FMIC bypass valve
FMIC bypass valve I am getting ready to change from the twins to a fmic and was wondering has anyone venting the bypass valve to the outside? and did you have any problems doing this.
BOSS APPROVED! I have the newer pro-flo, I was told that if you vented it to the outside it would cause tuning problems with the maf when the car shifted gears. I was just wondering if anyone was having any problems with this set-up.
SSU Moderator
Joined: Nov 2001
Posts: 4,857
Likes: 0
From: Austin, TX
You are talking about a basic blow-off valve or bypass valve. Same thing, but usually 'bypass valves' are vented back into the intake tract. Blowing off to atmosphere is no big deal...but on an MAF car you have to make sure you are metering exactly the amout of air making it to the engine. So don't put a BOV between the MAF and the engine...put it in the intake area before the MAF, then you can vent to atmosphere or back to the inlet of the blower. If you vent after the MAF, before the motor, you'll run REALLY rich I assume.
The point of either device is to relieve the pressure between the turbo/blower and the TB when the TB closes when you let off the gas. the unit will bark or chatter when the air has no where to go, and in some cases (probably over an extended amount of time, or in extreme cases) it can damage the turbo/blower. The BOV/bypass just lets that charged air escape when the TB closes.
The point of either device is to relieve the pressure between the turbo/blower and the TB when the TB closes when you let off the gas. the unit will bark or chatter when the air has no where to go, and in some cases (probably over an extended amount of time, or in extreme cases) it can damage the turbo/blower. The BOV/bypass just lets that charged air escape when the TB closes.
If your setup is sucking the intake air through the MAF, you have to recirculate the bypass air because its already been measured by the MAF. The only way to vent to atmosphere on a MAF equipped setup is if your blowing boost through the MAF.
