Well, there's no arguing against feelings,lol;
but I gotta tell you;
A high stall convertor is like having two gears,infinitely variable between 1.8 and 1.1 then add the other 2 in the trans and another 1/2 in the loc-up, and you gotchr 4.5 gear automatic, disguised as a 3loc-up.
Idk what you have for a powertrain, but for this exercise it won't matter.
Let's say you currently have a
2.45 rear gear and a
2000 stall.
And let's say you have the
A999, so ratios are 2.74-1.54-1.00, and
A loc-up TC..
And lets work off the 5.2 Magnum dyno graph at the bottom
And lets say your 5.2, per the graph, has a maximum output of 156 ftlbs at 2000 stall.
1) Ok so how much torque are you putting down at zero mph@2000rpm?
with the auto;156x2.74 x2.45x 1.8(TC) =
1885ftlbs;(winner)
And with the NV3500; 156 x3.49x 2.45=
1334
no contest the automatic will blow the stick off the line; if you do not exceed 2000 rpm during engagement.
2) But what if you launch the NP3500 at 2800rpm?
From the graph, this 5.2 is making
~173 up there,so ;
with the NP3500; 173x3.49x2.45=
1479
the auto with 2000 stall is still
1885(winner)
But what if you installed a 2800stall into the auto? I mean fair is fair right..
OK, now 173x2.74x2.45x1.8=
2090 (winner) ftlbs at zero mph; now yur talking!
No matter how you slice it,When you do an apples to apples comparison, in this combo, the TC will always blow the stick away, at zero mph.
Ok from here on let's use the 2800stall TC.
3) Ok what happens when cruising at 30 mph when you floor it?
With the stick,30mph is ;1915 in second, 3190 in first. So for rapid acceleration, you will have to downshift into first. So then at 3190, say you are, per the graph, at
178 ftlbs now.
Then with the NV3500; 178 x 3.49x2.45=
1522 ftlbs
With the automatic, 30 will be 1410 in second/2500 in first, so it too will have to downshift. When it does, the Rs will climb to the 2800stall, releasing
173ftlbs, and 173 x2.74x2.45x say
1.5 in the TC =
1742 (winner)
if I over-estimated the TM at 1.5, and it's really 1.4, then
1626(still the winner).
But say I really screwed up and the TM is really just 1.32, then
1533 (still the winner)
4) Next, lets run the engine up to 4400 about peak power, thru two gears.
The stick will hit second at 41 mph, and 65 will be 4230
The auto hits 49 in first, and 65=3290
So at first glance it looks like the stick is gonna be quicker.
But this does not take into account the TM in the TC! At the bare minimum I would expect 30% average TM, Yes I'm guessing, in first gear, and say 15% in second average.
So, we have already seen the Auto blow the doors off the stick to 30mph; I can't say when or if the stick will catch the auto between 30 and 60, but my opinion is;I seriously doubt that it will.
But don't miss the point; The hi-stall auto will put more torque down, all the way from start to finish.
6) As to cruising; the stick wins at 65=1560 verses 1980 with the auto.
But here's the catch; If you cam it, the intake may not clean up until after 2000, so between 1560 and 2000 you shouldn't expect much if any better fuel economy. And once cleaned up there is at least a 400 rpm plateau where fuel economy will vary,only a little bit, at a steady speed. This is not true for the stock cam.
7) As to the fun factor rowing gears? .... Well considering that second gear with a 2.45 rear gear, is good to 74 mph@4800, you got yourself a 3 gear car, namely; first, second and overdrive. IDK how much fun that's gonna be.
If you shortshift outta first, the shift rpm will be;
30=3200; going into second at 1960.
40=4250; going into second at 2610.
If you have been following along you mighta got the idea that the 2.45 rear gears are the real problem; and you would be mostly right. But the very wide 1-2 split of 2.14/3.49=61% is another bad deal.
And the 2-3shift is just as bad.
But the point is the same no matter what rear gear you put in it.
But if you just want a manual trans for the overdrive, well, there's no arguing against what you want..........
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Thank you for the info most of it made sense lol.
Now it never crossed my mind on a higher torque converter, when i say a mild built 318 i have a set of engine quest heads already and plan on ordering the edelbrock preformer intake manifold with there 600 cfm carb and cam to match, then deck the block and do a complete rebuild on everything else so if my numbers are right that should put me at about 250 ish hp (dont quote me on that lol) and the manual is more of a preference! P