sccsiouxland

Ok, I'm not versed in forced induction. Maybe someone can explain.
What is the purpose of a blow off valve? Do all turbo engines have one? Why do I see modified blow off stuff for sale?

Thanks.

wiki'd it and have a better idea of what it is. Still don't understand why someone would modify it.

Ok Russ, people modify the blow off valve for a couple of reasons. Guys that are running more boost then stock will do it because the stock blow off valve might not keep up with the extra boost. Somtimes the spring in the stock valve will not hold the extra boost, again if you are running higher then the stock boost level. Seen that happen on a car. Once in a while you get the guys that just want the louder BOV. We call those people ricers.

Perhaps bypass valve might be a better term that BOV. From what little I've seen the bypass valve doesn't vent directly out but can around to the input and the BOV vents to the outside world. Correct?
In that case, changing the spring in the bypass valve may allow more boost. Keeping in mind that these parts are research at length by the engine builder and it might not be the best idea to willy nilly change stuff.

the spring is for the waste gate which by passes the exhaust so the turbo's dont get all the power to spool up.

Congrats on the new car. I see you decided to not follow the break in period per the owners manual! Love the picture!

I think your looking at the trip odo. I think I had over a 1000 miles on it.
Now the long wait...

A blow off valve is what discharges the air on the cold side of the turbe when the throttle plate closes, this is to prevent a pressure wave from moving backwards and hitting the turbine and stopping the blades which is very had on the bearing. Most OEM turbo set-ups vent this back upstream (after the filter but before the turbo) so there isn't any noise, if you put a bov on a car like this is will run very rich everytime you shift as the air goes to the atmosphere instead of the combustion chamber.

What a lot of you guys are describing is the wastegate... that is what you can put different springs inside to change the pressure at which the wastegate opens and begins to let exhaust gasses around the turbo to limit the speed of the turbine.