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How bad are these numbers for a stage 3 FiST?

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#1
Hey guys, I have a 2015 FiST that's had the cobb stage 3 mods for about a year now. It's stock otherwise. I'm pretty certain I have a serious boost leak somewhere, but haven't been able to find it yet (tightened clamps around the fmic etc, sprayed soapy water). It's so bad that the car almost feels naturally aspirated--it revs out with no noticeable turbo surge. Feels like substantially less torque than stock, zero torque steer under any circumstances. Before the leak (or whatever turns out to be wrong) it was insanely torquey, could usually spin the wheels in 3rd without pushing too hard.

I pulled some data using the AP and was trying to figure out if the measured boost etc. is consistent with what I'm actually experiencing. The data isn't that clean--I did a bunch of fairly gentle pulls in 3rd just hard enough to be sure I wasn't going to get any bite (i.e. boost would have kicked in by then if everything was okay). My theory is a leak because I can hear a hissing noise that wasn't there before, but it's eluded me so far.

Here's a link: http://www.datazap.me/u/3pedaldevil/log-1464231069?log=1&data=4-9

Does that look like just a boost leak somewhere, or am I losing my mind?

Thanks for any help/insight!
 


frankiefiesta

1000 Post Club
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forked river
#2
Get under the car and check the coupling coming off of the turbo. Mine recently popped off and I was only seeing 2psi and had a loud whistle. Also I suggest switching to T bolt clamps
 


OP
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Thread Starter #3
Thanks for the tip re the T bold clamps, and actually that coupling is about right for where the sound seems to be coming from. I bet that's it.
 


dyn085

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#4
I look at a lot of long datalogs and yours looks particularly funky, but it doesn't look like it's funky because of a boost leak. Try datalogging a WOT pull with your foot to the floor because your pedal inconsistencies are skewing a lot of the info. Also consider updating your AP3 with the newest revisions of tunes because whatever revision you're on is an older one.

If you're convinced that there's a boost leak then you should look into getting a smoke test done.
 


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#5
[video=youtube;atretf9u-Mc]https://www.youtube.com/watch?v=atretf9u-Mc[/video]

MCM Goodness.
 




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