Thinking about getting one, do they work? I had the latest map installed and I lost rpm on top with little to no change in mid range,going in today to have it changed back. I have been working all season to get my sled to run right up high (by high I mean from 5000 to 7500ft) the best I have been able to get is an average of about 8000rpm, most of the time only 7950rpm. I have the SLP single, blue pink primary spring and 68 MTX weights, on a 163 09 D8. I had the up date to the double ring pistons done in OCT. Last Year I was able to do 8150rpm with stock pipe and HPS can with stock clutching. Tried that again and only could get 7900rpm and lost a lot of track speed. Would like to just get it back to 8150rpm. I am starting to get a little frustrated. Will the power commander help ? and who has the best map ?