[TR] GT6 3.27 ratio was GT6 Cabriolet

[aribert neumann]

My '71 GT6 was originally a non OD trans.  I acquired the OD trans to be
able to have a more relaxed cruising rpm - had I changed to the 3.89 ratio
when I changed the trans, the engine revs for a given speed would have been
virtually the same as w/o the OD.    I intentionally kept the 3.27 diff
ratio.   I ran the car w/ the 2L and OD and 3.27 for about 15K miles before
I did the body and engine (2.5L) swaps.  I thought the 3.27 and the OD was
an ideal everyday combination - whether putzing in stop & go traffic or
zipping along on the freeway early in the morning heading off to work.
After destroying 2 diffs in 4 years, I built up a Mazda diff similar to the
GRM Ro-Spit  project car.  Unfortunately the lowest numerical rear axle
ratio available for this combination of Mazda parts is 3.667 - for me not
as bad as the 3.89 but not as sweet as the 3.27.  My car is a '71 GT6
convertible (78 Spit body), '73 TR6 engine, head milled 0.140, street cam &
triple Webers.  I would guess that the engine is somewhere in the 130 hp
range that you are aiming for.



From: jmbs46 at comcast.net
To: "List, Triumph" <triumphs at autox.team.net>
Cc:
Date: Fri, 27 Feb 2015 17:48:03 +0000 (UTC)
Subject: [TR] GT6 Cabriolet
Hi folks.

I have a couple more questions on the GT6 I was hoping for some wisdom here.


2- I also understand the diffs are pretty much the same as far as power
handling. I plan on getting and overdrive, so is the 3.89 ratio from the
Spitfire is what the factory used in the US. But, apparently the German
GT6s with OD used the US non OD ratio, the 3:27, maybe that is better for a
more relaxed cruise? Not planning on drag racing much, but also don't want
a car that cant get out of its own way.
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