I agree these little rotary pumps are a lot of fun and they will click off a decent e.t. and you can pull a sled around. How ever if you really want to be competitive you gotta have a p-pump or a pair of CP3's. There's just no comparison to a modded 13mm p-pump at 5000rpm or a common rail being fed by twin rotaries (cp3's) at 4500rpm!!! To compare you would have to run twin VE's which has been talked about but isnt worth the time or effort. I own two VE trucks. My duallie has made over 450cc of fuel....and still makes deep into the 300's now so the pumps can fuel but not enough for fierce competition.
Still a hell of a lot of fun in such a light chasis though. LOL.