Hey guys my name's Matt and I'm currently looking at purchasing a 2005 MR in Georgia, but before I go down there to look at it I have a question about the BOV that is on it. I used to have a 97 GSX and am very familiar with the 4g63 of that era but not as well with the Evo's. The pic I posted is the one of the MR i'm looking at and it seems like it doesn't vent back into the intake and I really don't want that, but i'm not sure? Any help on this is greatly appreciated.

 

I cant see that well but from the looks of it, they have the bov on there wrong. It is infact aftermarket, and is not a recirc set up. The valve needs to be attached to the intercooler pipe, and from the looks of it, its connected to the intake pipe. If thats the case its gonna be hard on the turbo and potentially damage it.

 

Look closer, looks like the pipe from the UICP for the BPV is connected to the back of the BoV he has on there now (See the second bolt head to the top right of where the clamp bolt head is on the intake pipe). Looks like a VTA - BpV combo valve like the go fast bits valve, although, this one doesn't look adjustable like theirs is..

 

Ah ok I see it. If thats the case then its a split like 50/50 or so. Gives you the sound of an atmosphere release, but still maintaing some drivablity. Correct?

 

It still looks wrong? The piston chamber on the BOV is vertical in the pic (should be sideways), and it seems that the piston end is connected to the intake pipe, rather than the return pipe. Is there heavy surging on boost?

Looks to be a Turbosmart Dual Port (older version) for the Evo.

 

Yeah it's a turbosmart dual port. I actually bought the car Friday. It's hooked back up into the intake but also vents to atmosphere through the trumpet looking side. The way it's made though makes the air go into the intake first because the put about a 1/3 or so "plate" on the atmosphere side so the piston can't let air go out that way if it's not under heavy boost. You can also adjust it by turning the red part but i'm leaving it alone for now until I can figure out what all is done to the car and get a tune. Kind of neat but I'd rather have something more quiet.

 

If there is in fact the 'whoosh' sound of the venting on higher boost, then it's hooked up correctly. You should hear a flutter on lower RPM, then the signature whoosh on higher boost. To my knowledge you can remove the trumpet and fit a blanking plug to make it full recirc like the stock BOV.
Could you get another pic of the BOV from a different angle?

Side note: Even if the piston side is installed the right way (from the return pipe), it can still be installed incorrectly in terms of 50/50. The way the 50/50 works is that there are 2 ports on the BOV for venting. They are on opposite sides, but one hole is higher than the other. The lower hole is for the recirc, while the higher hole is for VTA on 50/50 mode.