Vehicle Tuning Setup Help by Irvin Parrett

8 jaren 6 maanden geleden #112941 door Dave
Tires and Brakes

Tires

Lowering pressure will decrease temperature as raising will increase temperature. The hotter the tire the quicker it will wear. Lowering the tire pressure creates a greater contact patch which will increase the grip you will feel. However, the greater the contact patch the more tire wear will occur. Lowering the tire pressure too much reduces grip. Sometimes lowering the tire pressure too much will give you too much grip causing turning too strong and the rear doesn’t slide. In these instances raising the tire pressure will benefit the handling. If the tire pressure is too high then the tires will overheat and very little can be done to cool them or prevent excessive wear. Overall reducing the front tire pressure will help solve the problem

If you have mid-corner understeer (Understeer occurs when traction is lost at the front wheels while cornering, forcing you wide on a bend despite applying the correct steering angle. When viewed by an observer, this action looks as if the driver has applied insufficient steering lock (or under steered). If you're car is understeering, you're scrubbing off speed and missing the optimum line, so it's not a quick way to take a bend.) lowering the tire pressure will help.
If you have mid-corner or exit oversteer (Oversteer occurs when the rear tires reach the limit of adhesion in a corner before the front. This leads to 'the back coming out' The good thing about oversteer is that you normally go through the hedge backwards, thus preventing expensive repairs to the front of your car. If you manage to performed sustained, controlled oversteer this is know as drifting.) then reducing the rear tire pressure will help.

Brake Balance

Adjusting the brake balance is highly dependent on your braking style.
Trail braking - This involves braking later and continuing to brake into the early phase of the corner before the apex. This can help improve your lap times, but also pushes your car closer to the limits of grip.
Straight line braking before a corner and before beginning to turn-in.
Often you use both types on a track depending on the corner. If you’re trail braking and have turn-in understeer, then move the brake balance rearward. If you’re trail braking and the rear begins to slide on turn-in, then move the brake balance forward. If you’re breaking in a straight line and the rear axle locks move the brake balance forward. If your braking in a straight line and the front tires lock causing you to go straight into the gravel, then move the brake balance rearwards. You’ll often find that the brake balance is good on one corner and horrible on another. You can adjust the brake balance while on the track increments of 1 all the way from 100% in the front to 100% rear. Adjusting the brake balance on the fly allows for optimal braking in every corner. As the tires wear they will begin to wear at different rates. To help stop this you can have more brake balance on the least worn tires. Also as the tire wears the more likely it will lock. If you’re running a brake balance of 73% you may find that the fronts begin to lock. In order to stay out longer before a pit, you can adjust the balance rearwards on the track.

Traction Control

The Final basic adjustment in the tires and brakes is the traction control slip. Reducing this value will allow the traction control to intervene sooner allowing less wheel spin. Increasing this value will let the car have more wheel spin before the traction control activates. On corner exit you can apply the power only if the traction control kicks in reducing your exit speed. If this happens increase the traction control. Alternatively, in corner exit you may apply the power and the rears slide. If this happens, then decrease traction control to allow traction control to decrease the wheel spin.
Generally, the tighter the corner, the rears will spin. If you have many slow-speed bends a lower traction control slip is advised. This is done to preference some drivers like to drift and others can’t handle the car sliding out.


