1981 Pontiac Firebird Trans-Am
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With ever tightening emissions restrictions in the late 70's and early 80's GM engineers were utilizing all kinds of exotic methods to still keep the fun in their muscle cars while still being environmentally conscious and that's where the 4. 9 Turbo comes in. The 301 Turbo was unique in that it had a stronger block with thicker cylinder walls than the '77-'81 301 naturally aspirated unit, it also had newly developed internal components, such as for example lower compression pistons, (lower compression due to the forced induction pressure of the turbo system) a relatively mild camshaft, a high pressure oil pump to ensure adequate oil to the oil-cooled Garrett TBO-305 Turbocharger, a rolled fillet crankshaft with 2 instead of 5 counterbalances, a fully baffled oil pan, and a high pressure fuel pump, a unique single plane intake, side and turbo-specific exhaust manifolds, and an Electronic Spark Controller(ESC) using a knock sensor to retard timing when detonation is detected. The M4ME (E4ME for 1981) 800 cfm Rochester Quadrajet, unique to the 301 Turbo, had super rich 'DX' secondary metering rods and...