This guide has been in the making for months now. It has taken this long due to time constraints on my part. Please note that the guide is based in part on GT3 & GT4, but the theories can be applied to any version of the game.
Understanding the simple physics of weight transfer is key to tuning cars. When stationary, the weight of the car is distributed evenly on all four wheels. Where does the weight of the car go during acceleration? The rear wheels, right? Likewise, during braking the weight is transferred to the forward wheels. Also, during cornering the weight is transferred to the outside wheels. That is, in a left turn, the weight of the car goes to the two wheels on the right (when looking at the car from behind).
Understeering and Oversteering
Understeering is the lack of responsiveness of the carís front in turning into a corner. That is, the car doesnít want to turn. Generally, FWD and 4WD cars exhibit understeering characteristics.
Oversteering is the tendency of a carís rear to slip out in mid-corner. That is, the car spins out too much. Generally speaking, overpowered RWD cars exhibit oversteering characteristics. Oversteering is not the be confused with "Drifting" or "Power Sliding". Generally, drifting is induced
with wheels losing grip intentionally and should be controllable
with the throttle. Whereas, understeering and oversteering is uncontrollable and unwanted.
Our aim is to get rid of understeer and oversteer as much as possible, since it ruins lap times and tire wear. Although in real life, a slightly understeering car (very slight) is always faster than an oversteering car.
The Spring Rate controls the transfer of weight of the car. During braking and acceleration the weight of the car shifts forward and backward. Softer front springs aid in shifting the weight to the front, thereby reducing understeer. Softer rear springs allow the weight to transfer to the rear, consequently reducing oversteer. Alternatively, to induce understeer or oversteer, do the opposite and stiffen the corresponding spring rates. Keep in mind that spring rates that are too soft produce a car that is not as responsive as one with a stiffer spring rate. So, you have to find a compromise.
Let's use a medium weight FR car (1200kg) as an example. Since you want more grip at the rear during acceleration in an FR car, the spring rates, if hard, resists the weight to the rear, making the rear hard and want to fight back, loosing grip. So we want to make the rear take more weight during acceleration for better grip = reduce rear spring rate from 16 to ... let's try 13 first. Test it again, see how that goes.
FR cars have more varied requirements. FR cars seem to prefer a slightly lower front spring rate to reduce understeer. Set your front springs up to 2kg lower. But if you experience too much oversteer, reduce rear springs.
MR cars prefer a more neutral spring setting, that is, close front and rear settings.
In an FF car, since the driving wheels are in the front and weight goes to the back, during acceleration, we make the rear spring rates as stiff as possible to resist the front wheels from loosing too much grip by reducing weight transfer to the rear while accelerating. However, the front spring rates must not be too soft (low spring rate#) as most of the car's weight is up the front.
So the next big question is how much Spring Rate is not too much or too little?
This question will depend on the weight of the car itself.
Use this as a general guide only.
Light cars 1000kg or less = values of 9 Ė 12
Moderate weight 1000kg to 1400kg = values of 12 Ė 15
Heavy cars 1400kg upwards = values of 15 Ė 17
Rally cars on dirt only = values of 5 - 7
Spring rates also help soak up the bumps and ripples of an uneven road. Take for instance any city track ripple strip riding is unavoidable, a softer string rate will aid in riding over the strips. As a general rule, reduce your spring rate values by two from the above figures on city and any bumpy tracks. It's easy to make your car too stiff. If this happens, the suspension will not be able to deal with bumps and will hop its way around turns instead of compliantly absorbing the bumps and finding traction
Ride Height is the height of clearance the car has between the bottom of the car and the road. The ride height has an impact on the car's centre of gravity, and thus on its behaviour when cornering or braking. Basically any shift in weight.
In general, lowering the Ride Height will bring the centre of gravity of the car lower, making the car more responsive by decreasing body roll because the weight of the car is now lower.
Raising the Ride Height will have the opposite affect, which will increase body roll.
That was the generalised bit.
Like with all parts of the car that you can tune, Over tuning and Under tuning will each have their drawbacks. A lower ride height in the front than the rear will induce weight transfer to the front increasing the load. This may be what is wanted.
