Hi guys,
Harold from HP Autosport had heard about my exhaust slut status from M3post and my e9x days (I owned 5 e9x M3s with 33 different exhaust combinations). He asked me to review the new Borla exhaust prototype. It is a single muffler configuration with valves that use the stock electronic valve controllers. It is currently designed as downpipe back, so eliminates the secondary cats. Not technically emissions legal but will likely still pass a sniffer and won't throw a CEL since the secondary cats are unmonitored.
The valves are controlled by the stock scheme - Comfort mode has the valves closed until about 4000 rpm or heavy throttle, sport and sport plus keep them open most of the time except 1200-2500 rpm where they partially close to prevent drone.
This is a nice sounding exhaust. It's very mild most of the time but decently aggressive and loud without sounding immature under heavy throttle. The video should highlight some of both the aggressive music and the relatively mundane regular driving. It's shot from multiple angles - what you hear from the side of the car is more representative of what you'd hear from the windows being down, the mic close to the bumper is much more raw and aggressive but only what you'd hear directly beside the car under heavy throttle. It doesn't seem to drone much at all at steady state, but is aggressive when you get into the throttle. There is no mistaking this for stock, that's for sure!
Exhaust videos are always difficult, so I've tried to shoot from a variety of angles and positions to give a better representation of real world. Video is shot with a GoPro Hero 3 Black and a GoPro Hero 2 with an external Sony stereo microphone. The mic near the bumper makes the exhaust sound raspier than it is, the mic on the window is much more representative of the sound you hear both inside and outside.
This should be available in the next few months! Saves a good amount of weight, as well. (I'm not selling it and it's not on my car, so PM Harold at HPAutoSport or email
Harold@hpautosport.com for more info)
Here's the video - love to hear your thoughts.