One other thing to consider is the compression ratio of the B18A/B vs. B18C1/5...
Volumetric efficiency(pretty sure that's the correct term) is an indicator of output per liter(hp/liter). The higher the volumetric efficiency, the more power cranked out of any given engine. Supercharging/turbofying/nitrous-ing(?)
and increasing compression increase volumetric efficiency. Increasing compression "squishes" the incoming mixture more. Forced induction(and nitrous too) cram more O2/fuel mixture into the cylinders. Any of these actions raise cylinder pressures... which increases temperatures and can cause detonation(when the fuel mixture "lights off" before the spark plug fires).
In the case of the B18A/B, the lower compression ratio allows higher boost levels than with the already high compression B18C1/5. The GS-R engine(C1) will take more boost than a Type R(C5) because of the same reason.
The following might not make sense... but anyways:
Atmospheric pressure is around 14psi... on any boost gauge, the "zero" reading is actually 14 psi(but it's zero relative to the ambient air). SO! Adding boost can be seen as going above the 14psi which means that if a naturally aspirated engine makes 350 hp, the same motor at 14psi of boost(28psi now) will (theoretically) make 700hp. The limiting factor is detonation(also of note: piston strength and material, rod strength, umm... head gasket construction, head-bolt locations, to name a few, also the higher you try to boost, the hotter the intake air gets which robs power)
Pah! I'm long-winded. I still love my GS-R but I'm putting too many miles on it... damn...
Quote:
Common misconception: GSRs (B18C) make more power than the LS/RS (B18A/B), period.
B18Cs have 1797cc of displacement. B18A/B has 1834cc of displacement. <snip>
|