Forza Motorsport 4 Tuning Guide and Car Upgrades


Turn 10 Studios have introduced quite a few changes in Forza Motorsport 4 physics especially how tires react to real world situations, how track bumpiness affects the driving, steering has been overhauled, and how suspension works in the game.

The goal of tuning your car is to make the right trade offs for right scenarios and this guide will help you do just that. It is really important that you only upgrade the right components of your car and you may end having to adjust all these components again just to make it drive-able.

Our goal is to walk you through each tuning option, give you the pros and cons, and give you insight how that specific part will hold under different conditions.

For this reason, we have taken the suggestions of the pro’s and have written them in a precise way to help you understand the basics of tuning and upgrading your engine parts in Forza Motorsport 4.

Table of Content

Forza 4 Car Tuning

Forza 4 Car Upgrades

Forza Motorsport 4 Car Tuning

Advanced Tuning tips by Manual Clutch, CerebralColton, and KTLR.

Tire Pressure

I have already explained why having good tires is important to get the best out of your engine. Tire pressure affects a tire’s grip, responsiveness and wear so adjusting front and rear tire pressures under different circumstances is important to keep that grip. You need to adjust the front tire pressure when the tires are cold so that they can reach their grip potential after they heat up to race temperatures.

Maximum grip potential of a tire ranges from 180 to 200 degrees. You can use the telemetry to get an idea about the grip potential of your tires and what setup you would need in race.

Peak friction of the tires is generally 32 psi but, you are doing even if you are somewhere between 30-34 degrees. You will still have necessary grip. You will know the tire temperatures and PSI once you have raced through few laps and tires have heated up.

When your tires heat up, you may need to do some adjustments to keep them in good grip range. The general rule is if the tire center is hotter than edges, tire pressure is too high and you need to reduce 1 psi for each 5 degree temperature difference.

If tire edge are hotter than center, tire pressure is too and you need to add 1 psi for each 5 degrees of temperature difference. If inner edge of the tire is hotter than outer edge, your tires have too much camber so you need to decrease negative camber.

If outer edge is hotter than inner edge, there is too much toe or not enough negative camber so you need to increase negative camber or decrease toe-in. If the tire is below peak temperature range, tire pressure is too high or tire is too wide or springs are too soft at the axle. In this case, you need to decrease tire pressure or reduce the tire width or stiffen up the springs and sway bars on the axle.

If the tires are above peak temperature range, tire pressure is too low or tire is too narrow or springs and sway bars are too stiff at the axle. In this case, you need to increase tire pressure, increase tire width or soften up springs and sway bars on the axle.

If front tires are hotter than rear tires, your car will under steer. This is because, too much front spring/sway bar, not enough rear spring/sway bar, or front pressure is too high or front tires are too narrow or rear tires are too wide. In this case, soften up front spring and sway bar, stiffen up rear spring and sway bar, decrease front pressure or increase rear pressure.

If rear tires are hotter than front tires, your car will over steer. This is because, too much rear spring/sway bar, not enough front spring/sway bar, rear pressure is too high, front pressure is too low, rear tires are too narrow or front tires are too wide. In this case, soften up rear springs and sway bar, stiffen up front spring and sway bar, decrease rear pressure or increase front pressure.

Your best shot to help you adjust these settings appropriately is Telemetry. Instead of following your guts when adjusting the tire pressure, do a quick 3 lap session in quick race and find out your tire pressures and other variables that will help you adjust your tires’ pressure for that track.

Alignment

Camber, Toe, and Caster are the three major alignment parameters. Let’s first see why these alignment parameters are important to adjust.

Camber is the inward or outward tilt of the wheel, which makes it the most important alignment adjustment for a street car. If you want maximum cornering force, set camber of the outside wheels on the ground to about -0.5 degrees.

It is good to have some negative camber as it increase cornering force but the important question is, how you would know how much negative camber you need for a particular track ?

You will find this out in a quick session before the race by measuring the temperature profile across the tire immediately after completing few laps. You want the inboard edge of the tire slightly hotter than the outboard edge.

Toe affects three major aspects of car performance. Tire Wear – excessive toe-in or toe-out can cause the tires to scrub, since they are always rotating relative to the direction of the travel.

If you set too much toe-in, it will cause accelerated wear a the outboard edges of the tires and if you set too much toe-out, it causes wear at the inboard edges of the tires.

Straight-line Speed – When the steering wheel is centered, toe-in causes the wheels to tend to roll along the paths that intersect each other. Under this condition, even with slight steering input, the rolling paths of the wheels don’t make any turn so toe enhances the straight-line stability and helps you keep the speed.

