A few questions on tuning

[mikeyc]

I like to race cars that go around corners quicky and being new to GT6 I have read the various tuning threads and guides which have helped greatly with my understanding of what is happening to the car and how bits and pieces react. The thing is, these red front tyres, sometimes into, but mostly out of a corner under power. Sometimes two but mainly the outside front. My question is. How do you determine if the front tyre is skidding from lack of grip of the front end generally, or, is the front tyre skidding because of way too much weight moving to the outside causing the outside front only to lose grip and so go red? Comments and possible remedies please.

Second question is how do you determine when your springs are too stiff or too soft?

Next one. At what stage of spring adjustment do you start adjusting shocks?

For example: If you are tuning a car with racing hards you would be able to bump up the springs fairly high and then how would you know you have gone far enough and its time to adjust the shocks for the fine tune?

 

[Thorin Cain]

I like to race cars that go around corners quicky and being new to GT6 I have read the various tuning threads and guides which have helped greatly with my understanding of what is happening to the car and how bits and pieces react. The thing is, these red front tyres, sometimes into, but mostly out of a corner under power. Sometimes two but mainly the outside front. My question is. How do you determine if the front tyre is skidding from lack of grip of the front end generally, or, is the front tyre skidding because of way too much weight moving to the outside causing the outside front only to lose grip and so go red? Comments and possible remedies please.

Second question is how do you determine when your springs are too stiff or too soft?

Next one. At what stage of spring adjustment do you start adjusting shocks?

For example: If you are tuning a car with racing hards you would be able to bump up the springs fairly high and then how would you know you have gone far enough and its time to adjust the shocks for the fine tune?

This may be of some help, some one asked about this in here recently, the last post on page 3 and then page 4 should give you a couple of ideas. for your first question. GT6 Tuning Guide 1.15

For your second.

Soft springs:


Pros: Allows wheels to stay in contact with the road surface over imperfections which helps to maintain grip.

Cons: Allows body roll in vehicles and encourages weight transfer which can lead to instability during quick or violent directional changes.



Stiff springs:


Pros: Minimises body roll therefore making the car more stable and predictable during cornering. It also allows a lower ride height to be used because of the reduced likelihood of bottoming out the suspension.

Cons: Causes car to skip over bumps which can cause a loss of grip and twitchy, unpredictable handling.

I find this helps a lot to get me in the right ballpark. 👍 And helps with your third question...

You really want the best of both of these. You are looking for the best balance between stability and agility, so once you think you are pretty close to what you want and nothing else you do with the springs helps in any way, then it's time to move on to the dampers. There's no short cuts I'm afraid, just trial and error.

I hope these could be of some help, and please don't think I was having a pop at you by quoting the guides. These guys just explain things better than I do.

 

[demonchilde]

The thing is, these red front tyres, sometimes into, but mostly out of a corner under power. Sometimes two but mainly the outside front. My question is. How do you determine if the front tyre is skidding from lack of grip of the front end generally, or, is the front tyre skidding because of way too much weight moving to the outside causing the outside front only to lose grip and so go red?

I agree with Thorin 100%.

I will add this about Q1;
I am guessing you already know to play with your dampers on this, but know that if the front C and rear E don't seem to fix the issue, that ballasting kg to the back a bit and starting all over again is next.
My advice is simple, utilize your 3 settings tabs.
What helps me is Apricot Hill. the S curves in the first 1/2 of the track. drive through them, turn around, go back through, repeat back and forth until you know what your needing to work on.
This is where the 3 settings tabs comes in.
tab1 try front Comp 3, rear Ext 3
tab2 try 5 and 5
tab 3 try 8 and 8
make notes <-----important.
Now try moving weight backwards to rear 1 place. (like go from 50/50 to 49/51)
Now try your 3 tabs all over again.
make notes.
See where I'm going with this, lol?
Once you get good responce from a setting, now you can play with fine tuning around those.

Thorin is correct, trial and error is the name of the game.
Hope this helps a little.

 

[F1Racer68]

Looks like @Thorin Cain and @demonchilde already answered most of your questions.