Ride height will also impact the available suspension travel rate, so make sure the spring rate is high enough to prevent the suspension from "bottoming-out". Having the ride height too low and suspension won't work very well. The trickiest part is to have your ride height as low as possible, for maximum tire grip and overall neutral handling balance, while still allowing for enough suspension travel. In order to do this effectively, compensate a lower ride height by adding more spring rate.
Lower front and Higher rear ride height - the weight of the car is shifted towards the front. Provides more stability while accelerating. Brake response is faster since weight is already where the braking power is highest. Best for FF, FR and 4WD cars. (Be careful though, if itís too low, you will find the car twitchy and liable to veer off in random directions under heavy braking).
Equal front and rear ride height Ė weight is distributed equally. Best suited for MR cars.
High front and Low rear ride height - the weight of the car is shifted to the rear, provides immediate throttle response during acceleration. Braking response will suffer, however, since more weight shifting during braking from rear to front is required. As such, this configuration is not used very often. If used, probably only FR cars would benefit.
In GT3 and GT4, try to allow at least 10 points from the minimum ride height. And set the rear about 5 points higher than the front. This allows sufficient suspension travel to keep the car stable under heavy braking and weight shift towards the front of the car. On very bumpy roads like Nurburgring or El Capitan, increase ride height and reduce spring and shocks. This ďsoaksĒ up the bumps more effectively.
These work in conjunction with Springs and Stabilizers. To dampen the oscillations of the spring after travelling over bumps and dips. When weight transfers from back/front and side/side, or when you go over a bump on the road, the wheels/tires compress (bound), and when you are past the bump the wheel returns to equilibrium after the compression (rebound) basically the suspension movement, right ? With me so far?
Bound damping affects how far the suspension travels up, towards the wheel well. When the suspension is on its way back down, rebound damping affects how far it goes the other way. More precisely, bound damping affects the compression rate, while rebound damping affects the expansion rate.
If you make your bound damping too stiff, your car will be skittish over rough surfaces. Rebound damping also affects your steering as you transition into and out of corners.
In general, stiffer springs are better suited for flat tracks with sharp turns. They prevent your springs from coiling too quickly, which decreases the dip you have when cornering and braking. Softer springs are better suited for winding, coiling tracks, but theyíll also lengthen your braking distance.
is the rate at which the shock compresses. Rebound
is the rate at which the shocks decompress. So having bound at 9 and rebound at 2, make the car stiffer when absorbing a bump, compression is harder. The suspension on rebound will not return as fast. This suppresses weight transfer. Not very good because the tire won't make contact with the ground fast enough causing slip = Oversteer. Okay for FF, bad for FR cars. On the other hand, bound at 2 and rebound at 9, absorbs more bumps, but returns the shocks the opposite way fast. You'll find the car literally jump over small bumps. This is also undesirable, as the tire is not in contact with the road. Try this on a Rally car in dirt to see the exaggerated affects, you'll know what I mean. Bound at 7 and rebound at 6, keeps the tires stiff and return to the ground slower. Having bound at 6 and rebound at 7, will result in a good stiff compression of shocks and a higher bound means the tires return a bit faster to the ground but not too fast. This is the ideal configuration, a slightly higher rebound.
Now adjust front bound and rebound to have lower values than rear bound & rebound. This will result in more weight transfer to the front, for example during braking, to provide more grip into the turn.
FR car oversteering? reduce rear bound.
FF car understeering? reduce front bound OR increase rear bound & rebound.
4WD oversteering? reduce front bound AND reduce rear rebound.
MR cars - keep bound and rebound figures the same. MR cars need to be treated a bit like FR but try to keep both front and rear figures the same.
Controls the roll of the car from side to side and helps stabilise the car during cornering. Stiff makes the car respond well to sharp turns. Ie, when you turn the steering wheel (or PS2 controller) you notice the car react to that quicker. Car feels more stable. Downside to that, is if Stabilizers are too high, it reduces weight transfer to the outside tires, reducing grip during cornering and causes understeer or oversteer. Softer allows the car to lean into the turn giving greater grip. But too soft, causes the car to be unresponsive. Eg, Car understeers too much = reduce front stabilizers or likewise increase rear stabilizers. Make the front value less than the rear to reduce under steer. On lower powered cars, less than 450hp, tire spin is less of a risk, so stabilizers can be increased. Take a Mazda MX5 LS setup for an example. Stabilizers at 7 and this thing flies for a <400hp car. On high powered cars, always start with a value of 4 and fine tune from there.
