[TR] high engine rpm

[Ted Schumacher]

John, to determine diff ratio, exception being a limited slip or welded 
diff, with 1 wheel held statinonary, rotate the driveshaft.  mark the 
driveshaft adn a refernece point ofn the rear wheel.  Count the number 
of drveahft turns needed to get 1 wheel revolutioln.  Multiply this by 
2. Example, a 3.45 diff wil ltake "almost 1 3/4 turns of the driveshaft 
to acheive 1 rear wheel revolution.  1 3/4 times 2 is 3.5.  You will 
find it takes "slightly less" than 1 3/4 turns so you have a 3.45.  A 
3.7 ratio will take more than 1 3/4 turns but less than 2 turn to 
acheive 1 wheel revolution. Ted

acs25m at swbell.net wrote:

>I own a TR250 that I am having problems with. The car had 185/65r 15 tires
>on it when purchased. I knew that these were not the right size tires and it
>was causing my Speedo to be off. Well I recently purchased replacement
>205/70r 15 tires and with my wife pacing me in another car the Speedo is now
>correct. My problem is that the engine is still running at a higher rpm than
>I think it should. At 60 mph my tack registers right at 3500 rpm. I
>downloaded an excel spread sheet that was talked about on line and the only
>way to get that rpm reading would be with 4.55 gears. I don't have an
>overdrive and highway driving makes the car overheat. Short of removing and
>disassembling the rear end is there any way to tell what rear-end gears are
>really in the car.
>
>Any help would be appreciated,
>
>John R Maneke
>_______________________________________________
>tedtsimx at bright.net
>
>This list supported in part by the Vintage Triumph Register
>http://www.vtr.org
>
>Triumphs mailing list
>Triumphs at autox.team.net
>http://autox.team.net/mailman/listinfo/triumphs
>
>
>  
>

-- 
Ted Schumacher
tedtsimx at bright.net
http://www.tsimportedautomotive.com
108 S. Jefferson St.
Pandora, Ohio, USA 45877
Fax: 419.384.3272 (24 Hrs.)
Phone: 800.543.6648 (US & Canada)
Tech/ Gen. Information/ Worldwide: 419.384.3022