a friend told me that without sacrificing the warranty of my evo i can buy a lighter flywheel and crankshaft. he told me that it would 't put stress on the engine and at the same time it would probably give me more wheel power keeping the stock engine hp. i'm new to car tuning so and evo is my dream car so it may sound stupid of me buying my dream car and don't know about the mechanics (like takumi in inital d) pls. help me out

 

A lighter flywheel and crankshaft will VOID you warranty.
The only thing I can confirm you can do without voiding your warranty is a catback exhaust (10-15HP increase).

 

your friend is an idiot. Installing a new crankshaft means a complete tear down of the motor, and removal of the transmission. You will have basically removed every bolt imaginable for the crankshaft...if there was something that would void your warranty, THAT would be it.

 

The flywheel's inertial mass spinning around is what keeps the car from bogging or lurching off idle. In other words the stored kinetic energy in the moving flywheel helps to suplement the engine's low torque at low rpm's and helps get the car moving from a stand still.

A lighter flywheel will not GAIN any power but the reduced mass will take less energy output away from the engine, allowing the engine to rev quicker. This is a plus for road racing where starting and stopping is not so important. However on the street the trade-off is bogging/stalling or jerky starts. You'll be forced to compensate with more revs from a start.

The crank shaft is the main rotating assebly that all your pistons are attached to and is the single element holding most of the rotating parts in your engine together. Not usually ever messed with unless your hardcore and wish to either exceed 8-9k RPMs
or stroke (increase the displacement of your engine from 2.3~2.4L).

You need exhuast an ECU flash (I prefer the ones with boost control). I think you'll be impressed. Goodluck