I have a 94 with stock twins. About two weeks ago I started hearing a scraping noise when engine is under a load. I believe the problem is with the secondary turbo because when accelerating I hear the scraping the boost goes down to 9psi(normally runs at 14psi) Sometimes is scraps and no power and somtimes it doesn't and then is power and sometimes it doens't scrap and still no power. Oh is 14psi normal conditions. I have a downpipe intake exhaust(still have main cat),bigger intercooler and a hks bov. It always smells really rich at idle but the a/f meter says 13.6. Normal? Could the cat be clogged adding back pressure to the turbo and cause one to fail??



Anyone have any ideas.





I plan on going single but for now may rebuilt twins so car will run right if that is the problem.



Thanks For your Help

at what rpm do you hear this scrape? is it a shrill metal to metal sound? have you tried lowering the boost? and if you have do you still hear it?



go single and forget about this crap https://www.nopistons.com/forums/pub...IR#>/smile.png

from 4k up and I can't lower boost I have no controller.

hmmm how are you boosting up to 14 on a normal basis? you know something is wrong with your turbo control system cuz its only supposed to boost up to 10lbs (10-8-10)

I have to definately chat that bout sounds like it's boosting properly with 9-10psi but can it still run to 10psi on one turbo and still have a lack of power???

oh definately a metal scraping sound like a tin can scarping thick metal