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Hi guys what's up? I thought I give you some insights that I learned from tuning in FM5 & 6.

I'm a long time Forza player started with Forza 1 all the way up to FM6. I used to race with other people tunes and only started in FM5 with tuning myself knowing that this would be a long and cumbersome journey :-)

I usually drive and tune only cars I would personally buy and drive and I generally don't use so-called leaderboard cars. Instead I tend to choose cars that nobody else drives and try to push them to the limit. I usually do multiplayer lobby racing so for all of my cars I'm aiming to create a general purpose build & tune that works on most of the tracks. My main class is B right now with some minor C/A/S/R racing.

Notes before reading:
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I often refer to car chassis and suspension stiffness as influencing factors for tune settings. These refer to "built-in" properties of a car that can't be changed and are part of the car model in Forza. In general older cars tend to have more flexible chassis and suspension while modern cars and especially race cars have stiffer chassis and suspension.

There are also in-between car types possible, e.g. think of a historic race car which may have a stiffer chassis than a modern production car but maybe a less stiffer suspension.

Another note:
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This guide is not intended to describe how the different tuning parts like ARBs, springs etc. affect car handling or how to dial out over- or understeer. This has been already described numerous times especially in these excellent tuning guides:

• Worms Tuning Guide
• DL Tuning Guide

I urge everyone to read through these guides to get an understanding what the different tuning parts of a car do and how they affect car handling before continuing with this guide.

This guide focuses on HOW to setup the different tuning parts and provide suggested RANGES for tuning parameters.

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Tires

I have a simple rule for setting up tire pressures and have yet to find a better method:
- Stock / Street: 28
- Sport: 28.5
- Race: 29

Reasoning for different tire pressures is that besides grip tires also provide a basic level of rigidity and therefore control. Softer tire compounds like Sport or Race compound provide more grip but also have less rigidty than Stock or Street compound. Increased tire pressure compensates for lower level of rigidity of softer compounds.

There is no need (as sometimes in FM5) to have different tire pressures for front and rear wheels. From my experience this will always create a slight imbalance (over- or understeer). Fine tuning over- and understeer should be done with –>ARBs, –>Springs and –>Dampers.

Keep in my mind that the series tire compound may not be Stock compound for all cars. For most race cars the series tire compound is Race compound (only Drag compound is available as upgrade), likewise for some sports cars the series tire compound is Sport compound (only Race and Drag compound available as upgrade). Set the tire pressures accordingly.

Note: This method will provide peak tire performance starting 3rd lap for average sized race tracks, the first two laps are needed to warm-up the tires.


Camber

Camber settings are car type specific. As a general rule of thumb: older cars require less static camber because the more flexible chassis / suspension creates more dynamic camber. Modern cars with more rigid chassis / suspension can be run with higher camber. However due to very high forces during cornering for gp race and prototype race cars its the other way around: older gp and prototype race cars require higher camber than modern gp and prototype race cars.

Static Camber should be set so that the (dynamic) Camber on the apex when you start accelerating out of a turn is around 0 to maximize tire contact patch which in turn provides maximum tire grip. This is especially important for the driven wheels.

Front camber is usually higher than rear.

Also generally AWD and FWD cars require more camber than RWD cars to combat inherent understeer.

Usual ranges:
- older cars: -1.5 to -0.5
- modern cars: -2.5 to -1.5
- older gp race cars: -3.0 to -1.0
- modern gp and prototype race cars: -1.5 to -0.5

Keep in my mind that tire width directly influence camber settings:
- Increase tire width: reduce camber; decrease tire width: increase camber --> this is due to wider tires increase contact patch, so for optimal grip camber needs to be reduced as well.


Toe

I usually don't touch toe as this from my experience creates almost always unwanted imbalance during turning.

The only exception is that I use rear toe-in (max. -0.3) for production cars with high –>Caster (>=6.0) as I find this improves accelerating out of turns, i.e. reduces on-throttle understeer.


Caster

Caster is also a car type specific setting. As a general rule of thumb older cars require higher caster than modern cars and race cars requiring lower caster than production cars. However due to high forces during cornering GP race cars and prototype races cars generally need high caster that provides extra stability during cornering.

