Eurocharged ATX (Austin, Texas) is getting very nice numbers out of the motor. Take a look at the modifications:
Stock Trans (at the moment)
2x Walbro 450cc in the factory baskets
Custom Fuel Lid for Passenger's side
-10AN from tank, through external FPR and Filter
Split factory rail with -6 inlet on each
Mods - FBO
American Racing Longtubes
77mm S/C Pulley
Eurocharged ATX Flex Fuel
We are talking bolt on modifications with an upgraded fuel system for ethanol. Nothing crazy there yet the engine design which is well over a decade old is showing 643 horsepower to the tires.
They plan on doing some further tuning with higher ethanol contents but suffice it to say the W211 E55 is an all time great.