I have an 05 8 GSR thats bone stock except for the hks bov(VTA) that came with the car. Im looking to replace that part. I looked at the Tomei Bov

https://frsport.com/Tomei-191186-Blow-Off-Valve-Mitsubishi-EVO-7-9_p_21239.html

Can someone tell me if this part recirculates or vents to atmosphere? Thanks in advanced

 

This is a recirculated diverter valve. Pretty much identical to a stock IX DV. I wouldn't spend $171 on that. Just search the classifieds on this forum and find a used IX metal DV. Will cost you $50-$100 on avg.

 

Thanks for the tip! I will look at that. I just needed to know because i need to replace the bov, i believe its causing the evo to run lean

 

Because you car isn't tuned for it. In order to run a fully VTA set up on a stock ECU VIII/IX you need to switch to speed density. in stock form the car runs off of a MAF.

 

Okay, thanks for that tip as well! Now if i were to get the diverter valve, would i need to tune it for that as well?

 

Not if the car has never been even tuned