This is a FX Royal Racing Engines Small Radius Short Off Road Manifold. For Maximum performance and reliability use only original FX manifolds. There are different types of FX manifolds each designed for particular track conditions and for particular engines. These recommended manifolds will help optimize performance for the majority of track conditions. However for some specific track conditions or for some fine tuning of the engine settings you may want to change the manifold as desired.

FX has made the following recommendations: 

• FXE659501: FX 2100 Tuned Pipe (Top Speed):
  
• FXE659700: Short Manifold, Small Radius
• FXE659701: Medium Manifold, Small Radius
• FXE659702: Long Manifold, Small Radius
• FXE659502: FX 2108 Tuned Pipe (Bottom End):
• FXE659704: Medium Manifold

Manifold Suggestions:

• Short: Suggested to be used for tracks with long main straights and to achieve the highest RPM but lower performance from bottom.
  
• Medium: Suggested to be used for medium or standard tracks.
• Long: Suggested to be used for short tracks where the performance from bottom is required but the RPM will be lower.