They combine the best low possible end and midrange torque - great top-end.
For best performances, we advise to fit them together with our Evo Race Airbox and Ram-Air Scoop kit, available here:
FRONT FAIRING STAY WITH RAM AIR SCOOP BY GRT FOR APRILIA RS660 – www.mbspecialparts.co.uk
EVO RACE AIRBOX KIT FOR APRILIA RS 660 AND TUONO 660 BY GABRO RACING – www.mbspecialparts.co.uk
These Variable Velocity Stacks are automatically managed by the main ECU; you'll need specific map from UpMap store.
UpMap T800+ sold separately, here:
UPMAP T800+ FOR APRILIA RS660 TUONO 660 – www.mbspecialparts.co.uk