Aerodynamics and Chassis

Downforce

Downforce can be adjusted individually on front and rear of the vehicle. The higher the downforce the more grip you will have in a corner. However, downforce increases the aerodynamic drag of the vehicle. This increase of drag will reduce the top speed. The downforce should be at a minimum as tracks such as Monza or maximum at tracks such as Watkins Glen. Downforce will only benefit car handling at medium speed and high speed corners. At low speed you’re not traveling fast enough to generate enough downforce for it to be noticeable.
If on medium and high speed corners you’re having understeer than increase the front downforce. If on medium and high speed corners the rear begins to excessively slide then increase the rear downforce.
There are two methods to choosing your downforce in competitive racing. You can run at the lowest controllable downforce level so you are one of the fastest cars on the straights. This will prevent cars from catching you if you are leading, or will help you catch the cars in front of you. Most overtakes are completed on the straights as this is the safest way. The second method is for overtaking in the corners. For this you run at a slightly higher than normal downforce level to allow you to follow closely behind the car ahead. The high downforce will allow you to carry more speed into the corner. Eventually the driver ahead will be pressured into a mistake allowing you to make a nice simple overtake. Alternatively, you will get a better exit provide the straight following the corner isn’t too long. This will allow you to get ahead. When leading it is also helpful that you can exit the corner faster and any advantage the drivers have on the straights will be negated by your superior corner speed.

Longitude and Weight Bias

Longitude and Weight Bias is a useful tool to change the weight balance of the car. If the car is understeering on corner entry, then move the weight bias rearwards. If the car is over steering on corner exit and corner apex (Apex or clipping point is the innermost point of the line taken through a curve. The apex is often, but not always, the geometric center of the turn. Hitting the apex allows the vehicle to take the straightest line and maintain the highest speed through that specific corner. It is often near the tightest part of a corner.) then move the weight bias forwards. This behavior is due to the weight change on the car during cornering, braking, and acceleration. As you brake naturally the front of the car gets heavier. Having a rear weight bias will help stop this effect. When you are cornering the car rotates (unintelligible) front tires. The further-er away from the front tires the center of mass is the greater so more over steer will be felt. Alternatively, if the center of mass is at the front of the vehicle the rear will slide less which will compromise your exit speed. When you are accelerating the rear squats causing the weight to transfer to the rear axle. Having a forward weight bias will reduce this effect. A forward weight bias is required here as often you are accelerating while turning the wheel. So, any rearwards weight balance will dramatically increase the rear sliding. Extremes should be avoided here, as this will give unpredictable handling. I tend to run anywhere between 60% so, 10% front bias and 40% so, 10% rear bias depending on the car. Front engine FWD cars you want to run with a rear weight bias. Front engine rear wheel drive cars you normally want to run with a front weight bias. Rear engine rear wheel drive cars you want to run with a front wheel bias. Mid-engine rear wheel drive cars are tricky as these tend to be unstable and unpredictable. These will often stay around 50% mark. All-wheel drive cars have a tendency to understeer this is not always the case but normally the default handling. For these a rear weight bias will be required.

Alignment


Tow

The tow can be changed front and rear. Increasing the front tow (tow-in) will increase the amount of grip during corner apex but, reduces the grip on corner entry but will be able to hold the apex better once you get there. Decreasing the front tow (tow-out) will increase the corner entry grip but, will reduce the corner apex grip. So, the car will feel sharper on tow-in but will begin to wander out wide as you take the apex of the corner. Increasing the rear tow (tow-in) will reduce lift-off and power over steer. So, when you let off the throttle the rear will be more controllable. When you apply the throttle when exiting the corner the rear will slide less. Decreasing the rear tow (tow-out) will increase liftoff and power over steer, so when you let off the throttle the rear will begin to step out allowing you to slide into the corner. When you apply the throttle the rear will slide more allowing you to straighten the car sooner for a better exit. Tow depends on track and largely your driving style. Some like a car that is on rails and does not slide at all. They will have lots of rear tow-in. Some like a car that can slide about. They will have rear tow-out. Some like a (unintelligible) car. They will have front tow-out. And some like a car that can hold the apex. They will have front tow-in.

