Horsepower is just the mathematical product of torque and rpm with a constant
factored in. So at a given rpm the only way to increase the horsepower is to
increase the torque the engine develops.
If you were to have an engine with a perfectly flat torque curve from idle
until the the engine self destructed the horsepower curve would continue to
increase in a straight line until the engine self destructs. The horsepower
only increases after the torque peak if the drop in torque is less than the
increase in rpm, back to the torque x rpm function. So if the torque stays
higher than what is required to over come weight, mechanical friction and wind
resistance the vehicle will continue to accelerate.
The best point to shift then will be when the point at which the torque drops
below the point at which a shift in gears puts the engine in an rpm range that
the torque x the multiplication factor of the new gear is higher than when you
shifted.
It's all about torque, horsepower is just away of expressing the combination of
torque and rpm.
Dave Clement
99 SLT+ CC 4x4
In article <20050825035439.54076.qmail@web33213.mail.mud.yahoo.com>,
dkramarsky68@yahoo.com (Dan Kramarsky) writes:
>
>
>
> DMLers;
>
> I have been told in the past, the best way to find shift points is to get an
idea of the
> torque output curve on a chassis dyno. then you want to shift just on the
other side of
> that curve where the engines's torque starts to drop off. ( this is overly
simplified i
> know)
>
> Can someone explain this idea to me again? Or if you have a link to a web
page or a good
> book on the subject, reply with that info. thx.
>
> And is it really the torque output curve i need to look at, or is the HP
output curve?
>
>
> -dan
>
>
> Dan K.
> '92 Grey Dak CC, 318, 4x2, 46RH, 3.55 rear, 235/75R15, PS, PW, PB, PL, AC.
>
> Mods: Cool air, K&N oil/air, Autolite 3924s, re-located IAT.
>
> Future: Swap motor for a slightly modified Magnum 5.9L engine.
>
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This archive was generated by hypermail 2b29 : Sat Jan 05 2008 - 19:13:05 EST