Silent ARC recirc valves?

[SVTong]

So I just installed a pair of ARC blow offs that have the re-circulation kit on them. Aside from some hose re-sizing, they swapped directly with the stock recircs. I was pressed for time, so I wasn't able to play around with the adjustment screws, but the car drove fine all day today. The only thing is that I can hear nothing coming from them, and the car doesn't really feel too different. I've heard that throttle response is supposed to improve, and that even with recirc valves, you should still hear a bit of "psssht". Are the valves set too tight, and should I be concerned about compressor surge?

Oh, I haven't really brought the car up to full boost yet, as I didn't want to wreck anything until I've got them adjusted properly.

[mcfly]

if they were too tight you would hear it. Stock twin setups do not have traditional compressor surge off throttle. If will have one initial spike and vent out either of the turbos.


Ideally you shouldn't be able to hear anything with recircs, at least on a gtr as the piping is so long.

[victoriaGTR]

if they were too tight you would hear it. Stock twin setups do not have traditional compressor surge off throttle. If will have one initial spike and vent out either of the turbos.


Ideally you shouldn't be able to hear anything with recircs, at least on a gtr as the piping is so long.

thats funny my stock recircs were quite loud... i could hear them release easily. someone once asked me if i was running a/m bovs.

[SVTong]

So I should be ok running them as-is?

[GTR-Dad]

If you want to believe they're actually venting when you lift, I'd be looking for something a little more conclusive than someone saying theirs don't make noise either.

Reality is that they're either venting or they're not. Both scenarios could result in the observation - silence.

Think of ways to determine whether or not any air is flowing when it should be. This could done a few different ways.
You could try disconnecting them from the intake, capping the intake, putting a diaphragm on the BOV outlet, going for a spin, and checking to see if the diaphragm is ruptured.
You could insert a thermocouple probe in the recirc line and watch for temperature change when the BOV should be active. (Vented air should be a different temperature than air that's just sitting in the recirc line.)

There are probably some smarter ways to do this, but I can't think of them right now!

GL,
Dan

[SVTong]

That seems to be closer to what I was looking for. I'll try out the diaphragm idea this weekend when I have a bit of time.