Camber


The camber angle can be changed individually at each corner of the car. Camber angle will always be negative. Camber angle changes the angle of the tire under static conditions. Negative camber has the top of the tire leaning into the car body. Having the top of the tire leaning in will put more load on the inside shoulder of the tire. As you turn the vehicle weight transfers to the outside. This weight transfer squishes the tire so the contact patch gets larger. The more negative the camber angle, the more centralized this contact patch will be. The greater the camber angle the faster the tires will begin to heat up when you’re on track. This combined with the greater contact patch size will increase the grip you feel during cornering. You can adjust left and right camber angle to help balance the tire temperatures. In a straight line however, the contact patch is not being squished into the ground as much, so a larger camber angle will actually reduce the contact patch size. Under braking this reduction of contact patch size will increase your braking distances. Under acceleration out of the corner the rear will slide more and more wheel spin will occur as weight will transfer back to the center of the vehicle and the contact patch size will reduce. If you have corner apex under steer increasing the front camber will increase the grip and reduce the under steer. This increase in front camber angle will however, will give more turn-in understeer as the contact patch will be smaller then. If you have corner apex over steer, increasing the rear camber will reduce this. This is as the contact patch will get greater thus increasing the rear grip. The increasing camber angle will make the rear of the vehicle more snappy and make you more prone to sudden loss of control. I would always adjust the camber angle first before adjusting the tow of the vehicle.

Suspension

Ride Height

Ride height can be adjusted individually at each corner of the car. Unless you are oval racing the left and right ride height should remain the same. Having different left and right ride heights will change how the car feels during left and right cornering (unintelligible) an unpredictable car. Generally, the lower the ride height the better, as there will be less weight transfer during cornering, braking, and acceleration. This is due to the spring travel being shortened. The shortened spring travel will mean the car body will move less when loads are applied. The tire load won’t differ as much and the car will be more predictable. Going too low however, will cause the car to bottom out. When a car bottoms out the car body is in contact with the road. This causes a sudden loss in control if it occurs during cornering. If the front bottoms out you’ll get under steer and the car will feel like you are driving on ice. If the rear bottoms out you will end up in the gravel or exit the corner facing in the wrong direction. Having the front ride height higher will cause the car to understeer. This is as the weight transfer will be felt more by the front axle than the rear axle. Raising the front ride height also stalls the front aerodynamics. If the front aerodynamics stall then less downforce is being created than what should be generated. Raising the rear ride height will make the car over steer more as the rear of the car will have a larger weight transfer than the front. Raising the rear ride height can also increase rear grip on medium and high speed corners as the rear wind will be exposed allowing for a cleaner air flow to generate downforce. This cleaner air flow generates more downforce than turbulence flow. Raising the rear ride height to far however, will stall the rear aerodynamics of the car and you will feel a sudden loss of rear grip. This is as the air gets into the diffuser becomes turbulent and the diffuser will stall. Ride Height will affect all areas of the corner. Set the front ride height as low as possible, so just before the car bottoms out. Then set the rear ride height to your preference. It will normally be higher than the front but, how high depends on how much you like the rear to slide.

Sway Bars

Sway Bars or anti-roll bars increase the spring stiffness during cornering as the weight begins to transfer the sway bar will twist thus increasing the spring rate of the axle. The increase in spring rate means more force is required to deflect the suspension. Sway bars only act during cornering and have no effect on straight line driving. Sway bars act along the axle so, can only be changed front and rear. The softer the sway bar the more predictable the car will be. This is as spring rate won’t change as much so you have a car that feels the same at every corner. Soft sway bars however, have the effect of creating more body roll than stiffer sway bars. The more body roll the more likely of the car bottoming out during cornering. A soft sway bar and a low ride height do not mix well. Stiffer sway bars make the car more (unintelligible) as you do not have to wait for the car body to settle or move from left to right before changing direction. Sway bars affect all areas of the corner. If the front sway bar is stiffer than the rear the car will understeer. This is as during cornering there will be less weight transfer so, the contact patch will be smaller than if there were a greater weight transfer. You’ll want to increase the front sway bar stiffness as far as possible however, as the reduction in car body roll makes the car more predictable. If the rear sway bar is stiffer the car will over steer, as the rear contact patch won’t grow as much during cornering so the rear will have less grip. You will want to reduce the rear sway bar if it feels as though the rear of the car is trying to overtake the front. Sway bars can be adjusted on the fly in Project Cars and you can increase or decrease. I would advise that you do this cause some corners the sway bars may be too stiff and you will get under steer. In other corners the body will excessively roll and this should be prevented for predictable handling.

