New Forza 3 Tuning Calculator

forza-3-tuning-calculator Feuerdog has done it again, his latest tuning calculator has been released for Forza 3.

Before continuing, please note that a tuning calc is not the end-all solution. It is generally a good starting point for a given build. That said, on to the goods:

The calc is here at Google Spreadsheets, which should open in your browser. Look at the top left and select File and Download As. I recommend you download the Open Office format.

Open Office is an open source (free) alternative to Microsoft Office. I use it every day. The full suite can be downloaded from

Open the file locally and save it to work with it. Here are Feuerdog's instructions:

1. In the yellow fields you will select a drivetype(FF,FR, FA, MR, MA, RR, RA), and enter the vehicles weight(lbs) and front weight distribution. This info is availiable in the upgrade and car selection areas.
FF = Front engine, Front wheel drive.
MR = Mid engine, Rear wheel drive.
RA = Rear engine, All wheel drive.

2. In the blue fields you will get all of your suspension geometry settings instantly.

3. The orange fields are optional, but will add small compensations into the values to compensate for aerodynamic downforce and differing tire widths. Tire widths are the first three digit number in the tire size located in the tire width upgrade screen. If you do not want to compensate for aero or tires then leave these cells blank.

- The calcs are not tested or designed for dragging or drifting.
- Front tires that are wider than rear tires may result in calc errors.
- The aero and tire compensation calcs are estimates, and untested for use with FM3.
- You can trick the calcs for understeer/oversteer by changing the front weight distribution input.
- Due to limitations in this older set of calcs, some cars will still feel "understeery".
- I guarantee nothing.
- Always, always, double check your figures and settings. Even a single 1% of difference can have an impact on handling.
- Also keep in mind that some parts that you change in FM3(cooling upgrades for example) and weight reductions will change your weight distribution around. So even something as simple as an engine upgrade can change the weight bias of the chassis.
-Always recalc your suspension after upgrading parts!
- The aero and tire compensation calcs are OPTIONAL. They are very simple modifiers to begin with.
The aero compensations simply add spring stiffness to each axle.
The tire width compensation simply changes the weight bias to compensate for grip.

- The suspension calculators have always had mixed results with the R-classes in previous FMs. I don't know if FM3 will be the same yet or not. I hope not. With the new blended classification and stiffness modifications the only real hurdle may be aerodynamics.
- The current state of the calcs is actually a little stiffer than I wanted to make them. There are several reasons for this:
1. A limitation in the calcs relating to dampers.
2. Stiffer springs help counter high aerodynamic downforce.
3. The spring strengths are realistically higher in FM3 anyways.
4. Stiffer springs helps limit roll, and therefore keeps camber settings low.

Another version of this calculator that includes metric units of measurement is available from Slave Munky here.

Slave Munky Calc FEATURES
- supports both imperial and metric units
- print area enabled so you can print out your setup and make notes
- FM3 suspension dynamics by feuerdog
- tire pressure settings based on curb weight/load on tire
- an all new optional automatic transmission sheet
- intergrated transmission calc with calculated final drive ratio and individual gear ratios.
- full car list with performance figures and prices
- full rim list with weight loss %
- stiff suspension values for the ADVANCED tab for a stiffer suspension and mostly likely faster lap times
- Aerodynamics sheet still under construction


To tune any car make sure you are in it and go to: cars x (car list) the LB until you reach the data needed (ex: power rpm, curb weight, redline rpm, etc.)
4.input into sheet
5.if aero parts are installed, write the default vaules into advanced>aero>default downforce.
6.if using the stiff suspension values, make sure you recheck these numbers for any change you make in weight and downforce.

Also check the Forza 3 section here at 360 Maniac for more info on tuning. Good luck and get racin'.

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Comments (29)


  1. easy way out says:

    so your urls are trash and dont even work. the one i got from peoples comments wont fully work either. you can only put 1/4 of the cars info in. WTF! a little help here???

  2. david says:

    anyone know of stock car gear ratios to get good top end speed, my car hits 210, not good enough, please help!

  3. vicar of death says:

    i can tune cars for toy abd help u in any way u need

    my gt is vicar of death

  4. Jr is a fraud says:

    Didn’t want to jump through all of the google hoops to download this. Be carefull where you sign up, they will bombard you with spam, then take over your PC. As much as I’d like to have it, it’s just not worth the risk. It’s nice to see it in open office format, at least the microsoft hoops wont be an issue.

  5. add italiaroxstar says:

    yo i can tune up cars for you for free and give cars FREE i can buy parts for free so you need a hook up i could help you out just be sure i am online

  6. weston marlatt says:

    i cant get the tuning caculator can u help me

  7. Anonymous says:

    this is a cheap way to tune a car i do everything my self it is all about rial and error for the guys that use this i only have one thing to say u r not true racers

  8. Doc says:

    So where is this amazing calculator then?

  9. FORZA BEAST says:

    Hey anyone got Forza 3 for the xbox 360 my gamertag is

    demonslayer204 add my gamer tag I have Camo Paint jobs and I can tune your cars to top speed….

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