[Molina330]

Excuse my ignorance but back when I was younger I remember the Supra's and GTRs and others had a sick sounding blow off valve. Is that not possible with M4. Again I'm not sure please don't beat me up about this.

[Ghozthunter]

I believe they are electronic wastegates that recirculate the air back in. In order to get a similar bov sound you will need to install a cold air intake system.
I did this on my g20 and the turbo sound increased dramatically. No performance increase just the pleasure of hearing the turbo.

[Molina330]

Originally Posted by Ghozthunter

I believe they are electronic wastegates that recirculate the air back in. In order to get a similar bov sound you will need to install a cold air intake system.
I did this on my g20 and the turbo sound increased dramatically. No performance increase just the pleasure of hearing the turbo.

No cold air is available at the moment : not sure

[Ghozthunter]

They will start to pop up soon. In the meantime you can remove the charcoal filter, I hear it increases the sound a little bit.