Brake Pressure and Cooling

Brake Pressure

Brake pressure controls the force applied to stop the car when you press the brakes. Having a high brake pressure will make brake distances short but, will leave you more prone to locking up the wheel. This can be countered by modulating the brake which is when you slowly apply the brake up to its maximum pressure then start letting off the brakes as the car slows down. This is most easily done using a pedal box. If you struggle with locking brakes and brake balance adjustments don’t work, then reduce the brake pressure. It will increase your stopping distance as less force is applied to slow the vehicle but, will reduce the likelihood of a lockup. Set the brake pressure to be the highest possible as this will give you the shortest braking distances, but low enough to prevent rear lockups.

Cooling

Brake Ducts

Brake Ducts changes how fast the brakes cool. Cold brakes provide no stopping power. Overheated brakes also provide no stopping power so, you must control the temperatures of the brake by using the brake duct. Tracks like Monza you want to run with a closed brake duct that while the brakes will overheat the long straight afterwards will cool the brakes. Tracks like Monaco where you are constantly applying the brakes you want to run with an open brake duct to allow the brakes to cool between corners to prevent overheating. Too opened a brake duct however, will cool the brakes too much and you will lose all braking performance between the corners. The more closed the brake duct the less the aerodynamic drag of the vehicle so, the car will have a higher top speed. Run with the most closed brake duct possible without causing the brakes to overheat. Remember races are longer than qualifying so, if you begin to notice thermal buildup during practice you may want to open the brake duct to prevent this from becoming an issue in the race.

Dampers

Bump, Rebound, and Bump Stop. All three of these settings can be set individually for each corner of the car. Unless you are oval racing it is advised that you keep left and right the same. Front to back, on the other hand, is a different matter. Nine times out of ten they will be different.

Bump Stop

A Bump Stop is a small rubber ball or cone attached to the top mounting plate of your spring. The goal of the bump stop is to prevent the spring from colliding with itself when it is compressed. If the spring collides with itself you will get some very unpredictable handling with any shock cannot be absorbed. The bump stop increases the force required to fully compress the spring. The bump stop can be non-linear or they can be linear. In Project Cars the bump stops are linear, so this helps things. Instead of the cars behavior gradually changing as the spring is compressed the car will be normal and then suddenly very different, so when you notice the handling has suddenly become very different you know you’ve encountered bump stop. What is this different handling? Imagine the spring break has just doubled and the car is very suddenly stiff. If encountered on the front you’ll get under steer. If encountered on the rear you’ll get over steer. If you have a soft spring and to keep it soft then you want a high bump stop, this is to stop the spring from compressing too much and reaching the stage where it collides with itself. If you have a firm spring and you want to keep it that way then you want a low bump stop. The high spring rate should stop you from ever fully compressing the spring, but for those occasions where there is a sudden suspension mode the bump stop will be useful. Remember you should really never encounter bump stop. If you do it’s suggested you increase your ride height or increasing your spring stiffness. The bump stop is there as a safety device to stop you from losing control by preventing the spring from fully compressing. It really shouldn’t be used for anything but, preventing that from occurring.

Bump and Rebound

Bump is when the damper is compressed and Rebound is when the damper extends. You want different behavior for both of these. Fast and Slow – Slow is when you’re cornering the weight shifts gradually so, the springs and dampers actually get compressed and extended. Fast is when you go over bumps in the road then the suspension has to react quickly. You want different damper behavior in both of those circumstances. The damper ultimately resists the suspension displacement. So, in bump the damper will reduce the amount that the suspension is compressed. In Rebound the damper will reduce the amount the suspension extends. The stiffer the damper the more resistance you have. The more resistant it is the quicker the suspension will reach steady state and the less weight transfer there will be. Steady state is when the suspension compresses it’s not a linear compression it oscillates. These oscillations are bad for handling. If you have wheel turn it to full lock. If you have a controller pull the stick in one direction. This demonstrates oscillation. Now, when you let go the wheel will self-center and the controller stick will also self-center. Imagine that was a spring it wouldn’t self-center. It would go past the neutral position and go the other way and then start coming back and going backwards and forwards. That’s an oscillation. The damper aims to reduce this.

