Speedtoys

What are some opinions on how much is resonated back thru the throttle body to the airbox -vs- other sources under the hood?

Im not complaining about it, just wondering its source.

Petza914

On my supercharged '79, I had an open K&N filter and the car was very loud. Going to a closed carbon fiber airbox that draws air through the front passenger fender liner made the far much more enjoyable to drive and has me using much more of the rev range, as before, it was just too loud and sounded like it was going to explode anywhere beyond 4,000 RPM, my point being there is a lot of intake roar. My car is decatted with a 928MS stainless Y-pipe and a Borla exhaust so that probably added to the total sound, but its great now.

Old intake setup followed by new intake setup

dr bob

In a previous life, I had a 911 engine mounted midships in a tube-frame with some skin on it for a weekend autocross car. It had plates on it so I could drive it to-from, and had absolutely the quietest mufflers I could find. The intake bells had oiled-foam socks on them, and provided no intake noise attenuation at all. I was "invited" to a CHP vehicle inspection session for exhaust noise after a roadside visit. Officer asked me to rev the engine. I gave it a gentle bump, and it was quiet enough. He told me to really rev it, and it got a little more bump but still OK. I explained that most of the noise is intake not exhaust. Rev it HARD!. So I did. Six large toilets flushed simultaneously but in harmony. Fortunately he was a sympathetic car guy. His comment: That sounds even better than our cruisers!