Words And Photos: Richard Holdener

Sometimes it pays to be lucky rather than good, and this test is proof positive. Usually, we design a specific procedure to test a particular part or combination, but in this instance, the test simply fell right into our laps. For the 2014 season, Lucas Oil’s own drifter extraordinaire Joon Maeng was in the process of upgrading the 6.0L LS2 powering his 240SX. Since the motor was still in the car, the unique situation that unfolded allowed us to run back-to-back tests of the performance upgrades on both the engine and chassis dyno. We all know that the LS motors, including Joon’s LS2, respond very well to head and cam upgrades, but we were curious to see what the difference was between the engine and chassis dyno. A back-to-back dyno session is the best way to determine real results, but how often do you get to test the combination on both the engine and chassis dyno?

The test started on the chassis dyno when the 240 SX was brought to Westech Performance for tuning. The LS2 in question was pretty stock, featuring a FAST 92mm intake and throttle body and long-tube headers. The internals of the LS2, including heads, short block and camshaft remained stock. Using a Holley EFI system, Westech’s Ernie Mena threw a tune on the LS2 that allowed it to produce 394 hp at 6,000 rpm and 410 lb-ft of torque at 4,500 rpm. Though nearly stock, the LS2 V8 offered a combination of power, drivability (torque) and reliability unmatched by a typical turbo 4-cylinder. Despite the torquey nature of the V8, what race driver is satisfied with the current level of power? We all want more, but the more must also come without the typical penalty of reduced reliability. Lucky for Joon and Lucas Oil, the LS2 had plenty of power inside just waiting to be unleashed.

In stock trim, the LS2 offered decent power and even more potential, thanks to ample compression, 6.0 liters of displacement and the 2nd best set of factory cathedral-port heads ever offered by GM (behind the 5.7L LS6). What the combination really needed was a more aggressive cam profile, but what better way to take full advantage of the cam than with a set of ported heads? As good as the stock 243 castings were, they were even better after the guys at Total Engine Airflow worked their magic on them. After application of the Stage 2 CNC porting, the flow rate of the 243 heads increased to 320 cfm on the intake and 260 cfm on the exhaust. The heads also featured a 2.04/1.57 Ferrea intake valve set, a dual-spring combination that allowed up to .650 lift and even lightweight titanium retainers. Thanks to full CNC porting, these TEA LS2 heads were capable of supporting over 650 (normally aspirated) horsepower, or more than enough for stock-displacement drift motor.

With the heads ready to run, it was time to select a cam profile. The TEA heads would support plenty of camshaft, but the limiting factor was adequate piston-to-valve clearance. Due to the lack of valve reliefs, the factory flat-top pistons limited cam timing for the LS2. More power was available with increased duration, but we erred on the safe side since drift motors spend a lot of time bouncing off the rev limiter. For this LS2, Crane supplied a healthy hydraulic roller cam that fit within the confines of the available piston-to-valve clearance. The Crane profile offered .600 lift, a 232/236-degree duration split and 114-degree LSA. The cam and head upgrade allowed the motor to breathe properly at higher engine speeds. Despite the mild cam specs, the results were more than worth the effort. After running the stock motor on the chassis dyno, it was removed and run on the engine dyno. On the engine dyno in stock trim, the LS2 motor produced 476 hp at 6,200 rpm and 465 lb-ft at 4,800 rpm. Now it was time for the mods.

With the engine still hot on the engine dyno, we replaced the stock heads and cam with the TEA-ported 243 heads and Crane cam. As in the car, the engine was run with a Holley management system. Equipped with the TEA heads and Crane cam, the modified LS2 produced 560 hp at 6,600 rpm and 494 lb-ft at 5,300 rpm. The heads and cam increased the power output of the LS2 by 84 hp and 29 lb-ft of torque. These LS motors never fail to impress with their power production. After running on the engine dyno, the modified LS2 was installed back in the car and tuned once again by Westech’s Ernie Mena.

After tuning, the modified LS2 produced 461 hp at 6,600 rpm and 428 lb-ft of torque at 4,900 rpm. On the chassis dyno, the head and cam package picked up 67 hp and 18 lb-ft of torque. If we do a little math here, we see that the difference between the stock power output (394 hp vs 476 hp) on the engine and chassis dyno equates to 17.3%. The difference between the modified outputs (461 hp vs 560 hp) on the engine and chassis dyno equate to 17.7%, meaning the gains stayed consistent whether measured on the engine or chassis dyno. In this dyno duel, it looks like round 1 was a draw.

The LS2 was run in stock and modified trim on the chassis dyno. After installation of the TEA-ported 243 heads and Crane cam, the power output jumped from 394 hp at 6,000 rpm and 410 lb-ft of torque at 4,500 rpm to 461 hp at 6,600 rpm and 428 lb-ft at 4,900 rpm. The ported heads and cam shifted the torque curve slightly higher in the rev range (by 400 rpm), but the peak torque increased by 18 lb-ft.

The head and cam swap was actually performed on the engine dyno. Run on the engine dyno after being pulled from the 240 SX, the LS2 produced 476 hp at 6,200 rpm and 465 lb-ft of torque at 4,800 rpm. After installation of the TEA-ported heads and Crane cam, the peak numbers jumped to 560 hp at 6,600rpm and 494 lb-ft of torque at 5,300 rpm. The difference between stock and modified on the engine and chassis dyno remained at just over 17%.

Sources

Aeromotive
aeromotiveinc.com

Crane Cams
cranecams.com

Holley/Hooker
holley.com

Lucas Oil
lucasoil.com

Total Engine Airflow
totalengineairflow.com