Guys,
Finally got my Fox 35 happy with a 9x6 prop on open uniflow tank, 7% N, 27% (50/50) oil. I am doing 5.0 lap times on 60' C to C lines. I want to get a little more speed to around 4.85 ish (to handle the wind). I am using an ST NVA. My choice to pick up say 400 rpm without going full 2 cycle seem to be - bump the nitro to 10 -12%, change the NVA to reduce the spraybar to 0.130" or go to the high compression head. The easiest is to try the nitro first, I am concerned that to much nitro could cause a problem with the shaft breaking. Assuming a lean ish 4 cycle, how far can you push the nitro before you get into shaft breakage range with the light load 9x6?
Seems that to get to the rpm needed (which it does easily in a medium 2 cycle) a certain BMP is needed no matter what method is used but is the nitro more of a hammer blow then just more fuel/air from the larger venturi? If the HC head is used does this also have the same effect as the higher nitro?
What has been the experience of the group?
Best, DennisT