FORD HORSEPOWER AND TORQUE CURVES
If you study the performance curves you will see two major benefits of GearSplitting; increased
horsepower and multiplied torque. As an example, we'll use the E40D/4R100 trans chart
with a 4.10 rear and both the 7.3DI Diesel and Fords new high rev V10. For the diesel engine the ability
to keep the engine in a narrower band is even more important than the gasoline powerplants
because of the lower rpm range where power is made. Gaining a 4.92 multiplier plus the ability
to drop only 500rpm onshift instead of a thousand makes a dramatic difference. Notice if you
rev to 3400rpm (way above the power) in 2nd and then shift to 3rd your engine speed drops to
2210 rpm. With the GEAR VENDORS you can rev to just 2650 with great hp and torque and a
20% greater torque multiplier in 2ndover and drop to only 2200rpm onshift to 3rd.
As an example, with the new High Rev V10 since gears are multipliers of torque
at 4000 rpm in 2ndover the torque multiplier is 4.92 where without the GEAR VENDORS you
would get into 3300rpm in 3rddirect at 4.10. The difference in engine torque is only 10lb ft.
but the difference in the multiplier is 4.92 vs 4.10. That's 20% more working torque (net). At
this same moment horsepower at 4,000rpm is 300 instead of 250 @ 3300 which is 20% more
horsepower with all the reliability of your stock powerplant.
To figure the drop in rpm or torque multiplier from one gear to the next,
calculate as follows: Final Drive Ratio of gear you are shifting to, divided by the gear you are
shifting from, minus 1, times 100. The difference from 1stover to 2nd is even more dramatic.
This is why if you are towing or loaded heavily, the best way to reliably
improve performance is with the GEAR VENDORS UNDER/OVERDRIVE™. It's the same reason the
big 18 wheelers have 2 and 3speed auxiliaries for 10 to 15 gears.
Click on graphs to enlarge.
Ford 5.4L PN102

Ford 6.8L V10

Ford 7.3L V8 DIT Navistar Diesel

Ford 7.3L V8 IDI Navistar Diesel 
Ford 7.3L V8 (Non Turbo) Navistar Diesel 
Ford 7.5L E/F E4OD 
GEAR VENDORS, INC. 1717 North Magnolia Avenue, El Cajon, CA 92020
Toll Free 8009999555 • Telephone (619) 5620060 • Fax (619) 5621186
