I now run at Radiator cap pressure. I installed my 21psi cap back on. The coolant took a little while to heat up but it stabilized at 182-184. It was 70 deg. today. So, It appears to work like a champ. I need more time driving the car to see how it does at different temps. So far, I am happy. I didn't puke anything into my coolant tank. That's Perfect. Now, it is time to turn it up some more and see what happens. We shall see how it acts at 21psi of boost, then on to 23psi if all is well. I need some higher temps, it was spinning perty good at first before I got some temp into the tires. I am able to lay down 17psi of boost in 2nd gear. I have it ramped in from 12psi. I do rev to 8000rpm.