Yeah, since the flapper valve has lateral play across its seat on the housing, then the wastegate's bypass port exit diameter is best left alone. The margin for error is quite small at the bypass port's exit..

Also, since the bypass port is siamesed with a relatively thick, cast, axial divider wall and the seat area is hardened(I suspect), then material removal is a real b**ch in that area. I tried it with long-shanked carbide burrs and there really isn't much that you can do at the bypass port's exit.

To improve flow out through the bypass port(s) enough to control most creep issues, I have found it sufficient to port the entrances to the bypass ports located at the initial transitional turnin to the port and that is located in the turbine inlet area right beyond the manifold/turbine housing inlet flange.

 

I'm very sure it's not an issue with the O2 housing. I bought this especially with wastegate flow in mind. I'm not sure you can really tell from this picture, but it was the best i could find showing the size of the port, and the divider on the Invidia unit. The entire housing is cast stainless and has a very short divider, probably only 1" long separating the two sides. You can easily fit a golf ball down it.

I'm leaning more towards the porting of the turbine housing, or my wastegate mod... more towards the wastegate mod as it's easier for me. I'll post up a pic to show what i'm talking about later on.

I have checked to make sure the flapper can travel further, and it is indeed limited by the wastegate and not the 02 housing.

if the pic doesn't show below, here's the link
http://www.invidia-usa.com/Products.aspx?ProductID=137

 

Here is a picture that outlines what i'm looking to do.

This won't affect how far the actuator comes out. It will change how far it goes back in. The limitation should be when the spring & diaphragm hit the top of the actuator housing.

I'm not looking to cut the rod, but the hat that sits against the actuator body when there is no pressure pushing the actuator out.

 

Why would you cut it when you can loosen the jamb nut and back the end out?

 

If i'm not mistaken, there's no nut on the back of the actuator. If there is, then i need to make sure that backing that out will actually give me more travel of the wastegate arm.

If this does work, I'll thank you for the easy way out.

 

can you just get an aftermarket wastegate or an o2 dump. Cut and move? Amazing

 

sounds like you need to port the hotside of the turbo. the waste gate area is not regulating in time for your boost....so it spikes, creeps, and when the wastegate actuator catches up, it cant waste enough off so it is forced to go through the turbine wheel instead of the wastegate area.

 

The Forge WGA is not an 18 PSI unit. The Forced Performance HD WGA is the one advertised as being an 18 PSI unit. Whereas in actuality it(the FP WGA) is an 16-18 PSI unit. The Forge unit on the other hand, should be adjustable to levels way below 18#.

 

I still think that you are barking up the wrong tree with your proposed mod of hacking the WGA cannister's hat. Just leave that puppy alone and don't mess with it.

Instead, measure the diameter of the O2 housing's merge hole and if it's smaller than a golf ball....then enlarge it. If you should find that the O2 porting mod alone doesn't control creep, then do as I say and port the entrance,(turn-in radii) of the wastegate bypass ports in the turbine housing's inlet area.

Incidentally, I'd gladly do this porting job for you but it is probably not economically feasible as I live in Central America. Having said that, I would, however, like to get away for the 4th of July weekend to see the fireworks displays in Boston.

FWIW, and, IMO, your idea of modding the WGA cannister's hat or the actuator rod is somewhat lame, and at best, hairbrained. Please understand I am not trying to be a shmuck. Rather, I am only trying to avoid possible problemos for you. If you don't believe me, then call the tech representative at Forge Motorsports.

If, however, you are still hellbent on modding the WGA, then, I suggest(again FWIW) that you first hack up the stock IX WGA, and not a perfectly fine, billet aluminum, Forge WGA. Just my O2.

 

If you make it to boston for the 4th, you're welcome to my party if you port my hotside!

As for the O2 housing, i know that's not the issue. I had that issue with the Megan Racing O2 housing and got rid of it.

I am thinking of still doing the WGA mod, and to your point, on the stock IX WGA, not the forge one.

 

What about putting the stock one back in and tighten until you get what you want?

 

The stock WGA has a bit more travel for adjustment than the FP WGA...

 

did u end up fixing ur boost creep?
iam having similiar issues and looking for some answers as well.
free bump!