Each car has a "natural" caster that suits the cars suspension geometry best. You wont unlock the full potential of a car when the caster is not set to the cars natural caster.

Usual ranges:
- very old production cars 7.0
- older production cars & muscle cars: 6.0
- modern production cars & older race cars: 5.0
- modern race cars: 4.0
- prototype race cars: 5.0-6.0
- older gp cars: 7.0
- modern gp cars: 6.0

Higher caster creates turn-in resistance (off-throttle understeer) while lower caster reduces turn-in resistance (off-throttle oversteer).

Older cars benefit from more turn-in resistance (i.e. high caster) whereas race cars are held back with too much turn-in resistance.


ARBs

ARB setttings have a direct relation to chassis stiffness and vehicle weight, i.e. the more rigid the chassis is the lower the ARBs can be set. Likewise the less the car weights the lower the ARBs can be set.

20 is good middle ground for modern production cars around 3000lbs. Increase ARBs for cars with more weight and / or less rigid chassis (e.g. older cars). Decrease ARBs for cars with less weight and / or more rigid chassis (e.g. race cars). However due to high forces during cornering gp race cars and prototype race cars require higher ARBs in relation to weight than other cars to provide extra stability during cornering.

Front and rear ARB distribution has a relation to weight distribution, so in general a car with more front weight should have also higher front ARBs than rear. This is however not as simple as 1:1 distribution according to weight distribution because springs and dampers also affect car balance during turning.

A good starting point for ARB distribution for RWD cars is 1 per 1% weight distribution, i.e. for 51% front weight distribution the front ARB should be 1 higher than rear ARB. Older cars and muscle cars require higher spread (>1 per 1%) while race cars require lower spread.

==> Example: ARBs for a modern production car with 3000lbs @ 51% wd would be: Front: 20 + 1/2 = 20.5 and Rear: 20 - 1/2 = 19.5.

The same applies to AWD and FWD cars but they generally require a lower spread than RWD cars to combat inherent understeer.

Keep in my mind that adding chassis reinforcement upgrade increases chassis rigidity, i.e. ARBs should be reduced accordingly.


Springs

Spring rates have a direct relation to car weight, weight distribution and chassis / suspension stiffness. More weight requires stiffer springs and more flexible chassis / suspension require higher spring rates on the non driven wheels (front for RWD) and lower spring rates on driven wheels (rear for RWD).

Distribution of front and rear spring rates is influenced by weight distribution, so cars with more front weight will require also higher front spring rates. As with ARBs this is not a simple 1:1 distribution according to weight distribution as for instance the drive wheels are usually run with lower springs rates in relation to non driven wheels to reduce wheel spin.

As others suggested a good range is between 1/3 and 1/2 of the slider though there are exceptions where you need to run above or below that range.

These are the ranges for spring rates I usually operate (given in percentage of distributed front / rear weight):

RWD/AWD:
Front Springs: 95%-90%-80%-50% (old car --> modern car --> race car --> gp car)
Rear Springs: 50%-80%-85%-95% (old car --> modern car --> race car --> gp car)

FWD:
Front Springs: 50%-80%-90% (old car --> modern car --> race car)
Rear Springs: 95%-90%-80% (old car --> modern car --> race car)

==> Example: front spring rate for a modern RWD car with 3000lbs @ 52% wd would be 3000 / 2 * 52% * 90% = 702lbs

As with ARBs keep in my mind that adding chassis reinforcement upgrade increases chassis rigidity, i.e. spring rates should be reduced accordingly.

Also when adding –>Aero spring rates need to be increased to compensate for added downforce, this is usually in the range of 0-5 lbs depending on amount of added downforce.

Similarly when increasing tire width spring rates need to be increased as well to compensate for added grip. This is usually in the range of 0-5 lbs depending on increased tire width.


Ride Height

Ride height works as an additional stabilizing factor like aero and a higher ride height generally allows you to brake and turn faster. However raising ride height also raises the center of mass which hurts turning. So there is a sweet spot for each car which I call optimal ride height.

In general for older cars the optimal ride height is higher than for modern cars and for race cars the optimal ride height is lower than for street cars.

Always keep front and rear ride height level , i.e. keep the sliders aligned. Having front and rear ride height sliders unaligned almost always creates slight imbalance during turning from my experience.