Corners Entry – If the car is set up with toe-out on the front tires, any small steering angle will cause the inner wheel to steer in a tighter turn radius than the outer wheel. Under this condition, the car will always be trying to enter a turn, rather than maintaining a straight line speed.

Now we are left with Caster. It’s tricky, and difficult to grasp but let’s try. Caster is your angle to which the steering pivot axis is tilted forward or backward from vertical, as viewed from the side. In a car, ball joints connect your wheels and steering column. The angle between the joint and the steering is called the caster angle.

You have positive and negative settings for the caster. It’s your low and high settings in Forza Motorsport 4. High caster setting is good for straights but makes it harder to turn, low caster is good for turns but makes it harder to keep the straights.

Tuning these settings depends on your style of driving. Do you understeer or oversteer through turns ? This will decide how you should go about tuning the alignment in Forza Motorsport 4. Remember, it will need great deal of trial and testing before you will finally fine tune the alignment of your car.

Tuning Camber
To adjust Camber, stop the car on a straight road with no elevation and go to telemetry to note the camber angle the car makes with the road. If it matches the setting you have tuned then you are on a flat surface.

Do a quick race and after three laps, watch the replay. Launch Telemetry and go to ‘Tires Misc’ to get what you need. You need to note the several times you see a positive camber for your front and rear tires by looking at the camber angle.

Once you have noted down these values, go back to tuning adjust these settings as follows:

  • Positive camber on straights – Decrease camber by .1
  • Positive camber on turns – Decrease camber by .1
  • No Positive camber on straights – Increase camber by .1
  • No Positive camber on turns – Increase camber by .1

We can conclude that positive camber reduces traction and stability. Now, let’s tune for cornering:

For Left Turn

  • The right Tire must be less than or equal to 0.0 degrees.

For Right Turn

  • The left Tire must be less than or equal to 0.0 degrees.

We can conclude that close to 0 better the handling and anything that’s above 0 means that the tire is not helping you. You must have negative camber and if you are tuning for drag racing, set camber and toe at 0.

Toe
Toe improves the handling of the car for corner entry.

Front Toe + Rear Toe 0

  • Better Corner Entry Any Car.

Front Toe – Rear Toe 0

  • Reduce Steer Sensitivity Bad Corner Entry.

Front Toe 0 Rear Toe +

  • Under steer tendencies but Better Corner Exit in any Car and stability under braking.

Front Toe 0 Rear Toe -

  • Slow Corner Exit.

Front Toe + Rear Toe +

  • Provides stability under braking and creates over steer tendencies in cornering.

Front Toe + Rear Toe -

  • Amazing Handling on any car but can cause under steer.

Front Toe – Rear Toe +

  • Amazing Handling on any car but can cause over steer.

Front Toe – Rear Toe -

  • Oval track.
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By Zawad Iftikhar

Zawad is the lead editor of SegmentNext. He primarily manages what gets published on the site. He is a finance student and PC games enthusiast.


Around The Network
    • DJ-Kemical

      Could sum1 PLEASE tell me how 2 upgrade my cars in Forza 4 please? I DONT want to automatically upgrade. Any help will be very much appreciated! My email is Devorejarrett@gmail.com -Thanks in advance!!

    • Wright

      hi my name is Selby, I’m a new player to fotza 4. I completed everything on gt5. I don’t know how to save the races on forza 4, and when you download the car packs I don’t know how to get them to come up I read your article on tuning and I found it to be very helpful.

    • NC Bubba

      I purchased ForzaTune also. Waste of money and time. After some real research, I have found set-ups that work much, much better. The keys to remember are that every car is different, and that for every different car, there are innumerable combinations of upgrades, etc. that will alter how the tires, suspension, gearing and brakes need to be tuned to acheive maximum grip, acceleration, etc. The long and short is: be willing to spend a lot of time with it if you consistently want a spot on the podium.

      A good place to start is this equation for setting front and rear spring weights:

      Front spring weight = car weight / 2 x front/rear weight distribution ratio (in decimal form)

      Rear spring weight = car weight / 2 – front spring weight

      For example: Let’s say you have a Charger Daytona that you’ve upgraded…its current weight is 3189 lbs and the front/rear weight distribution is 62%. Divide the car’s weight by 2 and you get 1594.4, then multiply by 0.62 (62%), and you get 988.59. This is your front spring weight. Then subtract this from 1594.4 to get your rear spring weight of 605.81.

      Lots of other points are also important, but if you have been struggling to get a good basic tune, I GUARANTEE you will smile from ear to ear while driving a freshly tuned car using the above equation (I was laughing aloud and flashing all kinds of teeth on my first lap at Hockenheim after discovering this formula).

