Dampers and spring rate - how do they work together?

  • Thread starter JesasSpice
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does anybody have a good breakdown, of how dampers and spring rate work together...? My tuning is awesome...and I'm wondering if I have this down or if I'm just fluking it...I've read a lot of stuff but some of it is even conflicting...
 
I thought I had a pretty good understanding of matching damping rates to spring rates based on link ratios and wheel travel. Very little of my real world experience seems to transfer over to GT's virtual world. After setting up a car based on my knowlege, I am often surprised when a friend sends me a totally illogical set up for his car and it actually works better :nervous:

I don't know what physics model Kaz is using for suspension but I can't help but feel he pulled it out of thin air. Often times a front engine rear wheel drive car will rotate and turn better if the rear springs are set higher than the front spring level. The additional weight of the engine in the front always requires stiffer springs than the rear by a factor of 2 or 3 times in the real world. Typically, the rebound damping is matched to the spring rate very closely in order for the wheel to move up and down smoothly and follow the contour of the track surface. Seeing spring rates (in the game) set at 8 or 9 with dampers set at 1 or 2 makes no sense other than we have no way of knowing exactly what the 1 thru 10 settings actually corelate to.

To me, it's just not very real and I'm often surprised at what works and what doesn't. Everything just seems to be based on a classic "trial and error" technique and not anything based on actual suspension theory :nervous:

This, of course is my personal opinion :)
 
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Seeing spring rates (in the game) set at 8 or 9 with dampers set at 1 or 2 makes no sense other than we have no way of knowing exactly what the 1 thru 10 settings actually corelate to.
I think you hit it on the nail right there. The settings for springs/dampers/brakes are not absolute, they are relative to what you started with!

Almost all cars start out with something like 2/2 or 1/1 for springs and dampers and brakes at 5/5 (except some of the more exotic models). But I'll be damned if a spring/damper setting of 1/1 or 2/2 on a Cappucino is the same as 1/1 or 2/2 on a Corvette Z06. Same goes for brakes: every car starts out at 5/5. Yet some are more front biased (or even rear biased) than others to start with. I've tuned cars with a brake balance of 2/6 and they were still front biased. So the '2' at the front is actually higher than the '6' at the rear.

That's why I've always tuned by behavior, not by numbers. If the behavior of the car tells me to set the brake sensitivity at 1/9, the springs at 1/9 and the dampers at 9/1, that's what I'll do. ;) But I don't think the physics are faulty, it's just the dials/sliders that are not comparable. If you keep that in mind, you will find there is indeed logic in there.
 
this is what was bothering me...because the setup I run for my tuned Evo X is superb...now the GT-R is also a front engine four wheel drive with variable 4WD...granted the weight is different, but I have to set it up completely differently for it to work well...the GT-R is a tough car t tune I've found btw. I know there are other things, like the track and wheelbase that make differences...and even the torque curves are different, but still, you move those sliders and you don't really know what you're doing with that car.
 
I think you hit it on the nail right there. The settings for springs/dampers/brakes are not absolute, they are relative to what you started with!

Almost all cars start out with something like 2/2 or 1/1 for springs and dampers and brakes at 5/5 (except some of the more exotic models). But I'll be damned if a spring/damper setting of 1/1 or 2/2 on a Cappucino is the same as 1/1 or 2/2 on a Corvette Z06. Same goes for brakes: every car starts out at 5/5. Yet some are more front biased (or even rear biased) than others to start with. I've tuned cars with a brake balance of 2/6 and they were still front biased. So the '2' at the front is actually higher than the '6' at the rear.

That's why I've always tuned by behavior, not by numbers. If the behavior of the car tells me to set the brake sensitivity at 1/9, the springs at 1/9 and the dampers at 9/1, that's what I'll do. ;) But I don't think the physics are faulty, it's just the dials/sliders that are not comparable. If you keep that in mind, you will find there is indeed logic in there.

Good explanation 👍

But it doesn't explain how, for instance, lowering the ride height at the rear actually increases front end grip ?
 
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Can someone please elaborate on exactly what the dampers and spring rate means in terms of the tuning (separately of course)?
What influence each one has when set as high or low value and what is the basic technique to find out which parameter to change (dampers or spring rate) and to which direction?
A "quick guide" like: when car understeer - you need to change X parameter lower/higher, will be great.
 
Can someone please elaborate on exactly what the dampers and spring rate means in terms of the tuning (separately of course)?
What influence each one has when set as high or low value and what is the basic technique to find out which parameter to change (dampers or spring rate) and to which direction?
A "quick guide" like: when car understeer - you need to change X parameter lower/higher, will be great.

I think Scaffs guide to tuning might help you even though its for GT4 but the same basic principles apply. You can find it here: https://www.gtplanet.net/forum/showthread.php?t=104034
This article could also be helpful:
http://auto.howstuffworks.com/car-suspension1.htm
 
Like you I was initially confused at GT5P's tuning settings. They just didn't seem to make any sense. Why would having the rear springs on a FR car stiffer than the front work? The front should be dragging on the ground! It wasn't until weeks later that I realized the settings are car dependent. A spring setting of 6 on the Z06 tuned is not the same thing as a 6 on a Ferrari 599. With that out of the way and that in mind while tuning...

