I want a basic setup for reducing under steer

[Middle]

Basically i have a DB9 that under steers horribly, could someone just post a setup of a car that has no under steer, so i can get an idea of where i should be setting my values!

Thank a bundle ;]

 

[SleazyBig slim]

stiffen your springs alot more in the front then in the back, also tune your brake bias to something like 3 front and 8 in the back:tup:

 

[Renfro88]

Start by making your rear springs stiffer. If that doesn't work stiffen up your rears even more and then make your front springs softer.

When I tune a car I start by going in big increments, like 15-25 pounds, and then as you start to find the sweet spot lower the increments to around 5 pounds each.

 

[Middle]

so i have front spring rate as low as possible and rear as high as possible... still loads of under steer, i think i need to so something with the diff, and what about the dampers?

Thanks

Unrelaed: I was jut playing in an online dickabout session and challenged a guy in the black racing zonda to a race round top gear test track. I was in a Lotus Elise... and i destroyed him... Seriously that car is phenomenal!

 

[Litzner]

stiffen your springs alot more in the front then in the back, also tune your brake bias to something like 3 front and 8 in the back:tup:

Do not use brake balance to loosen a car, unless you are doing it solely for a drift only setup.

 

[Vulcao]

so i have front spring rate as low as possible and rear as high as possible... still loads of under steer, i think i need to so something with the diff, and what about the dampers?

[...]

It's the opposite, dude . The higher the number, the softer the spring. So, the values for the rear must be low, and the front ones must be high. I don't recommed making rear springs stiffer in FR cars because you can lose grip and consequently acceleration at low speeds, even at straights. And don't just set everything to min and max, or your car might end up very unstable. Find the right balance instead. If you notice that when you start turning your steering wheel your car suddenly turns a lot and then stop turning so well, and then turn again and then stop turning and keeps on this cycle when turning, maybe your front springs are too soft.

I suggest you to change also the camber on the front wheels. I don't know the values exactly but you can start by 2.0.

I hope this helps.

 

[Litzner]

It's the opposite, dude . The higher the number, the softer the spring. So, the values for the rear must be low, and the front ones must be high. I don't recommed making rear springs stiffer in FR cars because you can lose grip and consequently acceleration at low speeds, even at straights. And don't just set everything to min and max, or your car might end up very unstable. Find the right balance instead. If you notice that when you start turning your steering wheel your car suddenly turns a lot and then stop turning so well, and then turn again and then stop turning and keeps on this cycle when turning, maybe your front springs are too soft.

I suggest you to change also the camber on the front wheels. I don't know the values exactly but you can start by 2.0.

I hope this helps.

Are you sure about the higher the value the softer the spring? That does not seem right to me.

 

[MrGrado]

camber can be tuned for cornering grip or tuning understeer/oversteer. try -4.5/-2.5 and -3.0/-1.0 etc to get what you are wanting. higher negative rear toe will give more oversteer too but i suggest working on camber first so you can get higher overall grip and tune out understeer.

High rear spring rate means less weight transferred to rear with acceleration and therefore front can still steer good but you can ruin your cars ability to ride bumps and curbs. Remember DB9 is likely to have more weight over front wheels so equal spring rates should work fine to start with.

 

[Vulcao]

But the guy is saying the car is understeering even with more weight over front wheels.

In GT5P* and GT4* Japanese version (NTSC?), the higher the value the softer the spring, trust me. 👍 So again, if a car is understeering, front springs need a higher value.

[EDIT] *I don't know about GT5, though

 

[HurlingDervish]

When you increase the "spring rate" you increase the kgf/mm

kilogram force per millimeter...

1 kgf = ~9.8N

To me that sounds like the more force per mm would make the spring harder, no? The less force on the springs would make them softer. Thus increasing the spring rate slider would make the springs harder.

I could be wrong but that's what it seems like to me.

They should probably rename "spring rate" or at least give better examples. I had no luck with google to find the answer, maybe someone else will

 

[freshseth83]

I think in GT5 it's not based on a 'value' but just their 'setting' if higher = softer than that's what GT5 goes by. It's not real life.

