mine was set at 5000 per the dyno of my car, however, when i put on the 64mm TB, it seemed to stutter at that vtec x-over, so i put it up to 5500 which feels the best for me so far. i need to get the car on the dyno again, after doing TB, intake mani, and now i have an adj. fpr. i have a b16 using CTR cams and springs/retainers. pills, you dont find the 4400 xover to be too early?