Quote:
Originally Posted by madfast
 i expected a much flatter torque curve. is this D-4S related perhaps? in the literature there is talk of the engine using a mix of DI and PI in low and mid rpm, and DI only in high rpm... |
The graph shows a "before" and "after" D4-S, with a 20NM gain and 10KW gain by using D4-S. The torque curve shape itself is more a function of the ports and combustion chamber [the main items that affect VE].
Thanks for the translation; it makes sense technically. DI can control cold-start and WOT combustion much better than PI. PI would be used mainly during low and medium load cruising, where stoich is relevant and wall-wetting or knock isn't an issue.
I still want some real numbers bolted on that graph to make it logical.
At this point, based on the written specs on the scan, the dyno graph might actually be an "example" of how D4-S is effective, not the actual FA20 engine output.