Forza Horizon 5 and earlier games allow you to install different transmissions that unlock forward and final drive gear tuning. As you upgrade other parts, you may find that the old gears no longer match the new power band. In the right situation, a new gear tune can dramatically improve your lap times and make the engine’s power more usable.
You want to choose gears that keep your engine spinning in a sweet spot known as the power band. This gives you the best acceleration from your engine even as you change vehicle speed.
What is the Power Band?
The power band is the range of rpm values where you maximize acceleration. It starts where maximum torque happens and typically goes up to the maximum engine speed.
When engines have max torque at a low rpm, the power band is much wider. It’s the type of engine that will throw you back in your seat immediately, like a big V8 or a quickly spooling turbo. And if the engine can breathe well, that acceleration will keep pulling until you shift.
For these engines, it is less important to get gearing perfect.
When Gearing Matters Most
The engines with a max torque rpm much higher in the rev range are the ones where gearing is especially important. Classic examples would be Honda engines like in the S2000. Fall out of the power band and you will have trouble keeping up with a minivan.
General Approach for Tuning Gears By Hand
- Install race transmission and note at what rpm value the engine makes max torque.
- Go to the tuning menu and start with a final drive ratio between 2.8 and 3.0. Choose higher for engines with less peak torque, and lower value for engines with more torque.
- Pick a first gear that gives the best acceleration value according to the simulated 0-60 times. This may take some trial and error as you slide the values.
- Use gear graph to pick a second gear that starts at or close to the rpm value for max torque.
- Make each remaining gear 60-90% of the previous gear, with the higher gears becoming increasingly close to the previous gear value. This should create a smooth arc on the gearing graph.
- Note the estimated top speed and decrease the final drive slider for more top speed at the expense of some acceleration.
Recommendation: Use a Gearing Calculator
The math behind gearing can be a bit confusing. You can do it by hand looking at the graph, but it takes about 1/10th of the time if you use ForzaTune Pro, which includes a gearing calculator. Visit this guide to see how to tune gears using a gearing calculator.