FIRST OFF I KNOW THERE IS 100's of threads about this but no answers in plain sight.


Recently I moved my MBC up then down then back up about 3psi now my car Flutters @ 1psi 1/3 throttle throttle and on 21psi WOT.

I have a open 02 dump and stock turbo with 10.5 hotside and a Greddy S BOV

My MBC is hooked up from actuator>mbc>turbo

The BOV is ran from Intake manifold to BOV also the BOV screw is screwed out pretty far

This is really annoying as I know the turbo is tight as I checked it for shaftplay and I do not want to damage it over time. My question is this compressor surge or just because of the open O2 dump and how do I fix it


Thanks

 

A big contributor to the flutter could be a bad vacuum source. Make sure the wastegate and the BOV are both getting properly sized and valid vacuum sources.

 

so today I'm gonna do the single spring mod see if it helps

 

Is your bov open at idle? Adjust the bov so that it just barely unseats at idle but doesnt open full. You also need to use the boost only ref port when using two springs.

 

i dunno if its open at idle I'll have to check

 

That valve usually stays closed at idle due to the design of it.When you do the single mod ,make sure you use teflon tape to stop any type of leaks from occurring while the valve is in action.All of these type of valves tend to flutter at part throttle but should release with one quick shot of no flutter at wot.You will have to adjust the screw on top,till you reach the right setting.I have a samco and has a slight flutter too at part throttle but,when I go wot there just one quick release and sound like whip.Check to see while the valve is open if there's any type if rips and tears in the diaphram since there known for that.Good luck.