1 : Target Boost/Power - only then one can walk to the desired power.
Let say u want 100hp on wheel, then the mod/cost will differ
2 : minor area that need attentions :
a - good oil filter. never settle for cheap oil filter. good one cost more but worth every single penny.
b- good water-pump. cool down head/block - prevent less heat soaked to the engine. less heat = more power [ not to confused with engine operating temp]. If engine for high revv or racing, take out the thremostat. Why? less restriction to the water passage
c - get high powered radiator fan. constant on the radiator fan - cool down the engine. buy another one spare. mine dead after 6 month [ori kancil] due to contant on. noted the engine temp always below 1/2. if you can find aluminium radiator [L9] or other make, take IT!!
d - head gasket [ original]. if so happen ur head taken up, see the ori head gasket. clean it up with #600 sand paper. clean the surface. wash with petrol a bit - do not soak in petrol. dry clean. apply good silicon gasket and pressure it to the head open installation. make sure leave the engine for a day to fully "mate" the block n head
e -flywheel . for nomal use road, reduce it to 3/4 of the original weight. i think its about 9kg. i skimmed to about 4.5 kgs - for drag purpose oni.. pure drag better use steel (buat sendiri). original flywheel do not over skimmed, nanti crack bila high revv. custom made steel can solve the thing.
f - spark plug, plug cable. another hot issue. please stay with original cable plug . i reckon it good for 100hp. original plug edi good enuf. NGK-R or ND is good. DO NOT Adjust the GAP if got problem, instread get NEW ONE! Silap bikin, piston pecah, pasal core cair and hit the piston... Standard L2 ignition is good enuf unless you using after market ECU like haltech, microtech etc.
g- earth grounding cable. DO IT!! one of the cheapest mod.. so far none claim it increase HORSEPOWER [dyno proven] but your electrical devices works better. engine got better response because equal electrical power distribution. it do makes sense ...RM40-90 for 6 point.
h - another hot issue. Use SYNT OIL. It do increase HP [dyno proven]. after all, dalam 10,000 km baru tukar lagik.
i - please WARM up the engine fully about 5-10 minutes before tekan pedal for high revv. Logik? let the oil circulate around the engine, and the engine have its OPTIMAL operating heat!! kalu Blow Off Valve and turbo timer being use for a reason, this is the same as well
j - for stock downpipe, open it up. buang sarang lebah (careful - its poisonic) .. its good for 1-2 hp. try it and u feel the turbo spool a bit quicker. custom made downpipe and dumpipe. the bigger dumpipe (bukan downpipe) the lesser the backpressure and faster turbo spool .. 1-1.2 inch for L2 standard or mild mod is ok. for downpipe, 2-2.25 inch is OPTIMAL for low to mid high boost (0.7-1.5 bar)
k - cold air intake. hmm , many ppl heard of it. but still do the mistake. for low or standard to mid high boost, usage of the standard air filter box is appreciated. but make sure the front intake having a direct under the front grill hose, beli PVC dari kedai hardware and sambung.. every 2 degree decrease in air-temp, an increase of 1 % in power.
l - intercooler. selagi boost tak tinggi, there 's no economic reason to change it. front mount, yes look nice but high cost. but are you sure that it will have the OPTIMAL power for the RM you paid? guess what? long piping, more hotter the air becomes, more power loss incurred. you may feel that your car is powerful but i believe its more towards PHYCHOLOGICAL effect. intake mouth and exit mouth of the intercooler must be the same size.2 " recommended for mid to high boost. VR4 intercooler is a NO NO. FREE FLOW intercooler is the best. 4E-FTE have a good intercooler (ARC the best -- mana nak cari???)
m - throttle body ? another debated question. best low to mid boost, leave it as it is. if got extra RM, go and rebore 1mm out of the throttle body. its very 2x cost effective for more free flow air ...