First off, as the title states this is complicated, but I'm going to be as informative as possible to help other people possibly diagnose my problem....so this may be a little long.
2005 WRX
txs TBE
PnP manifold and PnP gutted stock upipe
Cobb SF intake
walbro fuel pump
750cc injectors
CSS TMIC
EvoIII16g (PnP, coated)
AP v.2
Protune (91oct and e85)
I just finished installing and was tuned a couple days ago. I noticed 2 issues after the tune. 1) In higher gears (mostly 4th and 5th) when I let off the gas there is a fluttering noise coming from the turbo. 2) In higher gears (mostly 4th and 5th) when I roll on the gas from low rpm (2500-3000) the turbo starts to stutter when I reach full boost, but the stuttering smooths out and goes away after the engine revs another 500rpm. Sometimes the latter problem is so severe that the car actually bucks with the stuttering, and in 5th gear it won't rev any higher until I let off and then reapply gas.
I spoke with the tuner and a tech at txs and both had different ideas about the problem. My tuner thinks the stock bpv can't hold the boost in pushing (20psi) and so it is opening up prematurely and causing the stutter while under hard acceleration. He also thinks the bpv is causing the flutter during shifts, because it can't flow enough air to relieve the pressure left in the intercooler when the TB is snapped shut which is causing compressor surge.
The txs tech thinks they are 2 seperate problems. He thinks the bucking under acceleration is caused by overboosting and that the stutter is caused by boost cut happening repeatedly and very quickly. Like my tuner, he also thinks the noise while shifting is compressor surge due to the factory bpv not being sufficient.
So, my tuner discredited the txs techs first theory by saying that hitting boost cut, which he set at 22psi, would give a CEL and make the car bog badly, like it was out of gas or something. He told me to try the $0.16 mod ($0.16 BOV mod - Page 7 - NASIOC, so i did. It made the problem much worse, even though it's supposed to make the stock bpv hold more boost. After the mod I got the loud "squirrel" sound when shifting from ANY gear. So I reversed the mod and am back to where I was after the tune. My tuner suggests I get and aftermarket recirc valve that can handle more boost and is adjustable.
I just want to see if I can figure this out before I drop $200-$300 on a bpv that may or may not help.
Man that was long. Thanks for any ideas you might have.
2005 WRX
txs TBE
PnP manifold and PnP gutted stock upipe
Cobb SF intake
walbro fuel pump
750cc injectors
CSS TMIC
EvoIII16g (PnP, coated)
AP v.2
Protune (91oct and e85)
I just finished installing and was tuned a couple days ago. I noticed 2 issues after the tune. 1) In higher gears (mostly 4th and 5th) when I let off the gas there is a fluttering noise coming from the turbo. 2) In higher gears (mostly 4th and 5th) when I roll on the gas from low rpm (2500-3000) the turbo starts to stutter when I reach full boost, but the stuttering smooths out and goes away after the engine revs another 500rpm. Sometimes the latter problem is so severe that the car actually bucks with the stuttering, and in 5th gear it won't rev any higher until I let off and then reapply gas.
I spoke with the tuner and a tech at txs and both had different ideas about the problem. My tuner thinks the stock bpv can't hold the boost in pushing (20psi) and so it is opening up prematurely and causing the stutter while under hard acceleration. He also thinks the bpv is causing the flutter during shifts, because it can't flow enough air to relieve the pressure left in the intercooler when the TB is snapped shut which is causing compressor surge.
The txs tech thinks they are 2 seperate problems. He thinks the bucking under acceleration is caused by overboosting and that the stutter is caused by boost cut happening repeatedly and very quickly. Like my tuner, he also thinks the noise while shifting is compressor surge due to the factory bpv not being sufficient.
So, my tuner discredited the txs techs first theory by saying that hitting boost cut, which he set at 22psi, would give a CEL and make the car bog badly, like it was out of gas or something. He told me to try the $0.16 mod ($0.16 BOV mod - Page 7 - NASIOC, so i did. It made the problem much worse, even though it's supposed to make the stock bpv hold more boost. After the mod I got the loud "squirrel" sound when shifting from ANY gear. So I reversed the mod and am back to where I was after the tune. My tuner suggests I get and aftermarket recirc valve that can handle more boost and is adjustable.
I just want to see if I can figure this out before I drop $200-$300 on a bpv that may or may not help.
Man that was long. Thanks for any ideas you might have.