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      04-22-2014, 08:15 PM   #66
bradleyland
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Quote:
Originally Posted by Powerslide View Post
Exactly - I absolute love my S65 to death - best engine I've ever personally owned. But don't get me wrong - but you're making 414 hp only at a single, discreet "point in time" - i.e., at 8300 rpm. With the S55 - you may only be 11 hp peak hp better - but you're there for a heck of a lot longer period of time - 5500 to 7300 rpm over and over again (1st through whatever gear you're at when you decide that you don't want to risk going to jail). I agree that this engine will be much faster - given that you can be at a virtually constant 425 hp as you accelerate (assuming you shift at 7300 rpm) - whereas the S65 you have to wait until 8300 rpm just to get to 414 hp, then when you shift at 8300-8400, your rpms drop what - 1800-2000 rpm (so now your hp just instantly dropped from 414 to 325-350, or whatever it is, gradually building back up to 414 by the time you again reach 8300)...

With naturally aspirated engines, peak horsepower used to be the most important single factor for acceleration (relative to the car's weight and other factors too, of course). Now, with turbos making very wide, flat power plateaus over a wide rpm range - it seems the most important single factor for acceleration is for how wide of an rpm range (or for how long of a period of time) can the peak power be maintained?


I get so sick of explaining to people how two cars with identical "peak" horsepower can perform so differently. I remember when VW introduced the 1.8T with 180 HP (peak), but it out performed the 200 HP 24v VR6 engine available at the time. The 1.8T was underrated, but the biggest advantage was the earlier swell in power.
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