You guys with a gear vendors overdrive unit, is it worth it? I'm really on the fence about pulling the trigger and ordering one.
Show pics and any tips on install.
My setup is 360 magnum, 904 w/2800 stall, 8 3/4 w/3;55 gears possibly going to 4:10 gears.
Tom
You know, I got to doing some math;go figure.
If you had an A998 with ratios of 2.74-1.54-1.00 and you bolted a GVOD onto that, and started splitting gears......then you would have
6 very usable ratios of
2.74-2.14-1.54-1.20-1.00-.78 and splits of
.78-.72-.78-
.83-.78
Combo A)
If you had the power to go 103, you could use 3.55s and use the first 4 ratios and shift at 6000, with road speeds of
47-61-84-103@5730 and still cruise at 65=2240 @zero slip; like as if you had 2.77s in the back.
Accelerating up the on-ramp, you might shift at 3600;you would probably shift 1-2- 2od and then drop it into 3od at 65mph
But the thing is, you can't backshift the GVOD under power, so you'd have to rig up an electronic ignition kill for the few microseconds it takes for the GV to outshift. It takes slightly longer to outshift than I can clutch and pull the stick, so I hit the GV outshift a few milliseconds early.
Combo B)
If you did this, you could run 4.10s, and maybe one size smaller cam, and shift at 5800, for roadspeeds of
40-51-71-90-103@5500 and maybe she'll be just as quick. But your 65 will now be 2580@zero slip;like as if you had 3.20s in the back.
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IMO, you don't need much more than two gears for zero to 60; but not less either,lol. So I'm liking combo A for a streeter.
But I'm liking Combo B for the dragstrip........ for the short fifth ratio;
and nuttin wrong with 2.5 gears for 0 to 60.
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Splitting the 904 is almost as good... maybe better. The ratios are
2.45-1.91-1.45-1.13-1.00-.78 with splits of
.78-.76-.78-.88-.78
You would need to run 3.73s to work with that 1.13 ratio, (assuming a 103 trap again). And with the 1.91 second ratio those 3.73s would hit 60=5600; pretty sweet.
And at the dragstrip, using the 4.10s to use direct again, you would gain that really short 4-5 shift of about 700 rpm, so that's cool.
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Just remember; while the GV is outshifting it can't have power running thru it.
But on the in-shift she'll take full power, and squalk the tires even at part-throttle.
