Tranny gear ratios for DSMs

According to the Shop Manual CD, here are the gear ratios for 1G NTs, 1G/2G FWDs, 1G/2G AWDs, 2G 2.4 Spyders, Galant GSXes (GGSX, AWD nonturbo) and Galant VR4s. The Shop Manuals for the different years sometimes conflicted with the Tech Manual (the CD only has the early Tech Manual, so only covers 1Gs), so I put what I thought were the proper numbers in some places - thanks to Mike at RRE for corrections. I have put the Galant GSX in the Turbo section to make it easy to compare with the GVR4 and EVO GVR4.

NonTurbo
Gears1G NT2G NT 2.02G NT 2.4
1st3.3633.543.166
2nd1.9472.131.833
3rd1.2851.361.240
4th0.9391.030.896
5th0.7560.810.731
R3.0833.423.166
 
Primary1.096??
Secondary3.941??
FINAL4.3223.943.625

Turbo
Gears 1G FWD2G FWD1G AWD
MT
1G AWD
AT
2G AWD
MT
2G AWD
AT
GVR4GGSXEVO
GVR4
1st 3.0833.0903.0832.846 3.0832.5512.8462.8462.571
2nd 1.8331.8331.6841.581 1.6841.4881.6841.6841.600
3rd 1.2171.2171.1151.000 1.1151.0001.1151.1151.160
4th 0.8880.8880.8330.685 0.8330.6850.8330.8330.862
5th 0.7410.7410.666NA 0.666NA0.6660.6900.617
R 3.1663.1663.1662.176 3.1662.1763.1663.1663.166
 
Primary
(gear toothcount)
1.208
(29/24)
1.206
(29/24)
1.275
(37/29)
1.125
(?/?)
1.275
(37/29)
1.228
(?/?)
1.275
(37/29)
1.680
(?/?)
1.275
(?/?)
Secondary
(gear toothcount)
3.437
(?/?)
3.437
(?/?)
3.866
(58/15)
3.611
(?/?)
3.800
(57/15)
3.55
(?/?)
3.866
(58/15)
3.100
(?/?)
4.260
(?/?)
Transfer
(gear toothcount)
NANA1.090
(24/22)
1.090
(24/22)
1.074
(29/27 ?)
1.074
(29/27 ?)
1.090
(24/22)
1.090
(24/22)
1.090
(24/22)
 
Final 4.1534.1534.9294.062 4.9294.3594.9295.2085.435
 
Rear Diff ratio
(gear toothcount)
NANA3.545
(39/11)
3.307
(43/13)
3.545
(39/11)
3.307
(43/13)
3.545
(39/11)
2.846
(?/?)
3.545 ?
(?/?)
Gears 1G FWD2G FWD1G AWD
MT
1G AWD
AT
2G AWD
MT
2G AWD
AT
GVR4GGSXEVO
GVR4


The "Primary" ratio is the Intermediate Shaft driving the Center Diff on an AWD or the Output Shaft on a FWD.

The "Secondary" ratio is the Output Shaft driving the Ring Gear on the Front Diff - the actual ratio of the axle shaft rotations compared to the tranny internals.


Primary x Secondary  =  final - this affects the rpm of the engine vs the rpm of the front axles.

Secondary/Transfer  =  Rear diff
The two must equal each other for an AWD car to roll without burning up the center diff (which is why you shouldn't run tires with different diameters F/R on an AWD).


If someone wanted to change the final drive ratio on an AWD, you need to change the ring gear on the front diff along with the stubby Front Output Shaft that is driven by the center diff. These are both inside the transmission. Then the rear differential ring and pinion gears must be changed to match. The rear diff ratio will be slightly different but will equal out when multiplied by the 1.090 of the transfer case. IF the Galant GSX gears will fit in an AWD TEL, they would probably work pretty well for a high powered AWD drag racer - you'd have to launch at a slightly higher rpm, but each gear would give a higher mph than before, so you could leave it in each gear longer. Top speed could be over 200mph using GGSX gears in a TEL AWD with enough power to spin at 8K (using a TMO ECU to allow the higher limit).

Note that the AWD has the tallest 5th gear ratio, if swapped to a FWD trans it would raise the top speed considerably (if you had the power to pull it).

One thing to note here - gear ratios run opposite of what you would think. The higher the number on the gear, the faster the engine spins, hence the lower the road speed. This is why a 0.666 5th gear is an overdrive - on older cars, the 4th gear was often 1:1, and if they had a fifth, it was about 0.8:1. So that numerically lower 5th gear allowed the engine to spin slower for the same road speed, or in other words, for the same engine speed, allowed a higher road speed. That's also why that old Mustang you raced with 4.11 ring gears in the rear topped out at about 120 instead of the 140s it could do with the stock 3.x rear gears (the reason for the 4.11s is better acceleration).


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Last modified: Aug 28, 2000
Copyright 1999-2000, Tom Stangl
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