Did I happen upon a learn-at-home course in Mathematics here! :)
Jerry - 1968 GT6 MK1
Ron and Angie wrote:
> Charles,
>
> Here's the formulae:
>
> mph = (rpm * tire_diam) / (gear_ratio * 336)
> rpm = (mph * gear_ratio * 336) / tire_diam
> gear_ratio = (rpm * tire_diam) / (mph * 336)
> tire_diam = (mph * gear_ratio * 336) / rpm
>
> And if you don't know your tire diameter:
>
> tire_diam = 2 * ((section_width * aspect_ratio) / 2540) + rim_diam
>
> And the gear ratio is overall gear ratio, which would be transmission gear
> ratio times the final drive ratio.
>
> Ron
> Dalton, GA
> 62 Triumph Vitesse Sports 6 77 Triumph Spitfire 1500
> 84 Nissan 300ZX Turbo 92 Ford Tempo GLS
>
> -----Original Message-----
> From: Charles Ackerman <C2H60_@email.msn.com>
> To: triumphs_list <triumphs@autox.team.net>
> Date: Tuesday, September 22, 1998 12:40 AM
> Subject: Wacko Speedo/Tach?
>
> >
> >Hi everybody,
> >
> >Recent posts about incorrect speedo/tachs got me wonder'in.
> >So I got the TR on the road with a pen and paper. (Tire size 195/65R15)
> >MPH RPM RPM (OD)
> >30 1500 1300
> >40 2000 1600
> >50 2400 2000
> >60 2800 2400
> >70 3300 2700
> >Is there a formula to determine if the speedo/tach. is wacko?
> >
> >Charles Ackerman '70 TR6 CC51493LO North Bend WA
> >
> >
> >
> >
> >
> >
|