Slow Bump and Rebound

Cornering - The suspension will compress so bump on the outside for this is where the weight transfers to. The inside of the car will begin to rise so, the suspension on the inside will rebound. So, slow bump will resist the weight transfer again on the outside wheels making the car more predictable. Slow rebound will resist the weight transfer by stopping the suspension from extending so, in effect holding the weight back. This is why slow bump and rebound are much stiffer than fast is that they are preventing weight transfer. The stiffer they are the more it slows down the weight transfer through the corner. So, the more predictable the car will be as it will slow down any under steer to over steer transition. You don’t want it too stiff though otherwise it will be like driving a car with no suspension and the car will be very difficult to drive. The stiffer the front is the more understeer you will feel. The stiffer the rear is the more over steer you will feel.

Fast Bump and Rebound

This is when you’re going over curbs or a very bumpy track. Tracks like Monaco are more sensitive to fast damper settings than Silverstone. The fast settings are softer than the slow as here you want the suspension to react quickly to bumps in the road. If the suspension acts slowly the tires will be at risk of not being in contact with the road. Obviously, if the tires aren’t in contact you don’t have a lot of grip. Fast bump is how quickly the suspension can deflect after going over a bump. Too stiff and the tires are at risk of jumping over the bump. Too soft and the car is at risk of bottoming out or, the spring compressing too much.

Fast Rebound

Fast rebound is how quickly the suspension extends to come in contact with the road surface. Too soft and the car can bounce. Too stiff and the suspension doesn’t extend fast enough and the car could bottom-out. With slow and fast settings it is up to you to find the right balance. There is no golden ratio. Generally, the front is softer than the rear. Generally, the rebound is stiffer than the bump. There is not normally a huge difference between these values but the rebound to bump difference is normally larger than the front to rear difference. Dampers are a good way to fine-tune the handling without major changes to other parameters.

Radiator

Radiator in Project Cars refers to the radiator opening in the bodywork. The smaller the radiator opening (the more closed on the slider), the better. This is as openings in the bodywork will dramatically increase drag as recirculation zones appear and the air is dramatically slowed. The increase in drag will reduce top speed of the car. The bigger the opening the more downforce you are also losing as the bodywork is less smooth. So, less downforce is being generated by the wings and other devices on the car. A smaller radiator however, will lead to increased engine temperatures. This will increase the wear on the engine and will end the engine life being shorter. A smaller radiator will also cause sudden engine failure to be more likely. Always run with the smallest radiator you can get away with without compromising the reliability of your car. Throughout the race monitor your engine temperatures as shorter runs may hide heat build-ups that will become more apparent in the race.

Differential

Slip Preload

Always start with a slip preload. This is because this will affect your acceleration and deceleration differential behavior. A lower number will allow for better turning and the car will over steer more. This is how the differential is more opened. A higher number will make the differential closer to locking and the car will be more planted but, there will be more under steer.

Deceleration Lock

Deceleration lock is felt when you are off-throttle. If you are off-throttle and the rear doesn’t slide when cornering then reduce the deceleration lock as this will give better rotation and more over steer. If the rear slides too much when off-throttle then increasing the deceleration lock will give you more control and the rear will slide less. The best way to test this is too find a medium speed corner. Approach the corner with too much speed but, slow enough that you can take the corner. So, to take the corner all you have to do is lift off the throttle. When you lift off and turn in see what happens to the rear.

