blkthghts

Ok fellas I have been @ a few cars shows and I am really digging the sound of these blow off valves. My question is though do they really serve the purpose intended. Which is suppose to back of the amount of air that goes back into the turbos. Hks sells them for the 300zx for about $695 b/c of the big boost turbos. CAn anyone speak on this cool valve.

DeezGst

The HKS SS's are nice BOV's. You should be able to find a kit for around $550 or so. The Apexi kit can be had for around $330 or so. I've ran both on previous cars and both are a great performing BOV.

The purpose of a BOV is to prevent pressure surge to the turbo. (Back pressure against the compressor blade when the throttle is closed, which can lead to pre-mature turbo failure) Your Z already has stock recirculatory valves, which serve the same purpose as aftermarket BOV's...only real difference is they recirculate into the intake stream.

There is no performance increase (hp wise) when you switch to a aftermarket BOV. Aftermarket BOV's may have a little better response then the stock valves, and will hold more PSI. Really there is no need to unless you have plans to upgrade turbo's and run high amounts of boost...The reason a lot of people switch them for aftermarket BOV's is indeed the "cool sound"

Also take note that most aftermarket BOV's vent to the atmosphere. When you do this some cars will experience rich conditions in between shifts etc.. as the air that is being released into the atmosphere has already been metered by your Mass Aif Flow. Just some food for thought. Do a search at tt.net for more info.

Derek