Originally Posted by wesside
Only intake, headers, exhaust. I just would like alittle more power on bottom end the top has plenty. It would be nice if vtec kicked in @ say 4,000-4,400 rather then 5,500.
Are you sure that you dont already have a reprogramed ecu? With my stock p13 ecu my vtec swiches over at 4500 with my reprogramed ecu it doesnt switch over until 5800. If all you are looking for is a sooner vtec engagement then get an apexi V-AFC II.
You have to remember that 4cyl make power in completely diffrent ways than v8s(using v8 for illustration purposes because they make more low end torque than a 4cyl). A v8 makes the vast majority of its power from displacment. It uses the pure size of the pistons and length of the stroke to make power. A 4cyl makes its power from revs. The higher the rev generaly the more power the engine makes(this goes for N/A engines only)
To understand why that is you first must understand what horse power is exatly. Horsepower literaly means usable power. The way to state the usable power of an engine is torque times rpm divided by a constant varible of 5252 equals horse power this is expressed as t * r / 5252 = h.
So because a v8 makes a majority of its torque as soon as you press the pedal it makes all of its horse power at the low end. Just the same a 4cyl makes very little torque but is much more efficent at keeping on to it for alot longer. so there for makes ALL of its horse power at high revs.
I hope that has helped you understand why it is nearly impossible for you to make a 4cyl have low end power w/out either forced induction like a super charger/nitrous or going into the bottom end and boring or stroking the engine.
I know i said alot to say a little but To answer the question at hand its not REALLY going to make that big of a diffrence moving your vtec. You are better off switching your ecu to get more top end. Something like i have that will allow your engine to rev to 8000+ rpms,(it increased my 1/8 times by more than 3/10s that almost a full second in the 1/4) rather than trying to get low end power that is virtualy unacheivable with out going into the bottom end of the block or going forced induction remember thats what your engine was made for high rev horse power not high displacement torque.