It sounds like you used the same cap with both gaps. I can't say how your bang voltage differed between the static and SRSG gaps, but if it's similar, I would not expect to see a difference in performance between the two. It's only because I was able to use a larger Cp with the SRSG that the bang size (.5*C*V**2), and hence performance increased.
Regards, Gary Lau MA, USA
Gary,