Well, it's been a little while since I posted. I've been too busy driving the Evo since I picked it up a few weeks ago. Will show pics later. Anyways, my problem is that when I have the car in gear and I let off the accelerator I hear what sounds like a metallic popping or grinding noise. I don't know if it's my drive shaft or the exhaust. Has anyone experienced a problem like this. Is this normal or am I going insane. Also, I raced another Evo last week and he said he was losing horsepower from his aftermarket Blowoff Valve. Does this sound right to anyone. I know that the MAS sensor is confused if the air is not re routed back into the turbo, but I wouldn't think it would make a significant difference

 

Do a search for decel noise, its been covered a zillion times. I've been in very few AWD cars that do not have it to some degree or another.

As far as the BOV, the general conseneus seems to be 100% vent and you will loose HP. 50% vent is probably not significant. 100%recir. and you probably won't notice anything. Again do a search(top right corner of page) and you will find these topics have been covered many times over.

 

Power loss is related to the inability for the valve in the BOV to open/close in a timely fashion and create a solid seal at WOT/high rpms. It pays to do your research before you buy aftermarket parts, that's basically what it boils down to.