Subaru Enthusiasts Car Club of the Sierras - View Single Post

sperry · 2003-01-30, 08:17 PM

The stock BOV is actaully a really good BOV. Plus it's recirculating, which means the compressed air that the other (loud whooshing) BOVs just vent to the atmosphere gets put back into the intake.

Recirculating some or all of the air helps keep lag down during shifts because the compressed air is still in the system while the turbo is not compressing (i.e. during a shift, or when you get off the gas).

On a 4EAT, the BOV doesn't make quite as much of a difference as the 5MT because you can keep on the gas during shifts. If you want the cool sound, check out the 50%-50% recirculating BOVs, since they vent half the air back to the intake. I think that GFB one might be a 50-50, but check to make sure.

Also, don't listen to the monkey... he's all hopped up on fumes from his big-ass 5.0! Acutally, all the stuff he said about the BOV is correct... with this addendum: no BOV = bad, vent to atmosphere BOV = good (and sounds cool), vent to intake (recirculating) BOV = better.

The reason you hear the "psssst!" sound on rally cars is that they run vent to atmosphere BOVs *and* an anti-lag system. No need to keep that compressed air in the system when you're intentionally backfiring the motor to spin the turbo! Get of the gas in one of those cars and you hear: "PSSHHHHHT!! BANG! BANG! BANG!" But then you have to replace the turbo after every weekend.

2003-01-30, 08:17 PM	#10
sperry The Doink Real Name: Scott Join Date: Nov 2002 Location: Portland, OR Posts: 20,335 Car: '09 OBXT, '02 WRX, '96 Miata Class: PDX/TT-6 The way out is through	The stock BOV is actaully a really good BOV. Plus it's recirculating, which means the compressed air that the other (loud whooshing) BOVs just vent to the atmosphere gets put back into the intake. Recirculating some or all of the air helps keep lag down during shifts because the compressed air is still in the system while the turbo is not compressing (i.e. during a shift, or when you get off the gas). On a 4EAT, the BOV doesn't make quite as much of a difference as the 5MT because you can keep on the gas during shifts. If you want the cool sound, check out the 50%-50% recirculating BOVs, since they vent half the air back to the intake. I think that GFB one might be a 50-50, but check to make sure. Also, don't listen to the monkey... he's all hopped up on fumes from his big-ass 5.0! Acutally, all the stuff he said about the BOV is correct... with this addendum: no BOV = bad, vent to atmosphere BOV = good (and sounds cool), vent to intake (recirculating) BOV = better. The reason you hear the "psssst!" sound on rally cars is that they run vent to atmosphere BOVs and an anti-lag system. No need to keep that compressed air in the system when you're intentionally backfiring the motor to spin the turbo! Get of the gas in one of those cars and you hear: "PSSHHHHHT!! BANG! BANG! BANG!" But then you have to replace the turbo after every weekend. __________________ Is you is, or is you ain't, my con-stit-u-ints?