I have been changing the spark advance on my BOA using a Tweecer and did some testing on the 1/4" mile with speed and timing. The funny thing is I didn't see ANY difference in stock timing and advanced timing. So I was under the impression the Tweecer didn't work correctly. After that I tested the 1/4" mile again but with the CPS moved about 5 degrees to give more advance. But again, I didn't see any performance improvement over standard!