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| Overview | |
|---|---|
| Manufacturer | Pontiac |
| Production | 1980–1981 |
| Layout | |
| Configuration | V8 |
| Valvetrain | Overhead valve |
| Chronology | |
| Predecessor | 301.6 cu in (4.9 L)Pontiac 301 |
ThePontiac 301 Turbo is an engine thatPontiac produced for the 1980 and 1981Trans Am. It was aV8 engine with a displacement of 301 cubic inch which produced an officially factory rated 210 hp (157 kW) and 345 lb⋅ft (468 N⋅m) of torque in 1980. In 1981 it underwent some changes and offered a conservatively rated 200 hp (149 kW) and 340 lb⋅ft (461 N⋅m) of torque.[1] The Turbo Trans Am was first added to the Pontiac model lineup in 1979 as a 1980 model year, and was the first production Pontiac V8 engine to use forced induction; in this case through an exhaust-driventurbocharging system. It was only available for the 1980 and 1981 model years, which were also the last two years of this body style of theTrans Am before it was succeeded by the all-new third-generation F-body in 1982.
The 301 Turbo was unique in that it had a stronger block with thicker cylinder walls made from reinforced materials compared to the '77-'81 301naturally aspirated low-deck block, and featured a lower compression ratio (lower compression due to the increased pressure created by the turbo system). The 1980-81 naturally aspirated 301 used in the Trans Am and Formula used the 301T block.Further it had newly developed internals such as forged pistons, a relatively mild camshaft, a high pressure oil pump (60psi) to ensure adequate oil to the oil-cooledGarrett TBO-305 Turbocharger, a rolled fillet crankshaft with 2 instead of 5 counterbalances, a fully baffled oil pan, and a high pressure fuel pump (10psi), 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 a remote vacuum source for the primary metering rod enrichment circuit; the "PEVR" or Power Enrichment Valve Regulator. Boost was regulated by a wastegate, and was delivered to dealerships with a standard factory limit set to 9 psi (+/- 1 psi), although measured real-world factory default settings ranged from around 7 to 10 psi. The wastegate could be safely user-adjusted to 15 psi by adding alcohol or water injection, or even higher with heavier modifications.[2]
The 301 Turbo package (RPO code LU8) required factory air conditioning (C60) due to a turbo-specific heater core box, and featured automatic transmissions (TH350 (non-lockup) for 1980, and THM350C (lock-up) for 1981) with a 3.08 positractionlimited-slip differential rear axle ratio (G80).
Because the engine still used acarburetor instead offuel injection, it could not take full advantage of the forced air through the turbocharger. The low-octane fuels used in the early 1980s could have caused severe detonation under boost, had it not been for the ESC.[3][4]