i have a piper 285, i had to get a vernier pulley to get it set up properly. you get nice amount of torque but it idles very rough, i'm having a load of work done on mine and it should run smoother after that. you may have to have the idle adjusted in order to smooth it out a bit but its gone through 2 or 3 MOT's with it in and passed on emissions with no adjustment. if this is used round town alot it may get on your nerves a bit as it is pretty lumpy. i'm sure mine could've been set up alot better in the past though.