I recently read a post by a car guy who proclaimed he could guarantee a quicker e.t. on almost any car just by making the rear gear deeper—say from 3.08:1 to 4.11:1. While on the surface this may sound like a safe statement, its generality set off a little warning buzzer in my head. While for many applications this may be true, there are literally thousands of exceptions. The whole idea of gear ratio can be viewed as leverage to help accelerate the vehicle. But remember that torque is what applies that leverage and accelerates the car. Adding gear ratio is like multiplying torque. However, more engine torque means you don’t need as much gear ratio as you would with an engine with less torque. For example, I plugged a 3,650-pound car into the Racing Systems Analysis (quarterjr.com) Quarter Pro dragstrip simulation program with a big-block making 550 hp and 590 lb-ft of torque. With a 3.55:1 gear and a 28-inch-tall rear tire, the car simulated at a 10.84 at 124.4 mph with a 1.56 60-foot time. Next, I changed only the rear gear to 4.56:1. The simulation recorded a 10.86—0.020 second slower with a slower trap speed of 122.7 mph while the 60-foot time remained at 1.56. What this revealed is that more gear did not help the car accelerate—in fact, the deeper gear made the car slower. I next tried a taller 3.23:1 gear and found the car simulated the original 10.84 with a slightly slower trap speed of 123.8 mph and the same 1.56 60-foot time. If this same car had a 327ci engine, then the scenario would change because its smaller displacement will make less torque and need more gear to help it accelerate. What many enthusiasts don’t realize is that with more torque comes better acceleration without the crutch of a deeper gear. So the bottom line is that a deeper gear isn’t always the answer to a quicker e.t.