When you have tires that get well over 600 hp and 700 lb-ft of torque to hook up in second gear, it's a freak show like no other. I'm talking tunnel vision, the seat feeling like it's about to fly out the rear window. The neck-snapping pull is malicious. The sound of the 3.6-liter bursting out over 190 wheel-hp per liter can only be described as frightening. And fantastic.
Aesthetically, a stock Porsche 996 Turbo is pleasing. This one goes a couple extra miles with TechArt inlet splitters, a TechArt Type 2 front bumper cover and a GT2 wing. This yellow beauty is owned and built by Stephen Kaspar of Imagine Auto, a Porsche and Audi performance shop near Kansas City. Although it's Kaspar's personal car, it serves as the proving ground for many of the aftermarket Porsche components his company sells. With this car, in cooperation with EVO and Garrett Integrated Automotive Corporation (GIAC), Imagine Auto has developed the IA GT700 package.
At the heart of the system are a pair of turbochargers machined in KKK K16 housings, giving a much higher flow capacity, but maintaining a stock fit. The turbos are powered by exhaust pulses exiting through custom stainless steel headers with Burns collectors, and breathe through a Fabspeed cat and muffler exhaust system.
The engine sucks cool air through aluminum and carbon fiber air ducts, which is then compressed by the turbos, further chilled through a larger pair of inter-coolers, and then punched through the stock intake manifold for combustion. The heads have only been upgraded in the form of light porting and updated valve springs. When the throttle is shut, the trapped boost gets shot out of twin IA custom billet bypass valves.To match this tremendous amount of air with enough fuel, a large, in-tank (so it's quiet) Bosch racing fuel pump feeds stainless steel fuel lines to injectors rated at 92 lb/hr (replacing the stock 42 lb/hr squirters) while GIAC custom software for the GT700 package controls the pulses.
The software has been flash-loaded to allow OBD-II port switching of up to three different custom programs. On 92-octane, the turbos push 17.6 psi (1.2 bar) boost with a more conservative ignition map, reportedly good for 600 wheel-hp. On 100-octane racing fuel, the custom-sprung wastegates regulate 19 psi (1.3 bar) boost, but the ignition maps are also much more aggressive. With the sweet-smelling, slower-burning fuel, the car spins Imagine Auto's Mustang dynamometer to a mighty 705 wheel-hp and 758 lb-ft of torque in two-wheel-drive mode (610 hp at 17.6 psi to all four wheels when tested in all-wheel-drive mode is still stunning).
Think about it for a minute: 758 lb-ft of torque at 4300 rpm to the wheels. This is a hard-working engine, enough to produce more than 700 wheel-hp as early as 5300 rpm and sustain that power all the way through to the redline.
High cylinder pressure means each stock piston is subjected to extreme heat. To protect them, Kaspar had the tops ceramic-coated and added dry lubrication to the skirts, which are oiled by a GT3 oil pump. Cylinder pressures of this magnitude have also been known to cause cylinder heads to lift. Stainless steel head studs are there to prevent that from happening. To cope with the tensile loads of large displacement components operating at high rpm, Carrillo connecting rods mediate between pistons and crankshaft.
Making sure everything operates within acceptable parameters, a fully programmable HKS Data Camp system monitors revs, injector pulse width, oil temp, oil pressure, auxiliary temp, auxiliary pressure, boost, EGT, fuel consumption and mph. The unit will also print the material on a spreadsheet via a serial port. The screen can be customized to display digital dials (pictured previous page) or just plain numbers.
Speedline Corse wheels (9x18 front, 12x18 rear) are wrapped with Michelin Pilot Sport 2 245/40 and 315/30 tires. Behind them are Porsche GT2 six-pot calipers with custom 13-inch rotors, and Pagid Yellow pads. A 15-way adjustable JIC coilover suspension system with monoball adjustment rounds out the rolling stock.
The brakes and grip are there, as expected from a factory turbo Porsche. The suspension is not too stiff and the ride is comfortable on the street. It doesn't exhibit the body roll you might expect with so much grip, nor does it squat heavily under acceleration. It's the right compromise.