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Re: Gear selection challange--which ones?

To: WmTSmith@landracing.com, William T Smith <WmTSmith@landracing.com>
Subject: Re: Gear selection challange--which ones?
From: William T Smith <WmTSmith@landracing.com>
Date: Wed, 27 Jun 2001 20:59:44 -0600 (MDT)
KT, Have you decided what gears and tires you are 
running? wmts

Quoting William T Smith <WmTSmith@landracing.com>:

> KT, heres my best shot
> Torque corrected to 6000' corrected alt.
> Eng capable of 8600-9000
> tires all the same type
> 
> I would run the 3.07 with the 27" tires in direct. 
That 
> shoud give you app. 850 torque to salt. at peak 
torque 
> in direct, 8600 is good for 225 mph. If you can turn 
> 9000 (235 mph) In direct with fuel you will have a 
> better chance than trying to pull the od or bigger 
tire.
> 
> you have a 9% OD but your tires only go up 4% the 
> larger the number of the overall ratio gear Ratio, 
> Trans Ratio, and Tire correction the better shot you 
> have of pulling all the other drags.wmts
> 
> XXL
> 
> 
> Quoting Keith Turk <kturk@ala.net>:
> 
> > Good question Bill..... the current answer is that 
> the Peak Torque is the
> > same as the Peak HP.... right around 8300 rpm..... 
> and the motor freely
> > spins above that number.... drops off about 35hp at 
> 8700 rpm....
> > 
> > Were going back in the morning to work on the peak 
> torque number.... it's
> > not real impressive right now.....
> > 
> > K
> > ----- Original Message -----
> > From: "William T Smith" <WmTSmith@landracing.com>
> > To: "Keith Turk" <kturk@ala.net>
> > Cc: <land-speed@autox.team.net>
> > Sent: Sunday, June 24, 2001 7:25 PM
> > Subject: Re: Gear selection challange
> > 
> > 
> > > KT,
> > > What RPM peak Torque and how much
> > > how much peak Torque at max power
> > > With these two and your trans and RA ratios we 
can 
> get
> > > this done and I bet it will not be in OD and I am 
> just
> > > guessing ! wmts
> > >
> > >
> > >
> > > Quoting Keith Turk <kturk@ala.net>:
> > >
> > > > Thought I would share the joy's of running a 9" 
> Vs a
> > > quick change....
> > > >
> > > > I have been waiting on a dyno sheet to start
> > > selecting the right gear for
> > > > speedweek..... keep in mind I have the axle's 
out 
> and
> > > the Driveshaft out so
> > > > it's an easy time to swap them out.
> > > >
> > > > The motor makes it Peak power at 8300rpm ( 
> correction
> > > from previous post )
> > > > So we are looking to spin it around 8600rpm or 
> so....
> > > >
> > > > we have 3.25 gears as well as 3.07's..... and 
> three
> > > sets of tires ranging
> > > > from 26" .... 27".... and 28"
> > > >
> > > > There are Two ways to play this game 
> mathmatically...
> > > both of which are
> > > > accurate and can cross check each other.....
> > > >
> > > > 1.  Finding MPH
> > > >
> > > > Rpm X tire height in Inches  divided by 336...
> > > divided by the gear...
> > > >
> > > > for example.... 8500rpm X 26" = 221000 divided 
by 
> 336
> > > = 657.73 divided by
> > > > 3.25 = 202mph   then we could pitch the 
Overdrive
> > > into the fray by dividing
> > > > that 202mph by the .91 OD which would give us an
> > > output speed of 222.393
> > > > mph...... this just happens to be 3mph faster 
then
> > > the current record in
> > > > the
> > > > class.
> > > >
> > > > 2.  Finding  Rpm
> > > >
> > > > MPH X Gear ratio X 336  divided by tire hieght 
in
> > > inches
> > > >
> > > > for example.... 225mph X 3.25 X 336 = 245700  
> divided
> > > by 26" tire = 9450
> > > > rpm
> > > > Obviously a bit much till we X it by the OD 
of .91
> > > which is 9450 X .91 =
> > > > 8599.5 rpm
> > > >
> > > > So that gets you through the Gas record..... we 
> want
> > > to consider the Fuel
> > > > record as well.... as that is where are best 
> chances
> > > are with a Motor
> > > > designed to run on Nitrous Oxide.   the record 
is
> > > 230mph in that class...
> > > >
> > > > Here is the challange ... come up with the best
> > > combinations and the
> > > > reason's why..... I think I have already 
decided 
> how
> > > we are going to do it
> > > > and Beleive it or not the example I just gave 
> isn't
> > > the best combination in
> > > > my Humble opinion..... thou it's not a bad 
> choice....
> > > it just might not be
> > > > the BEST choice as there are other things to
> > > consider .... such as Drag
> > > > associated with running in OD and the Tire size/
> > > wheel bearing speed.
> > > >
> > > > I'll Give fella that comes up with the best 
> choice a
> > > So-Al T-shirt...
> > > >
> > > > Keith
> > > >
> > > > ///
> > ///

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