I would like to know . What is the different btw these 2 engines . I would like to tune my engine.from 340hp to 380hp pls advice thx.

 

based on the XF's their would be no internal difference..with a difference that small would be ECU tuning.. a simple Remap should fix that

 

ECU, maybe different exhaust, maybe different intake.

no one knows for sure what parts are different internally. but the chances are high that its 1 (or all) of the 3 I just listed

 

Supercharged engines don't need efficient intakes or exhausts. Naturally aspirated engines do benefit from these areas. Almost all modern engines are already optimized for intake and exhaust.

To make a supercharged engine more powerful is child's play. You increase boost at the top end of the rpm range. For more power you can usually change the blow off valve software, modern mechanical supercharging systems borrow architecture fom turbocharged setups. They are tuned to overboost with a software controlled blow off valve which usually bypasses boost pressure back to the intake side.

To increase torque you need to fit an overspeed drive pulley so as to increase combustion chamber pressures across the rpm range.

The limits are detonation, desired fuel economy and reliability.

For road cars the limits are generally the numbers desired for the brochure to justify a price premium for S or RS models!