For those who were wondering why anyone would want a 4.55 differential
I've forwarded the reply to the same question from the TVR e-mail list.
Please don't reply to me about this. I'm only forwarding a message with
TR content from the TVR list.
John T. Nichols
'58 TR3A TS32093L 'O'
'86 TVR 280i
-------- Original Message --------
Subject: Re: Ring and Pinion Source
Date: Wed, 29 Sep 1999 21:13:25 EDT
From: Rikrock@aol.com
To: Stephen.Hill@gems7.gov.bc.ca, tvr@autox.team.net
In a message dated 99-09-29 15:28:43 EDT, Stephen.Hill@gems7.gov.bc.ca
writes:
<<
Nick, for those of us who are a little out of the loop on this, can you
please provide a little background. What ratio would my 1972 TVR (TR6
drive
train) have in it? Why are the 4.55 so desireable? And what would
they
have come in? Thanks a bunch. >>
Stephen and all,
I'll help Nick out here...he's probably quite busy putting the "Duke of
Oil"
together. That's what he calls his TR4A vintage racer.
TVR's with the TR6 drivetrain were fitted with 3.45 diff gears, unlike
the
TR6, which was normally fitted for export with 3.73 gears. I'm not sure
why
TVR chose the taller gears, but it may have been to get a higher top
speed.
Or maybe they got a better price on them from Triumph!
The 4.55 gears were available through the Triumph Competition Dept.
When
used with an overdrive tranny, they are the hot setup for racing on most
tracks. Hillclimb and autocross cars work well with these gears, or the
4.88's, which Triumph also offered. For street use, don't even think
about
the 4.88's (but let me know if you have a set). The 4.55's COULD be
used on
a street machine, I suppose, but ONLY with an overdrive tranny, and you
would
be in a tough situation if that overdrive ever stopped working!
A nice swap for your TVR would be to fit a TR6 3.73 diff. Better low
end
response without giving too much top end away.
Regards,
Rich Rock
Pottstown, PA
TR's and TVR's
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