i put on a berk test pipe today and i decided to block one side of my dual tanabe exhaust, i was suprised that it was quieter than before it SEEMS to have a little more mid power but vtec felt a little...wheezy. the exhaust note is fine. has anyone else lost their mind and done this?? any ideas on it??

 

Assuming yoru butt dyno is accurate, the loss in top end power could be due to the reduction in flow area caused by blocking a pipe (you're now trying to shove as much flow down 1/2 the area), and/or by turbulence/pressure waves caused in the exhaust.

If there was a gain in mid range power this could be due to beter management of the exhaust flow out of your engine. Each pulse of exhaust that comes out of your engine (each time one set of valves opeon) provides a high pressure spike. Since exhaust has a little bit of mass, as the high pressure pulse goes down the pipe it can create a lower pressure zone behind it. If the pulses are timed right (your mid range in this case) one pulse can actually suck out the pulse behind it, reducing the work the engine has to to to pump the exhaust out, so more power goes to your wheels. The bigger the pipe, the closer together the pulses have to be for this effect to occur(usually).

Hope this helps

 

gracias.