Internal Wastegate Issues

[holland]

It seems I'm having problems with either my turbo or my internal wastegate. I'm running a Turbonetics 50 trim w/ Bullseye housing... it looks really simliar to the V-trim. No matter how much I turn my boost up it wont go past 14psi. I disconnected my actuator arm off of the wastegate flapper and tied the flapper closed.

Theoretically that would give it infinite boost right? Without the wastegate to open to release the pressure from the turbo wheel then it should just keep on boosting until I saw more than 30psi and the motor blows??

So the guys at RRE told me I needed to do one more test on it. I needed to take off my BOV and put a block off plate on it and drive the car to see what the turbo does. I'm not quite sure what this test will do though.

Either way I'm guessing its the wastegate flapper door or the turbo fan wheel. I'm thinkin of going with the EVO 3 GT turbo.... anyone have any suggestions???

 

[holland]

Does anyone have any ideas on why the turbo would not boost at all if the wastegate was closed shut?

 

[IslandTSI]

I dont think blocking off your BOV or disconecting your wastegate are very good ideas. Did you check for boost leaks?

 

[CanadianTSi]

If you took the Actuator Arm off the flapper then that would allow to flapper to blow open at any boost pressure, therefore no boost.

All you have to do to test it is to dissconnect the vacuum hose going to the WGA, this will give you unlimited boost so be very careful.

 

[Staytuned]

Blocking off the BOV would eliminate the possibility of the BOV opening up under boost....therefore I good temporary test to see if it's holding any boost at all. Also a good boost leak test would help too.

 

[holland]

Yea, I need to block off my TB and do another boost leak test. I've already taken off the actuator and tied the flapper both open and closed. Both times it made NO boost at all, which is really strange. I figured one of the directions would make infinite boost but nope.

My buddy tighted the grip of the actuator on the flapper arm today and it definitly holds a solid 14lbs finally. So with the actuator being the only thing I changed and with it holding more boost than before, it seems it might be the wastegate door.

Another strange thing it does, when I floor the footpedal I start to get knock and the engine kinda bogs down but if I hold the pedal about 3/4 of the way down the car will rev all the way up and make 14lbs. But the second I give it more gas it will start to knock, pull timing and bog the engine down...

 

[kenamond]

Like CanadianTsi said, pull the vac line off the WGA. This removes it from your boost controller, and the WG should stay shut. It may eventually start to leak, as the spring in the WGA may not be able to hold the flapper shut after you get to a certain level of ex. mani. backpressure.

If you block off your BOV, I wouldn't drive it around too much that way. It will disable the BOV function which will eliminate the BOV as a possible source of a leak, but you'll surge your compressor when you lift the gas pedal (for shifts, etc.), too, which isn't good for your bearings or compressor wheel. If you block that off (and the recirc tube on your intake pipe) and start seeing reasonable boost (that you can increase beyond 14psi), it looks like your BOV is leaking.

Not sure about the knock issue at WOT.

StayTuned also had a good question: have you done a boost leak test recently?

Sounds like you may have more than one problem.

 

[holland]

I finally got the chance to do a boost leak test today and sure enough. My brand new Greddy RS is leaking again. The guys at RRE took the diaphram out of it and refolded it because it had a kink in it. Maybe it ripped in the kinked area, I need to take it off and have a look. I doubt slowboy will replace it but I've read somewhere that I can buy just the diaphram.

I'll be buying a 16G soon so I figure I'll pull my 50trim off and see if the wastegate is toast or not. Either way I'd rather have the 16G.