Some interesting results from yestedays race.
I freshened up the two Brood blueprinted motors (monster and p2k2) and shaved the leading and trailing edges of their new 767 brushes (with no hole this time) down to 1.7 width to match them to their comm widths according to the "scientificus formulaeus" above.
The previous brushes were 769's (with holes) that were shaved down to a 1.9 width in the post above. The gearing changed slightly on both.
With the monster my avg lap times were off by one or two tenths, but the power was pretty consistent all the way through to the last lap where it only dropped .15 from my fastest lap time. However, it came off the track a little hot at 204F.
The p2k2 was another story. I had my fastest run (knocked off five seconds) and lap of the day which was only .06 off my record lap time. It came off the track at 177F.
Then I reverted back to my old self and idiotically decided to use one of my buddy's prime motors in the main, instead of sticking with the proven p2k2.
Don't get me wrong, he (the Ikenator) does great "personal" motor work and after testing it for the right gearing, it was faster down the straight and had great pull out of the corners. However, it just didn't squirt me out of the corners as fast as the p2k2 and you could see the power fading the last couple of laps. I ended up loosing about a tenth on the average lap with it compared to the p2k2. Considering that very few passes are attempted at the end of the straight where your entering a tight chicane and pileups are frequent, I should have stayed with the Brood p2k2 power and increased the rollout by .5.
In reflection, I think the p2k2's spinup and efficiency are deceptively fast, whereas you think your going slower and are actually going faster. You can gear it to the moon as well.
I'll have a lot more tuning info later this week, as my dyno buddy (aka "The Mad Scientist" in electric drag racing circles), the Ikenator and I will be devoting half a day to tuning a stable of stock and 19t motors in preperation for the upcoming North/South Shootout race in NC. We'll be comparing dyno results from a CE 45, three fantoms (one older and two newer) and the little ol Orion.
We'll definitely be playing with brush shaving/holes and such.
Thanks for the info "CJ", your cover is blown.