BMW F30 328i - DIY Exhaust Valve with multiple selections. HD

Bought an exhaust valve set from China Web-Taobao. Welding work done by exhaust shop and self DIY another new chip set for opening exhaust valve with engine rpm timing. (My previous chip set only can turn On & Off exhaust valve, no rpm control). **Plug in sound system with base woofer for better sound. Button 1. Off Button 2. On Button 3. On when 3500rpm Button 4. On when 2000rpm