Atmosphere BOV V.S Recirculating BOV

[drakered6]

HI, I own a 97 gs-t eclipse spyder and am looking to start upgrading the complete turbo set up on this car starting with the blow of valve. Im new to turbo set ups and am wondering whats the difference between atmosphere BOV set up's and recirculating BOV set up's? Which is best?

[Blackcrow64]

Neither is better than the other. They are just personal preference on if you would like the BOV to be louder or not. HOWEVER, if you vent atmosphere then you must be running a GM MAFT. The reason for this is because the ECU is expecting that vented air to be recirculated back into the intake. If it is not present then you will be running too rich. Some people say it affects their performance and sometimes idle, some people never notice anything with it. Regardless, the proper way to vent atmosphere is to use the GM MAFT if that is the route you would like to go. If not, then you can upgrade the BOV and just recirculate it without any other mods. The aftermarket BOV will hold more boost than the factory plastic ones which start to leak much past the stock PSI... I think I covered everything... Hope it helps.

[drakered6]

What is a gm maft?

[ned032002]

I read somewhere that in ome cases after a hard pull, if the bov is not recirculated the car will stall out because of the air not coming in as expected.

[LandoAWD]

Get a 1g BOV and READ UP.

If your MAF is in front of your BOV; always recirc.

Don't do a MAFT "upgrade" (they suck anyway) just to run an atmospheric BOV. The whole point of upgrading MAFs is to increase allowable airflow. The 2g MAF has gone 10s, so that isn't an issue.