If you thought the horsepower wars were coming to an end, think again. GM announced this week the horsepower and torque ratings for the all new LT4 engine. Accomplished with a single camshaft and only 2 valves per cylinder, this should have the Europeans worried. The 2015 Corvette Z06’s 6.2-liter supercharged V-8 is the most powerful ever produced by Chevrolet making 650HP and 650LB-FT torque! These numbers are very impressive and are more than many European supercars with a much heavier price tag. In fact the LT4 is just seventh on the list of the highest horsepower cars available in the US. Considering the top three are hybrids, the LT4 Z06 is a serious contender in the Super Car category.
The dyno chart shows the LT4 makes 457LB-FT torque just off idle and 625LB-FT torque by 2800 RPM. Peak torque comes in at 3800 RPM and peak horsepower at 6400.
The all new LT4 will be built at GM’s Bowling Green Assembly Plant in Kentucky, and Tonawanda Engine Plant in New York. Built with direct injection, cylinder deactivation and continuously variable valve timing, the LT4 is the one of the smallest and lightest 650-hp engines in the industry.
The new LT4 engine is based on the same Gen 5 small block foundation as the Corvette Stingray’s LT1 6.2L naturally aspirated engine, incorporating several unique features designed to support its higher output and the greater cylinder pressures created by forced induction, including:
- Rotocast A356T6 aluminum cylinder heads that are stronger and handle heat better than conventional aluminum heads
- Lightweight titanium intake valves
- Machined, forged powder metal steel connecting rods for reduced reciprocating mass
- High 10.0:1 compression ratio – for a forced-induction engine – enhances performance and efficiency and is enabled by direct injection
- Forged aluminum pistons with unique, stronger structure to ensure strength under high cylinder pressures
- Stainless steel exhaust manifolds and an aluminum balancer that are lighter than their LT1 counterparts
- Standard dry-sump oiling system with a dual-pressure-control oil pump.