Apex with a MCX turbo. It has the 310 kit but will probably only run it on pump gas the first time so max 12 lbs boost. Just wondering where a good place to start would be. Right now it is clutched for 10000 ft. It has the 8BU weights in it and a blue/green/blue spring. Secondary is a stock helix ( not sure what angle ) with a silver spring. I took it out around here ( 2000 ft ) and it was bouncing off the rev limiter at 1/2 throttle with the boost turned down as low as it would go. Just wondering if the 8BU's will work for 6000 to 7000 ft or am I wasting my time? Also. Are these springs any good or do I need to different springs for that elevation? Also. What recomendations for riding the flats at 2000 ft? Any help would be great. First time to the mountains with this sled and I want it to be at least close for clutching. Thanks guys