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Re: [ST] Higher RPM for racing?
The basic problem is that nobody knows how to build an engine that has great power and torque at low rpm. If you think you have an one, somebody could make more power by making the engine running more rpm.
So what you are asking about is just not real.
Low rpm has some advantages when it comes to fuel efficiency, all related to friction. But the over riding rule is that it takes fuel to make power; more power takes more fuel.
David W. Funk
-------------- Original message --------------
From: "Joel Ashman" <ashmite@xxxxxxxxx>
> > You are keeping the engine on the boil anyway, really never letting it
> > down below 6k or 7k on the REALLY tight corners, so the trade-off of the
> > loss of down low power and driveability isn't an issue - you simply don't
> > run the bike down there.
> Make sense, but my question is, Could you run the motor down at 3000 RPM if
> it that's where it's power was and it was cranking the rear wheel fast
> enough to maintain the speed needed through the turns?
> I guess this started when chatting with a friend from work who is a
> mechanic. We've been discussing fuel economy and modern engine design and
> it seems most engines are heading towards new limits of Redlines. But I was
> thinking that an engine that didn't redline as high but had a proper tranny
> and great HP and Torque would be just as useful on a track especially given
> that higher engine RPM's mean greater heat, greater heat expansion, more
> wear, increased friction. I guess in my strange way of thinking, if you are
> turning the rear wheel at the same speed, who cares how fast the engine is
> turning if it's making peak HP and torque in the current gear?
> We've been theorizing that with current gas prices, we may start seeing a
> swing of more fuel efficient motors, and one means to achieve this is to
> slow the average RPM down so that the motor isn't consuming as much fuel.
> But to do this, the engine has to be able to perform as well at 1000 RPM as
> it does at 2000 RPM. I'm using an old car of mine as an example that cruised
> at 65mph at 2000 RPM. It stands to reason that it would get twice the fuel
> mileage at 1000 RPM. Ok, I realize that the fuel injection computer and
> other factors might affect this, but it's a good estimate.
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