[Shotimes] Dyno charts

Tue, 21 Jan 2003 08:59:54 -0500

That makes no sense. Horsepower does not drive the wheels. Torque, torque,
torque. I don't see what's so hard to understand about it. Horsepower is a
bob-dang number based on TORQUE and only relates the amount of work being
done in comparison to 150% pony power. It was introduced during a time when
people understood how much work a horse could do, and motors were far and
few between. Peak HP is nothing more than the point where the decline of
TORQUE overcomes the increase in RPM and therefore HP must drop.

I haven't heard any valid explanations as to why anything other than peak
torque would be the best rpm to run a motor for max acceleration when in
combination with a CVT (unless the CVT is not a true IVT!!!). The motor does
the most work at peak torque, period. The most force is achieved at peak
torque. Force moves the damn car. Not HP. HP doesn't do a damn thing other
than compare your motor to a damn four-legged animal. Have I mentioned this
before?

Try running as 220hp SHO v6, anywhere in the rpm range you want, against a
'93 Mustang 5.0 at peak torque (205hp, 275 Lbft). I guarantee the 5.0 will
beat the snot out of the V6. Max HP only meant something way back when all
motors performed basically the same, with very similar max rpm, and similar
torque curves. And this only works on geared cars, and only when they are
geared similarly.

Now, if you want to start a motor off at max rpm, and let the tranny bring
it down to peak torque, sure, because you can make use of the rotating
potential the motor can build before launch.

Of course, as far as CVT's are concerned, they are new to the automotive
market, and are probably subject to the same piss-poor programming and
design flaws we find in the automatics. I'm sure it'll be a good number of
years before we start to see the advantages of a truly well-built and
controlled CVT system.

David P

95MTX

~
----- Original Message -----
From: "Ron Childs" <rchildssho@hotmail.com>
To: <jpotter8@bellsouth.net>; <shotimes@autox.team.net>
Sent: Monday, January 20, 2003 10:40
Subject: Re: [Shotimes] Dyno charts

> What I am saying is that if peak torque is at a low rpm, and you run the
> engine at low rpm, you are not going to get squat for h.p. at the wheels.
A
> CVT will not multiply horsepower. You give up torque in exchange for rpm
(at
> the wheels) as you accelerate. It takes a given amount of hp to propel a
car
> at a given speed. If you have 400 lb-ft of torque at 1500 rpm, you still
> only have 114 horsepower.
>
> Your car will only accelerate as fast and go as fast as 114 hp would take
it
> at that rpm. If your engine will maintain that torque at 3000 rpm you
would
> then have 228 hp an be able to go that much faster. Horsepower comes from
> rpm as well as from torque.
>
> -Ron Childs
>
>
>
> >From: "D Potter" <jpotter8@bellsouth.net>
> >To: "Ron Childs" <rchildssho@hotmail.com>
> >Subject: Re: [Shotimes] Dyno charts
> >Date: Sat, 18 Jan 2003 06:37:51 -0500
> >
> >Uh, Ron, as far as I can tell, when you compare ANY two rpms, you will be
> >moving more pounds of car per unit of time at the higher rpm EVERY time.
> >
> >Unless you meant something else, in which case I can honestly state that
I
> >have no idea what you were trying to say there.
> >
> >Peak hp is not some magical number that means something as far as engine
> >performance is concerned. It is nothing more than the point at which the
> >percentage of decrease in torque exceeds the percentage of increase in
rpm.
> >
> >It seems to me that it would make sense to run a CVT based motor at peak
> >torque during WOT and at lower rpms during non WOT conditions to maximize
> >fuel savings. Unless someone finds a way to equalize or reduce frictional
> >losses as rpm increases.
> >
> >
> >DP
> >
> >
> >
> >
> >----- Original Message -----
> >From: "Ron Childs" <rchildssho@hotmail.com>
> >To: <jpotter8@bellsouth.net>; <BJamesjr@aol.com>;
<shotimes@autox.team.net>
> >Sent: Friday, January 17, 2003 12:13 PM
> >Subject: Re: [Shotimes] Dyno charts
> >
> >
> > > Your engine will be doing the most work (moving more pounds of car per
> >unit
> > > of time) at peak h.p.
> > >
> > > -Ron
> > >
> > >
> > >
> > > >From: "D Potter" <jpotter8@bellsouth.net>
> > > >To: <BJamesjr@aol.com>, <shotimes@autox.team.net>
> > > >Subject: Re: [Shotimes] Dyno charts
> > > >Date: Fri, 17 Jan 2003 11:40:57 -0500
> > > >
> > > >You are going to get the most pull at peak torque, not peak hp.
> > > >
> > > >
> > > >----- Original Message -----
> > > >From: <BJamesjr@aol.com>
> > > >To: <shotimes@autox.team.net>
> > > >Sent: Thursday, January 16, 2003 12:56 PM
> > > >Subject: Re: [Shotimes] Dyno charts
> > > >
> > > >
> > > > > > Several cars now, and more to come have CVTs, Continuously
> >Variable
> > > > > > Transmissions. Although their behaviour depends on programming,
> >the
> > > >ideal
> > > > > > for performance is to let the engine rev to peak hp and the
tranny
> > > >will
> > > > > > adjust and accelerate the car. Wide torque band no longer
> > > > > > needed.
> > > > >
> > > > > This concept has always interested me, although I'm still
skeptical
> >of
> > > >the
> > > >internal workings of the CVT's themselves.  The computer could track
> >your
> > > >throttle position and speed and determine from that if you were
trying
> >to
> > > >maintain steady state speed or accellerate.  If you are trying to
> >maintain
> > > >steady state speed, the computer can calculate what rpm is most
> >efficient
> > > >for the engine in terms of fuel usage at that power level and tell
the
> > > >transmission to shift as required to put the engine at that power
> >level.
> > > >For accelleration it can do the same- determine what power level you
> >want
> > > >and what engine rpm is best for that level of power output.  At some
> >point
> > > >it would have to determine that the power output you want is beyond
> > > >efficient operation and begin transitioning to higher rpm's, all the
> >way
> >up
> > > >to eventually the rpm equating to peak horsepower at WOT.
> > > > > _______________________________________________
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