Question About Throttle to Engine Volume Increase Ratio

A couple years ago I was digging around in Beam's lua and somehow figured out how to adjust how much louder the engine got when hitting the gas. As of late I haven't been able to figure out how I did it and was wondering if anyone knows how to do it. I've already scoured all the the main luas pertaining to engine, sound, and drivetrain but can't find it. Any help would be very much appreciated! Thanks.

 

Thanks so much! I'll try it.