[CLICK HERE TO SEE VIDEO OF THE 370Z ON TRACK.]
TURBO VS. SUPER
With our Greddy twin-turbocharged 370Z outputting 136.4 whp more than Dai's HKS GT-supercharged 350Z, comparing the forced induction options of each seems like an apples-to-oranges comparison at first glance. But the torque differences-only 37.4 lb-ft in our favor-tells there's more to be considered. In the spirit of competition, Greddy USA sent over dyno data generated when tuning their 350Z bolt-on turbo kit at low boost on a test car, comparable to Dai's 350Z outfitted with the HKS GT supercharging system. Comparing each system may just prompt you to pick a new favorite.
Looking at the graph, both forced induction systems offer significant power and torque increases over stock. The turbocharged option offers more peak power and torque, but the supercharger produces it in a linear fashion, delivering more low-end power and torque, and better throttle response since it stays "spooled" in proportion to engine revs (whereas turbos need an open throttle to build boost), which arguably makes tuning a supercharged system easier, too. The belt-driven supercharger also takes up less space in the engine bay than two turbos, manifolds, wastegates, etc., and runs cooler than exhaust-driven, water- and/or oil-cooled turbochargers, meaning a smaller intercooler can be used and no supplementary engine oil cooling is necessary. And HKS' GT system retails for nearly half Greddy's bolt-on kit.
The downside of supercharging is upgradability. With tuning and fuel enrichment, Greddy's bolt-on turbo system is good for up to 440 whp on the included components, and up to 650+ whp by tuning larger injectors. Larger turbos (up to a large 20g or small 25g) can fit on the Greddy manifolds for power levels up to 800 whp or more with the proper fuel and tuning. A custom pulley would be needed to increase the boost of the supercharger system, and even upgrading the compressor to the largest aftermarket one available won't deliver the peak power turbocharging can. Then again, the bigger the turbo, the bigger the lag, and with a bigger supercharger . . . well, there never really is any lag.
www.hksusa.com / www.greddy.com