While Chevrolet and GMC arguably tread the exact same ground in terms of medium and heavy-duty trucks, one thing is for certain: the Duramax has a rightful place in performance history. For more than just the commanding sound of a turbo diesel eight cylinder engine, it’s also got a staggeringly good history of being the go-to for off-road recovery and payload.
But that all gets lost in the excitement of a road race, doesn’t it? And why not. The Duramax feature package is an optional upgrade in both the GMC Sierra and Chevrolet Silverado HD series of medium to heavy duty pick-up trucks. It’s an upgrade worth every penny in terms of performance, too. Let’s see why.
The latest Duramax LML is a 6.6L turbo diesel with a renewed focus on decreasing emissions. In order to do this, General Motors had to drastically redesign it from previous engines to improve oil flow, temperature monitoring and increased durability.
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One of the really unique features is the fuel injection system. As diesel enthusiasts know, this fuel type can be quite tricky. In colder temperatures or degraded conditions, it c
One of the really unique features is the fuel injection system. As diesel enthusiasts know, this fuel type can be quite tricky. In colder temperatures or degraded conditions, it can clump up and become quite viscous and thick. That’s why the new Duramax RPO LML 6.6L has a new pressurized piezo fuel injection system which pushes diesel into the engine at 29,000 PSI. That’s enough force to blow through a half foot of hardened wood. Thankfully, they only use the best steel and alloys in these durable engines.
What do we get at the end of GM’s attempt to build a perfect triumvirate of power, durability, and emissions control? The Duramax RPO LML 6.6L packs 397 horsepower at 3,000 rpm and 765 lb-ft of torque. That’s an improvement from the 2010 LGH 6.6L from 2010. The LGH Duramax was rated conservatively at 335 hp and 685 lb-ft of torque. Certainly impressive but no where near as efficient in terms of fuel pressurization and consumption.
Let’s not forget the Duramax LMM. Famous for it’s turbocharged and intercooled aspirating overhead valve setup with a Bosch high pressure common rail injection system, it was featured exclusively in the Chevy Silverado HD series from 2011 until 2014. Off the factory floor, it pulls 765 lb-ft of torque at an amazing 1,600 rpm. That’s great considering the redline for the 2014 Silverado HD is 3,450 rpm.
Silverado Package Upgrades Are Key
Even though GMC and Chevy tread similar styles, the Silverado 2500HD is truly a truck that stands out amongst the rest. With an entry price of around $33,000 MSRP, it’s an attractive step for many truck drivers into the world of heavy duty performance. It has a maximum towing capacity of 17,190 lbs and a whopping 3,500 lbs of payload. That’s nothing to sneer at. Yet why are we seeing a Chevy Silverado 2500HD gladly eat another Duramax’s dust? Quite simply, it all comes down to packages and upgrades.
Sure, the standard Chevy Silverado 2500HD features an LMM 6.6 L Duramax V8. But a turbocharged diesel is only really good at pulling and hauling. In order to make the most out of all of that engine’s performance, twin turbo diesel kits can be purchased in the after-market.
Twin Turbo Diesel Kits for the Duramax
The biggest improvement that can be made to a Duramax is a twin turbo upgrade kit. The PPE 45/50 Compound Twin Turbo kit for GM’s Duramax is also perfect for the Silverado. It’s specially configured for an LMM configuration – so buying a used 2011-2014 Silverado not only saves money on the truck itself but it also brings in the possibility of spending those savings on getting twin Garrett turbo chargers working in unison.
In the end, however, it’s not just a twin turbo charge package for GM’s Duramax line of engines. It’s also about getting the engine’s computers to respond intuitively to racing. Having the engine know when it needs to spool up both turbos means having all of the Duramax’s nearly 800 hp (with twin turbo) at a moment’s notice. Ford Mustang drivers, eat your heart out for sure.
But that sort of performance can either come from two ways – manually tweaking engine performance or electronically. And for newer models of both GMC Sierra and the Chevy Silverado, electronic tweaking may be much easier.
