Neuspeed GTI Vs. Stock GTI
It wouldn't be completely accurate to say that Bill Neumann invented watercooled Volkswagen performance tuning, but Neuspeed is certainly among the oldest and most respected Volkswagen and Audi tuners in North America. european car recently spent some time with Aaron Neumann, the company's technical authority, learning about Neuspeed's suspension modification program for the MkIV platform, the GTI 1.8T in particular.
Neuspeed's overall objective is highly satisfied customers who drive their cars on the streets. That means high levels of fit and finish and attention to detail, simple, straightforward installation and good day-to-day performance, taking into account the wide range of enthusiasts' commitment and budget.
With the smooth highways in Europe, many European tuners like to use stiff springs to control roll, but Neuspeed prefers to use moderate spring rates that will be compatible with healthy original-equipment dampers and still provide a smooth ride on much rougher U.S. roads. When spring rates are set, the cornering balance is dialed in with anti-roll bars.
On the MkIV Golf and New Beetle, the front spring rate is approximately 150 lb/in. and the rear is about 140 lb/in. The Jetta, perhaps because it is considered a more sedate vehicle, uses a front spring rate of less than 110 lb/in. but the same rate to support the trunk. Motion ratio, the relationship between wheel movement and spring movement, is very close to 1:1 on both the front and rear of the car. Neuspeed knows not every customer will also buy performance dampers to go with its springs, so Neuspeed's first step, the Sport springs, are designed to lower the car about 1 1/2-in. and work with the stock dampers.
The rear spring rate is 170 lb/in., because that's all the damper will handle. The front spring rate is increased to 220 lb/in. Aaron stated that making the front springs too soft will allow the car to get into the front bumpstop more often, leading to a "porpoising" oscillation. Even though Neuspeed's Sport springs are designed to work with a stop damper, installation of aftermarket sport dampers such as Bilstein or Koni (both are available from Neuspeed) is highly recommended for best performance.
Neuspeed's Race springs are more aggressive, with 220 lb/in. in the rear and 285 lb/in. in the front. They also lower the car another 1/2 in, which brings the long-travel, foamy bumpstops (sometimes called "supplemental springs") into play, effectively adding even more spring rate with a highly progressive curve. For this reason, high-performance dampers are required with race springs.