Pressures: I run lower pressures on dirt and offroad than I do on tarmac. I do generally look for 33psi (2.27bar) on tarmac. I also look for equal pressures on the tires when they’re up to temp. Gearing: Set final gear to the max speed you want (or can obtain), set 1st gear to get the wheelspin you want off the line, adjust others to ensure you stay in the powerband with each shift, leave the top gear alone. Alignment: There is no 0 camber setting that will work for every corner. Some corners have more, others less, and your line and speeds will vary. Tune for time in the course and the feel of the car. Antiroll Bars: Stiff ARBs keep the car flat through cornering, meaning the inside tire has a larger contact patch than it would if allowed to roll more. Too stiff and you prevent sufficient weight from getting to the outside tires, reducing grip. How you balance them depends on how you prefer to tune, but I prefer to use them to account for unsprung weight and grip characteristics. Some people like to match weight distribution. Some people just go 1/65 and hope for the best. Springs: High enough to handle your sprung weight and aero over your targeted surface, not so high that the tire loses contact with the road over bumps. That gives you a pretty broad range of spring stiffness. Within that, springs that are too soft will result in the car becoming unbalanced under weight transfer. (also, watch this: What's The Best Suspension - Soft or Stiff Springs? - YouTube) Dampers: Tuned to reflect your spring settings. If you’re running soft springs, run proportionately soft bump. Rebound should be between 1.5 and 2.0 times the bump rating. Differential: There is no universal setting. My tunes vary wildly depending on the car’s characteristics. This should be the last thing you tune on the car. Use this to neutralize oversteer and understeer related to acceleration and braking.
A couple of things to add, that he didn’t address. If your castor is too high, you will get what l think they call layout. Your front end will pull you almost off the road. You’re going beyond the limitations of the combination of your tire/wheel size, camber, and ride height. As l said, it will feel like your front end is pulling you off the road, and when you get airborne you’ll end up sideways, because it’s so hard to get back to center. If your castor is correct, your wheels should line back up to center almost on their own. When exiting corners, you shouldn’t have to correct. I can basically let go of the wheel once l’m exiting the corner. Start at 4 degrees, then go from there. As l said before, camber, wheel/tire size, and ride height will change this number, but not by much. Everything l drive is between 4 and 4.3 degrees.
With regards to camber: On the “tires/General” section of the telemetry, it shows your camber as you drive. I assume you know this because you mentioned zero camber on your inside tires when cornering. Hit a dirt road or field. Driving slowly, you should be flipping between negative and positive camber. The negative symbol should be flashing on and off. My front is between -.9 and -.7. There’s a thread that l explain camber in more detail. It’s titled fh4 camber. I commented yesterday on it, so it should be easy to find. Also, if you’re on flat ground, not moving, the friction numbers should be the same on all four wheels. preferably at 0. If you’re not at 0, it’s a good indicator that your contact patch is off. Your tires will also heat up too quickly and get too hot. Good luck, and greetings from Tennessee, USA
Hello from Minnesota. We still have snow on the ground.
Just note that all of my tips will be for tarmac, since that’s what I tune best at. For off-road, you might have to ask other people. Suspension tuning is all about balance!
Tires: I’m still trying to figure out tire pressures, but I’ll tell you what I know. More weight = more tire pressure. This also applies to weight distribution, so if the car has 55% of it’s weight up front, then you’ll need a little bit more pressure in the front and a little bit less in the rear. You want the tires to have enough pressure to be responsive and quick. Too much tire pressure, though, and your contact patch between the tire and the road will shrink, resulting in less grip and a skittish feel. Too little pressure, and the car will respond slowly and be a little sluggish. This is one thing you’ll have to play around and experiment with, but once you figure it out it helps a lot!
Gearing: Before you tune gearing, look at your engine’s power band by going to the upgrade menu and go to one of the engine upgrades. You should see a graph showing two lines: torque and horsepower. The shape these lines make will determine how you would set up your gearing. Engines of larger displacement (American V8s, for example) have a lot of torque in the lower RPM range. Engines of smaller displacement (Like Japanese I4s) don’t have as much torque, but they got some good power higher in the RPM range.
