Quote:
Originally Posted by Ryephile
Having a tight torque and power peak isn't typical for production engines, but seems more common for Japanese designs, where high-revving is typical.
Ok, stepping into the current benchmark for n/a high-revving; the Ferrari 458 Italia. The BMEP numbers are 178 PSI @ 3250 RPM, 222 PSI @ 6000 RPM, and 183 PSI @ 9000 RPM. Those are some fantastic and even numbers given the almost 6k RPM range.
Another benchmark, the M-B SLS-AMG, has peak torque BMEP of 191 PSI @ 4750 RPM and a peak power BMEP of 173 PSI @ 6800 RPM.
For the FA20 to have a 187 PSI @ 6600 RPM and 183 PSI @ 7000 RPM is only giving a short window of its torque curve. Those BMEP figures are respectable for a modest-cost engine; they're competitive with both the Honda S2000 engines. The AP1 S2000 had a torque to power peak window of only 800 RPM, with only a 3 LbFt drop in that window. That's not too far off the 3 LbFt drop in 400 RPM the FR-S specsheet is claiming. If that torque drop is even, that would put the BMEP around 179 PSI at the 7400 RPM redline. Seems OK to me.
I'm sure we'd both like to see the full torque curve, but at this time, the two data points we have point to a respectable engine, especially considering its alleged price point.
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To me the 400 rpm range says that they threw a lot of effort at a narrow operating range window, to achieve a meh BMEP number. Look at the other Toyota numbers I put up.
Consider that the BEAMS motor is port injected, has 11.1:1 CR and kicks the ass of these hypothetical FA20 brochure motor's output. 197 bhp @ 7000 (same 200 PS) but
159 lb-ft @ 4800
Now consider that the D4-S injected 2GRFSE gains 7.5% BMEP with 3.2% more rpm at power peak and 8.2% increase in BMEP with 2.1% more rpm at torque peak, over the conventional 2GRFE.
For the BEAMS motor to hit the 210/170 number thrown around it would only need a 6.6% gain at power peak with no rpm increase (less frictional losses) and a 6.9% gain at its torque peak.
Now if Yamaha could pursue the FA20 as an extension of its 3S development, it could be entirely plausible that this thing makes 210 bhp @ 7000 rpm and 170 lb-ft @ 4800 rpm. Or they could spread it around and give us 200 bhp @ 7000 rpm and 170 lb-ft @ 4000 or something...
What basically started this thinking is that I'm suspecting that these press releases, leaks and such are deliberate mis-information.
Another thing is the 53/47 split, yet aluminum H4, firewall mounted battery and aluminum hood? Compare with a Supra's 53/47, long steel hood, long iron L6. WTF?