6.2 Liter LSA Engine - ZL1 In Sheep's Clothing

The difference in horsepower and torque ratings are said to be attributable to the ZL1's unique induction system

Randall D. Allen Feb 14, 2012 0 Comment(s)
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We feel your pain; the ZL1 that you have on order, or are lusting about, is almost at the dealer and you can't wait to get behind the wheel and mat the pedal to the floorboard. While you wait, let's take a look at the LSA used in the 2012 Cadillac CTS-V for insight into the power potential of the LSA in stock and modified forms. GM has been putting the 6.2 liter LSA engine into Cadillac CTS-V's since the 2009 model year and in that platform they are rated at 556 horsepower at 6100 rpm with 551 lb-ft of torque at 3800. When the ZL1 debuts it is rated at 580 horsepower at 6000 rpm and 556 lb-ft at 4200. Both engines use the sixth-generation Eaton supercharger that displaces 1.9 liters per revolution and generates a maximum boost of 9.0 psi. No other changes to the LSA's internal specs have been released leading us to surmise that the cylinder heads and camshaft are identical. The relatively low lift, low overlap of the camshaft (198/216 at .050 with .480/.480-inch lift) is designed to promote a smoother idle and excellent low-RPM driving characteristics while the LSA specific cylinder heads are modified versions of the L92 and LS3 heads, which are roto-cast with premium A356T6 alloy that significantly reduces porosity in the castings making them stronger. The difference in horsepower and torque ratings are said to be attributable to the ZL1's unique induction system, which features a lower-restriction air filter, dual inlet paths and improved supercharger housing airflow. On the exhaust side, while the CTS-V has "high-moly" cast iron exhaust manifolds, the Camaro uses stainless steel manifolds and has an active dual-mode exhaust muffler.

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According to Andy Mages, owner of ADM Performance, "When Cadillac released the LSA into the CTS-V in 2009 we found out that in stock form the engine would put down on average about 455-rwhp and 450 lb-ft of torque through the automatic (GM Hydra-Matic 6L90E) and an additional 20 horsepower and pound-feet of torque if equipped with the Tremec 6060 manual transmission. As soon as the CTS-V was released we saw the potential of the platform and started developing packages to take the LSA from 650 through over 900 crankshaft horsepower utilizing the stock supercharger. The Stage I package is rated at 650 crankshaft horsepower and features an overdrive supercharger pulley (either a Lingenfelter upper pulley with a 2.55-inch diameter and ADM ported snout or a Lingenfelter lower harmonic balancer with a 9.17-inch diameter pulley), air intake and tune." There are also Stage II and Stage III packages, which are rated up to 750 crankshaft horsepower, and still utilize the stock bottom-end. However, after that ADM begins custom tailoring the build to the owner's needs. "With a ZL1 on order and packages already designed for the Camaro we are prepared to offer the CTS-V and ZL1 customer a full range of options to meet their budget and horsepower goals."

To demonstrate the Stage I package we used a 2012 CTS-V wagon with a 6-speed manual, which the owner requested that we keep as close to stock appearing (and idling) as possible yet still generate at least 675-700 horsepower. This made the Lingenfelter upper pulley and ADM ported snout the best option, since the lower harmonic balancer would be easier to detect. Since the CTS-V intake comes with a restrictive stock filter and the intake tube has the tendency to at least "partially" collapse at elevated boost levels we teamed up with Halltech to test their CTS-V Stinger Carbon Fiber Cold Air Intake System. The system contains an attractive carbon fiber intake tube and K&N air filter. Halltech recommends modifying the stock air-box for additional air flow and advertises that the intake system makes 20 rear wheel horsepower on a stock CTS-V without tuning.

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