Updates to the 2006 L32
3800 SERIES III SUPERCHARGED 3.8L V-6 (L32)
2006 model year summary
Full descriptions of new or changed features
Supercharger gasket revised
An aluminum gasket carrier is added to better seal the supercharger assembly, reducing emissions.
Intake manifold revised
Upgraded side gaskets for the intake manifold and a laser-welded purge valve reduce noise.
Composite rocker cover
The rocker arm covers are changed to a stronger, more durable composite material for high-ileage durability.
Catalytic converter size and substrate composition optimized
A larger volume converter with a revised mixture of precious metals is added to further reduce emissions.
Front cover revised for new water pump
A new water pump with more robust gaskets is incorporated into the front cover of the engine to increase high-ileage reliability.
Rod and crankshaft bearings changed to lead-free
As part of an ongoing effort to eliminate toxic materials in powertrain products, the bearings have been replaced with materials free of lead.
GMs 3800 is to V-6 engines what the original Chevrolet small block is to the V-8. The Series III enhances the 3800s reputation as a competitive and contemporary engine, with output, efficiency and emissions levels that meet or beat overhead-cam engines. And it does so with superior low-end response.
Since the first 3800 was introduced by Buick, more than 25 million have been built, and its configurations and technology have continuously evolved. Both the enthusiast and business press have raved about the 3800; it has been selected as oneWards Auto Worlds Ten Best Engines in the World three different times, as well as named being named to several lists in 2000 as one of the best engines of the 20th century.
The 3800 Series II V-6 was first supercharged for the Buick Park Avenue Ultra. The result was output and performance comparable to competitive V-8s, with the efficiency of a V-6. The durable, highly refined design of the standard 3800 allowed most major engine components, including block, crankshaft and cylinder heads, to be used for the supercharged variant without modification.
The 3800 Series III, launched in 2004, was developed with several goals: improve quality, performance and flexibility; reduce noise, vibration and harshness, as well as cost of ownership; and deliver contemporary features such as electronic throttle control. Each goal has been achieved. Moreover, these objectives were achieved without reducing fuel economy or increasing unit cost.
The L32 is available in the Pontiac Grand Prix GTP.
The following represent key features of the 3800 Series III SC:
A stiff powertrain (engine and transmission combination) helps make a vehicle quiet and free from bothersome vibrations. By reducing primary and secondary vibrations, as well as ancillary resonance from accessories and their brackets, noise and vibrations are minimized.
The 3800 Series III SC debuted as a quiet powertrain, but in the quest for an even greater feeling of quality and refinement, GM Powertrain engineers added braces to
increase the robustness of the connection between the engine and the transaxle. Two braces are used, one on the front of the powertrain assembly, the other on the rear. Each brace works to make the individual engine and transmission assemblies a structural single unit.
Another major step toward improved engine refinement comes from the added stiffness provided by a cast aluminum oil pan, which provides a structural member on which the engine mounts and powertrain bending braces attach. In place of the 2004 engine's stamped steel oil pan, a robust cast aluminum oil pan is now used. This strong yet lightweight pan adds stiffness to the engine, helping it resist twisting and bending, further improving the engine's feeling of quality.
The oil pan design also benefits from the use of an advanced RTV sealer with silicone to reduce the possibility of oil leaks.
The 3800 Series III SC is fitted with highly sophisticated, segment-exclusive Eaton Gen V supercharger. It provides the Grand Prix powerful acceleration, with power ratings of 260 horsepower (186 kw) and 280 lb.-ft. of torque (380 Nm).
The 90-cubic-inch Gen V supercharger is very efficient. While its exterior dimensions are slightly larger than the previous unit, it boasts:
The P05 PCM provides state-of-the-art electronic engine management in the 3800 Series III. The PO5 has 50 percent more random access memory (RAM) than the
previous-generation P04, twice as much read-only memory (ROM) and a 60-percent increase in clock speed (approximately 25 MHz). It allows more integration of powertrain and vehicle systems, such as electronic traction control and heating, ventilation and air conditioning (HVAC) operation, and it provides more sophisticated diagnostics, particularly for the Onboard Refueling Vapor Recovery (ORVR) system. Moreover, it takes full advantage of features such as the ultra-fast oxygen sensors and electronic throttle control.
The 3800 Series III SC features electronic "drive-by-wire" throttle control. With ETC, there is no mechanical link between the accelerator pedal and the throttle. A potentiometer at the gas pedal measures pedal angle and sends a signal to the throttle actuator controller (TAC) module, which is integrated in the throttle body and passes the signal to the powertrain control module (PCM). The PCM then directs an electric motor to open the throttle at the appropriate rate. ETC delivers outstanding throttle response and greater reliability than a mechanical throttle. Cruise control functions are integrated into the throttle control, reducing the number of engine parts and simplifying assembly.
Grand Prix's ETC is programmed with 19 separate throttle maps, or curves, tailored to deliver engine response according to the driving situation. At lower speed the curves are more progressive, for more subdued engine response. During parking lot maneuvers, for example, a given application of the gas pedal will deliver less engine power. At medium to high speeds, the throttle curves are steeper for more aggressive engine response.
The 3800 Series III has hot-forged powdered metal connecting rods. Powdered metal is more durable and reliable than conventional cast iron, delivering greater anticipated life. As importantly, the powdered metal rods are stiffer than the cast iron parts they replace.
The 3800 Series III is equipped with a "returnless" fuel injection system that eliminates fuel return lines between the engine and the fuel tank. Because it delivers only the amount of fuel need by the injectors, and returns no fuel to the fuel tank, the returnless system eliminates heat transfer from the engine to tank. This reduces the amount of vapor generated in the tank, and captured by the Onboard Refueling Vapor Recovery (ORVR) system.
Because of their cylinder configuration, 90-degree V-6 engines can create torsional vibration in the crank essentially flexing along the length of the crankshaft at certain engine speeds. The Series III Dampolator delivers the benefits of both a damper (at higher engine speeds) and isolator (at lower engine speeds). This computer-tuned crank balancer consists of two separate discs with two rubber springs of different thickness. It is effective at both ends of the rpm range and as a result, reduces vibration and harshness regardless of engine speed.
The air conditioning compressor bolts directly to the 3800 Series IIIs engine block, without struts or braces. This direct mounting considerably reduces vibration at the compressor and contributes to the overall reduction in noise, vibration and harshness.
Oxygen sensors are located where the exhaust manifold runners meet, before and after the catalytic converter. They measure oxygen levels going into and out of the catalytic converter. Using readings from both sensors, the PCM manages various engine operations in a fashion that minimizes exhaust emissions. The ultra-fast sensors allow the exhaust system to achieve this "closed loop" operation in matter of seconds, effectively monitoring oxygen levels before and after the catalytic converter for maximum emissions reduction.
The 3800 Series III features a more efficient dual-brick, close-coupled catalytic converter that is mounted closer to the engine than on Series II engines. So positioned, the catalytic converter achieves light-off the temperature at which exhaust emissions are most efficiently oxidized more quickly. This considerably lowers emissions during cold starts.