The turbo installation takes...
The turbo installation takes place on a Specter Werkes/Sports GTR built around a Corvette Z06. All of the mechanical work was performed at Lingenfelter Performance Engineering's Indiana facility.
Turbo kits are comparatively rare, when compared with the plethora of supercharger systems on the market. That's because, unlike most bolt-on blowers, which easily can be adapted to a variety of vehicles, turbo kits present unique challenges. There's more to contend with in the routing of inlet and outlet tubing between the exhaust manifolds, turbocharger(s), and engine intake.
At a minimum, major changes are required of the exhaust system. Of course, all that plumbing changes for a different vehicle, whereas adapting a Roots blower, for example, requires comparatively minor revisions to suit the accessory drive and intercooler mounting.
To put it simply, turbo kits are expensive to engineer and produce, but many enthusiasts prefer the higher-rpm application of power, the adjustability of the performance, and the on-demand power that doesn't compromise daily driving characteristics. Often, enthusiasts must rely on custom-designed systems-and hope the shop they've entrusted their car with knows what it's doing.
LPE removes the Z06's LS7...
LPE removes the Z06's LS7 engine and rebuilds it to suit the demands of turbo-charging. That includes a short-block with a new, forged-steel crankshaft, forged-steel connecting rods, and lower-compression 9.0:1 pistons. The heads also receive high-temperature-resistant Inconel exhaust valves.
Decatur, Indiana-based Lingenfelter Per-formance Engineering's (LPE) solution to turbo systems is a hybrid of sorts, which blends the attributes of a fully engineered kit with the precision fitment of a custom system. The company has designed Corvette-specific kits, but it fits them individually to each vehicle for a more accurate and precise installation-much like a custom-tailored suit versus a "close enough" off-the-rack one. LPE also rebuilds the engine to make it boost-friendly, including forged-aluminum, lower-compression pistons and an upgraded rotating assembly.
"There are enough vehicle-to-vehicle variances that we feel our method is the best at ensuring the best installation and a more robust engine," says LPE's Jeff Myers. "And typically one of the side benefits is, most customers report better fuel economy in normal everyday driving."
We recently visited LPE's shop to follow the installation of the company's twin-turbo system on a C6 Z06. In fact, it was the blue Specter Werkes/Sports GTR Z06 that wowed SEMA attendees last fall and was previewed in VETTE earlier this year. With the 505hp LS7 as the foundation, LPE rates the system at a stunning 800 hp. Notably, the kit sacrifices nothing in driveability, such as air conditioning, power amenities, and the like.
The turbo system is designed...
The turbo system is designed to mount the turbochargers directly to custom, heavy-duty exhaust manifolds. In the low-slung Corvette chassis, that still puts them at the bottom of the engine compartment, which helps keep heat farther away from the engine and air intake system.
LPE's system uses a pair of medium-size Garrett ball-bearing turbos and an air-to-air intercooler. The turbos are mounted low in the engine compartment, which helps minimize underhood heat. The mid-size hairdryers also offer an optimum combination of tremendous airflow and minimal lag. In fact, lag is, for all intents and purposes, nonexistent here. The turbos spool quickly and deliver a smooth yet incredibly forceful application of power.
Here are the basic elements of the system:
• Two Garrett GT30-series turbochargers
• Custom exhaust manifolds
• Custom air-to-air charge cooler
• Upgraded fuel system
• Kenne Bell Boost-A-Bump
• Upgraded oil cooler
• Custom oil-scavenging system
• Custom Corsa/Specter Werkes low-restriction exhaust system
• Reprogrammed factory controller.
Although boost in any turbo system is tunable, the base LPE system delivers about 10-12 pounds to help the 7.0-liter engine produce 800 horses. The turbo system isn't installed until after the rebuilt engine is lowered into place. We should note, too, that our photos provide an overview of the installation. There are far more details than we have room to show, but what we've shown here provides an excellent glimpse into the major components and procedures involved.
One of the other pre-installation...
One of the other pre-installation procedures involves prepping the engine for the oiling requirements of the turbos. That involves swapping the stock oil cooler for an aftermarket model, fitting a scavenge pump to pull returned oil from the low-mounted turbos, and adding a feed line (seen here) that sends the circulated oil back to the pan.
The system's installation...
The system's installation starts with bolting on the exhaust manifolds. With the hood removed and the considerable chassis clearance on the Corvette, it's easy to do from the top of the engine compartment.
With the exhaust manifolds...
With the exhaust manifolds and their oxygen sensors in place, the first turbocharger is hoisted into position on the passenger side, sliding onto the mounting studs protruding from the exhaust manifold's mounting flange.
LPE uses many hard lines in...
LPE uses many hard lines in the system, including the oil-feed and return lines at the turbo, which require custom fitting to account for the slight variances among vehicles. After the first turbo was installed, for example, this line was measured and cut to fit the oil-feed line to it.
The hard oil-feed line wraps...
The hard oil-feed line wraps under the oil pan and up to a T-junction in an aftermarket oil cooler. The bottom fitting is reserved for the driver-side turbo's feed line.
The installed oil-feed line...
The installed oil-feed line is seen routing away from the turbo and along the oil-pan rail. Installing the line at this point in the project is necessary, because access to it would be almost impossible after the down tube and other sections of the system are installed.