Switzer’s P800 Upgrade Kit Pushes a Stock GT-R to the Limit

Key Word: Reliability

[pullquote]SWITZER HAS PERFECTED VR38 REMOVAL AND INSTALLATION DOWN TO A SCIENCE. FROM START TO FINISH, THEY HAD THE ENGINE OUT, KIT INSTALLED, AND CAR BACK TOGETHER IN ABOUT 8 HOURS.[/pullquote] While increasing the original output of any engine would usually require a long-list of performance parts, Switzer’s P800 engine performance package consists of only the parts needed to reliably get the job done. While the GT-R’s factory turbochargers may be able to deliver on the order of 600-plus horsepower for a short period of time, Tym Switzer doesn’t subscribe to that notion. His concern with the stress on the hardware combined with the excessive heat generated by the stock units at very high speeds led to the development of upgraded turbochargers for the P800 kit.

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Unlike most performance parts that trade off low-end power for top-end and vice versa, the P800 package offers a no-compromise power solution. We saw power gains from just 2,000RPM all the way to 7,000RPM. While the stock setup plateaus after 5,000RPM, the P800 continues to climb up until redline.

While Switzer usually requires customers to have the kit installed at its headquarters in Oberlin, Ohio, Tym made an exception for us. Instead of shipping the car half way across the country, Tym and Leroy (one of Switzer’s master mechanics) flew out to California to install the P800 kit at the DSPORT HQ. The team at Switzer has perfected VR38 removal and installation down to a science. From start to finish, the duo had the engine out, kit installed, and car back together in about 8 hours. On Bok’s 2010 R35 GT-R, the P800 package delivered superior power from idle to redline. The P800 package increased power and torque across the entire powerband, reaching 710- plus peak wheel horsepower (800-plus flywheel horsepower) on 91-octane fuel at just 24.5 PSI of boost. While we were able to make over 710 wheel horsepower and 610  -lbs. of torque on our Dynojet 424xLC2 dynamometer, we were advised against pushing the transmission that far.

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The torque of the P800 package continues to build even after 3,250RPM where the factory torque curve tapers off. More impressive than the peak number is the massive area under the curve, a testament to the engineering behind Switzer’s P800 refinement package.

[pullquote]THE TURBO SYSTEM FEATURES SWITZER’S GT28-BASED, BALL-BEARING, BILLET-COMPRESSOR WHEEL TURBOCHARGERS WITH HIGH-PRESSURE WASTEGATE ACTUATORS THAT MATE TO THE FACTORY MANIFOLDS.[/pullquote] The exceptional power curve is the result of optimized boost response and volumetric efficiency from the P800 turbocharger system and cooling upgrades. The turbocharger system features Switzer’s GT28-based, ball-bearing, billet-compressor wheel turbochargers with high-pressure wastegate actuators that mate to the factory manifolds. Outwardly, these turbochargers don’t look any different than the factory units. A COBB Accessport V3 takes full control of the injector and ignition events to deliver optimized fuel and spark delivery. Tuned by COBB’s own Tim Bailey, the boost was dialed-in on the GT-R as in order to keep the torque
from rising past any rod-bending, clutch-slipping numbers.

Bok's R34 GTR Torque Curve Chart

Look at the massive increase in area under the curve. The P800 torque curve is superior to the factory torque in every way. There’s more torque down low and across the RPM range.

Bok's R35 GTR Cobb Access Port

COBB’s Accessport V3 has been used effectively to tune GT-R’s well past 2,000WHP. The AP also offers optional TCM flashing and clutch adjustment.

Beat the Heat

To support over 40-percent more power, Switzer’s P800 kit includes its proprietary MONSTER intercoolers to replace the factory intercoolers. These bolt-in units are designed to fit maximum heat exchange into the same space that housed the factory units, eliminating the need to cut, file or bend any mounts. In addition to the upgraded intercoolers, the P800 package also includes the requisite high-flow intake assembly and high-flow down pipes to free up airflow and keep backpressure to a minimum.

The CSF Race all-aluminum radiator utilizes a twin-core design and uses all factory mounting points and hardware.

In order to complement the upgraded down pipes, we selected A’PEX Integration’s RS Evolution Extreme stainless-steel cat-back exhaust system. This exhaust features fully TIG-welded construction throughout and a single 85mm B pipe to 50mm quad pipe design for optimum exhaust eefficiency. Whether it’s at idle, cruising, or at redline, the A’PEX Integration exhaust helps the twin-turbo six-cylinder engine breathe easier and gives the vehicle a menacing sound.

Bok's R35 GTR Apexi Exhaust