I'll put my cubeinator up against them anytime! bring em, on! i want a dyno showdown! seriously though, if they did make any power at all, alot of pro racers would be using them. I have a bit of time tinkering with banshee's but most of my two stroke engine experience comes from snowmobile racing engines. (tripple cyl 800cc, 200hp improved stocker) i have never and probably will never see any serious racers out there, who use these things. i used to spend a lot of time and money to find anything that would give me the slightest weight or HP adavantage on my sled. never once were these suggested to me by my builder who is a very reputable and well know one from Essex Junction in Vermont. if they were any good at all they would be on every race sled on the circuit and recomended by every reputable builder. and yes, these things are actually available for sleds! why waste your $200 on these when you can buy a set of race proven pipes, a good porting job, or other proven upgrades. this is in IMO. if ya just got to have them, go get em!