Boost flutter

[lamrith]

Would you like to try a test tune?

Do it do it do it

C'mon man try it, everyone is doing it....  hahahaaaa  1st sample is free...  local neighborhood tune dealer slingin the goods!!

[FoMoCoSHO]

Would you like to try a test tune?

Ah, the digital power pimp hard at work, lol.....

[Colorado-SHOBro]

Would you like to try a test tune?

When this is offered you better take the bait! take if from someone who has his tune at your exact altitude! He can work through the issues and get your car running right withing a couple revisions if not less. I may have been one of the test products and i'm damn happy with the results.

[DSMtuned]

I fear you are now starting to throw money at parts without proper justification....i thought you posted a log where desired tip is fluctuating....if thats the case then its likely not a hardware problem....something is telling the hardware to act a certain way

Yeah I did throw a wastegate solenoid at it because I found one for $15.  I can't find a copy of the PC/ED so I didn't have the test procedure for the solenoid. 

I'm getting frustrated with the lack of communication from the reputable tuner.

[DSMtuned]

Would you like to try a test tune?

Yeah I'd be happy to try one of your tunes!  I'm pulling my trailer across Colorado in a couple weeks and I'm worried my truck won't pull it.

[AJP turbo]

Check your PM

[DSMtuned]

Curious, have you tried to return the truck to the stock tune and see if the issue persists?

I need to try this.  Honestly, I really dislike the factory calibration and have been less than excited to return to stock.   
My truck has been tuned since a week after I bought it.   . With the downpipe I'll surely to get CELs on the stock tune.

[AJP turbo]

You really need to return to stock like mentioned by sho boat

Its really the first step in troubleshooting an issue with a tuned truck....you blindy already threw money at the truck already

You need to isolate and rule things out when possible and returning to stock achieves that

[DSMtuned]

You really need to return to stock like mentioned by sho boat

Its really the first step in troubleshooting an issue with a tuned truck....you blindy already threw money at the truck already

You need to isolate and rule things out when possible and returning to stock achieves that

Got it.  I'll do that today.

[DSMtuned]

UPDATE--  **FIXED**

AJP turbo was kind enough to build a test tune for me so I could rule out my tuner's calibration as an issue.  After loading his tune, I found the boost oscillation persisted.  This led me to believe the problem was mechanical. 

I had a feeling that the catch can check valves could be an issue because they are simple spring loaded flaps of rubber vs ball valves.  I took the check valves apart and found both to had failed, causing boost leaks! 

Next I built a boost leak tester.  I found a slit in the driver's side wastegate line under the clamp, where I missed it during inspection of the lines.  After fixing this and returning the PVC system to stock until I can get new check valves for the catch can, I took the truck out for a spin.

FIXED!!!!  Unbelievable!  I think it was coincidence that the boost fluctuation coincided with the downpipe install, or I worsened the wastegate line leak during the install. 

So I learned to not forget my roots of tuning DSMs and Subarus and go for a boost leak test right away instead of going down the road of more complicated problems.


Thank you all for brainstorming with me.  It's great to have a community like this to learn from.

[SHOdded]

Glad to know it wasnt the tune, and that persistence paid off!

[Colorado-SHOBro]

awesome glad it's fixed! what catch can setup do you have?


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[DSMtuned]

It's the UPR dual valve with the clean side sperarator.  I called them today and they are sending me the updated check valves at a discount.

Ajpturbo initially pointed me toward the catch can.  I never would have thought of that.