Could someone tell me if a vent to air dump valve does anything at all except make a whoosh noise?.....is there any way to eliminate the delay that occurs after a gear change on a Turbo car before the power comes in again?.....is a recirculating system intended to try and reduce this aforementioned delay?...thanks in advance....

 

The vent to air makes a neat noise, and accomplishes the same thing a recirculating valve does... relieves pressure on the turbo impeller. A recirculating valve is good for your ECU's mental processes, as it has already "seen" the air that is being released by the BOV, and is adding the appropriate amount of fuel via the injectors to achieve a safe air fuel ratio. Venting to air means that off boost the ECU is adding fuel for air that is no longer in the intake path... so it runs rich, bogs, stalls, etc. You can fix it with an AF adjuster, such as the S-AFC, which can be set to pull fuel at low throttle to counter the missing air. I prefer using a good recirculating BOV, and letting the ECU do its job.

 

Here are some pics of the valves that we have for the Evo series as well as Gen 2 eclipse. 2Cool has the valves described perfectly in their differences. Although, our BOV is designed to not set off any codes while the DV is the factory style replacement. 2Cool, sorry we didn't get a chance to chat when you stopped by last week. Had alot going on that day.

 

https://www.evolutionm.net/forums/sh...010#post265010

 

Hey Tom!

What is the difference in sound between these two?... Is the BOV doing a high pitched sound (like GreddyS for example) or is it similar to the Forge DV for 1.8T VW's (I used to have one of those with your DV and loved it), which is more of a psst or whoosh sound?

Thanks!

/Emil