Hi Jim and others who replied RE: OD RPM/MPH
On further review (it is Sunday after all) and after using the Dan
Masters formula's (now on his website).
I calculated that with my tires 205/70/15 I should have been reading
77.36 MPH at 3000 RPM in overdrive (4th). And that Jim should have been
going at about 71.6 MPH at 2800 in overdrive (4th) assuming he is
running stock 185/75/15 tires.
So Jim's gages are pretty close and my gages are pretty close (in my
case just the 2 MPH difference due to the tires). It was my math that
wasn't so good especially when I'm doing long division in my head doing
77.36 MPH down the road. And probably my timing between mile markers
wasn't so accurate either (a 0.5 second error means about a 1 MPH
error).
So Thank You to everyone who offered their numbers.
Bud Rolofson
Jim Altman wrote:
>
> According to Bentley's data 3000 RPM should be 75.3 MPH on an A type and
> 78.3 MPH on a J type. I presume many of us have close, but no cigar, tire
> sizes that will induce some variation. Roger Elliot's data is very similar.
> He said 25.3 for the A type whereas Bently sez 25.1 MPH per 1k RPM.
>
> Jim Altman jaltman@altlaw.com Illigitimi non Carborundum
> http://www.altlaw.com/metro/jaltman.html 69-TR6#CC28754L(O) W4UCK
>
> -----Original Message-----
> From: Fred Thomas [mailto:vafred@erols.com]
> Sent: Wednesday, September 29, 1999 6:50 AM
> To: levilevi@home.com; Jim Altman
> Cc: 'triumphs@autox. team. net' (E-mail)
> Subject: Re: Excuse my o/d gloat
>
> T/R 3, @ 2400, I'm doing 67 MPH, @ 3000, 76 MPH, very seldom ever go above
> that. On our trip to VTR 99, Dan Masters & I averaged 72 MPH, until Vermont
> & the mountains and we were always at the 3000 RPM.
> ----- Original Message -----
> From: <levilevi@home.com>
> To: Jim Altman <jaltman@altlaw.com>
> Cc: 'triumphs@autox. team. net' (E-mail) <triumphs@autox.team.net>
> Sent: Tuesday, September 28, 1999 10:38 PM
> Subject: Re: Excuse my o/d gloat
>
> >
> > Those RPM seen a little high for that speed. My gages read 3000 RPM and
> > 80 MPH on the way to Portland and back. And if I remember right I was
> > right around 2600 RPM going 75 MPH.
> >
> > I'm pretty sure my speedo is right cause I timed myself between mile
> > markers and calculated my speed and it came out right on every time
> > (amazing the things you'll do to pass the time out on the road).
> >
> > Wonder what others get? Listers, how bout it. What do yours read with
> > OD kicked in at those speeds.
> >
> > Bud Rolofson
> >
> > Jim Altman wrote:
> > >
> > > Got my OD installed in the 6 today and drove it home on the freeway. All
> I
> > > can say is WOW! What a difference! WOW! 2800 RPM at 70 MPH. Quite a
> > > reduction in noise.
> > >
> > > Jim Altman jaltman@altlaw.com Illigitimi non Carborundum
> > > http://www.altlaw.com/metro/jaltman.html 69-TR6#CC28754L(O) W4UCK
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