Acceleration Lock

Acceleration lock will be the most common thing to tune. A lower acceleration lock number will give a more opened differential when on throttle. This will give you better turning ability as the rear will slide more. However, if you are on full lock full throttle at low speed the inside wheel is likely to spin. This spin will cause the inside wheels to excessively wear as it is like doing a burn-out. A higher acceleration lock will make the differential closer to locking. This will mean the car is more planted but, it will understeer more when you apply the throttle.
When tuning a differential it is important that the car is balanced when off-throttle and when on-throttle. If the car under steers when off-throttle but over steers when on-throttle the car will wear you down and you’re likely to make a mistake. The best differential settings makes the car have the same handling whether on-throttle or off-throttle as the car will be predictable regardless of you throttle application. The worse you need is to be forced to lift off the throttle if there is an obstacle ahead for the car to suddenly understeer causing you to hit the obstacle more than you would have if you would have kept the throttle applied.

Gearing and Engine

Gearing

For Basic Gearing only adjust the final drive of the gear box. The shorter or, smaller the number is the quick you will change gears. This is as the car is under geared to allow you to have greater acceleration. Acceleration comes at a price though as your top speed will be limited compared to that of a car with a longer final drive. Acceleration is key at tracks such as Monaco but, at Monza while yes you can pull out the chicanes faster the straights are so long that you will easily be caught. Adjust the final drive so you achieve top speed when the car is in top gear and just about to red-line. If you feel you have the need to draft the car ahead in a race then allow some leeway before the red-line however, this will make you slower at qualifying.

Fuel Load

Fuel load is the fuel in which you start. Always run with the least amount of fuel you can as fuel is weight. Qualifying fuel load should be just enough for you to do and out-lap or 1 or 2 fast laps depending on whether you are a confident qualifier and an (unintelligible). The race fuel should be just enough to finish the race unless, you are endurance racing in which case how much fuel you’ll have before the first pit stop. When in practice find out how much fuel you use per lap then, multiply that fuel used by the number of laps you intend to run in qualifying to find the qualifying fuel load. Multiply the fuel used per lap by the number of laps in the race then add a safety margin so, you don’t run out. It is very unlikely you will use the exact amount of fuel for each lap in the race so, this is why you want a safety margin. One or Two Laps is usually enough. When you are drafting the car ahead you will use less fuel this is as there will be less drag as the car ahead is punching a big hole in the air for you and there is less resistance. Remember, fuel is used most when on throttle. If you are a person who frequently uses the throttle you will use more fuel then those who don’t throttle over-lap when on the brakes or, those who don’t lift the throttle to keep the turbo’s cold. Fuel averages can be measured on the car if the car has a multi-digital dashboard.

Brake Mapping

The Greater the brake mapping number the more throttle is applied by the ECU (engine control unit) when you are braking. The more throttle applied by the ECU the more fuel you will use. The ECU applies throttle to prevent the rear axle from locking. You can reduce the brake mapping setting if you feel comfortable doing this by yourself. The higher the brake mapping number the more the car will push into the corners so, the more the car will understeer. If the rear axle locks under braking then increase the brake mapping number.

Wastegate Pressure

Wastegate Pressure is the air pressure at which the wastegate will be opened relieving the pressure on the turbo. If the turbo pressure is too high it is likely to fail. The turbo pressurizes and feeds air before entering the engine. This means that fuel will ignite quicker as the maximum temperature during combustion will be higher. The fuel however, can detonate. Where rather than flame from propagating through the air/fuel mixture it instantaneously ignites. This will cause damage to the cylinder walls and the piston head and so, will increase wear on the engine. Have the wastegate pressure as high as possible as you will get more power but, make sure it is low enough to allow you to finish the race before the engine fails. The shorter the session the higher the wastegate setting you can use.

Restrictor

Restrictors will only be used if the series has a balance of performance rule or you are entering a car that has a superior top speed. The smaller the restrictor the less air will get to the engine. The less air the less power produced as the ECU puts in the right amount of fuel by measuring the air you will also use less fuel. The larger the restrictor the more air will enter the engine so, you will get more power.
De volgende gebruiker (s) zei dank u: marsj

Gelieve Inloggen om deel te nemen aan het gesprek.

  • Dave
  • Dave's Profielfoto Onderwerp Auteur
  • Offline
  • Gebruiker
Lees meer