When you’re tuning gearing, refer to the graph of the gears on the right. When adjusting individual gears, turning the slider towards speed would make the line for that gear grow longer and move slightly to the right. Sliding it to the acceleration side of things would shorten the line and move it to the left. Final drive extends/shortens all of the gears without changing the RPM range.
For tuning engines with a lot of torque in the lower RPM range, you must decide how many gears you want (If you don’t drive using manual shifting, I highly recommend learning to use it. It might be hard at first but with practice it’ll be like breathing). With these type of engines, it’s probably better to only use the first 4 gears. Basically I don’t touch the final drive and just lengthen the 4th gear to where 6th gear is, then adjust 3rd and 2nd gear to fill up the space that 4th gear left. This is so when you shift, your RPM drops lower to tap into those extra torque reserves. Then you tune the final drive so you’re going at top speed in your top gear (In this case, 4th gear) at redline.
For tuning engines that have more power higher in the RPM range, you want to have the individual gears tuned more for acceleration, and use more gears. You want the RPMs to stay higher in the range to keep the power high.
For general guidelines, you don’t want the gears to be too short or too long. Too short and you won’t get anywhere while shifting through all your gears. Too long and your car will struggle to move. First gear is especially important to tune. After tuning each gear, make sure to adjust first gear so you get a good launch. You want it long enough to gain good speed, but short enough so you don’t bog down.
Alignment: Camber adjusts the angle of the tires when looking from the front of the car. Negative camber turns the tops of the tires inward, while positive camber does the opposite. You want some negative camber in the car so when you turn, the outside tire is angled perpendicular to the road for maximum contact patch. Too much negative camber and the tires won’t align to the road properly, same condition with too little camber. Use the telemetry menu to tune camber by looking at the tire temperatures. If the inside of the tire is hotter than the outside while turning, then use a little bit less negative camber. If the outside of the tire is hotter while turning, then use a little bit more negative camber.
Toe is the inward or outward angle of the tire viewed from the top. Toe in angles the fronts of the tires inward, while toe out angles the fronts of the tires out. Toe in makes the car more stable but turn-in response is dulled a bit. Toe out makes the car more responsive but more unstable. You generally want toe in on the rear tires so they can be more stable. If RWD, do not toe out your rear tires! For the front tires, toe out would be more appropriate for better turn-in response. You generally would only use up to 0.4 degrees of toe, any more than that and the tires would start generating too much friction and would be detrimental to the car’s handling. You can try using more than that, but I just about only use 0.1-0.2 degrees both ways at most.
Anti-Roll Bars: Anti-roll bars are useful in the fact that they don’t do anything in normal up and down motion, but when the car rolls the ARBs twist and provide side to side stiffness. Stiffer ARBs load the outside tires more, while softer ARBs evens the load more. More roll causes the tires as a pair to lose grip, so you want to limit roll as much as you can without overloading the tires too much. Stiffer ARBs in the front increases understeer, while softer ARBs in the front decreases understeer. Stiffer ARBs in the rear increases oversteer, while softer ARBs in the rear decreases oversteer. You want to find a balance between oversteer and understeer so you have good grip in the corners without sliding or understeering. Remember, you want them as stiff as possible without compromising grip!
For RWD cars, most of the time you will have stiffer front ARBs in the front and softer ARBs in the rear, while FWD and AWD will have stiffer ARBs in the back and softer in the front. But ultimately this depends on weight distribution and tire setup.
Springs: Springs stiffness determines how much force it takes to move the spring a certain distance, so it should be fairly obvious what stiffer and softer springs do. Generally you want the springs to be as soft as possible without the suspension bottoming out (You can see if it is using the telemetry menu). You’ll also want to keep in mind your weight distribution and your tire setup. If your car is front-heavy (Which is very likely in AWD cars), you want stiffer springs in the front and softer springs in the rear. For mid or rear engine cars, the weight distribution might be biased towards the rear, so you’ll want stiffer springs in the rear and softer in the front. As for tire setup, a staggered tire setup (Rear tires are thicker than the front) likes to have softer springs in the front.
With ride height you want the car as low as possible without bottoming out the suspension or the car itself. Lower ride height requires stiffer springs, and vise versa.