I would like to add the following in response to your question about the springs:

• Springs support the weight of the car and allow the wheels to move in response to the track surface. This movement allows the tires to remain in contact with the road surface rather than skipping over it.
• Softer Springs provide more grip as the wheels/tires are able to respond better to varying track surface conditions.
  • Pros = more grip, better response to rough track surfaces, more stable (smoother) ride
  • Cons = Less responsive to steering input, more body roll, more weight transfer, ride height must be increased
• Stiffer Springs provide a more responsive feeling car in relation to steering input.
  • Pros = More responsive to steering inputs, better control of weight transfer, less body roll, ride height can be lowered
  • Cons = Rougher ride. Car is more prone to "skip" over bumps making it less stable and "twitchier". Less Grip as a result

Finding the "right" settings is all about feel. You want the springs as stiff as you can make them without getting into the negative aspects of a stiff spring. Also, take the ride height into account. Remember that ride height controls the Centre of Gravity of the car. The higher the CoG is, the less stable the car will be when cornering. A ride height that is too low can result in bottoming out, which has the same effect as an overly stiff spring of making the car "skip".

Once you have found a Spring Rate that you are comfortable with, then you need to adjust the dampers to fine tune the package. In regards to the dampers, I posted a rather lengthy piece about them on page 13 of @DolHaus 1.09 Tuning Guide thread (here) but I have also copied and pasted the main parts below.

In GT6 the dampers and settings work as follows:

• Low number = FAST (commonly called soft)
• High numbers = SLOW (commonly called hard)

So what's the significance of the terminology? It's simple. Dampers are NOT springs. They do not exert any force unless they are in motion and the force they do exert is resistance. Dampers are designed to control and limit the movements of the springs in order to dampen or stop vibrations. Without dampers on a car the wheel and car would continue to bounce after every bump much like the old horse drawn carriages did.

So what is a damper? A damper is simply a piston shaft inside a single or double walled cylinder filled with oil. As the piston is moved into the cylinder (compression) the oil resists the movement controlling the speed of the shaft. As the piston is pulled out of the cylinder (extension) the oil again resist the movement and controls the speed of the shaft. See the diagram below:

Note that nowhere in the diagram do we see a spring, or any other mechanism providing a lifting or extending effect. A damper connect to the cars chassis at the top and the wheel (A-Arm, or axle) at the bottom and is moved in and out by the movement of the wheel in relation to the chassis. As the wheel moves up due to a bump the damper is compressed. As the wheel is moved down by the spring the damper is extended.

By adjusting the speed of the dampers, we control how easily the piston can move through the oil. This is done by opening or closing valves within the damper that allow the oil to be "pushed" out of the way more easily, or to not be pushed as easily. For tuning purposes we need to consider the effects this has:

• Fast compression (low number) - allows damper to compress quickly, which means weight can transfer to that part of the car quickly
• Slow Compression (high number) - compression is slowed, which means weight transfer to that part of the car is slowed down
• Fast Extension (low number) - Damper is allowed to extend quickly from a compressed or neutral state allowing weight to be moved away from that part of the car quickly
• Slow Extension (high number) - Damper is prevented from extending, which means weight is held over that part of the car for a longer period

Understanding the impacts of the dampers on weight transfer is key in order to address many aspects of the tune. Weight transfer happens during braking, turning and accelerating. Controlling that weight transfer will provide you with a far better handling car.

After that, the last thing to work on is the Anti-Roll bars. These are used to control lateral (side to side) body roll only. They should be used to fine tune your cornering, whereas Springs and Dampers are used for all forms of weight transfer including Braking, Acceleration and Cornering.

I hope that helps.

 

[mikeyc]

Thanks boys for your time in replying. All good, the three of you have crystallised this issue for me, so now its back to Grand Valley and more laps. Much appreciated. Thanks again.

 

[PJTierney]

I have a follow up question about ground clearance; is there any objective way to know if a car is bottoming out? For example, are there any visual cues such as sparks or the car model clipping the track surface? I'm finding it hard to see the limit of ground clearance without suspension telemetry to be honest.

