kingtal0n

iTrader: (1)

just as an aside, I Note a healthy slant in the turbo oil feed. Many turbo manufacturers recommend no more than 20* of slant. I emailed borg warner and they were actually a little weary of the full 20* they recommend max, kinda like "yeah you can maybe get away with it buts it is a worse case scenario". I see in the picture what looks to be more than 20*.

let me tell you what I would do if I had a boost falling issue.
first pressure test everything. I mean everything, put boost pressure PSI into very conceivable orifice except the crankcase. Verify its all air tight. All lines/crevices.
Next a simple mechanical check for misplaced or misconfigured machinery, i.e. fire ring/wastegate type issues mostly.
Then you have it fairly narrowed down to the "setup", meaning its just "what it wants to do". My solution for that is to increase duty cycle as rpms rise. You can use boost duty vs RPM type controller or you can manually adjust the dial up as you increase in RPM etc... (If you are on a dyno and desire a flat torque curve, that last one works even though you would never expect to reproduce it on the street)

Johnv

I would reference the boost controller and boost gauge from the manifold, but use the turbo nipple to feed the boost controller solanoid. That way both controller ang gauge are seeing the same boost and maximum boost is available pre intercooler to control the wastegate via the solanoid.

stevieturbo

That is the correct and normal way.

However on some systems if they're really **** or inefficient that have huge pressure drops across their plumbing and IC units, some prefer to take the w/g feeds from closer to the intake as a band aid for the system.

The correct/sensible solution would be build a system where there is negligible pressure drop in the system