Hey guys, new to the EVO world, all of my knowledge is from Silvias so I'm sorry in advance for newb questions.

My EVO 7 has an 8mr BOV on it. It runs great. I bought a HKS SSQV with a recirc kit, installed it and it runs a bit oddly. It idles fine, drives fine, but after revving it or driving it, going back to idle in neutral will make the car almost stall. It'll fight the stall and go back to normal in a few seconds.

The 8mr BOV and HKS BOV look the same in that they both recirc, so I see no reason why HKS makes the idle dip so oddly.

Is this related to the tune that would already be on the car? I've confirmed piping and hoses are undamaged. Putting the old BOV on, the car runs fine again.

TIA

Yea if you search on here, there are other people that complain about that same BOV.

Maybe do a bosstleak test to see if air is leaking from the HKS bov.

Does the SSQV do like a partial atmospheric dump for noise or is it fully recirculating?

If its fully sealed and you dont have leak then it cant effect idle cause its all a closed system sucking air thru the MAF. But at full vacuum many BOVs will partially open so if its split in its dump it will also split what is draws in at idle/high vacuum. Is there a screw to tighten the preload keeping it shut at idle?

Welcome to the forums, vo777. Cheers

Hello and welcome

I agree with the above. It took me years to realize my TiAL QR was stuck partially open at idle. The car was originally MAF but converted to SD and we just disconnected the recirculation hose so I never noticed since the outlet was pointing down. Only recently when I tried swapping to the Q VTA base that I noticed that the BOV piston was partially open on idle. I am running a very soft spring but it works well and never bucks on low throttle/load. No issues whatsoever, but since you are on MAF, I feel like air is getting lost somewhere or setup incorrectly.

Apologies for the delayed response.

I think it might be partly atmospheric even with the recirc kit. Reason being is it sounds very distinct - which is why I've chosen it (apart from the list of HKS goodies that came with the car)

I've taken the BOV apart, and have not found a screw to adjust anything. I've also heard of people replacing an internal spring for other BOVs but nothing for HKS SSQVs.

The BOV is secondhand but Ive ensured it's genuine. I've recently found a lot of Evo guys don't run them because they're not fully recirc.

I am considering including it in the next tune, but everything seems to indicate I'd have to go MAFless to compensate, which I don't really want to do.