Using CO2 on one side of external wastegate?

[turbodave231]

I saw something interesting in BG this year. One of the faster twin turbo S2 cars was using regulated CO2 on one side of his wastegates. He used a boost controller to change the pressure of the CO2.

I have heard that alot of the Sport Compact racers use this setup. Is anybody else using CO2 on their Buick?

Dave