 

[Brokenparts]

Each car is going to be different so there is no solid answer for this question, not including track conditions, driver skill, different corners etc. but here is a general setup guide for reducing understeer.

softer front springs in relation to the rear
softer front roll bar in relation to the rear
softer front compression and extension settings in relation to the rear
less rear down force
if you have an adjustable diff lower the "braking response" setting, this will help the car turn in during deaccelartion or on the brakes
softer front brake settings in relation to the front


This is not more then a "general" guide and offers nothing more then a starting point for any veichle. The best thing you can do is learn how to tune the cars yourself, it will benefit you more then I or anyone else ever could.

Hope I helped 👍

 

[Brokenparts]

Do not use brake balance to loosen a car, unless you are doing it solely for a drift only setup.

If you reduce the front load under breaking, you are making more grip available for turn in so I dont see a reason not to use brake balance to help adjust how the car turns in

 

[premhz]

Stiffen the rear and soften the front springs. Only use low sway bar settings too. Try lowering our cornering entry and apex speeds. Fit better tyres too.

 

[1251Division]

When you increase the "spring rate" you increase the kgf/mm

kilogram force per millimeter...

1 kgf = ~9.8N

To me that sounds like the more force per mm would make the spring harder, no? The less force on the springs would make them softer. Thus increasing the spring rate slider would make the springs harder.

I could be wrong but that's what it seems like to me.

They should probably rename "spring rate" or at least give better examples. I had no luck with google to find the answer, maybe someone else will

You're right Dervish. The higher the value, the more force required to deflect the spring the given distance.

===

Consider two springs of equal length, say 1'-0", standing upright on the level ground. We will then place an identical weight on each spring, say 20-lbs.

Now let's say that one of the springs, Spring 1, has a stiffness, or spring rate, of 10-lbf/in, (pounds of force -- or "pound-force" per inch) and the other, Spring 2 has a stiffness of 5-lbf/in.

We now measure the deflected length of both springs. Spring 1 will measure (20-lb)/(10-lb/in) = 2-in shorter (total length = 10"); and Spring 2 will measure (20-lb)/(5-lb/in) = 4-in shorter (total length = 8").

From this example we can see that you would have to add an additional 20-lb to Spring 1 for the springs to be equal length.

(For more info -- more than you may have wanted to know -- see http://en.wikipedia.org/wiki/Hooke%27s_law)

I hope this helps!

 

[Fusion]

It is higher = harder springs just like real life. Look at the default values when you go from the height adjustable to fully customizable race suspension, they go up.

Have you tried adjusting anti-roll bars? Setting the back ones to higher than the front should induce more oversteer. This is me speaking from real life examples, if GT5 is not realistic, it may not work, but you would expect them to get such things right.

 

[shawtyoner]

One thing I don't understand when I read these posts is that everyone is saying to soften the suspension, yet race cars, or anytime a sports model comes out for a certain street going car, springs are always stiffer, so what gives?

 

[Malcolm Tucker]

What driver aids do you use? These can cause excessive oversteer, like GT4 (I used to install the 1.5 diff and turn all the aids off).

 

[Middle]

Thanks for the responses!

What i would really want to know is a definitive definition of the spring rate, which is stiffer high or low?

What i was hoping for would be somethign like this:

Nissan skyline GT-R V-Spec II NUR 02 by skylinemaster

Weight reduction-Stage 2
carbon hood
chassis reinforcement
full body kit
Rear downforce= 18

Engine= stage 3
computer= cpu tuning
Intake= sport manafold and racing air filter

EXHAUST
sport manafold
sport catalytic converter
titanium racing exhaust


Turbo= stage 3

Full customizable transmission
Clutch= twin plate
Flywheel= semi racing
Differential= ajustable lsd

LSD
Initial torque= 50/35
Accel sensitivity= 46/48
Braking sensitivity= 20/20

Suspension
full customizable
Ride high= -16/-19
Spring rate= 9.7/11.1
Dampers (E)= 7/7
Dampers (c)= 3/3
Anti roll= 3/3

Wheel Alignment
Chamber angle= 0.0/0.0
Toe angle= 0.00/0.19

Brakes= 8/8

Tyres= Racing Medium

But obviously related to a DB9!

