Finding The Right Rear Gears For Your Mustang
Sometimes finding the correct rear gear ratio to go with on your Mustang build can be difficult. You have to take intake type, transmission, tire size and many other factors into consideration when choosing the correct Mustang ring & pinion gear set to go with on your build. If your Mustang is a street car, then you may want to take highway speed RPM into consideration when picking a set of rear gears. The same goes for a drag-only car that will never see the highway, a much shorter set of gears would be ideal.
Rear Gear Ratio and Drag Racing
For example, on the late model Mustang with the 5.0L Coyote V8 engine and manual MT82 transmission, the ideal rear axle ratio is 3.73 when it comes to the quarter mile on a set of 28” rear tires. When you cross the quarter mile, you’re going to want to be at the top of fourth gear with this particular car, depending on mods. And a 3.73 rear gear ratio will allow you to do that. If you’re running 4.10s, then you may have to shift into fifth gear, thus costing you ET and possibly even MPH on the quarter.
Additionally, if you throw a supercharger or turbo into the mix, you’ll be crossing the traps at a much higher rate of speed. Meaning you may want to swap out for 3.55s or 3.31s since your MPH may be 130+ MPH rather than the slower 115 MPH you may have trapped on a naturally aspirated setup.
Ring and Pinion Gear Sets and Street Cars
Let’s say that you’re the type of Mustang owner that isn’t all about the dragstrip, and you’re more about driveability on the street. On most Mustangs, a great rear gear ratio to run with will be a 3.73 depending on your setup and 4.10s for a more aggressive setup. This will allow for decent off the line acceleration, but won’t sacrifice too much of your highway speed RPM. Why does highway RPM matter? Well, if you’re running high RPMs at 65 MPH, you will have a reduced top speed, decreased gas mileage and increased engine wear. Finding that happy medium is key, so be sure to do proper research before purchasing your gears and installation kits here at CJ Pony Parts!