Enhanced Performance Thrusters
Enhanced Performance Thrusters are alternative normal-space ship propulsion systems. It's offered as a replacement to normal thrusters and available for purchase at Farseer Inc. in Deciat and Palin Research Centre in Maia. Enhanced thrusters are available only in 2A and 3A variants, thus limiting the amount of ships they can be installed onto. On a sufficiently lightweight ship they result in about 40% speed increase: fitted with enhanced thrusters, Imperial Eagle is capable of boosting to 638 m/s!
Compared to normal A-rated thrusters, enhanced version has the same weight, lower integrity, much higher power draw, higher minimum and maximum supported hull masses, however the optimal mass limit is significantly lower, meaning any considerable speed increase can be achieved only on a stripped down version of the ship.
As per the thread
Mick Evens stated that 2A enhanced thrusters use exactly these values:
LinearAccelMassCurve MinimumMass 50 OptimisedMass 60 MaximumMass 120 MinimumMult 0.9 OptimalMult 1.1 MaximumMult 1.2 LinearSpeedMassCurve MinimumMass 50 OptimisedMass 60 MaximumMass 120 MinimumMult 0.9 OptimalMult 1.25 MaximumMult 1.6 AngularSpeedMassCurve MinimumMass 50 OptimisedMass 60 MaximumMass 120 MinimumMult 0.9 OptimalMult 1.1 MaximumMult 1.3
Meaning that they add a lot more speed than they do acceleration or turn rate.