When tuning, I've found it's best for me if I tune the car for the track and then go back and tune over-steer/under-steer. In order of tuning I go points, brakes, dampers, ride height, springs, toe, camber, and then down-force. I often go back and make further changes as I refine the set-up. You have to tune the weight first since it affects all other suspension settings.

Dampers
Affect the "bounce" in the springs, or how quickly the springs stop after an input. They are used during inputs into the suspension and have their greatest affect on corner entry and exit.
  • Overall Soft: suspension reacts quickly to bumps maintaining traction, quicker transition to over/under-steer, too soft and the car will be "bouncy"
  • Overall Stiff: slows down transition to over/under-steer, if to hard suspensions reaction to bumps decreased and may be bypassed
  • Front Stiffer: increases under-steer
  • Rear Stiffer: Increases over-steer
  • Test: Run over rumble strips

Ride Height
Changes the center of gravity of the vehicle which changes weight transfer.
  • Overall: lowering reduces lateral and longitudinal weight transfer during acceleration, braking, and cornering. To low and you'll bottom out the suspension of the car.
  • Front Higher: Increases understeer
  • Rear Higher: Increases over-steer
  • Test on corners

Springs
React to irregular surfaces and changing weight distribution. Take cars overall weight and its distribution into account.
  • Overall Soft: react to bumps w/out losing grip, but need taller ride height
  • Overall Stiff: reduces roll under weight transfer allowing lower ride height, too high and you'll skip over bumps losing grip
  • Front Stiff: Increases Under-steer
  • Rear Stiff: Increases Over-steer
  • Test under cornering

Toe, camber, and down-force also play a roll in over/under-steer. I'll leave that up to you to research how. Don't tune over-steer by changing brake bias or camber. You'll affect your braking distance and cornering traction.
 
That is why I am so thankful for the shared tunes on GTP 👍:)

I do not have the time for the trial and error; I also printed a copy of the GT4 tuning guides also found here on GTP. Thank's so much again:)
 
Like you I was initially confused at GT5P's tuning settings. They just didn't seem to make any sense. Why would having the rear springs on a FR car stiffer than the front work? The front should be dragging on the ground! It wasn't until weeks later that I realized the settings are car dependent. A spring setting of 6 on the Z06 tuned is not the same thing as a 6 on a Ferrari 599. With that out of the way and that in mind while tuning...

When tuning, I've found it's best for me if I tune the car for the track and then go back and tune over-steer/under-steer. In order of tuning I go points, brakes, dampers, ride height, springs, toe, camber, and then down-force. I often go back and make further changes as I refine the set-up. You have to tune the weight first since it affects all other suspension settings.

Dampers
Affect the "bounce" in the springs, or how quickly the springs stop after an input. They are used during inputs into the suspension and have their greatest affect on corner entry and exit.
  • Overall Soft: suspension reacts quickly to bumps maintaining traction, quicker transition to over/under-steer, too soft and the car will be "bouncy"
  • Overall Stiff: slows down transition to over/under-steer, if to hard suspensions reaction to bumps decreased and may be bypassed
  • Front Stiffer: increases under-steer
  • Rear Stiffer: Increases over-steer
  • Test: Run over rumble strips

Ride Height
Changes the center of gravity of the vehicle which changes weight transfer.
  • Overall: lowering reduces lateral and longitudinal weight transfer during acceleration, braking, and cornering. To low and you'll bottom out the suspension of the car.
  • Front Higher: Increases understeer
  • Rear Higher: Increases over-steer
  • Test on corners

Springs
React to irregular surfaces and changing weight distribution. Take cars overall weight and its distribution into account.
  • Overall Soft: react to bumps w/out losing grip, but need taller ride height
  • Overall Stiff: reduces roll under weight transfer allowing lower ride height, too high and you'll skip over bumps losing grip
  • Front Stiff: Increases Under-steer
  • Rear Stiff: Increases Over-steer
  • Test under cornering

Toe, camber, and down-force also play a roll in over/under-steer. I'll leave that up to you to research how. Don't tune over-steer by changing brake bias or camber. You'll affect your braking distance and cornering traction.


This is really helpful. Thank you so much for taking the time to write it detail.👍
 
This is really helpful. Thank you so much for taking the time to write it detail.👍

It helps when you're an engineer at a company in the auto industry. I work in materials and never deal with this sort of thing, but have access to those who do and more importantly books on the subject.

I made a simple spreadsheet that lists everything we can change in GT5P and the effect it has on vehicle dynamics. I also have a tab with tunings so that I never lose them. This means when you are tuning you never have to look anything up. It's all right there in an easy step by step spreadsheet.

You can make your own spreadsheet based off of the GT4 tuning guide. Not much has changed, except the physics are a bit better making these real world effects even more appropriate.

Now if someone could only cure my over-excited lead foot on corner exit.
 
hahaha. I think that's the problem that we all have, which translate into obessesive GT game players.....lol
 
Like you I was initially confused at GT5P's tuning settings. They just didn't seem to make any sense. Why would having the rear springs on a FR car stiffer than the front work? The front should be dragging on the ground! It wasn't until weeks later that I realized the settings are car dependent. A spring setting of 6 on the Z06 tuned is not the same thing as a 6 on a Ferrari 599. With that out of the way and that in mind while tuning...
Exactly like I said a couple of posts back: the numbers really don't mean anything, they're just a starting point. :) Let go of the numbers and let the game do the talking. ;)
 
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