Ranges (front ride height):
Older cars: 3.5-6 inch (gp car --> street car)
Modern cars: 2.5-4 inch (gp car --> street car)

Two exceptions of this rule::
- set ride height to lowest if the front ride height can be set below 2 inches, this seems to be the faster option provided you have enough aero
- use higher ride height if you have extreme power builds that require extra stability


Dampers

Damping stiffness has a direct relation to chassis stiffness, i.e. a more rigid chassis requires higher overall damping stiffness. Damping stiffness is the sum of bump and rebound.

Bump has a direct relation to front car weight and suspension stiffness, i.e. the higher the cars front weight is the higher the bump is required to avoid diving on turn-in. Also cars with stiffer suspension require less bump whereas older cars with softer suspension require stiffer bump.

Rebound has a direct relation to bump and chassis stiffness, the higher the bump the lower the rebound is required and vice versa. Also the more rigid the chassis is the higher the rebound can be set.

Rebound should always be higher than Bump.

Also generally AWD and FWD cars require lower bump and higher rebound than RWD cars to combat inherent understeer.

Usual ranges (RWD):
- Production cars: Rebound: 7-8 / Bump: 4-5
- Race cars: Rebound: 8.5-9 / Bump: 4-4.5
- Prototype race cars: Rebound: 9-11 / Bump: 5-7
- GP race cars: Rebound: 9-13 / Bump: 5-9

Usual ranges (AWD/FWD):
- Production cars: Rebound: 6.5-7.5 / Bump: 3.5-4.5
- Race cars: Rebound: 8-8.5 / Bump: 3.5-4
- Prototype race cars: Rebound: 9-11 / Bump: 5-7

The relation between front and rear dampers should mirror the relation of front and rear spring percentage rates, i.e. if the front spring percentage rate is lower than the rear spring percentage rate the front dampers should also be lower than the rear dampers and vice versa.
--> Example: if front spring rate is 50% and rear spring rate is 80% the front rebound/bump should also be lower than rear rebound/bump.

The higher the difference between front and rear spring percentage rate is the higher should also the difference between front and rear dampers.

Aero

Optimal Aero distribution is directly dependent on car weight distribution. The more front weight a car has the more rear aero is required in relation to front aero.

For standard Forza race aero kit equal aero distribution seems to be optimal for front weight distribution around 47%, i.e. the sliders for front and rear aero should be aligned for cars with 47% front weight distribution. For cars with front weight distribution <47% rear aero slider should be lower than front aero and for cars with front weight distribution >47% the rear aero slider should be higher than the front aero.

Optimal Aero distribution is more relevant on lower classes (E-B) where you don't always run full aero. In higher classes where you often run max aero anyway the effects are negligible.


Brakes

Brake settings from my experience are user preference and not car specific. I always run 48% brake distribution with 125% brake pressure which favors trail braking. Others that don't trail brake prefer more front distribution (i.e. brake distribution>48%).


Diff

Diff is for fine tuning corner entry and exit behaviour. It has a relation to chassis stiffness, i.e. cars with more flexible chassis require higher decel and lower accel, cars with more rigid chassis can be run with less decel and higher accel.

Usual ranges:

RWD: 68/35 is good middle ground for modern production cars, increase accel and/or decrease decel for cars with more rigid chassis/suspension (i.e. super cars, GT race cars etc.), decrease accel and/or increase decel for cars with more flexible chasssis/suspension

AWD: 68/0/100/70/35 is good middle ground for modern production cars, increase accel and/or decrease decel for cars with more rigid chassis/suspension, decrease accel a,d/or increase decel for cars with more flexible chassis/suspension

FWD: 48/0 is good middle ground for modern production cars, increase accel for cars with more rigid chassis/suspension, decrease accel for cars with more flexible chassis/suspension

Usual ranges (gp and prototype race cars):

RWD: 98/0 is good middle ground for modern gp and prototype race cars, decrease accel for older gp and protoype race cars

AWD: 100/0/100/0/100 is good middle ground for modern prototype race cars, decrease accel for older protoype race cars

FWD: 100/0 is good middle ground for modern prototype race cars, decrease accel for older protoype race cars

Note: for some reasons increasing and decreasing accel only works good in 2-step increments (i.e. accel should always be an even number) while for decel 1-step increments are just fine.

