Tune It Yourself

DLTuning presents...

This is compatible with Forza Motorsport and Forza Horizon,
whether using a controller or wheel setup!

Before using:



Adjustable (race) upgrades will be required for Springs & Dampers, Anti-Roll Bars (front and rear), and Aero.
It is assumed these are installed.

Tune It Yourself has been written in such a way that the user must
be prepared to dedicate a good amount of time to the tuning process.
The more time you are prepared to dedicate, the more success you will have!

Those who can quickly identify handling problems will get quicker results. If you are uncertain about tuning principles, it is highly recommended that you read our Tuning Guide, and get a good understaning of WHY we tune WHAT we tune!

Detailed instructions explaining how to maximise your results are written BELOW the calculator.

If you have not used this before, READ THEM FIRST!!!

                    Getting Started!       

Enter Required Vehicle Information.  

The only figures you need to source from the game are 'Vehicle Weight' and '% Front'.  Simply enter these figures into the relevant boxes.

Depending on the weight distribution of your car, you will be asked to enter either 'Front' or 'Rear' Anti-Roll Bar stiffness.  The stiffness you choose here is simply a starting point, and if unsure, simply enter the relevant default value shown on the Anti-Roll Bars tuning page within the game.  Generally, the more grip available, the stiffer you can set your ARBS.  Should you be tuning for a wet track, set the ARB strength particularly low.  i.e. 10 or less.  If race anti-roll bars are not installed, you may leave this field blank or enter '0'.  If at any point you wish to change the overall  ARB stiffness, simply adjust the number you enter in the box.

Front Aero strength is also to be chosen by you.  Assess the track you are tuning for, and decide on a starting value.  Start somewhere in the middle if you're unsure.  If Aero parts are not installed, leave this field blank or enter '0'.  When tuning cars above R Class, downforce begins to get serious, and extreme downforce levels often mask suspension problems while at high speeds.  If you choose to set your front and rear aero to maximun when tuning for higher classes (this is quite common), leave this field blank or enter '0'.

The Power to Weight ratio box, is simply here as a guide to help when building the car.  It will in no way help with the tune, nor contribute to the results.  It can be useful however to decide whether to remove weight, or add power from the upgrade options.  Simply enter the vehicle's horsepower in the 'Power' box, and the power-to-weight ratio is calculated.
​Once you have entered the required vehicle information, the results are displayed in the central boxes.  

Simply copy these over to your setup in the game!

​Please note:

Tyre Pressures' are not calculated!

Tyre pressures should be between 32-33 PSI or 2.20-2.27 Bar at race temperatue.  Use the in-game telemetry to ensure tyre temperatures fall inside the optimum pressures.  This will take a few minutes of driving!

Front and Rear Camber angles default to -0.8 degrees, and -0.5 degree respectively.  These defaults are a sensible starting ground, but should be correctly tuned for optimum results.  If you are not familiar with tuning camber, aim to have even heat distribution across the width of the outside tyre as you exit corners, leaning towards a slightly hotter outside edge if a perfect match is unobtainable.

Front and rear toe settings both default to 0.  This is intentional, as toe in any amount or direction causes tyres to scrub, which will reduce top speed.  For this reason I recommend saving any toe adjustments until last.  Don't avoid it completly though, as toe can be a valuable tuning area when other options are exhausted! 

Differentials are also not calculated.

Ideal figures may vary across large ranges when comparing low-powered cars to high-powered cars!

For help fully understand any of these areas, please click             to read our Tuning Guide.



Tune from the 'Test Drive' area of the game.
This will allow you to make changes your setup from the pause menu, without exiting back to the main page!

Every time you make changes, you must update the new figures into your tune and test the results!

Begin To Tune It Yourself


The lower the ride-height, the lower the centre of gravity.  Along with tyre compound, the low ride-height is what helps provide as much grip as possible.  Set the ride-height as low as you can, while allowing enough spring travel for your chosen track.  The lowest ride-height available is normally the best option, although on some bumpy tracks you should increase this by around 2-4 'clicks' above minimum to allow for extra spring travel.


