Bob, as always, your explanations are right on the mark. I have a T-5
with the 2.95 1st gear and a 3.54 posi. I can pull the biggest tree
stump out with ease.
If I had my druthers, I would have a 3.xx 1st gear, but I just drive it
like a standard MK1 Tiger top loader with 2.88 gears, and start in 2nd
gear. Works just fine. But if I really want to haul, or whatever, then
I use first.
There is another way at looking at from a very practical position.
How do you drive every day. Do you run the engine up to 2K, 2.5K, 3K,
3.5K rpm in each gear. Well there are charts in the archives that show
what speed, i.e. mph, you have for that engine rpm.
You will quickly find out what is right for your driving habits.
Now, if you want to be more spirited, you can adjust.
BTW, with my T-5, with .63 5th, and 3.54 posi, it is great on the
highway, i.e. low rpm, but it pulls without a problem, as I designed a
torque motor, not a high rpm motor, and at 1800 rpm, I have 80% of the
357 lb-ft of torque to play with.
Larry
Bob Palmer wrote:
>Tony,
>
>I'll try to get to the point of your question with a minimum of math. To get
>the equivalent of 2.88 gears in 0.8 5th gear is 2.88/0.8 = 3.6. The closest
>stock gears to this would be 3.54's. So, if you put 3.54's in, you will now
>have five gears, and fifth gear will be virtually identical to your
>toploader's 4th gear. Then there is the much more subjective question of
>whether you want this fairly tall final gear ratio. There has been much
>discussion on that subject lately and it depends on whether you want the car
>for high speed freeway driving at the one extreme, or for autocrossing at
>the other. If you like an even taller final ratio, then maybe 3.31's would
>be good. I know that some even stick with 2.88's, but that puts the rpm's
>really low and if you have any kind of cam in your engine, it's not going to
>like it and, of course, you will have less throttle response. So, for mainly
>highway use I would recommend 3.54's or 3.31's, but nothing lower. If you
>want to maximize autocrossing or drag strip performance, then a rear end
>ratios around 3.97 is what you need. (See my article on the Tigers United
>Website for more details.)
>
>Getting back to your other four gears, there is an important question of how
>these compare to your four speed. Let's keep it as simple as possible and
>only consider actual numbers for first gear, bearing in mind that the closer
>the gear ratio difference between first and fifth, the better overall
>acceleration you will get. This fact is alluded to in Ron Fraser's
>statement: "This is about 10% reduction from stock gears and will give you
>better acceleration in all gears." This probably could have been stated more
>accurately as "will give you better overall acceleration throughout your
>shift range". In any one gear, it doesn't matter where the gearing is, in
>the transmission or the rear end. But, as you accelerate and shift, with
>closer ratio gears you can keep the engine running closer to its optimum
>rpm's, thereby improving your overall acceleration.
>
>That said, let's compare gear ratio ranges for the four and five speed. The
>toploader uses 2.32 and 2.78 first gears in the close ratio and wide ratio,
>respectively. I don't know what first gear ratio you are going to get in
>your five speed, but I'm pretty sure it's even lower (higher numerically)
>than a wide ratio toploader. I see first gear ratios for T-5's of 2.95,
>3.35, 3.5, and 3.97. Assuming you get the lowest of these, the 2.95, it is
>going to pull stumps with say a 3.54 rear end compared with even a wide
>ratio and 2.88's. I strongly recommend for a relatively light car like a
>Tiger, and for performance reasons, get the highest (lowest numerically)
>available first gear in your five speed. I assume that's what Dale would
>give you anyway, but ask to make sure.
>
>Bob
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