Originally Posted by
allo80
If it's fluttering (fully sick sound) on throttle lift off or gear change then the valve is too stiffly sprung
I read a great article that says with the Forge that valve flutter is perfectly normal for this type of BPV with part throttle. IF it is fluttering on full boost that is most likely compressor surge. When I give it WOT in any gear it gives a nice suck and then PING! with zero flutter.
Oh hear I dug it up
"Each user will need to adjust their valve so that it will hold boost all the way to the
specified redline of their application under wide open throttle without experiencing
any valve fluttering at full-boost throttle lift.
If valve fluttering is felt at full-boost throttle lift, this is typically an indication that
the valve is adjusted too stiffly.
If the valve is leaking under wide open throttle before the specified redline of the
application is reached, this is typically an indication that the valve is adjusted too
softly.
Please note that valve flutter under partial throttle conditions or partial boost throttle
lift is a normal occurrence as IS NOT an indication of compressor surging. Partial
throttle or partial boost valve flutter is solely an indication that the valve is
responding to an inconsistent pressure differential on either side of the throttle body
as it is being modulated. Compressor surging would only be experienced if full-boost
throttle lift valve flutter is experienced and is not corrected immediately."
"The flutter is something you will experiance on the piston style BOV iT's valve flutter. This is what happens when the valve opens and closes very rapidly as the pressure in the bottom side and the top side get very close to equal. Mine does it between shifts under light loads. I have the turbo xs bov. the higher spring rate will eliminate some of it but You will have a less responsive bov."
Not sure where this came from, but I have seen it a few times quoted with no rebuttal. I discussed this with my tuner and he also said it was fine. Zero feeling of surge from turbo, just smooth gear changing all round.
On a side note....holy shit this BPV is far louder than stock. IT scares the crap out of people who are on the street or windows down. I frequently "PING" next to cars and they back off throttle thinking something is going wrong haha. I call part throttle boosting "Hitting the jackpot" as it goes butta chiiinggg" like its rainin gold lol
Last edited by nas711; 12-04-2015 at 09:55 PM.
2010 Gen 2 - "SPOOOL" (VIC) - Fully bolted
CORKSPORT TURBO | COBB AP3 | COBB DOWNPIPE | COBB REM | AUTOTECH HPFP | CORK SPORT 3" PS MAF INTAKE | COBB SF AB | CPE TMIC | CPE HEADERS | COBB 3 PORT EBCS | 3 BAR MAP| PEDDERS COILOVERS | DBA T4 SLOTTED ROTORS | CORKSPORT EYELIDS| FORGE V1 BPV| | MAGNAFLOW CUSTOM | VELOCITY RED | PEARL 2PAC STOCK RIMS | DUAL TUNED BY HPF ON E30