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  Update #1   Viper Green
Shark Werks GT3 8800 RPM 3.9L 502 HP Engine Upgrade

Just as the 2010 Porsche GT3s are reaching local dealerships with a new 3.8L motor installed, SharkWerks' Viper Green GT3 RS (AKA "ZKERMIT") is having its 3.8L motor removed.

The 2010 997 GT3s feature a 3.8L motor, a bump up from the 3.6L featured in the 2007-2008 997 GT3. We built a similar 3.8L motor for ZKERMIT and battle-tested it for 19 months with tuning performance partner, Evolution MotorSports. So after 100s of dyno runs, many track miles (some with pro drivers), and several state highways worth of road testing, we decided to up the ante.

Considering how great the 997 GT3 motor is from the factory, it's very hard to justify removing it from the car.

Surgery begins.

The intake and accessory belt, hoses and electrical connections are removed to facilitate the removal of the 3.8L installed some 11,000 miles ago.

Before the engine is lowered, coolant is evacuated. James must remove several covers, cross-braces and subframes, the rear sway bar, driveshafts, mufflers and SharkWerks bypass, transmission cooler lines and more.

The motor is gently removed from the car, carefully checking along the way to be sure nothing snags or extends beyond its capability.

It looks like Jürgen will be walking home today...

A mountain of accessories and items must be removed in order to gain access to the internal components: fuel rails, oil filler, air conditioning lines, emission controls, Variocam electronics and harnesses, valve covers, heads, and so-on.

  Update #2  

The remaining accessories are removed. Each side must be disassembled independently. Heat shields, coil packs, valve covers, timing chains, camshafts, lifters...

Bare water jacket removed from motor:

A collection of new, upgraded components to be installed:

Using the SharkWerks/Evolution MotorSports Spec 3.9 liter pistons with new liners, displacement is increased by over 8% (from 3.6 to 3.9 liters). The larger bore pistons also feature higher compression for increased torque and horsepower through the entire RPM range. There's a lot of time, effort, and R&D that went it to this so some of the specifics are going to stay under wraps.

The new components reduce rotating mass by 2 grams per piston and 21 grams per wrist pin, ensuring the motor freely revs and responds especially well at higher RPMs.

The Evolution MotorSports custom Exhaust and Intake camshafts – built specifically for the 3.9L, add more top-end power and overall performance. We set these up to be able to hit 8800rpms...
  Update #3  

Re-assembly begins as James installs the new pistons and hardware.

In go the Evolution MotorSports custom Exhaust and Intake camshafts:

Cam timing is performed using Porsche factory tools:

The motor, mostly assembled is almost ready to go back into the car:

  Update #4  

Once completely installed and thoroughly checked out, the car was started and idled briefly. Everything is checked again after a few minutes, and soon James has given the thumbs-up.

For its maiden voyage, the 3.9L motor propelled the GT3RS on a 500 mile drive, from SharkWerks to northern-northern California's coast, to meet with Snowboarder54 (a friend of SharkWerks and a huge GT3 fan).

Before any hard driving, the car was once again re-inspected by James. Now it's time to tune the car, which requires a 1500+ mile round trip to our performance partner and tuner, Todd Zuccone of Evolution Motorsports in Tempe, Arizona.

This also gave us a good opportunity to break-in and thoroughly road test the new motor.

Somewhere in the desert, we tested the effectiveness of our green camouflage. Maybe Sand Beige would've worked better here.

Much later, the car arrives at Evolution Motorsports, to begin tuning on this pleasant 110 degree day.

Big thanks to Geri Amani of Redlign Autosports for enduring the Arizona heat and taking some of these shots.

The car spent several days on Evolution MotorSports' AWD Mustang Dyno to tune and tweak every parameter of the fuel maps, ignition timing, camshaft timing and other parameters for safety, maximum performance, and reliability.

Todd Zuccone – Evolution MotorSports Founder and director of EVOMSit software development, used an ECU emulator / EPROM simulator module to live tune the ECU on the dyno. This type of technology allows live tuning of the ECU for instant mapping changes as well as live monitoring of the various EPROM functions. This is the kind of thing usually seen in Europe, but fortunately, we have some great footage which we will be uploading soon.

This is the emulator connected to the GT3 ECU which gets run through a special program on the laptop, allowing instant changes to be made to the ECU during the tuning process while still installed in the car.

For a full overview of the EVOMSit Tuning process, please view this article.
  Update #5  

More photos of the emulator inside the car:

While in Arizona, we also tested our ultra-light straight pipe exhaust to determine what (if any) restrictions the stock side mufflers had with 3.9L of displacement. The results on our car were certainly interesting and we were able to eke out a little more performance and again save some weight (these are too loud for the street and designed for track-use only):

And finally, the results... Not too shabby eh?

93 octane fuel, three plots on this first graph:
1) SharkWerks / EVOMS 3.9L with complete muffler bypass.
2) SharkWerks / EVOMS 3.9L with OEM side mufflers and SharkWerks Bypass Exhaust.
3) Stock 3.6L 997 GT3 base map.

Stock catalytic converters, stock headers, stock intake. Tests performed in 4th gear. Todd created a different file specifically for the side muffler bypass pipes. The software needs to be modified due to the changes in exhaust back pressure: there is no such thing as one size fits all.

91 octane fuel test, three plots on this graph:
1) SharkWerks / EVOMS 3.9L with OEM side mufflers and SharkWerks Bypass Exhaust running 93 octane fuel.
2) SharkWerks / EVOMS 3.9L with OEM side mufflers and SharkWerks Bypass Exhaust running 91 octane fuel.
3) Stock 3.6L 997 GT3 base map running 93 octane.

A few things you can see- there's a big jump in tq/hp down low over a 3.6. This is very noticeable from the moment you drive. Where the factory cams/tuning begin to fall off this motor just keeps on going and going to 8800. In fact from peak power all the way to 8800 there's only a loss of 5hp. This gives you more revs to play with and you start off with more power in every gear between shifts. An even more usable powerband.

It's been a fun journey getting to this point and we really feel like we've not only upped the displacement but in doing so have managed to keep the integrity and character of the GT3 motor. It actually revs even quicker and snappier than a factory 3.6 with LWF. She idles great, runs without any compromises and (to prove we're really green after some light-load fine tuning) actually managed to return on the journey home averaging 25.4mpg (a stock car going 75mph along the 5 freeway yielded 24.4mpg).

For those interested in pricing and more details please see our product page or contact us. Only SharkWerks and Evolution Motorsports will be performing this upgrade, so your car can be sent to either location.

The car really is peppy and a few local guys have already tried it (JWGT2, SnowBoarder54, Tony@TCDesign etc...) and the response has been good from these guys who we all look up to.

We'll have the product page/pricing info shortly but we're looking forward to doing it again to a certain silver 07 GT3 with 33K miles in about a month.
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