Tigers, and Tom,
I swapped out my Mk I Top Loader from the "close ratio" to the Mk II
"wide ratio" gearbox. A direct bolt-in, but does need a new helical
gear to match the stock Mk I / IA speedo ratio. (Not the cable end gear,
but the one that mates to it "inside" the box. You CAN adjust the
speedo to give correct speed, but the odometer will be off unless
"unobtanium" speedo gears (or a Mk II speedo) are used.
With the stock 2.88's the gearbox seems correctly geared for good
performance throughout the range, and feels MUCH better in performance
spacing. A direct comparison can be seen as a default in Bob Hokanson's
"Excel Transmission Calculator
<http://www.tigersunited.com/techtips/HokansonGearSpeedXL/pt-HokansonGearSpeedXL.asp>"
link. Even includes links to download a free Excel Reader.
This even includes a T-5 speed, set up with stock ratios.
For instance, with stock 2.88 rear axle, 23.25 inch tire diameter (stock
13" tires), at 5,000 rpm, here are the resulting comparisons:
First Gear 52 mph "close", and 43 mph "wide" (difference 9
mph earlier (quicker off the line)
Second Gear 71 mph "close", and 62 mph "wide" (difference 9 mph
earlier)
Third Gear 93 mph "close", and 88 mph "wide" (difference 5 mph
earlier)
Fourth Gear 120 mph "close, and 120 mph "wide" (difference 0 mph)
Change parameters for non-stock items.
Net result is shift points are at reasonable speeds, but always a bit
earlier shift points. This means quicker acceleration, while
maintaining the 1:1 top gear results. (still a bit high at cruising
speeds 72 mph at 3,000 rpm for either.)
This would drop to 2400 rpm with an 0.8 fifth 5-spd (JBA 1352-000-204
hard to obtain), as almost all have 0.63 or 0.68) - but watch those in
between shift points. With stock 2.88:1 rear end gears. A change would
influence results shown.
The 0.80 fifth (JBA-1352-000-202) would result in 72 mph at 2400 rpm.
The 0.63 fifth (Mustang 5 spd) would result in 72 mph at 2000 rpm. (LOW)
The 0.68 fifth (Motorsport 5 spd) would result in 72 mph at 2400 rpm.
The 0.68 fifth (JBA 1352-000-204) would result in 72 mph at 2400 rpm.
Get the "Calculator", and the free Excel Reader if you need it.
As the man says: "You pay your money, and you gets your choice!"
Tiger List Member Sandy Ganz has put up an "On-Line Tire Size and Gear
Calculator"
http://www.gtsparkplugs.com/GearCalc.html
As well as many other "Calculators" of interest to the sporting community.
Steve
___
Steve Laifman
Editor - TigersUnited.com
<http://www.TigersUnited.com>
Thomas Witt wrote:
> Nathan,
> To distill down what I have found:
> Many feel the 2-3 ratio spread on the overdrives is too great.
> Some feel the lower 1st gear (3.29 especially) is too low.
> And some feel the .70 4th gear is too little RPM for hills etc..
>
> For one or all combined reasons the consensus I got was it wasn't a
> good idea. The Capri/Mustang transmission is called an SROD. The
> knock on it (ratios aside) was that the shift mechanism wasn't very
> good. Also, I believed because the shifter was fixed, the location to
> the hole in the Tiger tunnel wasn't a match (???).
> In the end it was recommended to either run a wide ratio Toploader of
> use Tom Hall's kit and run a T-5.
> As it has been note others (not a majority) have different
> applications and for them the overdrive works.
> Tom _______________________________________________
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