Paul reread the equation.... RPM X Tire Size divided by gear ratio X 336 =
mph
This assumes a 1 to 1 trans.. otherwise you modify the RPM of the Engine to
create Torque as with 1st gear or Fuel mileage with overdrive...
your right in assuming the driveshaft goes around unaffected by the
trans... but we are using RPM... as part of the equation....
Let me make this simple and show you a little about how I use this
equation..
8000 RPM X 28" tire = 224000
-------------------------------------------- = 222.22 mph
3.00 gear X 336 = 1008
Since the Record is 219 in D gas Altered at Bonneville if I am lucky enough
to run that RPM with zero tire slip... Oh nevermind....you get the point...
Keith Turk
Austin Healey 100 / Bugeye / Box Sprite / Bonneville Land Speed Racer
Camaro ( D Gas Altered )
----------
> From: Paul A Asgeirsson <pasgeirsson@juno.com>
> To: kturk@ala.net
> Cc: pasgeirsson@juno.com; spritenut@Exit109.com; Lancer7676@aol.com;
mikkel@isa.dknet.dk; spridgets@autox.team.net
> Subject: Re: rpm -> speed calculation
> Date: Saturday, July 10, 1999 10:32 PM
>
> Overdrive or not, that has no affect on the output shaft/driveshaft speed
> where the speedodrive is located. Still it's a simple rev counter behind
> all the gears, so no consideration need be given the gear you are in, 1st
> or overdrive.
>
> Paul
> PAsgeirsson@juno.com
>
> On Sat, 10 Jul 1999 23:08:35 -0700 "Keith Turk" <kturk@ala.net> writes:
> >This formula assumes a 1 to 1 output shaft... if you have an overdrive
> >you
> >have to adjust your gear ratio accordingly.... Keith
> >
> >----------
> >> From: Paul A Asgeirsson <pasgeirsson@juno.com>
> >> To: spritenut@Exit109.com
> >> Cc: Lancer7676@aol.com; kturk@ala.net; mikkel@isa.dknet.dk;
> >spridgets@autox.team.net
> >> Subject: Re: rpm -> speed calculation
> >> Date: Saturday, July 10, 1999 7:37 PM
> >>
> >> On all mechanical speedos that have the drive from the transmission,
> >it's
> >> taken off the output shaft, which is the same as the driveshaft
> >speed.
> >> Makes no diference what gear it's in.
> >>
> >> Paul
> >> PAsgeirsson@juno.com
> >>
> >> On Sat, 10 Jul 1999 21:44:03 -0400 Frank Clarici
> ><spritenut@Exit109.com>
> >> writes:
> >> >Lancer7676@aol.com wrote:
> >> >
> >> >>
> >> >> Wouldnt the transmission ratio fit in there somewhere? Seems
> >like
> >> >5th gear
> >> >> with a 210 tranny would give you a different read than 4th gear
> >with
> >> >a rib
> >> >> case.
> >> >
> >> >I'm not sure here but I would think the tranny makes no difference
> >as
> >> >long as you have the speedo drive from said tranny in said car.
> >> >I mean, my 5 speed shows X mph in 4th and only the revs drop when I
> >> >shift to 5th.
> >> >Speedo stays the same.
> >> >I am not saying a different tranny in the car does not make for a
> >> >differnt reading, just that no matter what gear you are in, the
> >speedo
> >> >stays the same unless you step on the gas.
> >> >
> >> >
> >> >--
> >> >Frank Clarici
> >> >Toms River, NJ
> >> >Bugeye Sprite
> >> >67 Sprite
> >> >59 A40
> >> >http://www.exit109.com/~spritenut/
> >>
>
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