GM Manual Transmissions
Muncie M21/M22 (Also M20 and BW T-10)
Gear Vendors owes a lot to the Muncie close ratio trans. These words are
very similar for the M20 and T10 but with some slight ratio differences depending on model.
All M21/22 have the same 22% upshift and 28% downshift spread as the Gear Vendors.
Overdrive is the first reason you are going to add the Gear Vendors.
28.6% faster cruising speeds than you have now. Your 4.10 gears will cruise like 3.20s and
your 3.55 will cruise like 2.77s. If you are normally aspirated expect 28% better fuel
economy. If you have forced induction expect 50% better mpg.
Performance is what the Gear Vendors is all about. This product is a
very high-tech planetary overdrive. With our Auto-Launch circuit on you will leave the
line in 1st and as the engine gains revs it will automatically shift clutchless to
1st-overdrive. This means you are 28% farther down the track or street before you have
to clutch the car. This is key to acceleration as otherwise any manual trans car gives
up big hunks of time to an automatic on the 1-2shift. Gear Vendors 1st-over ratio is
only 7 hundredths different than having shifted to 2nd (not discernable and actually
closer in ratio).
It is not just 1st-over where you can use this clutchless shift. You can
be in 2nd just boulevard cruising and show off by stepping on the throttle and hitting
the Gear Vendors button on your sifter for 2nd-over which is identical (exact same ratio)
as having shifted to 3rd but only clutchless (and with a nice bark of the tires). Most
street guys will just grab a clutchless gear at whatever moment they start accelerating
and then progress up through the gear box leaving the overdrive on so that each gear is
just now up a step.
The bracket racers and serious street guys will flip the 3-4 side
cover lever over so they can easily have two clutchless shifts in the ¼ mile with just
one clutch depression. Flipping the 3-4 cover lever over lets them grab with a straight
pull back because it moves 3rd to the 4th gear position on the pattern. Just awesome
performance gains greater than a full second on the watch, increased mph and far more
performance than any 5spd or 6spd tranny swap.
So you get a 5th gear overdrive and at least one clutchless shift
to be used at any moment (we ship the kit with our 6speed car badges) and a huge
performance gain plus get to retain your period correct transmission in the car and
get the worlds strongest overdrive trans. Since your Muncie or BorgWarner is stronger
than any non-race 5 or 6 speed, the Gear Vendors is just he right way to get overdrive
in your GM manual performance car.
The Gear Vendors comes with a 30 day money back guarantee so you
know you will be happy with everything you get from us and how it installs and drives.
All our kits also have our 2year unlimited mileage, horsepower, and abuse warranty -
you can go to the dragstrip every weekend and still be covered - no other overdrive
can handle that.
GM/CHEVROLET FINAL DRIVE RATIOS
It is the gear under your seat that counts. Gearing is what you are
buying when you purchase a Gear Vendors Under/Overdrive. If you take a few moments to
study the gear chart for your transmission and rear end ratio combination you will see why
this product is so popular. The Final Drive Ratio shows you how many times the engine
turns for one complete turn of the tires. Gears are multiplier of torque. The mathematical
equation for Horsepower is; Torque X RPM/5252 = HP. Close ratio gearing lets us work both
the torque and rpm side of this equation for big gains in HP and performance.
| M21 4-SPEED Close Ratio - showing clutchless options |
| |
Axle Ratio |
4.88 |
4.56 |
4.10 |
3.73 |
3.55 |
3.42 |
| |
Trans Ratio |
Final Drive Ratio |
| 1st |
2.20 |
10.74 |
10.03 |
9.02 |
8.21 |
7.81 |
7.52 |
| Over |
1.71 |
8.35 |
7.81 |
7.02 |
6.38 |
6.08 |
5.85 |
| 2nd |
1.64 |
8.01 |
7.48 |
6.72 |
6.12 |
5.82 |
5.61 |
| Over |
1.28 |
6.23 |
5.82 |
5.23 |
4.76 |
4.53 |
4.36 |
| 3rd |
1.28 |
6.25 |
5.84 |
5.25 |
4.77 |
4.54 |
4.38 |
| Over |
0.99 |
4.86 |
4.54 |
4.08 |
3.71 |
3.54 |
3.41 |
| 4th |
1.00 |
4.88 |
4.56 |
4.11 |
3.73 |
3.55 |
3.42 |
| Over |
0.78 |
3.79 |
3.55 |
3.19 |
2.91 |
2.77 |
2.66 |
CHEVROLET / GMC Application Guide 2-Wheel Drive Manuals
GEAR VENDORS, INC. 1717 North Magnolia Avenue, El Cajon, CA 92020
Toll Free 800-999-9555 • Telephone (619) 562-0060 • Fax (619) 562-1186
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