While we haven't done any personal dyno testing for the regulators, we do all of our testing on track to both prove the reliability of the part and gauge the performance of it while in race conditions. So, we don't have any hard fact numbers on the torque curve, but we can attest to what the adjustment of the fuel pressure does to the air/fuel ratio while under full load on the track. Here is our best advice on tuning with our regulator:
The biggest gains we have experienced have been on the tracks that require a richer mixture to yield more low end through the mid range torque. We have found that tracks that require more torque and have 2nd gear turns like an air/fuel ratio of 12.8:1 rather than the preconceived notion of 13.2:1. The extra richness in fuel gives more pull in the lower RPM range, helping you out of corners. On tracks with high speed turns and no 2nd gear digging will like a leaner ratio around 13.2:1 or maybe 13.5:1 for the extra high RPM horsepower. Before the adjustable regulators, we were pretty much stuck with the 13.2:1 ratio our professionally adjusted meter came with, and it left us lacking torque in the low and mid RPM range.
It is hard to say exactly what will work for you and what works for us might not work for you, but one thing is for sure for all cars and that is air/fuel ratio's. Remember, 12.8:1 for low RPM torque and mid range, and 13.2:1 for high RPM horsepower tracks. This is where the dyno is deceiving, as you are trying to achieve the best HP, which is good for HP tracks but not torque tracks. While at the dyno, try to find what air/fuel ratio yields the best torque and you'll be ready to go when you get to the track!
UPDATE! Due to all commercial pump gas containing 10% or less ethanol, we've found that richening the mixture yields more power out of the corners. On our 1.8L SM, we've found that air/fuel ratio readings in the 11's (ie: 11.5 to 1) on the Innovate A/F ratio gauge in the higher RPM range has felt stronger coming out of the corners. We are yet to determine what is "too rich" as we have not been to the dyno, but we definitely felt a noticable loss in power by leaning out the mixture to 12.5 to 1, which is what was the previously the best known "roundabout" number. Once again, please visit the dyno to figure out what's best for your car and applications!