Hey guys, I just picked up an Evo 8 and the car currently has a recirculating bov I believe. The car was tuned this way. I was considering switching back to a conventional bov and wanted some input. Will switching bov's affect the tune? Also, I am having trouble even seeing as to where to swap it out, I recall on my last Evo that swapping bov's was easy and took 5 min. This car I can't figure it out for some reason, will somebody please re-enlighten me as I've been out of the Evo game for a while!! Thank you!! Here is a pic of my motor for reference:

 

The bov doesn't look recirculated in the picture. Changing a bov does not change the tune, or require tunign for the most part, but it will affect the driveability of your car. Since I see the car is still on a MAF setup, I think going back to a recircuted option is the best choice. I recommended an Evo IX OEM bov, or the Synapse DV as two solutions. Good luck.

 

If the car is still tuned on MAF then you should continue running a recirculated BOV/BPV (ByPass Valve). MAF cars don't handle vented BOVs well because air its metered fuel for is vented out of the system.

Switching BOV won't generally affect the tune if its the same type ie. recirculated or VTA. If you have a setup that is leaking and replace it with a BOV that is not leaking it could however.

Swapping the BOV is extremely simple just don't cut yourself on the sharp edge of the radiator fan. For some reason mine at least is like razor on the inside. :P

 

Your car is not recirculating right now, there is a plug that is going into the intake pipe closing it off. The BOV on there right now is in the lower right hand corner of the picture with the vacuum line coming from the side.

 

You have a MAF, therefore you also need a recirculating BOV

 

That's not recirculate its vent to air and if you want to go back stock you need a stock or recirculate bov first and a retune.

 

You in fact do have your current bov VTA. It will run fine either VTA or recirc. With VTA on MAF you will be richer between shifts because the MAF cannot meter the air being let out. You can tune it out a little with maf scaling but if you want to change the BOV back to stock that will be fine also. I would personally just get a good aftermarket BOV such as a Tial so you don't have to worry about it again if you plan to future mod your car and up boost levels.

 

Looks like you got the right answers to your question

Heres another tip: Put a detail on that engine bay

 

Thank you guys for the quick, good advice! Is very much appreciated!!


Also, will clean up the engine bay soon. I just purchased the car a few days ago.

 

Nice evo man! Got any more pics?