I flew my Topgun Mig29 powered by a JJ1800 and it flew very well. Our club field is 800 feet, all grass and it took a little less than half to get airborne. My airplane full of fuel weighs in at 22lbs. I'm using a Tam bifurcated pipe. I'm not sure how much thrust I'm getting but it sure is a lot to be able to fly my airframe with authority at the weight I described. I use to have a Wren 54 mk11 in it and performance was marginal so I put a JJ1800 in it. Overall, I'm completely satisfied with my engine. I bought mine from Gabe and Mark, the US Jetjoe reps.
Steve