is this for use on the street?
With an SBM?
@JoePole1 asked
On the street this is a pretty good idea.
>The A518 ratios are 2.45-1.45-1.00-.69od.. with 4.10s, the Roadgears are;
10.05-
5.95-4.10-2.83
> the A999 ratios are; 2.74-1.54-1.00 ............. With 3.55s the roadgears are;
9.73-
5.47-3.55
Rpms at 65mph are about 2290 w/4.10s and overdrive; and 2870 w/3.55s, both in LU ..
Notice that the first two gears are
practically identical, so performance will be about the same. At WOT, top of Second gear is already over 65mph with either trans; so basically, the only advantage you get from the od trans is the od.
But it doesn't have to be like this. That First gear, either of them, are pretty crazy on the street;
Say you ran the A999 with 3.23s, for roadgears of 8.85-4.97-3.55.. Ok then;
65mph in Second at WOT(10%slip) will get you
~4430rpm. (compared to 5300 with the 5.95 roadgear)
65mph in LU comes to about 2610, an easy rpm to tune for max fuel economy.
That 8.85 starter gear, with the A518 would take a reargear of 3.61 to match.
In any case, 8.85 wouldn't take much stall to fry the tires, with anything as big or bigger, than a 318, especially in a stock-tubbed, tire-size compromised, early Dart.
Jus saying.
I get that the A518/4.10s are a GREAT combo, especially for a small engine. But
I also get that with anything bigger than a 318, it is going towards overkill.
I also get that the A999/3.23s seem like they would be soft off the line, and they could be with a soft engine. But with anything bigger than a 340-4bbl, or a stout hi-cylinder-pressure 318, it won't be.
And by the time you get to a 360-4bbl, in a stock-tubbed Early-A, an 8.85 starter is a tire-fryer. Add a lil stall and you can't even floor it without tirespin.
I should probably mention that 4430rpm is about the rpm of peak hp for an early 318. So if yur engine is there at 65mph, in Second gear ....... you would have great passing power.
