New NST Pulleys for the TS

[CASTREX]

Originally Posted by andries

Can someone explain to me what's the meaning is of "10% underdrive" by the NST pulley?
Is it means that he is 10% smaller than stock?

Exactly... the diameter is 10% smaller tha the stock pulley.


Here is a brief explanation from NST website:

Think of it this way, underdrive means to slow down. Underdrive crank pulleys found at NonStopTuning are designed to slow down engine accessories and reduce parasitic loss.
Crank pulleys, attached to the outside of the crankshaft, are the source of power for a car's accessories. The alternator, power steering, water pump, and air conditioner are all belt driven units, attached to the crank pulley, that use horsepower from an engine to provide their own services. This draw of power by these accessories is called parasitic loss. NST underdrive crank pulleys increase an engine's horsepower by reducing the power required to drive these external accessories. By replacing factory pulleys with carefully resized units, the accessories are slowed enough so that their performance does not suffer, but just enough so that more horsepower is sent to the wheels and put to the ground. Where horsepower should be!

The R&D team at NST is dedicated to developing underdrive crank pulleys that provide great gains for track days and continue to deliver proper accessory output for everyday street use.

NST equipped cars do better on the track, benefit from increased accessory life on the street, and also deliver better mile-per-gallon fuel efficiency.