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So these are basically the things I learned from tuning in Forza over the last 2 years. Hopefully some of the tips may help!

Fifty

Edited by user Tuesday, September 19, 2017 11:52:10 PM(UTC)  | Reason: Ride height detailed

This is more helpful than the tuning guides.... Thank you for this, this is incredible
I may re-tune my 787b as i did it way different;y just to see how the two compare

Edited by user Thursday, July 21, 2016 5:53:14 AM(UTC)  | Reason: Not specified

Great! Let me know how you get along!

Added spring rate ranges and refined description for front and rear spring rates.

Edited by user Thursday, July 21, 2016 6:49:02 AM(UTC)  | Reason: Not specified

Great write up fifty. There are just 2 points that I disagree with in your guide.

#1. I don't recommend always slamming the cars. Certain tracks like nurburgring, and bernese cars will actually bottom out and cause more harm then good. I have a general rule that I run by and 4.5 in is the lowest I will go except in race cars if I can help it.

#2. The RWD diff 35/70 should promote access understeer and I would suggest starting at 50/30. The way the rest of your write up it it should have a good tune on it if they follow your guide and I think this diff would be a better starting point for Front engine RWD.

These are very small differences that I saw but other then that I have to give you an A+ on the write up and this should help everybody that reads it from the new tuners to even the experienced tuners.

Great Job again.

Hey Johnson,

Thanks for the kind words!

As for your comments I still stand by my suggestions.

The improvement in handling when having the ride height at minimum almost always weights out partial bottoming out. I've yet to see a car that runs better with more ride height. Maybe that has to do with that I run generally higher bump than most.

As for the diff I've tried many things and all of my setups now run decel between 34-36 and accel between 66-72 Trust me all without understeer issues.

Edited by user Thursday, July 21, 2016 10:58:07 AM(UTC)  | Reason: Not specified

I must have been reading your accel/decel wrong. I thought you were saying 35% accel and 70% decel. but with your new explanation I can see I read it backwards and now I agree with your settings.

The main part I see with bottoming out (lets say bernese) would be at the bottom of the hill. It can make your car feel like its pushing really bad but in all actuality its has bottomed out and just simply lost grip. That would be the main course I would stay up on ride height to get maximum grip around the whole track. For 95% of all tracks though I would agree lower is better I just thought you might want to add in there something about bottoming out for those that cant diagnose when it is happening to them.

Edited by user Thursday, July 21, 2016 11:24:12 AM(UTC)  | Reason: Not specified

I know exactly what you mean, this is really a tricky corner but if you encounter this in my opinion your front bump is too low and the car starts to dive and push.

I will have to give that a shot next time I build a car there and see how just raising the front bump will affect that corner. Thank you

Surely a very good guide.

Only i disagree with the breake setting. I allways prefer to reach out the best setting (shortest breaking distance) while using the calculator in the left side of the screen at tuning.

As example i will take non upgraded cars except the race brakes so we can only setup the breaks. Just to keep it simple, because like "fifty inch" allmost in every section said, its everything in "direct relation".

Let's take a 2005 BMW M3. Classic front engine rear driven.

Setting:

50% / 100% - breaking distance: 60 to 0mph at 133,0ft - 100 to 0mph at 319,2ft
48% / 125% - breaking distance: 60 to 0mph at 130,0ft - 100 to 0mph at 321,9ft
39% / 100% - breaking distance: 60 to 0mph at 102,4ft - 100 to 0mph at 269,6ft

A four wheel driven like a 1992 Alfa Romeo 155 Q4

50% / 100% - breaking distance: 60 to 0mph at 124,4ft - 100 to 0mph at 318,1ft
48% / 125% - breaking distance: 60 to 0mph at 132,1ft - 100 to 0mph at 327,8ft
40% / 102% - breaking distance: 60 to 0mph at 103,6ft - 100 to 0mph at 282,3ft

well i don't know how much 50 feet's are ^^ but i know that 15 Meters are lot...

All I can say here is: don't trust that numbers and in general don't tune according to those numbers.

The only valid benchmark is how the car feels on track and ultimately lap time.

