Whats everyones sled engaging at? I have 68 and 66 gram epi weights (came with 68, have 68 for 10000 elevation) with stock high altitude spring (120/320lbs) and sled doesnt start to move until 4100 rpm, on slomo video. And it is pretty jerky feeling. What spring can I get to get a 3400-3600 rpm engagement, i feel like this will cause bad trenching in my dry sugar snow.