      Like I said before, the finer points take a lot of time, so if you’re not a big fan or don’t have the spare tick-tock on your clock, don’t bother with all that…just settle for the middle of the pack and have fun.

    • Craig Borysowich

      the end of this page says “If you already had your bump” and then ends abruptly – did part of this post get lost?

    • Chris

      Hi, just thought Id add that ForzaTune ‘DisAgrees’ with your ‘Rules’ on Front/Rear Biased items, like Damping, Anti Roll Bars, Rebound and Bump.. On my FWD 97 Civic TypeR it was telling me to have everything Front Biased except the AntiRoll Bars.. But you say that Rear Biased is Highly Recommended for FWD cars.. Im not saying your wrong at all, I used the ForzaTune to get a ‘Base’ then tweaked it using your info and found it to have better results thanks to you.. Its just a warning to anyone that blindly follows ForzaTune..

    • Adam D

      I currently own a Lamborghini Countach LP5000 and have tuned it so it has the following stats:

      Speed – 9.5
      Handling – 6.4
      Acceleration – 10
      Launch – 10
      Braking 6.8

      It falls into the R2 class with a rating of 818, i need help with the handling/braking and how to get it to the top of R1. Thankyou!

      Gamertag : AdamD x

    • Paulo Hirata

      How to unlock tuning configuration? At this moment I can only configure tire pressure. Need I buy anything to unlock other configurations?

      • Jason

        Paulo,

        You need to upgrade to Race suspension/transmission, etc… To be able to adjust those for tuning for most cars. The stock transmission and suspension are non adjustable. If you don’t have a rear spoiler, you can’t adjust it. Look in the description under the parts in the upgrade shop and they will tell which upgrades are adjustable.

    • F4g

      I recommend iphone app Forza 4 gear
      Any car setup same taste

    • john

      i found iphone app “Forza 4 Gear”.
      tuning calculator app.

    • Samuel Tylstedt

      Hi!
      First of all, nice guide!
      But i’m not a native english speaker so I don’t know what you mean with biased under Dampening section. Do you mean to have front and rear set to the same value, or?

      Thx again for a nice guide ;)

      • http://segmentnext.com Zawad Iftikhar

        Front Biased would mean amount of weight on front compared to rear. It is reverse for Rear Biased Rebound. Explanation of how they work is already in the description of the specific section of the guide.

        Biased generally means more inclined towards…

        I hope I have cleared few clouds :)

        • Samuel Tylstedt

          Yes, thank you very much!
          It’s much clearer now :)

          Then i’ll see what good i can make this new knowledge. Watch out in the game ;)

    • arnie

      hi,
      in the Anti-Roll Bars section, there are sub-sections:

      Stiffer Front Anti-Roll Bar
      Stiffer Front Anti-Roll Bar
      Softer Rear Anti-Roll Bar
      Stiffer Rear Anti-Roll Bar

      one should be Softer Front Anti-Roll Bar.
      thanks for correction.

      • http://segmentnext.com Zawad Iftikhar

        Thanks for the heads up =)

        • arnie

          You are welcome ;) im glad you wrote this article .. because im not familiar in tuning. Im making my own notes so the next weekend will be only about tuning and testing :)) And this article is really long and full of useful info .. so its ok, there are a few mistypes ;)

          I found another misunderstanding – maybe it is correct, maybe not:

          Driveline –> Differential

          If you are driving a FWD Car, stiffen up the front different acceleration to force more power to the outside wheel but it can result in understeer

          If you have RWD car – stiffen up your front differential acceleration to force more power to the outside wheel but it can result in oversteer if you put too much power.

          is it ok, that in both cases you need to stiffen up the front diff.accel ?

          • http://segmentnext.com Zawad Iftikhar

            It’s correct. The difference is that you will get oversteer in RWD and understeer in FWD.

    • arnie

      hi, please make a review of this part in tire pressure section:

      If rear tires are hotter than front tires, your car will over steer. This is because, too much rear spring/sway bar, not enough front spring/sway bar, front pressure is too high, rear pressure is too low, rear tires are too narrow or front tires are too wide. In this case, soften up rear springs and sway bar, stiffen up front spring and sway bar, decrease rear pressure or increase front pressure.

      is it correct ? if too high front pressure i need to increase the front pressure ? the same for rear tires ..

      thanks ;)

      • http://segmentnext.com Zawad Iftikhar

        My bad. At that point, rear pressure is too high and front pressure is too low that’s why increasing front pressure is the suggested tuning.