FF drivetrain cars exhibit a slightly different response to the above, you want a higher front stabilizer setting than the rear. This will have an affect of reducing body roll of an FF car, keeping both tires firmly on the road rather than shifting all the weight to the outside tires and reducing grip. However, don't make stabilizers too high or you run into problems of over tuning.
Is the angle of the tires, as viewed from the top of the car.
For the sake of the different value notations in GT3 and GT4 I'll use a generic value notation in this guide. So when I say " -'ve one step from default value" take that to mean -0.5 in GT3, and -1 in GT4.
4WD and FF use -'ve two steps from default / +'ve one step from default (front/rear) as a start. FR and RR use 0 / -'ve one step from default. Negative toe in the rear wheels will stop oversteer because the wheels are at this angle /--\ (looking from the top of the car). That's great for corners but reduces acceleration on the exits and straights because there isn't as much tyre contact to the ground as a zero toe like this |--| . So as you can see there is a compromise.
/-\ = negative toe/ Toe In (view from Top of car)
\-/ = positive toe/ Toe Out (view from Top of car)
In 4WDs and FWDs use negative toe in front and positive toe in rear to reduce understeering. Quick physics lesson. Looking at the diagram above ... when going around a left hand corner the weight of the car leans to the right two tires. The negative front toe makes the car turn sharper left, while the positive toe rear swings the rear further out to the right, making the car point left into the left hand corner. In RWDs and MR cars, use neutral toe in front, and negative toe in rear to reduce oversteer. If RWD is understeering slightly, use negative toe front slightly and neutral toe rear.
The compromise of fixing understeering or oversteering using toe adjustments is that tire wear will increase. There is always a compromise in every adjustment, we don't live in a perfect world. Always try to reduce oversteer and understeer using adjustments to springs, shocks and stabilizers first. Only resort to toe adjustments as a last resort, since any toe value added will increase tire wear.
Unlike TCS, where it reduces power to all wheels equally for traction control, Limited Slip Differential (LSD) keeps tires from spinning by transferring it to the other tires that have grip. Usually during cornering.
Accel = during acceleration, Decel = during braking.
is straight forward. reduces tire spin during acceleration, reducing oversteer in FR cars and reducing understeer in FF cars.
, reduces tire spin during braking. Keep this low at 15 - 20, lest it induces understeer by way of reducing braking power.
: the initial strength of the LSD affect.
LSD is useless on cars with less than 450hp. There isn't enough HP in the car to cause wheel spin anyway. So why have it, as it slows the car down and causes extra understeer.
4WD, as little LSD as possible. LSD stuffs 4WD up big time, causing understeer. Think about it. 4WD already has grip to all 4 tires. If LSD is activated, it transfers grip to the other tires, which REDUCES grip to the tire loosing grip. Silly. You'll see a lot of setups here, that use strong LSD on 4WDs. They think this controls understeer, but really what is happening is that they are reducing the power to the wheels = slower car = less understeer. If you are gonna have high LSD on a 4WD to get rid of understeer, you might as just drive slowly around corners. Use TCS to control wheelspin on high powered 4WDs (greater than 500hp).
FF - High init and accel LSD. Decel LSD as low as possible. But most FF cars are very low power, so don't use LSD. Exceptions are the Type R, FTOs, etc with more than 300hp.
MR / FR - Init (depends on Car's HP), Accel higher to reduce oversteer on acceleration. Low decel LSD to reduce understeer on braking.
ASM & TCS
I hate ASM, it induces understeer. Anything above 0, causes the car to behave other than it should and negates the tuning done else where. Without knowing how to tune the car you can use ASM, but if you know how to tune it following the above guide, turn ASM off ! If you change nothing else with the setup of the car, change ASM to 0.
In GT4, you will see options for both ASM Oversteer and Understeer. This still does the same thing as ASM in GT3. The ASM Oversteer will reduce power to the spinning wheels during an oversteer situation and vice versa. Again, reduce these values to 0 before you start tuning.
ASM can be reduced to 0 even on unmodified cars.
