Re: DYNO RESULTS -- STOCK vs AFTERMARKET WHEELS

[Kevin Stoddard <herephydeaux@juno.com>]

Woa!  Steve,... you an engineer or somethin?  I haven't seen that many
equations in one place since College!
Jason, I think Steve handled the technical evaluation pretty well. 
Here's an interesting aside.  (Steve,... feel free to correct me if you
think I'm wrong.)  Think about the horsepower thing.  There are basically
two sets of forces working against the engine.  Forces external to the
car and forces internal to the car.  The dividing line is the point where
the tire meets the road.  Wind resistance and rolling resistance and that
sort of thing are external.  For a given car these stay pretty constant. 
(as a function of velocity.)  Then there is bearing drag, inertia, and so
on that are internal.  These are constant in a given car unless something
drastic is changed.  The important thing is that the external forces sap
the bulk of the horsepower.  (unless you have bad problems)  From the
standpoint of horsepower transmitted to the ground, if the wheel/tire
combos have the same OD the difference in horsepower to the ground should
be negligible.  (heavy wheels are like heavy flywheels,... they slow
acceleration, but once they are turning at a given speed the extra
horsepower required to keep them turning at a constant speed is an
insignificant part of the drag being put on the engine.)  So we want
lighter wheels to improve acceleration, rather than to increase
horsepower.  I could go on, but I don't want to put anyone who's still
reading to sleep. <VBG>
The bottom line is when you add up the torques acting on the shaft
turning the tire the greatest by far is the force being applied to the
ground (X tire radius,.. yadda, yadda,...) in order to move the car down
the highway.
-kevin in Texas
________________________________________________________________
YOU'RE PAYING TOO MUCH FOR THE INTERNET!
Juno now offers FREE Internet Access!
Try it today - there's no risk!  For your FREE software, visit:
http://dl.www.juno.com/get/tagj.

--
Email problems to: scirocco-l-probs@scirocco.org  To unsubscibe send
"unsubscribe scirocco-l" in the message to majordomo@scirocco.org