6.0-LITER 90-DEGREE V-8 (LS2) CAR ENGINE
2006 model year summary
New engine control module
Advanced direct ignition system
New target ring for camshaft position sensing
Full descriptions of new or changed features for 2006
New engine control module
The E38 engine control module (ECM) uses a 32-bit processor, which can handle the advanced
computing needs of advanced direct ignition and electronic throttle control. It replaces the
previous 24-bit controller. The new module incorporates the electronic throttle control (ETC).
Advanced direct ignition system
The crankshaft position is now sensed by the 58X Quick Sync system, which uses 58 sensors
to determine position, and increase ignition accuracy.
New target ring for camshaft position sensing
The cam position sensor reads a new cam target ring, with four segments that increases the
accuracy of the position readings.
Low maintenance
Dexcool coolant and spark plugs are certified for 100,000 miles. An oil life monitor built into the
ECM calculates stress on the engine during operation and alerts the driver when oil changes
are necessary. This eliminates unnecessary oil changes in vehicles that are driven in light-duty
conditions. Iridium-tipped spark plugs are also validated for 100,000 miles.
Overview
The LS2 car engine is the fourth-generation of the “small block” V-8, and was designed primarily
to meet requirements of 400 hp for the 2005 Corvette. This output was determined by a
projection that with the 0.28 Cd body of the 2005 Corvette, the car could achieve a 180-mph top
speed. Current applications are the standard Corvette and the Pontiac GTO. To meet the output
target, the displacement was increased over the LS1 V-8 through enlarging the bore from 99 to
101.6 mm, and stroke remains the same 92 mm as the 350-horsepower LS1 small-block
engine. Combustion chamber improvements, friction reduction, and a larger intake and less
restrictive exhaust combined to increase output. In addition, the maximum speed of the engine
was increased with stronger valve springs, rising from a redline of 6000 rpm in the LS1 to 6500
rpm.
The increased displacement requires more air, and the throttle body was enlarged from 75 mm
to 90 mm. It is mounted to a new multi-piece welded composite intake manifold that is tuned for
more flow. Intake breathing was improved by using a high lift camshaft developed to take
advantage of the free-flowing cylinder heads. During development it was determined the best
flow in the combustion chamber occurred with flat-top pistons. Power output is measured with
premium fuel; however, the engine is capable of using any common pump fuel. Catalyst
substrate improvements reduce restriction in exhaust system, as does the elimination of the
close-coupled “pup” converters of the LS1. Air Injection Reaction system was eliminated
because the new close-coupled converters warm quicker. Larger mufflers with tri-flow
technology, and less-restrictive routing of the exhaust pipes aid flow. Flow characteristics
learned from the LS6 engine development were applied to the combustion chamber shape on
the LS2 to improve output and efficiency. Finally, because of careful flow design and calibration,
the engine will operate with good drivability characteristics with a high compression ratio of
10.9:1, raised from the 10.1:1 of the LS1.
The block remains precision sand cast aluminum, strengthened with controlled cooling during
the casting process, and iron cylinder liners, a process carried over from LS1. To make the
bottom end more durable, floating wrist pins are used in the pistons. To reduce friction, piston
rings with less spring tension were found to work well in the 6.0L V-8.
Significant to the redesign of the engine is its placement in the Corvette. The engine sits about
an inch forward in the Corvette frame compared to the LS1. This allowed enough room to move
the exhaust catalysts forward, closer to the exhaust manifold, and the subsequent reduction in
warm-up time meant that the catalysts need no external warming device to meet projected
emissions, including cold-start emissions, up to 2008.