Try those settings on track and I would be surprised if 40% brake balance gets you the fastest lap time.

But anyway as I said brake settings are user preference.

Edited by user Friday, August 19, 2016 12:24:56 AM(UTC)  | Reason: Not specified

Aero section added

Added suggested starting point for ARB distribution

Edited by user Friday, July 22, 2016 1:51:50 AM(UTC)  | Reason: Not specified

Great, great write up, Fifty. There is a lot here to digest and learn from. Thanks for taking the time to do this!

Regards,
Snowman

Added description how to set camber

Hey Fifthy whats up dude good job on the guide, I see alot of similarities with my own guide. Its always good to see someone else's views, ideas and opinions etc. This will certainly help alot people out qith general setups 👍

Reworked damping distribution

Thanks a lot for this. Have been thinking about tuning myself, and this will be a great help!

Bump for last changes

Stock/street tires should only go down two points MAX for the best grip. And why is race tire pressure higher than stock, that does not make any sense at all.

Camber needs to be adjusted per track as each track is different so there is no base tune for that section because of unpredictable handle and the same goes with toe.

I don't think you know what roll bars actually do, as only part of that statement is correct and sketchy at that. Roll bars helps the cars get around the corners better depending on track without uneven weight distribution.

Springs again vary by track and those base settings would not work on tracks that have elevation change with a bumpy surface, you would not be able to control the car even in the straights and no turn in. And ride height is completely false, again with the previous sentence. That ride height will not work on most of the tracks in this game as you will bottom out and not be able to rotate the tires and turn the car in.

Those damping numbers need to be reworked big time. You can't have the same number for both, doesn't matter if it's front or rear as you will most likely have major hop in the car, go over one elevated rumble strip and you're in the grass. Bump and rebound need to be different.

Aero depends on what the game gives for the car, some have low numbers and some have high. Aero has little to do with weight distribution and more about increasing or decreasing drag. You need enough aero to not slow you down but also get the car around the corners easily.

Brakes is the only part I will agree with as it is user specific.

Diff is not just for turning exit, diff are when the wheels are under power and braking and depending how the car is built this will affect wheel spin under power and lockup under braking. It's better to start low to get a feel for the car so you don't spin and lockup. My suggestion would be 30% for both depending on how much power you have.

Hey Chef,

Thanks for your comments but I still stand by my general suggestions given in the guide.

The guide is meant for setting up a general RWD / AWD tune, There might be track specific settings that gives you faster lap time though I have yet to see a specific tune that is faster and in general I don't believe in track specific tunes, only track specific builds.

I won't argue with you about right or wrong in all the specific examples you mentioned as you obviously have a different tuning style, so each to their own.

But just for the sake of fun let's make a little challenge here: you give me a build / tune of your choice and I will try to come up with my own tune that complies to this guide and we let lap time decide, even on different tracks of your choice - how about that :-)

Edited by user Thursday, July 28, 2016 7:30:38 AM(UTC)  | Reason: Not specified

-3.5/-3.0 for older cars for camber. Ignore the telemetry. An exception is for very heavy cars. Caster also doesn't seem to matter much when you're running these high figures.

Newer cars do seem to need less.

Hi Sweve,

Do you have a specific example at hand for runningt hat high camber? I'm curious how it would stack up against my tuning style.

Mazda Cosmo, Ford Bronco, Holden Monaro, fiat 124, Mercedes 280sl, chevy nova, Dodge Dart, Dodge Charger, 69 trans am, olds 442, 73 Trans am, Alfa Milano, Porsche 550, etc. Pretty much every car. I start low and always end up high because the car turns in better. It's not bad with lower settings but the car definitely feels stiffer.

A class 99 Viper at Yas full night. We'll both run a version of the tunes. You put the build up of your base tune and once we run both I'll supply my version of the tune to put up. Not running for the leaderboard either.

Aspiration Swap:
Centrifugal Supercharger

Engine:
Sport Centrifugal SC
Street Intercooler

Suspension:
Race brakes, springs, roll bars
Sport Weight

Drivetrain:
Race trans
Street driveline
Race diff

Tires:
Sport Compound

Aero
Front and rear aero

That gives you all the options to use your base tune.