Is this right? Checking Basic Suspension Tuning for Validity

[Techy]

If there's any tuners out there, can you help me by validating the following information? Had been studying the basics of suspension tuning in GT5 for a while and I want to see If I got it right or not. If there's any flawed points, please post it, and report the correct answer. And if there's any points that aren't mentioned but is important, please do so. And finally, If you see any "not sure" & "??" in the information below, please answer it the best way possible

Please note that this is just basic suspension tuning. So don't post advanced suspension tuning or drivetrain-specific tuning.

-- STARTS HERE --

Negative Camber: The sideways inclination of the front and rear wheels. More value = more contact w/ road, but less contact in high speeds/straights. Less value = vice versa. Not sure of independent adjusting.

Toe Angle: The angle of the front and rear wheels when looking down. More acute on toe angle = stable on straights, unstable on corners. Toe-in to front = understeer. Toe-out to front = increased steering sensitivity. Toe-in to rear = improve cornering stability. Toe-out to rear = oversteer.

Ride Height: Negative value to front = oversteer. Positive value to front = understeer. Negative value to rear = understeer. Positive value to rear = oversteer. Negative on front and rear = less center of gravity, but tires unable to contact with the road. Positive on front and rear = more center of gravity, but tires more able to contact with the road.

Spring Rate: Hardness of suspension. More = less pitch and roll & more sharply the car will move. Influences car movement & steering. Not sure of the advantage of lesser spring rate.

Dampers (Extension): ??
Dampers (Compression): ??
Anti-Roll Bars: Influences car rolling. Not sure of the effects of adjusting it.

-- ENDS HERE --

Apologize if this doesn't belong in this sub-forum or if it's too much for you guys. Just want to make sure my tuning is done correctly.

 

[Mubble]

Negative Camber: The sideways inclination of the front and rear wheels. More value = more contact w/ road, but less contact in high speeds/straights. Less value = vice versa. Not sure of independent adjusting.

Not sure I understand how you've phrased that.

The more negative the value, the more the top of the wheel will sit inside the arch - kind of like this when viewed from the front or back of the car / \

So it means more of the tyre will be in contact with the road during cornering. However, the amount of camber depends on the spring rates and roll bar stiffness.

Generally you want more negative camber at the front, compared to the rear, as its the front wheels which will have more weight over them when cornering, pushing the springs down more, thus requiring more camber to keep the tyres flat with the road.

Toe Angle: The angle of the front and rear wheels when looking down. More acute on toe angle = stable on straights, unstable on corners. Toe-in to front = understeer. Toe-out to front = increased steering sensitivity. Toe-in to rear = improve cornering stability. Toe-out to rear = oversteer.

Hmm, there's no hard and fast rule here. Again, it depends on the drivetrain of the car, the engine location (due to weight distribution) and the rest of the suspension set up. Yes, toe-out at the rear may provoke more oversteer generally, but this in turn depends on the set-up at the front, as the front may understeer heavily, counteracting the rear.

Similarly, toe in at the front may make turn in sharper, but tends to cause understeer.

Just click on the question mark symbol when adjusting your camber and toe setting for all the general detailed info you need.

It's one of those settings which just needs playing around with.

Generally I set my front to -0.05 and my rear to 0.05. Then I test that and adjust it from there.

Ride Height: Negative value to front = oversteer. Positive value to front = understeer. Negative value to rear = understeer. Positive value to rear = oversteer. Negative on front and rear = less center of gravity, but tires unable to contact with the road. Positive on front and rear = more center of gravity, but tires more able to contact with the road.

Not really. The fact that a value is 'negative' means nothing really. It's the relationship between the front and the rear which is important here. Having -5 at the front and -5 at the back won't make any difference to having -10 at the front and back. Well, not any noticable difference.

Again, the ride height depends on the spring stiffness and roll bar rating. Yes, having the rear slightly higher than the front promotes oversteer, but this is affected much more by having the rear spring rates set stiffer at the back than the front.

I just adjust the ride height for visual impact as opposed to any handling effect.

Spring Rate: Hardness of suspension. More = less pitch and roll & more sharply the car will move. Influences car movement & steering. Not sure of the advantage of lesser spring rate.

Correct. Lesser spring rate is sometimes used help the car pitch into a corner more, which effectively means it uses more of its weight over the front wheel taking the cornering load, which can lead to more grip. However, it can also lead to understeer if the tyre can't control the additional weight.

Dampers (Extension): ??
Dampers (Compression): ??
Anti-Roll Bars: Influences car rolling. Not sure of the effects of adjusting it.

The anti roll bar setting probably has the biggest effect on cornering ability. Generally I set this slightly higher at the rear than the front - by about 1 or 2. So front 4, rear 5 or 6 for example.

Dampers - think of the car braking. The rear of the car will lift up, the front will pitch down. With accelerating, this is vice versa. The damper settings adjust how prominent this effect is. Theoretically, you want the car to pitch a bit when braking as it helps transfer some weight over the front wheels, which helps them bite in to the road. However, again it's a balance between combatting the tyres from becoming overwhelmed and skidding.

