RE: STS engine
I like the D21T as well. My son runs one in his XB8. I think it might be a little better than the V-spec that it replaced.
We have two off-road tracks here. Both have a different club racing group. At one of the tracks, all the guys are running big $$$ stuff. Last Wednesday, only two buggies were not running either a modified RB or Rossi. One of the two buggies is owned by this guy named Bill. Bill runs a Mugen powered by a STS. I do not know the details of his motor, but I do know he wins all the time. He runs at both tracks. If he does not break, he wins. Now I will say that this guy can drive. He could probably win with an old beater. Bill grew up in a town 26 miles away called Burkbarnett, TX. Same town Steve Slayden is from. They are both the same age. I found out the other day that they use to race electric together. Kind of cool.
Sorry to ramble, but my point is that I do not think this guy would run junk. Further, I'm pretty sure that STS power won two major titles in expert truggy last year.