TVS low and slow boost

[Justinb491]

So i have a 2014 Roush Raptor that always made 9lbs of boost and had a VMP tune. Then one day it just dropped to 7lbs. Still made plenty of power and felt normal, just dropped to 7lbs. Took it in to a well known mustang shop and had a VMP boostapump, smaller pulley and dyno tuned. Made great power and drove like a raped ape, but still only 7lbs. should be easily 10lbs. Thinking its the gauge or line i replaced both, nothing. Then a few weeks later I noticed the snappy boost is gone and its very slow to build boost. So now thinking its the bypass valve. Just replaced it, nope nothing. Still 7lbs. I have tried 3 different tuners and nothing. They all feel about the same. Last week I had a solinoid code and other then that no codes or issues. WHAT NEXT? Any direction to go would be great guys.

 

[bigmoose]

Have you tried a new belt?

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[Justinb491]

I replaced that once I saw it only going to 7lbs. Then after the pulley swap I put a new belt and tensioner on just in case. I see not belt dust at all.

 

[01yellercobra]

Seems like you hit everything most of us would try. Maybe it's an internal issue? Like a rotor seal or something is leaking boost out and it's slowly getting worse.