Traction Control System (TCS) is where power to the driving wheels is reduced in the event of wheel spin. Unlike, LSD, where power is transferred to the opposite wheel that is not slipping, LSD, reduces overall power to the driving wheels. Effectively slowing the car down to reduce wheelspin.
The main aim of TCS tuning is to use only enough TCS to stop wheel spin and drifting. No more, no less. This has the added benefit of preserving tire wear, but not sacrificing too much power.
Finding the right TCS figure for a car is a bit of a Trial and Error effort.
Light and More powerful cars will require more TCS. Heavier and less powerful cars will obviously need less TCS.
A general tuning technique I use is to start TCS at 0. Then ask myself, is the car spinning around slow corners and at take off?
If the answer is yes, then increase TCS by 2.
If the answer is no, then leave it at current amount.
Repeat. Until wheelspin is nil, then reduce TCS by 1. If still no spin then leave it.
You can use TCS to fine tune at this stage. If you want a car that oversteers, reduce TCS a bit from this figure you just reached.
You want to reach a point where the car is not loosing itís rear end around slower corners, while still keeping the TCS figure as low as possible to get the most power to the road. On take offs, reduced wheelspin on the spot will increase acceleration.
Fine tuning here can see increase tire wear benefits, but remember the more TCS you use the slower the car is, even if you have better tire wear.
However, when tuning TCS for 4WD cars, it is best to use close to no TCS at all. Since we have 4 driving wheels, there will always be at least one set of wheels with grip even if the other set is loosing grip. By having TCS on at any figure, will just be slowing a 4WD car down.
Always use 0 TCS for 4WD cars.
FR cars benefit the most from TCS.I find anything under 500bhp in GT4 will not need TCS. The weight of the car will also determine the need for TCS. Light cars eg F1, Sprinter Trueno Shigeno, can have TCS at 4 to 6 with great benefit. For heavier cars, start TCS at 3 and tune. You should not need much more than 5, unless you want to conserve more tire wear.
This is not THE rule, just a guide. Tuning is still required.
FF cars benefit from TCS a bit, but not as much as FR cars, since the driving wheels are also the ones that TCS will be affecting. Too much TCS and it slows the car's acceleration and reduces understeer. No TCS and it understeers. So with FF cars, use between 1 to 2 TCS.
Remember, the aim of tuning race cars is to make it as fast as possible, not slow it down with ASM or TCS or LSD. Let the driver do that. Your job as tuner is to get the car to be as fast as possible while still being as controllable as possible.
Use as little as possible on tracks like Test course. All other tracks, higher front DF reduces understeer. Helps stabilise the car at high speeds. Keep front and rear close to the same figure, with a slightly higher rear downforce. What I mean is, avoid figures like 0.5 front and 1.2 rear downforce settings. A difference of no more than 0.2 is advisable. Or in GT4 figures, a difference of no more than 20 between front and rear downforce is advised.
Exceptions for FF cars, where I regularly use max front downforce, with little rear downforce. This helps reduce front understeer and induce rear oversteer.
Only available on 4WDs. The figure in GT3/GT4 is the % amount of power delivered to the front tires. Keep it low to reduce understeer (ie towards 10%). A figure of 10% means that 90% of the power is driven in the rear wheels, making the car almost like a RWD. Except for rally cars. That should get you started.
Stronger front brake balance causes the front of the car to dip more than the back, that is, more weight transfers to the front wheels. Apart from having greater stopping power, it allows better tire contact to allow the car to steer into the corner while under brakes.
Stronger rear brake balance, will cause the rear wheels to lockup slightly (dependant on how strong you set balance) when the weight transfers to front during braking. Causing slight oversteer. Not a bad thing, you might want to induce a bit of oversteer in heavily understeering cars.
Too much front brakes and the front tires will lockup, causing severe understeer, which isn't good. And too much rear brakes can cause the back to lockup causing severe oversteer.
As you can see there is a cause and effect for each setting. Too much or too little of a setting will cause undesired effects. eg, too much front brakes and the tires lock causing understeer. Too little, and the car doesn't stop fast enough, causing the car to continue it's momentum straight ahead.
