Drivetrain Tuning Guide

Forza Horizon 5 tuning is as complex as it is important for reaching the maximum potential of your car. It’s a difficult skill to master, but once you’ve got the hang of it and are finally able to tune your favourite cars on your own, it’s going to feel very satisfying and worth the effort!

In this guide we'll focus on the drivetrain options and how to effectively upgrade them.

This guide was created with help from the following tuners:
  • TopTierRamen - a highly experienced tuner and player who leads Team Noodle in Team Wars; Ramen also maintains popular community spreadsheets (e.g. Road Tunes Sheet)

Transmission


For cars which still have their stock drivetrain (no conversion), the Street Transmission and Sport Transmission upgrades can often reduce the PI (Performance Index) of your car, giving you the ability to afford even more upgrades while remaining in your target class. This is especially true for RWD cars. It is always worth checking on these, since sometimes it costs a lot of PI to upgrade to Race Transmission or even remain stock.

If you have converted your drivetrain, such as swapping from RWD to AWD, then your car will already be on Race Transmission.

Note: The PI cost of transmission upgrades can scale depending on how much power you have added to your car, so you may want to revisit this decision after your engine upgrades.

  • Stock and Street Transmissions are similar in that they do not allow any tuning adjustments to the gearbox. Picking between these two is usually a question of PI and the actual length of the gears provided. You can usually see a difference just by looking at how your car’s top speed changes as you toggle between these two options. It is often the case that neither of these choices will be particularly good for your build, so you may have to upgrade to Sport or Race Transmission.

  • Sport Transmission is commonly the best choice if it reduces your car’s PI or is significantly cheaper than Race Transmission in terms of PI. This is because this upgrade allows you to tune the Final Drive ratio of the gearbox, which essentially enables you to define the range of all of your gears with just a single adjustable slider. This slider is at the top of the Gearing page in the tuning menu.

  • Race Transmission enables you to tune your individual gear ratios. Sometimes the default gear ratios for cars can be quite wacky or suboptimal. For example, some cars may randomly have a very long 5th gear or a very short 3rd gear. Upgrading to Race Transmission will allow you to smooth out these gears and adjust the ratios to improve the performance of your car. This upgrade is a tradeoff between the benefits of having full control over the gearing and the performance gained from other upgrades which you could spend PI on instead.

There are 6, 7, 8, 9 and 10-gear options for Race Transmission upgrades. The best decision relies on two things:

  • First, each additional gear increases your car’s weight, which in turn decreases your PI. Using a heavier gearbox can sometimes enable you to upgrade other parts of your car if the PI allows for it. In this regard, it may require some trial and error to see which parts you can combine with your gearbox to see what allows for the best power/weight. Keep in mind that even if you choose the 10 speed transmission, you can essentially delete the gears you don’t want by matching the ratios of each unwanted gear to the gear above in the tuning menu.

  • The second part of this decision relies on your car’s powerband. Some cars will perform better if they are able to stay in their engine’s optimal RPM (Revolutions Per Minute) range. For example, for offroad cars using turbo rally engines that like to be at low RPMs, or high performance cars using racing V12 engines that like to be at high RPMs, having more gears can allow you to stay in that optimal RPM window as you drive. This then becomes a tradeoff between time spent shifting (more gears = more time shifting) and the benefit from using your engine’s powerband optimally.

Clutch


If you drive Manual with Clutch, this upgrade will have no effect on your shift times. The only purpose of this upgrade is weight reduction. Out of all of the weight reduction upgrades, Clutch is very PI inefficient, so it is wise to look at other upgrades first such as Driveline.

If you are not using Manual with Clutch, but your car has a drivetrain conversion (e.g. RWD swapped to AWD), then the above applies and you will not reduce your shift time by upgrading. The only effect is weight reduction.

If you are not using Manual with Clutch, and your car is on its stock drivetrain, Clutch upgrades will make your shift times faster. Some high performance S2 cars are the exception to this, and will have the same shift speed regardless of your shifting assists. Still, this upgrade is very inefficient for PI cost, so it’s recommended to prioritize other upgrades first.

Driveline


This is a very popular weight reduction upgrade. Experiment by using different combinations of the driveline upgrade combined with other weight changing upgrades such as rims or rim size, number of gears in your transmission, flywheel, and more.

Differential


This should always be upgraded, since it does not cost any PI. Pick whichever differential matches the discipline that your car is built for (e.g. Race Differential for Road cars, etc.).

Thank you for taking the time to read our guide and we hope it provided you with helpful information! If you have any feedback or questions, or if you would like to contribute to our guides yourself, feel free to reach out to us on Discord!
(Last Updated: May 11th, 2022)
Conversion Tuning Guide