I have been an Engineer for 38 plus years and have worked in numerous factions of industry as well as I own my own engine building shop. Cryogenics has been around a few years. It is not a heat treatment procedure. It is for relieving stress built into the product as it was made and as it is machined. We have used it for years in tooling to keep tooling from fracturing in a stress riser. Does it work. I consider Oliver rods one of if not the best rod on the market. They were the first that I can remember to go to this process. When I was a consultant engineer, we ran many test back to back on reduction of cost in tooling, and in every case, we saw a dramatic difference in using this process. I have had my rear gears and my tranny gears treated with this for years because of the impact in launching with good success. On any engine part that can have stress riser. I treat them. I TRY to lessen the risk of failure in any engine part so that my customers will return. Are they faster. Never looked at it but I do know that if stress risers are evident that parts will distort and cause HP loss before failure. You be the judge. It is not black magic. It is only a sign of todays technology creeping into our beloved sport. Your only decision is does the additional cost offset the gain.
sorry for offering my opinion. It is mine alone.
racear2865