Soft springs will help maximise tyre compliance by soaking up the bumps far easier than stiff ones. On a particularly bumpy circuit, if the springs bottom-out, the car will lose grip suddenly, and will give you a misguided interpretaion of your handling problems! 

Open the telemetry screen while in Test Drive, and navigate to the 'Suspension' screen.

Begin to drive around your chosen track and keep an eye on the spring travel.  Should the springs hit their maximum travel at ANY point, increase spring stiffness by using the 'Overall Spring Stiffness' slider, located on the right of the 'Main Calcualtions' page.  If the springs are already quite stiff and the track is fairly bumpy, increase the ride-height a couple more clicks.

Should the spring travel not get close to the maximum available travel, lower your ride-height.  If it is already at the lowest available option, begin to lower the 'Overall Spring Stiffness' slider to allow more spring travel.

Adjusting the 'Overall Spring Stiffness' slider WILL NOT EFFECT THE CAR'S BALANCE!  This is accounted for in the calculations.

Your target is to get the springs traveling around 90-95% of their maximum potential.

* Should the front springs bottom-out before the rear springs, or vice-versa, use the 'Front Bias' or 'Rear Bias' sliders to correct just one
   end of the car.  It is however highlyrecommended to use the 'Overall Spring Stiffness' slider as a preference.  This is because adjusting
   front or rear spring rates independently WILL upset the balance of the car, and is not advised during this part of the tuning process.


Damping Stiffness

If your car is bouncing excessively and just won't settle after bumps (take an Alfa 33 Stradale out without tuning dampers and you'll see what I mean!), increase the 'Overall Damper Stiffness' slider to help better match the springs. This is a great tool and will stabalise the car with no tuning effort!  If the car skips over bumps too much, lower the stiffness - allowing the springs more time to react to bumps etc.

Adjusting the 'Overall Damper Stiffness' slider WILL NOT EFFECT THE CAR'S BALANCE! This is accounted for in the calculations.

Make adjustments to the damper stiffness' until you feel the car is firm, without skipping over bumps!

Damping Ratio

This adjusts the ratio of Rebound vs Bump.  The ratio suggested by Forza, says bump should be between 50-75% of the rebound.  The default here is a very safe 63%, and can be left alone, although less bump stiffness compared to rebound is sometimes a desireable characteristic.  Lighter cars tend to handle better with a lower ratio, while heavier cars tend to prefer a higher ratio.  Experiment with this option to get a feel for what suites your car.

Adjusting Damping Ratio WILL NOT EFFECT THE CAR'S BALANCE!  This is accounted for in the calculations.


Only now the Springs and Dampers have been set to a sensible starting point, begin to assess the overall balance of the car.

Adjust the 'Overall Balance Slider' to deliberately induce any desired oversteer or understeer bias.

Adjusting the 'Overall Balance' slider results in NOTICEABLE EFFECTS TO THE CAR'S BALANCE and will update figures to Springs, Dampers, and Anti-Roll Bars!  Make adjustments in small amounts, and re-test until the car's OVERALL balance feels to your personal requirements.  At this stage, remember you are looking for an OVERALL feel!  There's more tuning to come, so don't go looking for perfection just yet!  

If you find it difficult identifying oversteer from understeer, telemetry is very useful.  Go to the 'Traction' page and while cornering check to see if the front tyres go red before the rear (understeer), or the rear tyres go red before the front (oversteer).  

A balanced car will have both front and rear tyres turing red at roughly the same time.  This is what you're aiming for!

Anti-Roll Bars Only

Adjustments here carry the same principle as the 'Overall Balance' slider control, but changes are ONLY made to the ARBS. This is
particularly useful when you are happy with the existing spring and damper settings, and do not wish to change them.


Maybe..?  But for that special 'Tune It Yourself' touch... Keep going!
Tailor Your Tune
The Understeer and Oversteer Fine-Tuning pages contain the ultimate 'Tune it Yourself' tools! 

