Bob:
Go to http://sura1.jlab.org/~grippo/auto.html, scroll down the top
skinny panel and you will find such a program titled Bowling's RPM and
MPH calculator.
However, unless one has a digital tachometer readout, I doubt that you
can get an exact, accurate number of RPM's from the average analog tach
gauge to use in performing the calculation.
Paul Bartz
- -----Original Message-----
From: Robert M Fukumoto [mailto:fukf19]
Sent: Monday, August 17, 1998 1:40 PM
To: 'gmc motorhome mailing list'
Subject: GMC: Speedometer accuracy: RPM + Final drive size + tire
size = speed?
For my fellow GMCers who are smarter than I (which is probably all of
you), it sure seems to me that a way to check the speedometer accuracy,
if you have a tachometer, is to convert the RPMs, final drive size and
tire size to the correct speed. Seems to me that there must be a way to
convert rpms from the engine through the final drive to revolutions of
the drive wheels. Add to that the tire circumference and you've got
speed. My only problem is I don't have a clue how to do this. Any
engineers out there that can help?
BTW, after my maiden voyage from hell my wife did make me put an ad in
the paper to sell my GMC. However, she is softening and that combined
with not a single call in two weeks might lead us to giving it another
try next year. (I'm still working and with two teenage kids we really
can only use the coach once a year.)
Go to http://sura1.jlab.org/~grippo/auto.html, scroll down the top
skinny panel and you will find such a program titled Bowling's RPM and
MPH calculator.
However, unless one has a digital tachometer readout, I doubt that you
can get an exact, accurate number of RPM's from the average analog tach
gauge to use in performing the calculation.
Paul Bartz
- -----Original Message-----
From: Robert M Fukumoto [mailto:fukf19]
Sent: Monday, August 17, 1998 1:40 PM
To: 'gmc motorhome mailing list'
Subject: GMC: Speedometer accuracy: RPM + Final drive size + tire
size = speed?
For my fellow GMCers who are smarter than I (which is probably all of
you), it sure seems to me that a way to check the speedometer accuracy,
if you have a tachometer, is to convert the RPMs, final drive size and
tire size to the correct speed. Seems to me that there must be a way to
convert rpms from the engine through the final drive to revolutions of
the drive wheels. Add to that the tire circumference and you've got
speed. My only problem is I don't have a clue how to do this. Any
engineers out there that can help?
BTW, after my maiden voyage from hell my wife did make me put an ad in
the paper to sell my GMC. However, she is softening and that combined
with not a single call in two weeks might lead us to giving it another
try next year. (I'm still working and with two teenage kids we really
can only use the coach once a year.)
