Compressor surge or flutter?

[mott6904]

I have a rb20 with a 60-1 turbo and a greddy type r bov. I cant tell if my bov is surging or flutter. whenever i rev it up at idle i can feel air coming out of it. but whenever i drive it and give it some gas it sounds like it surging at all times. What is the easiest way to tell if you are flutter or surging. Do greddy type r have a flutter sound with a big turbo. it seemed to work fine with my stock turbo.

[Shocker]

most likely compressor surge, not sure if you can adjust your BOV or not... if so play with it.

[240slidekat]

how much boost are you running?

[Coolwhip]

yea, how much boost? Might be operating out of its efficiency range.

As well, do you have your BOV hooked up to a vacuumed source?

[mott6904]

Yes it is adjustable it is as loose as i can make it. Yes the vacuum line is hooked up to it. Im only running about 10 psi. i would assume that 10 psi would be out of range for the type r. It not a cheap knock off either. Why would it work when reving but then sound like it is surging under boost.

[Joe]

because theres no load at idle

its the same reason you cant build boost when you free rev.

[mott6904]

so i have a bad blow off valve? it isnt that old. Proballly a couple years but there cant be anymore than 4000 miles on it if that. And it worked fine with stock turbo. i would think the bigger turbo flows more and it would need to be tighter to work right .

[gawdzilla]

i've had one for about 3 years and have only "heard it" a handful of times, and even then i'm not even sure it works. what does it sound like when it opens? i just assumed the outlet was so large that it's kinda silent, haha. most of the time i hear compressor surge though. not really concerned about it as long as it doesn't leak under boost.

[hkst04z]

because theres no load at idle

its the same reason you cant build boost when you free rev.

you can build boost at a rev

[mott6904]

im concerned about it i dont want to replace my turbo after a year because my fins are bent all to hell. On my old turbo it was silent all you heard was a soft air flow noise. Nothing like a chirp or whistle like small bovs. But now with my new turbo it sounds like it is surging. I even loosend the spring all the way out and it still does the same thing. Thats why im curious about what a flutter sounds like instead of surging, unless surging and flutter is all the same. I would take a sound clip while im driving but im in the middle of putting a quest alternator and converting it to a wasted spark setup.

[gawdzilla]

eh, bov and turbo longevity is mainly a myth. i'm yet to see someone showing a turbo "damaged" by running no bov vs. one that is healthy by running a bov. i wouldn't be concerned about the life of your turbo without one. more often than not, the bov is just another source for a boost leak. IMHO, turbo timers and bovs are the most oversold "tuner" items

it can help transitional response and maybe build boost faster though by giving the air somewhere to go instead of shuffling back and forth and bouncing off the compressor fins/slowing them down. that is what i belive the factory recirc valves are for.

i'll try to take a vid of the "noise" mine makes...