Set brakes up for maximum stopping power without the front locking up. Depending on the car's behaviour, you can induce oversteer by setting higher rear brake balance. Finding the figure for maximum brakes just short of lockup will depend on the weight of the car (excluding speed) and to some extent spring rates. Obviously, a lighter car will reach lockup before a heavier car. OR, you can just use trial and error, watch the screen for smoke from tires during braking in a straight line. If it smokes up, the wheels have locked up, reduce brake balance. In general, finding the front's lockup threshold is more important than the rear. So adjust front balance first while keeping the rear brake low. Then adjust rear after you find the maximum braking figure for the front, usually 1 or 2 less than front will be good enough (because I'm lazy to repeat it again for rear ).
As long as the front doesn't lock up during braking, it won't understeer. Of course you shouldn't be braking while turning into the corner at the same time, that's too late. You should have done the braking before the corner and be at a speed where you can maintain throttle while in the corner and can floor it just after the apex of the corner.
Camber is the angle of the wheels in relation to the ground. The tire's relationship with the road changes as the suspension moves through its travel.
Ideally, you want a camber curve that keeps the tire straight up and down when you are driving straight, and leans the tire in slightly (1 to 2 degrees of negative camber) during cornering.
So a neutral camber will be |-| (while looking at the car front on),
A Negative Camber will be /-\,
And a Positive camber will be \-/.
(TOP LEFT) Positive camber: The bottoms of the wheels are closer together than the tops.
(TOP RIGHT) Negative camber: The tops of the wheels are closer together than the bottoms.
(CENTER) When a suspension does not gain camber during deflection, this causes a severe positive camber condition when the car leans during cornering. This can cause funky handling.
(BOTTOM) Fight the funk: A suspension that gains camber during deflection will compensate for body roll. Tuning dynamic camber angles is one of the black arts of suspension tuning.
Camber allows the weight of the car lean on the outer tires, providing additional contact in a corner. However, on level ground and straights, the more camber you have the less contact surface area the tire has to the road.
Thus a negative camber in the front tires is always recommended, and in most situations the front camber value should be higher than the rear. Rear camber should be as close to Zero or neutral as much as possible. Thus, providing as much grip to the rear as possible. Unless you are tuning to reduce oversteer, then a little negative camber is okay. On oval tracks, the inner wheels will need positive camber and the outer wheels will need negative camber to counter the angle of the track. Using camber to reduce oversteer and understeer should be treated as a secondary option to adjusting springs and shocks first. Unless you are intentionally tuning for a drift car. 4WD and FWD recommendations, start at default value 2.1 and adjust up to a value of 4. RWD recommendations, start at 2.1 and adjust up to a value of 3.
Using more camber than suggested is unnecessary and will result in reduced grip on flat straights and increase tire wear.
Note: in the GT series, you can only ever select negative camber values. So when the setup screen says front camber is 2.1, that means camber is at -'ve 2.1. Polyphony must have remove the -'ve since you can't set +'ve camber.
Ballast is a GT4 specific tuning option. Ballast allows you to add weight to an already light car, with the specific intention of altering the weight balance of the car. This works hand in hand with Weight Balance.
Weight Balance is also a GT4 specific tuning option and works hand in hand with the Ballast. After adding Ballast to the car, you are able to adjust the weight balance of the car. You can have either more weight in the front or the rear depending on how the car is behaving.
If you find the car oversteering, you could adjust the weight balance towards the rear, giving you more weight in the rear to reduce oversteering. Likewise, if the car is understeering, move more weight balance towards the front.
I will keep gear tuning to a simplified discussion here. As such we will be using the Auto gear adjustments.
A short gear will result in higher torque but a lower top speed.
A wide gear will result in lower torque but a higher top speed.
With that in mind, tune your gears for each track separately. Using the fastest straight on the particular track as a testing point.
If your revs are not reaching the redline at the end of the straight, you can shorten the gears, until you find the revs just reaching the redline. I find it easiest and quickest to just change the Auto Gears, rather than change the final drive ratio. Changing the final drive ratio does basically the same thing as the auto gear setup, but you could potentially mess up the way the car accelerates if you fiddle with final ratio too much. If you find the gears topping out too quickly on a faster track, just up the auto setting a bit at a time until your top speed just hits the redline.