Again, with the damper settings, the higher the number, the stiffer the damper. Therefore, a good base setting would be:

Extension: Front 6 : Rear 5
Compression: Front 5 : Rear 6

This allows some forward pitching when braking (as the front compression and rear extension is a little lower), but removes any unnecessary lifting when accelerating.

 

[Techy]

Thank you very much, Mubble. Much appreciated for your time 👍 And for the Camber response: What I mean of more and less value is higher negative camber and lower negative camber. And I already understand how camber works and how it impacts visual appearance. But thanks, though. By the way, I have 2 questions: What's pitch and roll, and car rolling?

 

[Mubble]

Pitching is when the car's nose dives down under braking - essentially the fowards motion of the suspension travel.

Roll is the just the sideways travel.

"Pitch & Roll" just incorporates both.

 

[iamjajo]

It's pretty early here so forgive me if I misread.

The toe descriptions seem wrong to me.

If you buy the customizable suspension. The default rear toe is usually +20, which is toe out. This setting will typically stabilize the car by inducing UNDERSTEER.

Toe settings have an additional effect besides aiding car stability. Having toe set at a value higher than zero aids the cars braking ability. The car slows quicker due to increased friction.

 

[Mubble]

It's pretty early here so forgive me if I misread.

The toe descriptions seem wrong to me.

If you buy the customizable suspension. The default rear toe is usually +20, which is toe out. This setting will typically stabilize the car by inducing UNDERSTEER.

I said toe out at the rear produces oversteer (or were you refering to the OP's description?)

I don't understand why the rear is always set to +0.20. It seem odd to me. In my opinion, this is a bad set up. Yes, a toe out at the rear would induce oversteer, but I'd want oversteer to come from a stiff rear setup, not the fact the wheels are pointing outward.

Toe settings have an additional effect besides aiding car stability. Having toe set at a value higher than zero aids the cars braking ability. The car slows quicker due to increased friction.

That might be true, however, I'm sure this is only noticable if you're using really big toe angles. And if your toe angle is reducing speed because the tyres are being dragged along the tarmac, then the set up is wrong.

 

[Techy]

Pitching is when the car's nose dives down under braking - essentially the fowards motion of the suspension travel.

Roll is the just the sideways travel.

"Pitch & Roll" just incorporates both.

Thanks! Another question: What does Initial torque, Initial acceleration, and Initial brake mean on an LSD? Does it mean when you have it higher, the LSD triggers according to initial torque or something?

 

[Mubble]

Basically you're setting the point at which then LSD kicks in. The easiest way to learn about this is to click of the question mark in the LSD settings screen. It explains in detail what each setting does.

 

[jack5428]

i didnt read all of your tuning thoughts but i will say this about ride hieght. your right on the front and have the rear backwards. I think.

heres how I think about it if you want more grip you raise the ride if you want less you lower the ride. say you have a car thats underpowered but you would like the rear tires on corner exit to slip some when you go full throttle and it wont burn rubber at all. lowering the rear will make the tires slip. if you have a car that roasts the tires to much on corner exit you can raise the rear ride and on some cars make it impossible for the rear to slip at all.

it works similar on the front. you turn the wheel and it doesnt want to turn very well so you raise the front and it will turn in more. it also will affect how the rear behaves tho on corner exit usually.

easy rule of thumb i find is if its understeering quite a bit. i drop the rear full and raise the front until it behaves acceptable both in turning in and corner exit. raise the front to high and its a super red tire drifting machine. just the right amount and good throttle control and its faster than heck. figuring this out got me my first top ten in a seasonal TT.

cars that oversteer to much...well usually Its not such a problem and i will run them as low as possible front and rear and adjust dampers and ARB and LSD to get them to behave and maybe use Steering AID Strong. Only on elises have i ever ran a higher rear ride hieght than the front. oversteer doesnt describe how crazy they handle.

 

[Johnnypenso]

This is just my opinion as a humble master tuner but I see a few things here I'd disagree with.

First, there is a bug with the front/rear ride heights. In theory, if you tune a car up with equal ride heights and it handles ok, then you lower the front, it should induce oversteer, as you are slightly increasing weight tranfer to the front under braking. However the opposite is true. Take any car you have that you like the handling of, raise the front +5 - +10 and it should understeer like mad. The opposite will happen. So, what I do is tune most of my cars with the equal ride height, then tune springs, dampers, toe etc. and do the best I can but if I can't tune out over or understeer that way without some wacky settings, I adjust the front or rear ride height up or down to get the effect I want. Most cars will handle quite well with equal ride heights and I'd say 75% of my cars are set at equal and lowest ride heights front and rear and the other 25% most are only 1 or 2 different in ride height.

Second, in my opinion, lowering the ride height as far as possible works with just about every car. The cars are more stable, and more predicable and corner faster. They are more stable and predictable because there is slightly less body roll.

Third, I've found that most cars can be tuned using almost the exact same formula for the settings. For example, most street cars weigh 1000-1400 kg after max weight reduction. on your average street car if you add up the spring stiffness settings to say 20 at 1000kgs and 23-24 for 1400 kgs and then divide that amount according to the weight distribution of the car you'll be pretty close to where you want to be. You'll find the weight distribution in the ballast settings.

