Quote:
Originally Posted by serialk11r
My point is that there are a lot of similarities; same bore/stroke, only cam phasing available, same power peak. Considering the FA20 theoretically has the D4S advantage on top of this, it's hard to see how it couldn't do better or at least the same. If it can make more torque at some certain point, it's not likely the torque will drop down even faster given the similarities. Just speaking strictly from a..."comparison" point of view.
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In my example it wouldn't be dropping 'faster' but slightly 'more' over a longer rev range. Increase the peak lower, have it drop off not too much worse, but over a wider power band allows a couple things. The response that some of the people here that are crying for massive torque numbers want. And by keeping the power peak lower than say the K20, and therefore mean piston speed, they lower reduce stress on the motor. They can get away with using conventional connecting rods compared to the 2ZZGE's vanadium steel rods for example, or lighter ones which again adds to response.
(This motor will also have less valvetrain friction than the 3S, and possibly less losses from vibration/balance due to the nature of the H4.)
Edit:
Food for thought...
3SGE BEAMS, high-power manual version
207 bhp @ 7600 rpm BMEP ~177 psi ~90% of peak torque
159 lb-ft @ 6400 rpm BMEP ~197 psi
1200 rpm separation
GT5 FA20
220 (b?)hp @ 8000 rpm BMEP ~178 psi ~85% of peak torque
170 lb-ft @ 6500 rpm BMEP ~ 210 psi
1500 rpm separation
Porsche GT3 (3.8L)
435 @ 7600 BMEP ~196 psi ~95% of peak torque
317 @ 6250 BMEP ~206 psi
1350 rpm separation