When upgrading to higher power levels, stock fuel injectors are short lived as they simply cannot deliver enough fuel to safely run more than ~380RWHP. These injectors are engineered and designed to flow larger amounts of fuel to keep up with the demand as airflow increases. Injectors are precision made and have exceptional calibration directly from the factory.  

This listing is for (1) single replacement injector, if you need a complete set see these listings:   740cc injector Kit , 740cc Kit for 90-94 TT with adapters