The Porsche Cayman GT4 RS Doesn't Exist, So This Shop Created It

We may earn a commission from links on this page.

Everybody loves a 911, but—and trust me on this—the Porsche Cayman GT4 is the best road car the company has ever delivered. The mid-engine layout gives it incredible balance, the six-speed manual makes it highly engaging. So when you add $20,000 in upgrades to that brilliant base, you’re pretty much into a superhero on wheels.

(Full Disclosure: Sharkwerks’ people wanted me to try out their work so badly that they asked me to drive their Porsche Cayman GT4 project car for a couple days, requested I flog it on the Angeles Crest Highway, told me to do some daily driving to test how livable it is. They also brought along a project 964 to play with, knowing I’m a massive fan of those. Another miserable road test, but I had to do it.) 

Porsche does a perfectly good job delivering what I consider to be the best lineup of performance cars on the planet. But some people still want to go faster, and that’s why tuner shops like Sharkwerks exist.

This Fremont, California outfit has been tweaking and tuning Porsches since 2005, and it’s got a mad workshop that makes the most of your Porsche’s canyon carving and track day attacking potential. Besides selling individual upgrade parts, Sharkwerks dials specific cars in for individuals with its own engineering and testing programs.

What Is This?

The GT4 is an epic car when it leaves the showroom, but many of us who have driven one thoroughly complain that the gears are slightly tall, and that Porsche may have only retained the 3.8 liter 395-horsepower flat-six engine from the 991.1 Carrera S to keep it from cannibalizing the 911 GT3.

Sharkwerks decided to produce its idea of what a GT4 RS would have been, had Porsche built one itself. And for about $20,000, plus your GT4, Sharkwerks will make one for you. With its history of churning out fast air and water cooled toys for hundreds of customers over the years, I had no doubt the company could execute this well, but when you’re working with a car this impressive out of the box as the starting point, you’re going to be graded on a serious scale.

Time To Crank Things Up

Powered by the previously mentioned 3.8 liter flat-six, the GT4 is no slouch but... it could be a bit faster. Addressing these concerns, the Sharkwerks crew went nuts with its existing software, plus clutch and flywheel products, software tuning from its partners at EVOMSit, and intake components from a company called IPD. Sharkwerks also engineers its own exhaust systems, and this GT4 benefits from the upgraded X-pipe with 97 millimeter tips. The results are astounding.

With the help of Guard Transmission, all of this Cayman’s gears minus first have been replaced with shorter ratios. The people at Guard know their shit, and have been cranking out performance transmission parts since the 1990s. The company provides transmissions and limited-slip differentials to teams in World Challenge and Grand Am racing, so it has a serious sandbox for research and development.

Second gear was always far too tall in the GT4, allowing you to run up to over 80 mph before needing to upshift to third. It also left you in a weird spot in the revs when you were playing on a fun road. You didn’t know if you wanted to wrap up second, or shift to a taller third gear. This has been rectified.

More power requires more grip, and Sharkwerks toyed with a bunch of parts and options before landing on SalterAero rear wing uprights, RSS canards to the front bumper, and an RSS ducktail to give a hint more aero out back. Surprisingly, Sharkwerks left the suspension parts from Porsche alone, but did give it bit more toe and camber through an alignment performed by their friends at TC Design. The intent by Sharkwerks was to give the car more grip in the corners, but to still be compliant and civil. They’ve nailed it.

How Was It On Twisty Roads?

Epic. This is the second-best Porsche package I have ever driven, next to the fine work of Singer, with its awesome $400,000 reimagined 964. The 3.8 liter engine now cranks out 40 more horses than the stock configuration, and it has much more usable torque throughout the rev range. Paired with Sharkwerks’ own exhaust upgrades, the engine screams once you get past 4,000 RPM, and inside the tunnels along Angeles Crest Highway I may have made a few extra passes, just to be sure I liked the sound.

As tested on the ACH over several runs up and down the mountain, I was more than satisfied with the new Guard Transmission setup. Throughout the tighter stretches, I could leave the GT4 in third gear and get more than enough flexibility to maneuver from corner to straightaway, and could even make good use of the shorter fourth gear out of a corner if I got too lazy to downshift. Downshifting is addictive though, as when you activate the sport exhaust button in the GT4’s cabin you get the finest of blips when you downshift, whether you’re a heel-and-toe pro or not. The gears sound straight-cut, and even though they aren’t, I do love this noise.

Completing the appearance, Sharkwerks added a set of Fifteen52 Outlaw 001 3-piece 20-inch wheels, which show off just enough of the famous Porsche PCCB carbon ceramic brakes and their bright yellow calipers. Michelin Pilot Sport Cup 2 tires wrap around those stylish wheels, which of course are immensely grippy. After several hours of ACH driving, they never got greasy, and never gave me a hint of complaint.

The aero updates add a noticeable difference, in addition to giving the car a racier look. Those RSS canards keep the front end more planted when you dive deep into a corner, and the SalterWerks uprights not only help add way more downforce, but also move the wing up high enough that you can actually see out the back window from your rear-view mirror. This is a big helper when you’re daily driving the car.

Speaking Of Daily Driving

Considering all these performance updates, the Sharkwerks GT4 is still civilized. While it has a new lightweight flywheel and stronger clutch package, that duo drops 15 pounds versus the stock assembly. The motorsports-focused clutch and pressure plate package it’s still really easy to drive. Somehow the clutch pedal feels lighter, and requires so little input to engage and release. Once I tricked my brain and left foot to operate the new clutch pedal feel to behave more like I would when moving the legendary Carrera GT from a stop, I pulled away from a stop smoothly and effortlessly.

The new exhaust is actually quiet when you aren’t stomping on the car, and if you haven’t pressed the sport exhaust mode button next to the shifter, it’s as quiet as your ordinary GT4. Yes, the upgraded gears affect the overall fuel economy, being so much tighter. Sharkwerks estimates that you’re only up a couple miles per gallon. I say that’s a fair trade.

What About That 964?

It is my sincere belief that the 964 is the best 911 generation produced; the perfect example of a smaller car with a brilliant air-cooled flat-six engine. The early 1990s 911 is classic and pure. No power adders, no crazy wings, and no driver aids. The 964 C2 is perfect, and I have driven dozens of iterations of them, from stock to wildly-tuned.

Normally known for their water-cooled projects, Sharkwerks has taken steps to improve upon my favorite 911 in many departments. What Sharkwerks has done only enhances the existing positive characteristics, while giving it just a bit more fun in every condition. From ITS software revisions to the updated intake, injectors, and exhaust, you feel a noticeable improvement in performance over the stock 3.6 liter flat-six, but it’s still subtle. Bilstein PSS10 coilovers paired with H&R sway bars give the 964 a ton of added grip, but don’t murder your teeth fillings over the bumpy roads.

The Recaro seats are actually from a finer pick-a-part lot, and the wheel is the classic Momo you’ve come to see in plenty of old Porsches, but with a softer, distressed wrap around it. Fifteen52 Outlaw 003 wheels complete the exterior, and that gold finish looks exceptional against Porsche’s classic Guards Red.

What’s The Verdict?

I’ve driven tons of tuner cars, and many of them have been Porsche projects. When you start tinkering with my favorite cars of all-time, and you invite me to take them for a spin, you better be good at this.

Sharkwerks has executed its vision on the GT4 and 964 pretty much flawlessly, and I can’t wait to see plenty more Porsche owners shipping their cars to Fremont, California to have this team work their magic. Maybe I’ll spend more time in their cars in the future too.