Marc Christ Associate Editor
July 1, 2010
Photos By: Pete Epple, Vision Haus Photography & Design

Chopping and Swapping
After disconnecting all of the linkages and wiring up top, we raised the car to disconnect the rest. Not surprisingly, the bolts holding the mid-pipe to the headers were rusted and seized. Frith used a cordless reciprocating saw to remove the old rusty pieces, but that left us short on components yet again. So we called our friends at Kook's Custom Headers. Kook's sent us a set of its stainless steel Two-Valve long-tube headers (PN 5998S), which retails for $1,046.80, and an X mid-pipe with catalytic converters (PN 6012), which retails for $507.32.

Since we would be replacing the K-member anyway, Jones and Frith decided to simply lower the engine and transmission from the bottom, still attached to the stock K-member. Though it comes out easy this way, it's much more difficult going back in. So Jones and Frith bolted the new UPR K-member in place and lowered the GT back down.

The next discovery we made was the trashed throw-out bearing. When Jones and Frith separated the stock TR-3650 from the back of the old iron-block, the bearing fell out in four pieces. At this point, Jones suggested that we go ahead and replace the clutch and flywheel. "If we even have a chance of seeing 700 rwhp, we need to go ahead and upgrade the clutch now," Jones insisted.

So with a last minute call to Centerforce, we had a DFX clutch assembly (PN 01800075) on the overnight flight. Built to handle more power and torque than we'll ever make, the kit retails for about $420. Centerforce also sent us its aluminum flywheel (PN 900200), a clutch pilot tool (PN 52010), a new throw-out bearing (PN N1714), and a set of clutch cover bolts.

Unfortunately, however, we failed to mention to our contact at Centerforce that we were going to run a forged crankshaft with an eight-bolt pattern flywheel. So when we opened the box, we realized the aluminum flywheel from Centerforce only had six holes. With the clock ticking, we grabbed an Exedy ultra-light steel flywheel off the shelf, since BBR is an Exedy dealer. Though it's 4 pounds heavier than the aluminum Centerforce piece (12 pounds), the Exedy flywheel (16 pounds) is still 10 pounds lighter than the stock part (26 pounds).

With the clutch situation resolved and the gearbox mated to the new engine, Jones and Frith dropped our modern Two-Valve in place. The headers fit nicely, as did the new X mid-pipe. Between switching to an aluminum block, swapping the stock K-member and A-arms for chromoly, and lightening the flywheel, we dropped well over 100 pounds off the nose of our coupe.

Under the hood, Frith assembled the front-end accessory drive. One significant component of the Tork Tech kit is its dedicated belt-drive system. Accessories run on a stock belt, while the TVS supercharger utilizes its own 8- or 10-rib system, specified at the time of purchase. The tensioner is even adjustable, depending on pulley size and boost levels, to eliminate belt slippage.

Frith then moved to the rear to upgrade the fuel system. Since the battery had been in the trunk and we were moving it back to the engine compartment, Frith removed the battery and utilized the old battery cable to feed power to the triple pumps.

Testing and Tuning
Since we had entered uncharted territory, much testing was needed. Tork Tech supplied us with three blower pulleys and three crank pulleys, allowing us a total of nine pulley combinations. It also sent us a larger inlet tube-just in case the stock piece was holding us back.

With the largest pulley on the nose of the blower, the 9-inch (smallest) pulley on the crankshaft, and the stock rubber inlet, Jones spun the rollers on the Dynojet, yielding 616 rwhp and 570 lb-ft of torque at 18 pounds of boost. Though the mildest combination of pulleys, the air/fuel ratio was dangerously lean, so Jones swapped the old SCT BA2400 mass air meter for a larger BA3000.

After trying almost every combination, Jones bolted on the small (2.65-inch) blower pulley and 10-inch crankshaft pulley. "The largest crank pulley with the smallest supercharger pulley is capable of spinning the supercharger to 27,000 rpm, but no one has ever spun one faster than 25,000 rpm," said Charles Warner of Tork Tech. Since a safe maximum speed for the blower is 24,000 rpm, we heed Warner's warning.

With the fuel pressure kicked way up, timing retarded, and C16 race gas in the tank, Jones spun the rollers yet again for what we had been waiting for-the glory run. To our pleasure, when the rollers came to a stop and the graph popped up on the screen, our Two-Valve had made 635 rwhp, 618 lb-ft of torque, and 23 pounds of boost. Even better, it made over 500 lb-ft of torque from 2,600 rpm on. "I wouldn't leave this combination on here for street use," Jones said with a cringe. So Jones swapped back to the 3-inch blower pulley and 10-inch crank pulley, which yielded a streetable 615 rwhp, 571 lb-ft of torque, and 20 pounds of boost.

Though it's taken a long time for Two-Valve technology to reach this point, it's exciting to see it blossom. Even in the shadow of Three- and Four-Valve advancements and the introduction of the new 5-liter, Two-Valves are not dead yet. In fact, as new and more advanced parts hit the aftermarket, SN-95 and New Edge owners have even more reasons to hold onto their Ponies.

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