Malfunctioning wastegate ACTUATOR, or is this normal??????? [VIDEOS]

[tsi1991awd]

I have been having a problem with boost. I have been boosting 20+psi even WITH the MBC turned all the way out (basically stock setting at this point)

I tested the wastegate actuator at 10psi coming from the air compressor, arm barely moved. Tested it with 25psi and it still barely moved. Tested it with 40psi and still barely moved....the video below is at 40psi. I tested it with 80psi afterwards and still moved the same.

Isn't the arm supposed to extend more??? I will post a video someone else took, just for comparison sake. First two are my video, last is someone else's.


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[Shadow21]

Thats odd. I just ran across this thread. I havent done a pressure test on my wastegate yet (turbo isnt on the car) its VERY VERY VERY VERY hard to pull. Im going to be boosting my 97 galant so i cant handle 20 psi spikes like you guys may be able to.. So im interested in this as well. Sorry i cant help you bro but im just posting here to keep track of the thread.

 

[tsi1991awd]

You can't pull the wastegate actuator arm. It takes quite a bit of force to get the spring to compress, so you'll never get it to move by hand.

Once the actuator arm is off of the flapper arm, you can move the flapper freely, as I did. Otherwise.....

 

[JusMX141]

Nope, that's all the further a MHI actuator moves:

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It's actually all the further the flapper has to open up if you have enough backpressure in the turbine housing to permit the exhaust to exit through the wastegate. It's not until full 3" exhaust systems really caught on that boost creep became a huge issue.

 

[tsi1991awd]

So you're telling me that it is completely normal for the actuator arm to barely move like that?

Why all of a sudden am I boosting 20psi, with the MBC set all the way out? I haven't done anything except put in 272 cams. That made the boost go crazy? Like I said, it used to be spot on. 15psi bang that's it. Now it keeps going until it hits fuel cut, so I back off the throttle to about 50% throttle and it's around 14psi.

What if I ran hose from the wastegate actuator to the J-pipe, completely eliminating the MBC....because maybe just maybe the MBC is screwy....I doubt it but you never know.

 

[hondaslayer1]

Make shure u find out what that wastegate will hold before u put just a hose there.

 

[tsi1991awd]

Well when I ran 10psi to the wastegate actuator, it moved just as far as it did in the video. Still doesn't account for how the boost is getting up so high.

Could it be due to the 272 cams I put in? That's the only mod I did, but I could've sworn I adjusted the MBC down after. But could've been before.

 

[dsmdeliveryboy]

Are the cams untuned?

 

[tsi1991awd]

They are Delta 272s, which are copies of the HKS 272s. We dropped them in along with BC springs and retainers and Supertech valve stem seals. Timing was set to -5. I dont have DSMLink yet, and I am also having an issue with stalling when revving or coming to a stop (I know it is because the cams). I just dont know if the high boost is from the cams...because the MBC is set all the way out (no spring compression) and the wastegate actuator doesnt open very far...which I guess it isnt supposed to but the video I posted of the other person testing theirs, that actuator arm moves twice as much as mine does.


Edit: So I just went outside, took the vacuum lines off from the J-pipe/MBC/wastegate actuator and used brand new vacuum hose to go from the J-pipe to the wastegate actutor only...eliminating the MBC. Warmed the car up, took it for a spin....guess what? Still boosted 20+ and this was at 3000-3500rpm range. I think it is because the actuator arm barely moves, but I guess that is not right since it's "supposed" to only move that much.