surge or normal?

WhatsaSTI · 05-08-2006, 07:05 PM

I think what I'm experiencing is compressor surge. From what I've researched, it has symptoms of what people claim to be compressor surge (low boost/low rpm shifts, i hear a flutter sound... high boost shifts, i hear the regular BOV whoosh).

What I'd like to know is, is my problem coming from my wastegate or my BOV? I have a TurboXS type RFL BOV and I have a stock STi vf39, catless downpipe and a cai at below 3000 rpm i get this turbo sound like a psh psh psh from the turbo not the bov at above 3000 rpm the bov blows off fine am i getting surge? and can i tell if its surge by the boost gauge?
Sorry... this research has confused me.

its only when i have lil to no boost its a psh psh phs
the sound is just like that from gti's and those supras

listin to this video its in the first few seconds when he is shifting gears at low rpm sounds just like this http://videos.streetfire.net/hottest...CC15D6C160.htm its at 6 seconds in the video

Ians06 · 05-08-2006, 07:38 PM

I'll reply for everyone else.....get rid of the BOV, no good. Also check Unabombers Manifesto for almost any question you may have about your subie!

Good luck!!!

WhatsaSTI · 05-08-2006, 07:42 PM

ive searched with no answere

Ians06 · 05-08-2006, 10:21 PM

My car has the same "flutter" under low rpm wot acceleration. I did not notice it until I changed to a catless DP, but I'm pretty sure it has always been there, I just could not hear it until I changed the DP. I would try swapping the BOV back to factory and I'll bet the psh psh psh goes away.

WhatsaSTI · 05-08-2006, 10:31 PM

i dont want to change the bov but im just asking if its normal and wont kill my car

Ians06 · 05-08-2006, 10:46 PM

Compressor surge happens when you have boost built up and you let off the gas fast and the throttle plate slams shut and the boost has nowhere to go, then the pressure pushes back on the turbo slowing or "surging" the turbo. That is bad. that is why our cars have a BOV or recirculator, so the pressure bypasses the throttle plate and the turbo and is re-routed back into the intake so you don't have "surge". I the valve is opening at lower rpm's you may be losing some boost, but I don't think you will do any damage, but.... without seeing or hearing it in person I don't know. But as I said if you think it is causing a problem I would take off the BOV until you find someone that can hear/see it and tell ya for sure.

ronnyek · 05-09-2006, 01:05 AM

I would be willing to bet 99% that the bov is causing surge. Not to talk mean crap about turbo xs, but I've had 2 rfls, and both of them caused worlds of surge. No ammount of adjustment whatsoever helped in the least.

I finally just swapped em out, and have been much happier. I'd like to hear blow off, but to be honest, I'd rather not cause damage to my motor. If you have to run a bov run the diaphram type.

05 wrx sti · 05-09-2006, 01:50 AM

BPV!!!!!!!!!! by past valve all the way

05-08-2006, 07:05 PM	#1
WhatsaSTI Scooby Newbie Member#: 84990 Join Date: Apr 2005	surge or normal? I think what I'm experiencing is compressor surge. From what I've researched, it has symptoms of what people claim to be compressor surge (low boost/low rpm shifts, i hear a flutter sound... high boost shifts, i hear the regular BOV whoosh). What I'd like to know is, is my problem coming from my wastegate or my BOV? I have a TurboXS type RFL BOV and I have a stock STi vf39, catless downpipe and a cai at below 3000 rpm i get this turbo sound like a psh psh psh from the turbo not the bov at above 3000 rpm the bov blows off fine am i getting surge? and can i tell if its surge by the boost gauge? Sorry... this research has confused me. its only when i have lil to no boost its a psh psh phs the sound is just like that from gti's and those supras listin to this video its in the first few seconds when he is shifting gears at low rpm sounds just like this http://videos.streetfire.net/hottest...CC15D6C160.htm its at 6 seconds in the video

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05-08-2006, 07:38 PM	#2
Ians06 Scooby Newbie Member#: 105698 Join Date: Jan 2006 Chapter/Region: South East Location: Johnson city,TN Vehicle: 2006 STI Black	I'll reply for everyone else.....get rid of the BOV, no good. Also check Unabombers Manifesto for almost any question you may have about your subie! Good luck!!!

05-08-2006, 07:42 PM	#3
WhatsaSTI Scooby Newbie Member#: 84990 Join Date: Apr 2005	ive searched with no answere

05-08-2006, 10:21 PM	#4
Ians06 Scooby Newbie Member#: 105698 Join Date: Jan 2006 Chapter/Region: South East Location: Johnson city,TN Vehicle: 2006 STI Black	My car has the same "flutter" under low rpm wot acceleration. I did not notice it until I changed to a catless DP, but I'm pretty sure it has always been there, I just could not hear it until I changed the DP. I would try swapping the BOV back to factory and I'll bet the psh psh psh goes away.

05-08-2006, 10:31 PM	#5
WhatsaSTI Scooby Newbie Member#: 84990 Join Date: Apr 2005	i dont want to change the bov but im just asking if its normal and wont kill my car

05-08-2006, 10:46 PM	#6
Ians06 Scooby Newbie Member#: 105698 Join Date: Jan 2006 Chapter/Region: South East Location: Johnson city,TN Vehicle: 2006 STI Black	Compressor surge happens when you have boost built up and you let off the gas fast and the throttle plate slams shut and the boost has nowhere to go, then the pressure pushes back on the turbo slowing or "surging" the turbo. That is bad. that is why our cars have a BOV or recirculator, so the pressure bypasses the throttle plate and the turbo and is re-routed back into the intake so you don't have "surge". I the valve is opening at lower rpm's you may be losing some boost, but I don't think you will do any damage, but.... without seeing or hearing it in person I don't know. But as I said if you think it is causing a problem I would take off the BOV until you find someone that can hear/see it and tell ya for sure.

05-09-2006, 01:05 AM	#7
ronnyek Scooby Specialist Member#: 60724 Join Date: Apr 2004 Location: Central Coast of CALI Vehicle: 06 CG STI-05 g35 ^ Needs trunk swap. PM ME	I would be willing to bet 99% that the bov is causing surge. Not to talk mean crap about turbo xs, but I've had 2 rfls, and both of them caused worlds of surge. No ammount of adjustment whatsoever helped in the least. I finally just swapped em out, and have been much happier. I'd like to hear blow off, but to be honest, I'd rather not cause damage to my motor. If you have to run a bov run the diaphram type.

05-09-2006, 01:50 AM	#8
05 wrx sti Scooby Specialist Member#: 106596 Join Date: Feb 2006 Chapter/Region: South East Location: Biloxi , MS Vehicle: 2005 CGM Sti 23psi GT35R+METH 471whp/448trq	BPV!!!!!!!!!! by past valve all the way