And to be honest i am thinking of selling it, as i can lap so much faster in my Lotus than i can with this. My only problem however is that it will only fetch about 50K and i invested >300K in it, so i can't really afford to do that. Unless you can sell it to other players for a better price?

Thanks a lot =]

 

[YellowG1]

One thing I don't understand when I read these posts is that everyone is saying to soften the suspension, yet race cars, or anytime a sports model comes out for a certain street going car, springs are always stiffer, so what gives?

What's important is the relationship between front and rear rather than the absolute value of how hard the spring is, at least for racing purposes.

I think part of the reason sports models of street cars have stiffer suspension is to improve turn-in and reduce body roll. I think this is something most consumers can notice pretty easily (as opposed to neutral handling); most manufacturers build in understeer, even for sports models, for safety purposes. 90% of drivers will brake when they encounter understeer; it's an instinctual response and the right response on the street. Plus understeer doesn't sneak up on you like oversteer does.

 

[Vulcao]

[...]

What i would really want to know is a definitive definition of the spring rate, which is stiffer high or low?

[...]

Now this is something I'm also interested in. Again, in GT4 and GT5P Japanese version, the higher the value the softer the spring, BUT... as far as I can remember, in those games the unit used (kgf/m or whatever) for the springs wasn't visible when tuning, so I think it was just a generic value, not a real spring rate with a real unit. I don't own GT5 yet, but it seems that now the unit is displayed and therefore the value is real. So, it is most likely the higher the value, the harder the springs.

I suggest you to try adjusting front springs to max and rear springs to min., and then try the opposite. When you get too much understeer, it means that your front springs are very stiff and your rear soft; when you get some oversteer, it means that your front springs are soft and the rear stiff.

 

[shawtyoner]

What's important is the relationship between front and rear rather than the absolute value of how hard the spring is, at least for racing purposes.

I think part of the reason sports models of street cars have stiffer suspension is to improve turn-in and reduce body roll. I think this is something most consumers can notice pretty easily (as opposed to neutral handling); most manufacturers build in understeer, even for sports models, for safety purposes. 90% of drivers will brake when they encounter understeer; it's an instinctual response and the right response on the street. Plus understeer doesn't sneak up on you like oversteer does.

Thanks for the response. +1

 

[psychot|K]

Now this is something I'm also interested in. Again, in GT4 and GT5P Japanese version, the higher the value the softer the spring, BUT... as far as I can remember, in those games the unit used (kgf/m or whatever) for the springs wasn't visible when tuning, so I think it was just a generic value, not a real spring rate with a real unit. I don't own GT5 yet, but it seems that now the unit is displayed and therefore the value is real. So, it is most likely the higher the value, the harder the springs.

I suggest you to try adjusting front springs to max and rear springs to min., and then try the opposite. When you get too much understeer, it means that your front springs are very stiff and your rear soft; when you get some oversteer, it means that your front springs are soft and the rear stiff.

You sure it was opposite in GT4?

http://www.gtvault.com/gt4/tuning-guide/

"Spring Rates

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."

 

[Litzner]

If you reduce the front load under breaking, you are making more grip available for turn in so I dont see a reason not to use brake balance to help adjust how the car turns in

Brake-balance should solely be tuned to optimize stopping power. To use it otherwise is mostly improper tuning, you would be using to correct the shortcomings in your own breaking ability, or using it in place where adjusting other suspension settings would have a superior effect.

 

[tyoelin]

Might want to try taking off the LSD. It's driver's preference of course, but I always driver better without one.

 

[Brokenparts]

Brake-balance should solely be tuned to optimize stopping power. To use it otherwise is mostly improper tuning, you would be using to correct the shortcomings in your own breaking ability, or using it in place where adjusting other suspension settings would have a superior effect.

so I guess trail braking is is just a bandaid for an ill handeling car?