21337R

First off I will admit that I am just a dreamer, my S2k is my daily driver and will be for awhile. Eventually, I hope it becomes my project\weekend warrior and that is why I am curious about this. I know that I will probably get flamed by all of the stroked torque junkies but honestly, If I was interested in torque I would buy a diesel. I have been a fan of high revving, high power, low torque power curves ever since I compared my 125cc dirtbike to a friend's 250cc
(back in the day). I actually prefer a gradual incline as opposed to a flat torque curve, it just feels more usable for my driving\riding style.

So... I was brain storming about sacrificing a bit of torque for more revs\power. From what I have read it seems that other than the obvious things like strengthening the valve-train to withstand higher revs, piston speed is the real limiting factor here. The F20C's pistons are moving at 4960 fpm @ 9k which is insane, its one of the fastest of all production vehicles. At 10k they would be at 5511 fpm , which made me wonder.. how much would I have to de-stroke this motor to keep the piston speeds near stock @ 10k rpm. Turns out that with a stroke of 76 the piston speed is 4986fpm@10k and the displacement comes out to 1807.4. Seems to me like this would be where ITBs could really become useful. My questions are, is this 87x76 even possible? Would the cost be way too high? If I went this crazy on an engine build the car would be fully stripped\race prepped and the weight loss + gearing would surely offset any torque loss. What do you guys think?

S2Kage

well, this question has been brought up before in the old NA thread... I just look at it like this; a fully built at stock displacement 1.8 GSR for all motor setup does not make nearly as much power as a fully built stock displacement 2.0 k20 ... I mean technology favors he K20 however, the sheer numbers explain themselves

LostMotion

If you are going to go all out like that, destroke the motor but then increase the bore to 89mm to get a little back. Get high quality internals and the best valvetrain you can. Rev to 10,500.

SgtB

The S stops making power before 9k. Why go higher?

ABCVTEC

Not to mention I don't think anyone makes a smaller stroke crank for our car...

midnightsunset

If you get different cams to match the new powerband you can make power past 9k

midnightsunset

Been looking at this myself and actually really considering going this route if my wallet can take it.

Like Carrera said, lower the stroke, but bore out the block. Get new Ti valves to match the new valvetrain and "maybe" some hollow cams to lighten the rotational mass and allow the cams to spin fast enough at the higher altitude.

ABCVTEC

Torque is what this car lacks. Not a lengthier powerband.

midnightsunset

F*** torque! As a matter of fact....F*** you!! j/k

What happened to your supercharged dyno queen? Notice you haven been spending some time in the NA forum. Am I looking at a convert?

ABCVTEC

I sold my S/C back in October. Been building a 2.4 slowly but surely.