Keeping abreast of current events is probably no more important in any other field than in the automotive industry. For aftermarket tuners, each new model year can present new challenges and new frustrations as the O.E. manufacturers revise and improve their products-or as they attempt to stay one step ahead of those who would seek to improve on those products, depending on how you'd like to look at it.
For guys like Neuspeed's Aaron Neumann, staying no more than a half step behind the manufacturers is an ongoing endeavor. The 2003 A4 1.8T Quattro is the company's latest take on Audi's latest version of its 1.8-liter turbo. Though the car may not appear all that different than, say, a 2002 Neuspeed-modified A4 1.8T Quattro, the big difference is to be found inside the engine's ECU.
"Every year the engine control units change," Neumann said. "When you start [upgrading and] running bigger turbos you start running into tighter limits within the programming." Therefore, the biggest challenge with the car was not in upgrading the hardware but in tweaking the support software present in the Neuspeed chip. In fact, the impetus to do this came about when Neumann's company was consulted for help with fuel tuning a car sporting goods from a popular German Audi tuner, after the supplied engine management codes proved incompatible with the upgrades that were present on the car.
Hardware upgrades on this particular Audi consist of Neuspeed's basic NS04 turbo upgrade package for the 1.8T. This includes a new cast-iron, high-flow exhaust manifold to support the larger turbo, the updated Neuspeed P-Chip and larger fuel injectors. The turbo itself has been upgraded from the factory K03 to a larger K04, and for this particular application Neuspeed runs what Neumann calls a "K04 Sport" (essentially a K04 turbocharger that's been imbued with a slightly larger compressor wheel). "Basically the biggest that could fit," Neumann said.
Other upgrades within the engine bay include a set of Pi-Thon hose clamps on the radiator hoses and various vacuum fittings-trick locking billet-aluminum fasteners that seal even better than they look-as well as a T304 stainless Neuspeed cat-back exhaust. Normally an open-element intake system would be part of the upgrades, but Neumann stated the A4/Passat's factory airbox is well suited to ingesting adequate amounts of cool air at speed, as well as shielding the intake from heat generated by the nearby turbo and catalytic converter. Even so, the addition of a K&N panel filter inside the factory airbox is something the company does condone.
Other upgrades applied to the car's suspension include a full Koni coilover kit, with height- and rebound-adjustable dampers and performance-wound springs. Though Neuspeed offers its own performance springs for this application, the exclusive use of Koni equipment was part of a joint effort by both companies to develop a true adjustable coilover system for the car. Neuspeed added its own anti-sway bar, a 21mm solid steel unit designed to help kick out the rear and tame the car's prevalent understeer. The front bar was not changed, mainly because the A4 runs a pretty big bar from the factory, a 31mm tubular steel unit.
"It's pretty good size," Neumann said. "Our biggest bar is a 29mm solid, and the car understeers anyway, so we decided developing a new bar wasn't really worth the trouble."