Meet Zkermit, the green 375kW GT3
Porsche’s GT3s (stock or RS) are amongst the purest of performance cars.
More engine speed and a little additional power never hurt anybody though, now did it?
When it comes to fettling high-end Porsches we expect a litany of German tuners making up the bulk of the market offering. The Americans though, are slowly making inroads too.
One of the better 911 GT3 go-faster kits we’ve seen out of the US is from Californian based SharkWerks. Although the name is peculiarly original, the engineering is quite old-school.
Sharkwerks is owned by a partners James Hendry, Alex Ross (Sharky) and Joan Wood.
Power numbers are gleaned using traditional chassis dyno tie-down techniques. With a 8 880r/min engine speed ceiling, would you like stand in front of it during peak runs?
What the Californian tuning concern offers with regards to 997 GT3s (the 3.6l models, not the latest 3.8) is a slight increase in swept capacity and engine speed, which translates into quite significant performance gains...
At first the 0.3l increase in capacity (up from 3.6- to 3.9l) seems almost inconsequential. Peruse the specification sheet and you'll notice Sharkwerks have not simply slotted in a set of their own lightweight pistons and let it be though.
The suite of mechanical moving parts has been changed quite significantly.
Reprofiled Sharkwerks intake and exhaust camshafts drive the valves, which remain stock Porsche items, whilst gas-expelling is routed via a radically redesigned exhaust system, which trims 7kg off the car’s total mass.
Exhaust plumbing features two cabin actuated routing patterns - one of which rocks to a hooligan beat.
More power, better sound effects
A key part of the Sharkwerks GT3 tuning kit is the bolt-on stainless steel muffler bypass system. Bolted onto the centre muffler, this bypass system is actuated from the cabin by a sport button.
Operating in default mode it channels gasflow through the side mufflers. Engaged in sport mode, the diverted default routing is bypassed for a more direct flow pattern.
The result is increased acoustic resonance across the engine speed range, and let’s face it - who doesn’t mind hearing each octave of a Porsche GT3’s flat-six crescendo?
Sharkwerks claims the 100cc increase in capacity and amalgamated engine modifications (including a lightweight billet crankshaft pulley) throw around 66 additional kilowatts into the equation, with rotational force peaking at 480Nm instead of 405Nm.
Perhaps the most appealing part of the 3.9l engine conversion is the rather disturbing 8 800r/min maximum piston-speed, thanks in no small way to the increase in capacity being primarily in terms of piston diameter, not stoke elongation.
The heady rev-limit nearly makes one forget about the 375 peak kilowatts, the other rather impressive number in this Sharkwerks GT3’s tale of tape…
For good measure the team at Sharkwerks have just acquired a 2010 model year 3.8l GT3, which is going into a similarly geared development cycle to the company's green Zkermit display car.
Some people just can't help themselves, now can they?