Jim,
This has been in my files for about a year and a half.
It should answer all your questions.
JOE IV
TR 250
WALLINGFORD, CT. USA
From:
Bob Lang <LANG@ISIS.MIT.EDU>
8/5/96 18:27
Subject:
Re: A Dead Horse named Tires
To:
Chad Jester <triumph@igc.net>
CC:
triumphs@autox.team.net
Hi,
Several folks asked for this. The results are based on "tires.xls", a
spreadsheet that has floated around on the net for quite some time. I am
not a tire engineer, and I take no responsibility for accuracy.
Note: do not try to go 6500 RPM with your stock TR6 engine!
I came up with 6500, because I wanted to see how many RMP's you need to
peg the TR6 Speedo. Hey, it was a long night!
Note: 225/60-16 is a nice match, but most racing rules won't let you do
this and stay "legal". That's the breaks.
I also pre-apologize for any formatting problems, I merely dumped some
numbers form Excel and read them into a simple text editor. Hopefully,
the numbers will look okay with minimal editing......
SW AR WS WW SW SH OD RPM RPM G GR FDR Speed Comments
185 80 15 5.10 7.28 5.83 26.65 780.38 6500 4 1.00 3.70 139.36 Stock TR6
225 60 16 6.20 8.86 5.31 26.63 781.08 6500 4 1.00 3.70 139.23 "Real Nice match
for ""low Profile"" tr6 tyre"
215 70 15 5.93 8.46 5.93 26.85 774.66 6500 4 1.00 3.70 140.39 Looks Ideal for
TR6 Replacement
205 70 15 5.65 8.07 5.65 26.30 790.90 6500 4 1.00 3.70 137.50
185 65 15 5.10 7.28 4.73 24.47 850.07 6500 4 1.00 3.70 127.93
205 50 15 5.65 8.07 4.04 23.07 901.57 6500 4 1.00 3.70 120.62 "Probably good
AutoX tire for TR6, like 4.30 gears"
225 50 15 6.20 8.86 4.43 23.86 871.82 6500 4 1.00 3.70 124.74 "Ditto to
above, JK Jackson endorses this."
205 60 15 5.65 8.07 4.84 24.69 842.62 6500 4 1.00 3.70 129.06 This is like
using 4.01 gears in the diff.
Legend:
SW == Section Width
AR == Aspect Ratio
WS == Wheel Size
WW == Wheel Width
SW == Section Width
SH == Section Height
OD == Overall Diameter
RPM== Revolutions Per Mile
RPM== Engine Revs.
G == Gear
GR == Gear Ration
FDR== Final Drive Ratio
Speed == Lower speeds indicate relative decrease in speed for equiv.
engine speed, all drive-line factors considered.
If anybody cares, I can put this info in web-readble form...
rml
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Quote: I don't need no steeeeenkin' ABS brakes.
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