Looking for a way to make more horsepower? We know the answer is yes, and Thermo-Tec lets you keep the power you have been losing, plus reduces underhood temps up to 70%! By keeping the exhaust gases from cooling, the exhaust gas velocity can remain high, thus improving the scavenging effect. And for every 10-degree decrease in air intake temp, expect horsepower gains of 2% with turbo chargers and 1% with carburetors. Normal installation on a pair of headers requires 2, 50'rolls.