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Old 01-20-2008, 08:37 PM   #1
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Yesterday I installed my new divorced gases downpipe from BEGi. Followed their instructions, didn't have any problems with the install.
Get the car on the road after letting it warm up and get all the crap burnt off the stainless steel. Everything is fine so far. I get about 10 minutes into my drive, and then suddenly the car will not make immediate boost. It only will gradually rise as I get higher in the RPMs.
So today, thinking that maybe something is up with the IC pipes since I had them off to loosen the turbo, I double and triple check everything. The turbo is tight on the manifold, the downpipe is tight on the turbine, and when the car is running there is no evidence of an exhaust leak anywhere.
So after checking everything that was moved around, I warm the car up for about 10 minutes and take it out, and it runs fine, boosts like normal. Then it starts doing the same thing again. It feels like the pressure is getting exhausted somewhere, but the BOV is sealing up normally, and according the the Link the wastegate is also functioning normally. I was thinking maybe a coupler was leaking, but I figured that would also be immediately noticeable, instead of happening further into a drive.
If anyone has any insight, please post up. This is driving me nuts. Thanks!
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Old 01-20-2008, 08:49 PM   #2
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If I remember right, an obstruction in the exhaust can have that effect. Maybe you rattled something loose in the cat?
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Old 01-20-2008, 08:54 PM   #3
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No cat. BEGi downpipe, FM test pipe, FM turbo dual exit.
But as far as seeing things, the exhaust seems normal, and sounds normal too.

I'm starting to wonder if the divider they used in the flange in the downpipe is disrupting the wastegate flapper. On my controller, the wastegate appears to be working normally, but IDK what it would display is the flapper is not closing properly. I only wonder that because they welded the bungs for the WBo2 sensor on the bottom of the pipe, when they should be welded to where the sensor tip is lower than any other part of the sensor (essentially on the top half of the pipe).

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Last edited by RotorNutFD3S; 01-21-2008 at 12:05 PM.
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Old 01-21-2008, 01:56 AM   #4
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If you can physically check the operation of the flapper that would help.

Temperature changes can make things come and go as the car heats and cools. It might be close tolerances on the wastegate that change only when it's toasty.

Boost leak test?
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Old 01-21-2008, 02:21 AM   #5
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Since you run a map based ecu this makes finding the source abit harder but still doable. I could well have been a loose coupler that allowed you to make boost for a little while and then got a bigger gap between it and the pipes. I have had this happen to me and it took me a few minutes to finally figure out that the coupler was blown almost all the way off, when looking or feeling on the bottom of it. The hose was tight and everything looked good uptop though. I think that alot of the begi WG clearance issue's where to much boost from a WG that had restriced out movement, the only way i could see it as being proped open is if by some wierd deal of expansion the flapper got stuck on the DP wich i find unluckly since you had normal boost to start. And the chances of the stuff expanding to where you would be stuck open are pretty slim to me. Anywho just thought i would through that out there GL man.
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Old 01-21-2008, 10:30 AM   #6
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I agree- disconnect the actuator arm from the can and check the movement. It really sounds like your gate is hanging open.
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Old 01-21-2008, 11:07 AM   #7
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Just got to work this morning, and everything was fine the whole way. Didn't romp too hard on it, but solid boost every time I wanted it. Still going to troubleshoot and see if I can find something to explain it, including checking the flapper.
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Old 01-21-2008, 11:43 AM   #8
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Quote:
Originally Posted by m2cupcar View Post
I agree- disconnect the actuator arm from the can and check the movement. It really sounds like your gate is hanging open.
I agree also.
Loosen the fasteners, take a mallet and gently hammer the downpipe downward as far as possible. Tighten fasteners. If that does not work, please give Corky a call.
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Old 01-21-2008, 08:58 PM   #9
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So just tried the wastegate flapper. Sure enough, it gets stuck, and then if it wiggles enough, it frees itself from being open.
I'll try the method that Stephanie suggested.
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