 

[demonchilde]

Well yes the game does show sparks but only on extreme bottoming out. Like the new Mazda vision car, take her for a ride on a bumpy track, even at max height the car is really low.
You will see height differences on replay. just change your camera to the chase setting.
You will also notice it in the feel of the drive. you will go from 100% control to wobbly in an instant.
Best way to test how low to set height is to run a track that jumps a little. Like the mountain track Eiger.
Theres a jump right after the starting line.
If you set-test-set-test on that jump (go medium speed, don't floor it), and find a setting that doesn't make you fight for control when you land, your golden.
HOWEVER, not all tracks have jumps to deal with like that. So if your going on a flatter track, you should lower it a tiny bit. Like daytona, has no real need to worry about bottoming out. But max low or max high is never really stable, so I advise you stay away from extreme settings.

Hope that helped some.

 

[DolHaus]

I have a follow up question about ground clearance; is there any objective way to know if a car is bottoming out? For example, are there any visual cues such as sparks or the car model clipping the track surface? I'm finding it hard to see the limit of ground clearance without suspension telemetry to be honest.

Bottoming out the suspension is quite difficult to do unless your springs are really soft (or going over big jumps). The tell tale signs are generally a dramatic change in handling characteristics in high load corners. You might feel it compressing and then suddenly letting go at either end and then rebounding, it will feel like the car is gaining and losing grip while bouncing if the front is bottoming out on entry, if the rear is bottoming out then you will get a much more dramatic snap of oversteer on exit.
Bottoming out the car is more common and happens when you straddle high curbs, this is noticeable as the steering or rear end grip feeling inconsistent and floaty.

The only way to know for 100% certain is to record a lap and check it in the data logger 👍

 

[PJTierney]

Does the data logger show ground compliance?

 

[DolHaus]

Does the data logger show ground compliance?

It shows suspension movement on the four corners of the car only, its not an overly accurate affair but you can tell by the general pattern if you are likely to be bottoming out the springs (large peaks of extension and compression)
As I've said before, unless your car is slammed and running really soft springs you'll struggle to bottom out the suspension through normal use so I wouldn't worry about it too much

 

[F1Racer68]

It shows suspension movement on the four corners of the car only, its not an overly accurate affair but you can tell by the general pattern if you are likely to be bottoming out the springs (large peaks of extension and compression)
As I've said before, unless your car is slammed and running really soft springs you'll struggle to bottom out the suspension through normal use so I wouldn't worry about it too much

This is very true. Extreme Ride Heights all cause their own issues, so you should stay away from them.

Remember though that the lower the ride height, the stiffer your springs will need to be in order to prevent the bottoming out from happening. This doesn't mean a drastic increase in spring rate, but you do need to take the ride height into account. Let's look at an example:

Generic FR street car, 1175KG, 54/46 weight distribution.

If we set the ride height front and rear at 90mm (average medium ride height) Then our spring rate would be as follows:

• Front Spring Rate = 7.05
• Rear Spring Rate = 6.01

And if we were to run the car at a Ride Height of 80mm then our springs would be:

• Front Spring Rate = 7.93
• Rear Spring Rate = 6.76

If we now lower that same car to say 70mm, then the springs need to be set as follows:

• Front Spring Rate = 9.06
• Rear Spring Rate = 7.72

The numbers above are not just random numbers. There are several variations of mathematical formulae that can be used to determine the correct spring rate. Several of those have been discussed in various tuning threads already. The one that I primarily use is as follows:

• (Total Weight x (Weight Balance Percent / 100)) / Ride Height = Spring Rate

In the example above the formula works like this:

• Front Spring Rate: (1175 x (54/100)) / 90 = 7.05
• Rear Spring Rate: (1175 x (46/100)) /90 = 6.01

I built myself a small spreadsheet calculator that I just need to plug my weight, ride height and weight balance numbers into and it spits out the spring rates.

NOTE: The above formula does NOT take into account the extra "weight" load of aerodynamics on race cars.

In regards to what can you see or feel if the car is bottoming out? In minor cases, such as bumps in the track you will see some sparks from under the car. In severe cases, such as over curbs, or severe bumps you may actually feel the car bounce sideways. If you feel a strong tendency for the car to step sideways in straight sections of the track, or in areas where you know the track is bumpy, then definitely look at a replay or the data logger info as you may very well be bottoming out.

I hope that helps.