Eaton's Twin Vortices Series (TVS) supercharger uses four-lobe rotors in place of the conventional three-lobe units, making it quieter and more efficient.
The parasitic loss to drive the supercharger is around 70 or 80 hp, but it would have been more like 120 hp with the old supercharger, Juechter says. For the LS9, the supercharger cranks out 10.5 psi of boost.

And for those of you who dream of swapping out the stock supercharger pulley to make like a billion horsepower, be aware that Meegan says, "We don't want people to do that. We have not made that easy."

The air molecules lucky enough to get sucked into the ZR1's V8 take a pretty straight shot through the intact tract, through the air filter, throttle body and into the supercharger inlet, nestled between the V8's cylinder banks. After that, things get a little circuitous.

The intake air molecules then get squeezed through the counterrotating rotors that look like gigantic black licorice twists. It then gets pushed up through a triangular hole in the top of the supercharger housing in between two long, narrow intercoolers.
A 90-degree turn either left or right leads our molecular heroes to an intercooler that Meegan claims can lower the air temperature by 140 degrees F.
The intercoolers are connected to a heat exchanger in the car's nose and filled with standard-issue antifreeze.

Once through the intercoolers, the now-chilled air takes another 90-degree turn down into the left or right cylinder bank of the engine.
Here it will enter a combustion chamber (the compression ratio is 9.1:1) through intake valves that have the same diameter as those in the heads of a standard LS3 V8.
The LS9's intake valves are made with lightweight titanium, however, and are set in cylinder heads made from high-strength aluminum.

Sandwiched between the heads and the block are head gaskets twice as thick as standard LS3 gaskets in order to cope with the upward force that's trying to send the heads through the hood. Upgraded fuel injectors are connected to a dual-pressure fuel delivery system (low pressure for low throttle load situations; high pressure for high load).
New forged-aluminum pistons (cooled by oil squirters) are connected by titanium rods to the steel crankshaft.

Spent air exits through exhaust manifolds identical to those on an LS7 motor and through 3-inch exhaust pipes capped off by vacuum-actuated flaps as seen on the Z06. The LS9's oiling system is similar to that of the Z06's LS7 as well.

It uses the same dry sump as the LS7 but has an additional 2.75-quart auxiliary tank that helps keep oil where it needs to be in a car that Juechter says can post lateral acceleration figures "comfortably over 1g."

It might seem strange, but the LS9 uses a lower-lift cam than the one used in the LS7, resulting in an idle that Meegan says is 11 percent smoother. Isn't this the baddest, leanest, most extreme, track-scorching, widow-making Vette from hell? Well, apparently, no.

Power Delivery
The monster motor is backed by a six-speed manual transmission that is a strengthened version of the TR6060 transaxle used on the standard '08 Vette.

This is a true close-ratio unit, unlike those of other Vettes, and 6th gear is no longer a fuel-saving ratio but instead the gear in which top speed can be achieved. "This buyer says, 'I can buy the gas. Just give me the performance,'" says Juechter.

A twin-plate clutch replaces the standard single-plate of all other Corvettes to handle the extra power and keep clutch pedal effort roughly equal to that of the Z06.

Chevrolet is sufficiently proud of this supercharged small-block to give it its own window in the hood of the 2009 Chevrolet Corvette ZR1. In fact, the ZR1's signature feature is this clear polycarbonate porthole that reveals the LS9's integrated supercharger/intercooler unit. That should leave no doubt about which element of the ZR1 is most important.

Even with the gigantic meats bolted to the backside, the ZR1 will be what is euphemistically called "traction limited."
In other words, all that power just goes up into expensive smoke when you try to lay the power down.

And since launching a car with so much horsepower can become a violent, axle-hopping mess, Chevrolet has come up with two novel countermeasures.

First are the rear shocks.

When you're stopped and the clutch pedal is depressed and you pile on some revs, the car assumes you want to launch it hard. It automatically softens the compression damping of the rear shocks, and this allows the rear end to squat and effectively shift more weight to the rear of the car for added traction.

At the same time, the rebound damping of the rear shocks goes up to 99 percent of full stiffness.
This means that the rear cannot spring back up under power in the up-and-down monkey motion of axle hop.

All this is perhaps the cleverest use of adjustable shocks that we've ever heard of.
Also, according to Juechter, the standard magnetic shocks allow the ZR1 chassis team to use softer springs than the Z06 for a more compliant ride.
To further mitigate power hop, Chevy has also fitted the ZR1 with axle half-shafts of different diameters (33mm on the right and 40mm on the left).