On some fast tracks like Tokyo, Test track, etc, you can increase the auto gears too, since it's top speed you want more than acceleration. If you find that your revs are topping out on long straights, then increase this auto gear a bit more. If, you are not near the redline at the end of the longest straight, then you have increased the auto gear setting too far, reduce it slightly (towards the left).
Then, on slow tracks, with lots of twisting, like the Cote D' Zor, or Seattle, you can decrease the gearing up to 5 steps from the default auto gear value, since it's acceleration you want not top speed. On the longest straight of these tracks, if you find that you are not reaching the top of 6th, or even lower, decrease the gears until the revs just hits the redline.
Yaw Control. Similar to LSD, this controls the distribution of torque to the left and right wheels. Seems to only be available on Mitsubishi Lancer EVO cars.
Helps 4WD cars reduce understeer and gives a faster turning ability.
If AYC is set too high there is even a risk of creating too much oversteer, and increases tire wear significantly. Although, the car's turn in ability is tremendous.
Try to keep this figure around 80 - 90 (middle), for the best compromise.
These are theories for RALLY setups only.
Needs to be low (~5-6kg/mm), to soak up the bumps on dirt. Have spring rates at high and you'll have one bouncy car everytime it goes over a small ripple on the dirt road. Increased ride height will compensate for the low sprig rates.
Needs to be high >140. Reason, on landing your jumps, it prevents bottoming out of the car. A higher ride height also compensates for lower spring rates by avoiding the car bottoming out.
These needs to be even on Bound and Rebound. Too much Bound shocks and the tires, don't make contact to the ground as fast after compression. Too much Rebound and the car will bounce upon decompression of the shocks. Now adjust between front and rear for fine tuning of understeer/oversteer control. Softer shocks to remove understeer, stiffer shocks to induce more oversteer. I have slightly, slightly more rebound on front usually, to bring the tires back to the ground a bit quicker after compression of the shocks. Providing better tire contact to the ground and reducing understeer. Eg, front 5/ rear 7 on bounds, front 6 / rear 7 on rebounds.
To your liking. But too much camber stops the car from drifting properly and reduces your tire contact to the ground, ie, less grip. But no camber is also not good. Drifts will be a bit more difficult to control. Keep it between 2.0 and 4.0.
Now, I'm not sure how GT3/GT$ treats toe. But in the game, I think, negative front positive rear helps reduce understeer (in GT3 = -1.0 / 0.5 are good figures to start. Or in GT4 = -2/-1). And Negative rear positive front reduces oversteer (0.0 / -0.5 are good figures to start in GT3 and 0./-1 in GT4).
These will help stabilise the car during drifts. But too much will cause the car to loose too much grip around corners. Have it at about 3 or 4. And remember that a lower value at front will help reduce understeer or likewise a higher value at rear will cause oversteer.
To your liking. As long as it's not too high, that it causes lockup. Generally figures up to 12 should be enough in Rally.
As low as possible or none at all. You WANT the tires to spin, to give you controllable drifts in the dirt. Having LSD turned up will stop the tires slipping and you'll notice more understeer in a corner, especially in dirt.
Important, not! As above, you want to drift and you want your tires to slip. So TURN these off (ie 0) ! You might as well play an arcade game with these turned on. Only exception is TCS, which can be used on high powered cars to reduce wheel spin. But use it sparingly, or else it causes more understeer.
Have it on the lower end, that is, if using the auto gears, to the left. This gives more torque rather than high speed. In most rally courses, High speed is not where you gain time, it's around those slow 180degree turns. Higher torque will get you out of the turns fast. As a starting point, use an auto gear value 5 steps to the left of the default auto gear value.
Yes, please. The more the better. However, keep it even at front and rear. Why? Too much rear downforce and you'll find the car's front flying up during a jump. Vice versa, for too much front downforce. During a jump it will go into the ground nose first. You want to land on four tires, not your bumper bars.
Preferably even to help control drifts. But in practice, I find lower VCD values (ie, more RWD) helps reduce understeer. For Rally, start at 30% and reduce slowly towards 10% to remove understeer as suited to your driving style.
There you all go. May you all go forth and produce awesome rally tunes. Disclaimer - of course, no two cars are the same or behave the same. The theory above is a good starting point. Finding the exact point of setup where the car behaves at it's best is a matter of trial and error and a lot of patience.