Sharkwerks Cayman GT4 Is Exactly How It Should Be
Porsche has built the GT4 to be near-perfect, but it’s just a few marks shy of the moniker. Sharkwerks in northern California, however, has made a few tweaks that have amped this car up to be exactly what it always should have been.
The salty sea air wafts in over the land, and we are shooting along highway one north of Santa Cruz. The weather is perfect and the roads are nearly empty. When slow moving traffic does appear, we simply move a cog down and slam the loud pedal to the floor. Anyone in the way is dealt with in rapid fashion. We reach our turnoff, a twisting mountain road that is relatively empty, just waiting to be ascended. This might be the best way to spend a Saturday afternoon.
Alex Ross and the rest of the crew at Sharkwerks are magic workers. They have managed to take a nearly perfect Porsche and make it better. The Cayman GT4 comes from the factory with nearly everything you need; close to 400 horsepower, a manual gearbox, and perfectly neutral mid-engine Porsche handling. The mid-engine platform has always been excellent to drive, but with the 981 GT4, Porsche made perhaps the best track car for the everyman. It's easy to drive, it's fun to drive, and it lays down quick lap times with minimal acclimatization time.
A lot of people who have driven the GT4 have said that it's great, but the gearing is too long and the power is too low. Sharkwerks has got you covered. With an IPD intake plenum, a set of Cargraphic sport headers with high-flow catalysts, and a EVOMS off-the-shelf tune, they've opened up the 3.8 liter engine, adding about 10% more horsepower to the wheels for a total of 425. The suspension on the GT4 is just so well tuned from the factory, that they've left well enough on that front, but the gearbox needed a bit of work.
After the gearbox was removed, some work with Guard Transmissions was done, crafting new gear ratios for the stack, and adding a much-needed limited slip differential. The stock 1st gear (3.31:1) and 2nd gear (1.95:1) were retained, but third, fourth, fifth, and sixth were adjusted accordingly. In stock configuration, the GT4's 3rd gear is a somewhat lofty 1.41:1, while the Sharkafied car receives a 1.65:1 ratio. This is probably the most important change internal to the gearbox. The car has a lot more mid-range modulation in 3rd thanks to this change, and there is a much lower drop in revs between second and third.
Similarly, the stock 1.41:1 fourth gear has been adjusted to 1.333:1, and fifth has been changed out from 1.13 to 1.10. Sixth also dropped from a 0.81 to a 0.962 in the car we tested, but Sharkwerks has not noticed much difference with the change to sixth, and will be retaining the stock 6th gear for cost-savings purposes on customer cars. These changes don't seem like they'd make much of a difference, but the car was especially woken up in 3rd and 4th, and I'd love the opportunity to test this car back-to-back with an unmodified GT4.
Perhaps the biggest change, however, has been the addition of a lightweight single-mass flywheel. The stock dual-mass flywheel is intended to provide a nicer street-driving experience with less chatter and a smoother clutch pedal. That softening of the car comes with a price, namely 28.5 pounds of rotational mass on the end of the crankshaft. The new Sharkwerks lightweight flywheel requires the owner to compromise a bit on noise, vibration, and harshness standards for an engine that is a bit quicker to rev and a more positive bite on clutch actuation. This flywheel is an astonishing 14.3 pounds, and is aided by a lighter and simpler clutch/pressure plate assembly.
With the gear ratios adjusted a little, using a less angled gearstack, and a lighter flywheel, Sharkwerks has managed to add back in some of what Porsche's GT division has lost in recent years. Thinking back to the 996 generation GT3, the car was raw and wild, requiring compromise, and exchanging speed for comfort. The current GT4 is excellent on track, but it does give up a bit of speed for street-usability. If you're willing to put up with a little bit more noise and higher revs, you might just love this adjusted GT4.
That exhaust note is excellent too, while we're heaping on the praise. The stock exhaust is tuned really well, and provides a great big-displacement rumble to work hand-in-hand with the high-revolution wail. As this is the case, only minor exhaust work was needed to make this car really sing. A set of Cargraphic-built headers are the perfect addition, and work really well with the stock muffler assembly. There's a bit more sound, but no additional downsides. The exhaust also adds a few more horses (which is expounded on with the EVOMS tune), and of course drops a few pounds over stock. Quality stuff, too. It's got beautiful welds that you'll never see again once it's installed.
At the end of the day, the complaints levied by actual owners of the cars, and the media that test them, found a few minor faults in one of Porsche's best cars. Sharkwerks, in turn, has amended them in rapid fashion. Their car is fitted with PCCBs, and a few other options to run it out to just over the 6-figure mark. From there, the full package "fix" as presented here is another 5-figure investment. The Cargraphic sport manifold is $3385. The IPD intake plenum is $1295. The EVOMS tune is $1365. The Sharkwerks "SWGT4" lightweight flywheel and sport clutch kit is $2400. The Guard Transmissions Limited Slip Differential is $2895. That adds up to $11,340, before you even add in the custom-cut gears and transmission rebuild. It seems like a lot of money, but when you consider that Porsche charges $7400 for carbon brakes, maybe it's not such a bad deal after all. Think about it, how much is perfection worth?