Another interesting discussion we had the other day was how quickly you could make a 400hp motor run in a relatively lightweight Mustang. I whipped out my trusty copy of Patrick Hale’s Quarter Jr. program and with a lot of rear gear and a close-ratio five-speed, and the simulation said we could run in the high 11s on a perfect pass with good weather and great traction. That assumes a lot, but on the other had, the simulation said we were only running mid-1.60-second 60-foot times. You can make the car 60-foot quicker by raising the launch rpm, and that helps a bunch. But the big thing was to run a 4.10 rear gear and use a close-ratio five-speed like the Richmond five-speed. That box has a 3.27:1 First gear with the following ratios: 2.13, 1.57, 1.23, and 1.00:1 in Fifth. This keeps the engine in its powerband. In fact, I looked at the recovery rpm after every shift (at only 6,500 rpm) and the rpm never dropped below 5,000 rpm. Keep that little motor in its powerband and then run through the lights at very close to the power peak, and high 11s at 115 mph with a 3,200-pound car is not too difficult. Most street cars are slower than this because they don’t run the deep gears and use a three-speed automatic, which creates a much greater rpm drop between shifts and slows the car down. While not dramatic, the difference between a four- and five-speed manual trans is a little more than a 0.10-second. Interesting, no?