For example, for a car weight of a thousand kgs you'd want a spring rate total of 20 front and rear, but split according to the weight distribution. So if it's 50/50 you'll get 10/10 for the springs. If it's 45/55, you'll get 9/11. If it's 60/40 as some front wheel drive cars are, you'll get 12/8.

Something that also works almost every time is setting the dampers and ARB at around 5/4/3 for a spring stiffness of 10 and then up to 6/5/4 for 11-12.

For most street cars with racing softs on 2.0/2.0 camber works well.

For RWD LSD, I set most cars to begin with at 8/12/5. I usually only change the ACCEL settings and then only to correct inside or outside wheelspin. If you are spinning out or losing the rear end coming out of the tight corners or under hard acceleration by lighting up the outside tire, lower the second value about 2 points at a time. If you hear the engine overrev out of the tight corners, you'll notice the inside rear wheel changing colour (lighter or maybe red in severe cases). I have never found any advantage to the extremely high LSD settings I see some tuners use on their cars and you'll find I think that a lot of them are tuned offline where there is enhanced grip levels. I run my GT-R GT500 car at 8/11/5 for online racing if I remember correctly, and have no issues with wheelspin at all on nearly every track, running 1:06's at Deep Forest and 1:16's at Trial Mountain online for example.

For FWD LSD, it's a little different and I start at 8/30/5. You want to avoid inside wheel spin at all costs under acceleration with FWD as it induces mad tire wear and lost acceleration. If this is occuring, set the ACCEL value higher, but this is not usually an issue with racing softs.

I tend to tune the toe last, and then only to either enhance rear stability under hard accleration by increasing + rear toe, or help with turn in if the car is stable enough to handle it by increasing - front and possibly rear toe. It changes by car. On a BMW GTR, a very neutral car, adding - front toe helps with mid corner and exit turning ability. On a 700 hp RWD car it might induce oversteer. You have to play with it to find what works. FWD cars naturally are very stable in a straight line and can benefit greatly from - toe both front and rear as can 4wd cars.

One other tip is, try to tune cars under around 550pp with as little downforce as possible. Under 500 pp, no downforce at all. Downforce does increase cornering speed slightly, but with racing softs its not usually an issue with street cars. In a PP limited racing room, less downforce = more horsepower and adding 35 hp by using less rear downforce will produce faster lap times in just about every case. Try it for yourself and see.

You have to set up your Transmission to account for the torque/hp curve of your cars engine. Let's say you are at GVE ad 550pp and topping out at 290 km/hr in real speed. Every car is different of course, but if your car redlines at say 10,000 rpm but power peaks at 8000 rpm at 450 hp and drops off to say 300 hp by the redline (guesstimating from the lame power curves they give you in the cars tuning page) it doesn't make sense to set your transmission to top out at 300 km/h when you'll be redlining and only producing 300 hp at top speed.

Depends on how sharp or gentle the power curve is, but in this case you'd want to set the transmission up to top out at about 350 km/h or around 8500 rpm in top gear when you hit top speed. You'll want to shift in every gear around 8500 rpm to keep the cars motor operating in it's highest power range. If the power drop is gentler you can shift at 9000 rpm or higher, and it's different from car to car, so you'll have to figure it out as you go.

Last, the brakes. Most people use ABS=1 and that's all you'll need. In real life, brakes are set up with huge front bias, because with racing tires and hard braking, 60-80% of the weight is on the front tires so a brake bias of 70/30 for example will work well.

In my opinion, in GT5, the neutral brake setting of 5/5 does not indicate equal brakes front and rear, but rather is the adjustment value for brakes that are already adjust properly for that particular car. So behind the scenes, the cars are set up for 70/30 for example, and the 5/5 is how you adjust that setting, not the actual value of the brake setting, if that makes sense.

I find most people put way too much front bias on the brakes, and even 5/5 is too much front bias. Most cars with 50/50 weight balance work well with 5/7 and 5/8 settings. To test this, take a car out to a track like GVE, and when you hit the start/finish line, floor the brakes and watch the tire temp indicators. If they both remain the same shade, the brakes are equal. If one is colder, you need to up that value. If one is hotter you can lower the value. You'll find that with all cars, 5/5 will almost always light up the front tires.

Setting up the the brakes properly also aids in cornering. If you have too much front bias, and hit the brakes at say 300 km/h in the first hairpin at Grand Valley, you'll heat up the front tires. When you begin to corner on hot tires, you'll usually find the outside front tire going red. Once it does this, it loses traction, resulting in understeer, push, and slower cornering speeds. With a proper brake setting and braking at the right place, you can usually avoid the red tire and corner faster, it's that simple.

 

[peterjford]

Lots of good info here, so I only have 2 small tips:

Increasing the rear toe-in can help with stability under braking with MR cars. If I am getting lots of lift-throttle oversteer (Elise!) I will increase the rear toe-in to about 35 and then do small adjustments from there.

On very bumpy ('Ring) tracks or if you like to pound the curbs, you might want to soften the dampers by -1 or -2 to keep the car from jumping and lurching too much.