Duramax Overheat Fix

Suncoast Automotive Performance has developed a set of Ram Air Hoods with the help and at the request of General Motors to help increased performance and engine cooling in their 2003 and up Duramax Diesel applications!

Early GM Service Parts Organization Concept Development.
In late 2005, General Motors Service Parts Organization procured and tested several aftermarket ram air hoods from various suppliers, one of which was Suncoast.  After GM Engineering's side by side competitive testing, quality checks, and design evaluations, GM selected Suncoast to develop functional ram air hoods for their Silverado, Silverado HD, and Sierra models.  Many owners have been having problems while towing moderate to heavy loads or in extreme temperature conditions.  According to GM, these models were experiencing overheating issues where, under extreme conditions, the engine control systems sensed an unsafe heat condition and initiated safety precautions to protect the engine.   This "limp" mode is a safety system that allows customers to continue to travel, albeit, at a slower pace to seek help and assistance.  Just one look at any Duramax forum online proves the issue is real and a bane to the Duramax owner community.

GMSPO Engineering developed criteria under which the Suncoast hood was to be designed to achieve the goal of reducing engine compartment temperature by 35 degrees C and top tank temperature by at least 5 degrees C without effecting engine calibrations.  Minimum effective air inlet area and minimum air channel cross sections were dictated by GMSPO.  Successful completion of wind tunnel tests, crash worthiness tests, Rain Intrusion, Snow Intrusion, Thermal test, Closure Validation (ie slam tests consisting of 3000 slams), Hood hold open test, CO intrusion test.

Beginning in early 2006 and extending into mid 2007, design, production development, and production validation testing was completed on Suncoast models 21011GM, 21012GM, and 25004GM for the Chevy Silverado HD,Chevy Silverado, and GMC Sierra vehicles. 

GM's approved interface to the air intake system we refer to as an open path.  We designed our hood as we normally do to channel the ram air to above the OEM stock intake.   We normally either cut open the top of the air box and install a K&N filter for a "Sealed Air Path" configuration or recommend a replacement of the air box with a cold air intake.  We often use Airaid or K&N but have also started working with others, such as AEM and Volant systems.  The GM engineers did not want to take on the unknowns of reconfiguring the intake so they simply recommend (and tested) the cooler ram air exiting the hood channel above the OEM air box so that the excess ram air could cool the engine compartment.  They recorded lower intake air temperatures in this configuration and also lower engine compartment temperatures when traveling down the road.

            21011GM                           21012GM                         25004GM

Added Heat Extractors for Extra Cooling of High Performance Engines:
Suncoast has gone a step farther than the original GMSPO design and added models 21011E, 21012E, and 25004E with heat extractor vents as we do on many of our hoods.  This style of heat extractor is in the aft section of the hood and is not visible from the road but further reduces engine compartment temperatures significantly while running (~20 to 30 degrees).  Remember, it is the lower engine compartment temperature that allows the trucks to operate in their normal mode and not kick over into the "limp" along, heat safety mode.  Additionally, once the engine is shut down, natural convective air currents take over and cool the engine and engine compartment faster by providing an easy path for the hot air to escape rather than be held in by the hood.

 

Suncoast Recommendation:
Suncoast recommends this configuration: ram air hood with heat extractors feeding a cold air intake.  This set up provides the Duramax owner the best of all worlds: increased horsepower, decreased engine and engine compartment temperatures, aggressive styling, and a fully tested GM Approved Platform.  This was GMSPO's original plan and Suncoast has taken it one step further.

Links to Model Specific Catalog pages:

Chevy Silverado HD
Chevy Silverado
GMC Sierra