At the top end, the stock head was cleaned up, given a valve job and assembled with stock valves and Supertech double-wound valve springs and titanium retainers. This is to reduce potential valve float issues at sustained high engine speeds on the track, since larger Jim Wolf Technology S1 intake and exhaust cams (0.390-inch lift and 275-degree) were installed along with adjustable cam gears. Since the KA uses a timing chain instead of a belt, the adjustable timing gears had to be set before the front cover could be bolted on. The head and bottom end squeeze a 1mm multi-layer Cometic steel head gasket, which has a stronger bore-sealing ring for boosted operation. The oil and cooling systems were augmented with a Goodridge oil cooler, remote oil filter mount, braided stainless steel lines and -10AN fittings.
Just as AMS prepared the long block to be shipped back, Symonds prepped the chassis with TEIN HE coilovers, using 9kg/mm and 7kg/mm springs front and rear respectively. This is more than twice the spring rate of TEIN's street set-up as the car would be riding on super-sticky Hoosier R6 track tires.
With 140,000 miles on the original chassis, it was only logical to replace the stock rubber bushings with Energy Suspension parts. The rear upper camber and toe arms were also replaced with heim-jointed units from SPL to cut down on slop in the rear suspension. SPL rear subframe pinch spacers squeeze the original rubber subframe bushings to minimize deflection. As proof of the S13's fundamentally sound lay-out, the only other addition to the race suspension was the use of DC Sports carbon steel strut tower braces, a Nismo front subframe brace and TEIN pillow ball tension rods to minimize toe change as the front wheels are loaded.
Even after the chassis and engine marriage, the laundry list of things to do on a racecar is endless. Symonds tackled the rest of the work himself, with the emotional and beer support of his wife. To handle track abuse and temperatures, the stock 240SX front brakes were upgraded to early-model 300ZX aluminum calipers, with the master cylinder and properly sized Brembo rotors to match, and Hawk HT-10 race pads. Since the rears were still stock, more aggressive Hawk Blue pads were used to compensate for the added front bias.
The stock 240SX transmission was retained with changes to the clutch and limited-slip differential (LSD) only. With few stoplight maneuvers on track, a smooth clutch engagement isn't critical, so an unsprung Clutch Specialties six-puck clutch and lightened chromoly flywheel was installed for direct shifts and negligible driveline slop. Symonds experimented with an OEM viscous-type differential (from a Skyline) for its predictable engagement, but the OEM unit failed and left him with peg-leg power mid-lap. He's now looking into a helical-type LSD. The final touches were performed at Backstreet Performance in Medina, Ohio, where a custom three-inch stainless steel side-exit exhaust was fabricated.
The racecar now weighed 2725 pounds (with driver). This left Symonds with a dilemma. In order to keep within the TTS class PWR of 8.7:1, the car had to stay under 310 wheel-hp, even though the built engine and Garrett GT2871 turbo was capable of making over 400 wheel-hp. Any more and the car would be bumped up into the higher TTU class with much more seriously prepped machines. This is where Symonds' turbo and engine management knowledge kicked in.