hi sifus n zthians..ive been reading the whole day on how to mod 4g93..damn blur now..hehe..im really clueless now n i really hope someone could help me out..really appreaciate ur help..hehe..what i read earlier on was how to build 4g93 na..its a really old thread..most of them said to do porting la,balancing la,lightening la and blueprint..im really new to all this..could someone explain to me??thanks alot in advance..i got a second hand satria gti n the previous owner did the exhaust system n engine grounding kit already n i just added in an open pod air filter..thats all..what can i do the gain more hp and top speed..hehe..but i use the car daily..thanks again guys
Easiest way to get more power is turbocharge ur car, simple stage 1 with bolt-on turbo, ECU & airfilter + exhaust. A simple kit like this can gain approx. 30-40% more power & since a smaller turbo is used the turbo-lag should be minimal & mid-high end power dramatically improved.
But since you asked about na tuning ok here goes,
Porting
Is to mill & polish any imperfection on the engine intake & exhaust port, giving smoother air flow thus enhance performance. Works great for turbo & na cars but quite labour expensive for the performance you get. Since Japanese engine intake & exhaust port nowadays are already very good only very little performance can be gained. Expect better throttle response, revvier engine & a little more hp.
Balancing
Usually done after lightening or changing the engine internals, shave off counter weight on crankshaft or tuning counter balance shaft to achieve perfect balance. The theory is simple, better balanced crankshaft => less vibration => higher rev achieve => more HP. Not recommended for original engine internals cause original internals are heavier & not as durable as forged internals. Which means original internals can't rev high without breaking apart so no point in balancing them.
Lightening
Swapping original engine internals (pistons, con-rod, crankshaft) for lighter, tougher parts. Lighter & tougher parts means the internals can gain or lose revs faster, able to rev higher & more durable than standard parts (if properly tuned). Expect free revving engine & 'jerky' on-off throttle. Great for racing but not easy to drive on normal road.
Blueprinting
Re-spec the engine to your needs. Original engine specs (eg. piston gap, valve clearance) is designed to allow better tolerance & durability. Blueprinting is to tighten or loosen all those gaps in the engine to suit the driver needs. Example skimming the block to get tighter valve clearance for higher compression. This is done to squeeze every last drop of performance out of the engine & usually done for racing, for normal drivers & normal cars its just overkill.
All these tuning you mentioned are just very expensive & in the end the power you gain is probably not alot more than a simple bolt-on turbo.