessing anything up to that would be fine.

[inmyshadow]

I ported the hole earlier. Its pretty hard to make the hole bigger with a .63 A/R housing. Porting the hole leads into alot solid material.

So I opened the hole as much as possible, which doesn't seem like much. Then I blended the hole where I couldn't remove much material. Hopefully it is all enough.

I also shimmed the wastegate when I put the topend back together. I just need to get some allen bolts so I can bolt down the swingvalve.

later

[Tony Hanna]

Just curious, why shim the w/g if you're already having boost creep problems? If you get it shimmed too much, the wastegate can won't have enough travel and it will actually make things worse. A large can should be good for a fair ammount of boost without shims unless the spring is weak.

[inmyshadow]

Its alot easier to shim my large wastegate can now, then when its on the car.



. A large can should be good for a fair ammount of boost without shims unless the spring is weak.