Dampers This one I have been stuck trying to figure out for quite a while now, only a couple of days ago did I figure out exactly how to tune them. Get some paper and a pencil if you need it, just so you can see visually what I’m talking about.
Dampers help control the movement of the suspension. Without dampers, the car would oscillate up and down like a guitar string. This would negatively impact handling because the tires will never be evenly loaded. Stiffer dampers have more resistance, while softer dampers have less resistance. The important part, though, is they only impact the suspension when it’s moving. Dampers will not have any effect on the suspension on the straights or in the middle of the corner, when the car’s in a steady state. The dampers come into effect when the car is doing a maneuver, i.e. braking, accelerating, steering, or a combination of both. In this sense, dampers can act similar to ARBs when moving (We’ll elaborate on this more). Dampers can improve acceleration and braking, but the main thing we’ll focus on is how we can improve handling in the corners in a couple of scenarios.
So just visualize a car and you’re looking at it from the top down. (I’ll make a diagram, too.)
LF 0-----0 RF
LR 0-----0 RR
Scenario: Braking + Turning Left (Corner Entry)
So when the suspension is compressed, the dampers go into their “bump” mode. When the suspension is extended, the dampers go into their "rebound"mode.
In this case, we’re braking and turning left. So the weight is shifting forward and to the right. Shifting forward, the front suspension goes into bump, and the rear suspension goes into rebound. Shifting right, the suspension on the right is going into bump, while the suspension on the left is going into rebound. Because this scenario has a combination of the two, the RF is going into bump, the LR is going into rebound, while the LF and RR are not too important (We’ll consider them neutral in these examples).
To tune the dampers for this scenario, we will be tuning only the front bump and the rear rebound. Remember that dampers act like ARBs when they’re moving, so a softer front bump setting will act like a softer ARB, while a stiffer rear rebound will act like a stiffer ARB and vise versa. So when you’re braking and steering and you want your rear end to have a little more oversteer, stiffen the rear rebound. If you want to have a little less understeer, soften the front bump. Just remember that suspension tuning is all about balance, so too stiff or too soft is never good for your car.
Scenario: Accelerating + Turning Left (Corner Exit)
Since we’re now accelerating and still turning left, the weight is shifting to the rear and to the right. This means the LF is going into rebound and the RR is going into bump, while RF and LR are neutral. To tune the dampers for this scenario, we will tune only the front rebound and the rear bump. Say you need a little bit more oversteer, then you can dial in more rear bump, and if you want less oversteer then use less rear bump. If your car is understeering a bit on corner exit, then you can soften the front rebound. If the front end feels like it’s a little loose and unresponsive, you can try increasing front rebound.
So as a general guideline, here is a layout of what to use when tuning dampers.
Front Rebound <— Corner Exit, Front Wheels (Increase = More understeer, Decrease = Less Understeer)
Rear Rebound <— Corner Entry, Rear Wheels (Increase = More oversteer, Decrease = Less Oversteer)
Front Bump <— Corner Entry, Front Wheels (Increase = More understeer, Decrease = Less understeer)
Rear Bump <— Corner Exit, Rear Wheels (Increase = More oversteer, Decrease = Less Oversteer
Dampers only effect suspension when in movement, for steady state handling tune ARBs, Suspension, and Downforce!
Differentials: Limited slip differentials allow the driven wheels to move independently of each other up to a certain point. Higher % means less difference is allowed between each wheel. 100% is a locked diff, while 0% is an open diff. When you’re on the throttle, the diff switches over to the “accel” setting, while when you’re off throttle the diff switches to the “decel” setting.
For front differentials, you almost always want the decel setting to be 0% to prevent any off-throttle understeer from the differential. The amount of accel you need depends on the amount of power the car has. You generally want the differential accel setting to be low enough to allow the car to steer, but high enough to prevent “one wheel peel”, “one tire fire”, etc. Basically when all of the torque goes to one wheel and the wheel breaks traction and spins. You want both tires to put down power.
For rear differentials, the same concept applies for the accel setting. For the decel setting, you don’t want it too low or the car will oversteer off-throttle. Too much and the car will have poor handling. Most cars when putting in a race differential automatically have 75% accel and decel, so I always set the accel to 50-65% and the decel to 25-35%. You’ll have to tune this by feel.
