Your first experience with the Corvette ZR1 is sure to be life-altering. It’s a car that changes your perception of performance. It redefines the words “quick” and “fast,” and it most assuredly makes the muscle cars of old seem like rally-striped tractors by comparison.
And then you get used to it.
It’s a guy thing, mostly. Sure, 638 horsepower is stunning, and the brutal acceleration of the ZR1 will have most passengers wondering whether their will is in order, but even if the car packed 800 horses from the factory, most owners would still inevitably wonder: Could I get 850 out of this thing?
Satisfying that need to push beyond the regular-production boundaries is the reason the multi-billion-dollar aftermarket industry exists in the first place, and owners of the 205-mph ZR1 are no different. In a previous issue, we showed how Detroit-area engine tuner Thomson Automotive (www.thomsonautomotive.com) bolts an LS9 supercharger to the 7.0-liter foundation of the LS7 to generate a nearly 800hp combination. That package comes with an approximately $35,000 price tag and requires an entire engine swap, however, while the bolt-on performance upgrade outlined in this story will add a significant 55rwhp bump to an otherwise stock ZR1, pushing its (flywheel) output beyond the 700-horse mark.
That’s not to say it’s a cheap proposition. The upgrade in question—Lingenfelter Performance Engineering’s (LPE) 710hp LS9 Supercharger System Upgrade—runs just shy of $5,300, when performed at the company’s Decatur, Indiana, facility. Or, you can order all the parts separately for about $2,500 and do it yourself, but that price doesn’t cover the tuning and chassis-dyno testing that’s included when LPE spins the wrenches.
The heart of the package is LPE’s unique, cast-aluminum front-supercharger-cover assembly, or “snout,” which serves as the housing for the blower pulley and air inlet (as well as the mounting point for the throttle body). LPE redesigned the inlet with a smoother, more direct airflow path. When matched with the company’s complementing 2.60-inch-diameter supercharger pulley, boost jumps by about 2 pounds—to approximately 12.5 psi—and airflow drawn by the blower increases significantly. The other components of the upgrade system include the following:
- A larger, 100mm double-bearing idler assembly that enables the original supercharger belt to be retained.
- One of LPE’s solid supercharger-isolator couplings. It replaces the stock, spring-loaded coupling, which can cause a rattling sound after time or even score the pulley shaft.
- A cold-air induction system that matches the new inlet position of the throttle body.
- A 160-degree thermostat that will kick on the cooling fans sooner to maintain a lower overall engine operating temperature.
Perhaps the most surprising aspect of the project is the relative ease with which the intake swap is made. There are no exotic tools required. The engine doesn’t have to be lifted off its mounts. Heck, apart from a little coolant that’s lost during the thermostat swap, no fluids have to be drained.
That’s not to say it isn’t a complex job, however. There are a million lines, hoses, and fasteners that have to be pulled off, unbolted, and/or removed—and then reinstalled exactly in the reverse order. Miss any of them, and the engine flat-out won’t run correctly, and you’ll spend hours chasing down the problem. So, if you don’t have a particularly strong attention to detail, and your mind generally fogs over at the sight of vacuum lines, you’ll probably want to farm out this installation to a professional.
We used LPE’s own techs, tuner, and chassis dyno, which made the job look nearly as easy as changing an air filter. They performed the installation in about a day, but give yourself a full weekend if you plan to do it yourself. DIYers will also need to get the tuning upgrade from LPE in order to make sure the higher-boost LS9 runs properly.
And if the proof is in the dyno numbers, those we recorded before and after the test demonstrated the system’s effectiveness in no uncertain terms. On LPE’s Mustang chassis dyno, the test car spat out 549 hp and 528 lb-ft of torque at the wheels in stock form. If you weigh that against the approximately 20 percent drivetrain parasitic loss that’s typically attributed to rear-wheel power, the results put the flywheel output a few horses above the factory’s 638hp rating.
After the blower upgrade and tuning, we rolled the ZR1 right back onto the same chassis dyno and recorded an eye-opening 604 rwhp and 589 rwtq, with a maximum boost of nearly 12.9 psi. That’s just about 725 hp and 706 lb-ft at the flywheel, improving the ZR1’s already enviable power-to-weight ratio to about 4.6:1—or one horsepower for every 4.6 pounds of the car’s mass. For the record, the 3,726-lb/612hp (and $330K) Ferrari 599 GTB Fiorano has a power-to-weight ratio of about 6.1:1. That means each one of those 612 prancing horses must lug around an additional 1.5 pounds when compared with the Lingenfelterized ZR1.
Kind of makes want to hang out in front of the country club and pick a fight—not that we would advocate such deviant activities.
|Chassis-Dyno Test 1|
|Peak numbers in bold|
|Chassis-Dyno Test 2|
|ZR1 with LPE Supercharger Upgrade|
|Peak numbers in bold|