I am running mine at 28 degs on a CH CDI. I haven't checked it to see if I can get more out of it by moving the timing but it starts and runs great at 28. My SuperTigre 51 and 90 conversions both run their best at 28 and I did check them at a variety of settings. The 51 idles better at 25 degs but doesn't make as many rpm's, the 90 runs it's best all around at 28. My G26 runs it's best at 28 and my DL50 does as well. With so many seeming to be happy at 28 I just set the 26 MVVS (same motor as the Evo) there and left it.