Follow the troubleshooting flowcharts for either understeer or oversteer problems you wish to correct.  

The suggestions are listed in order of the most effective first, so try this one before moving onto the next. Some suggestions however may not be suitable for what you want.  For example. If your springs are already as soft as you want to allow, don't lower them any further as they may bottom-out!  Simply try the next suggestion.


"I feel the car is suffering from understeer, but only in middle of the corner.  I don't feel there is any excessive roll in the car."  

Click on the 'Understeer Fine Tuning' bar at the bottom of the page to view the Understeer Troubleshooting Flowchart.  The first approach for Mid-Corner Understeer without excessive roll is to soften the front Anti-Roll Bar.

Move the 'Soften Front ARB' slider left a click.   The front ARB stiffness results are updated live to more suit your handling requirements.  To view the ammended results, simply return to the Main Calculations page.

Enter the new figure(s) and re-test.

"During corner exit, I'm suffering with lots of oversteer, although in the middle of the corner it seems ok."

Assuming you're not just getting on the gas too hard, too soon, click on the 'Oversteer Fine Tuning' bar at the bottom of the page to view the Oversteer Troubleshooting flowchart.  The first suggestion is to increase rear toe-in.  Move the 'Increase Rear Toe In' slider to the right a click.  The rear toe settings are updated live, and as in the previous example, return to the Main Calculations page to view the results.

Enter the new figure(s) and re-test.

Contine to use the Fine Tuning flowcharts, adjusting what is suggested as you go.


* Re-test after each adjustment!

* Do not change more than one area in between testing.  This will lead to a misunderstanding of which adjustment fixed the problem!

* The more you use 'Tune It Yourself', the more you will learn which components control certain changes in vehicle handling!

* Be prepared to dedicate some time to the tuning process.  Your results will be far more rewarding!

And that's that!

Just the way you wanted!

Special thanks...

The initial thought of writing a Tuning Guide for the players of Forza Motorsport and other racing simulators started nearly 18 months ago.  Being a huge Forza fan, and  keen to improve my own tuning knowledge, I set to work.  Days, weeks and months of research later, my notebook started to take shape into the Tuning Guide I am now very proud of!

I couldn't possibly label every single web page or book I have read since beginning this project, but in particualr I would like to thank the following people;

Eveyone in the Forza Motorsport Forums for their combined wealth of knowledge - What a community!  
John Schommer (Johniwanna) for his contnuing support towards FACR, along with Thorsten Schuch for putting me in contact with John in the first place!
Thanks to Anthony Curtis, Founder and Lead Instructor at Gallium Racing School.  Creating our tuning videos to accompany the guide was great fun and has been highly welcomed by all who have seen them!
Thanks to Mike at Guns, Cars & Digits for his tutorial videos on how to use formulae to help tune our cars.
And huge credit to Caroll Smith, Author of 'Tune To Win'.  This book is rammed with information on tuning cars and had a huge impact on my knowledge.

I would also like to thank every single member of FACR!  You guys are fantastic!  A true Forza family, with the friendliest attitude towards each other, both on and off the track.  
Thanks also to FACR's Admin for helping me test the calculator through it's final stages, and for the incredible amount of work you put in to help this community.

And many thanks to Stepahnie Shea for taking on the task of re-coding the calculator so it can be used here, for you all to use! ...And for putting up with several last-minute adjustments!  You have been an absolute star Stefanie, and I am truly grateful for your efforts!

And finally, the biggest thank you of all to my wife!  There's always something going on in the world of Forza for me.  It may be something on one of FACR's Facebook pages, or I may be desperate to set a lap in our hot lap challenge for the week.  I could be working on the calculator, or finishing off a voiceover for an unfinished tuning video. Either way, she's let me crack on with it, and for that I am seriously thankful!  Thanks Mrs Lacey!  You are my world!

I hope this calculator can turn the months of research and testing, into something both quick(ish), and reliable for eveyone to use. 

Thank you, and enjoy!

Dave Lacey |  DLTuning
29th April 2017