Updated: Spring Rate Ratios

[ACGreen86]

My question is pretty simple. Do the numbers displayed for spring rate actually matter, or is the spring rate slider simply a 0% to 100% slider with the numbers being arbitrary? Is 4.55 spring rate the same for two completely different cars, or would I use the slider position instead?

EDIT/UPDATE: Turns out I was able to find out on my own. It seems like the actual spring rates do matter and you can tune other cars to handle in a similar manner by using mathematical ratios. Here's what I wrote further down to try to explain how:

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Take the total weight of the car, multiply it by the percentage of weight from front/rear to find how much weight is over the front/rear. Divide the numbers by the spring rate from your favorite car, and boom you've got the ratio.

Example:
Car total weight: 1200
Car weight balance: 55/45
Spring rate Front/Rear: 8.00/6.00 <-- These are made up and not actual spring numbers for any car
1200 * .55 = 660 <-- Weight over the front wheels
1200 * .45 = 540 <-- Weight over the rear wheels
660 / 8.00 = 82.5 <-- Front Spring Ratio
540 / 6.00 = 90.0 <-- Rear Spring Ratio

Then, you just do the same process with a different car. When you get the front and rear weights, divide them by the appropriate ratio to get the spring rate you want.

This is an example of how you can make your own spring rate ratios. Note that it doesn't work for every car due to different models having different levels of grip, and cars that naturally have down-force will also handle differently. Your mileage may vary.

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[TexasTyme214]

I think the slider position is what's most relevant. 4.55 isn't the same from car to car and not necessarily the same from front to back on the same car (see the GT-R GT3).

 

[DolHaus]

The amount of weight acting on either end of the car will affect the springs relative stiffness.

ie.
If a car has 4.0kgfm springs at both ends and a weight distribution of 50/50 then both ends are sprung equally

If a car has 4.0kgfm springs at both ends and a weight distribution of 60/40 then the rear springs are effectively stiffer despite having the same numeric rating


A springs rating can depend on a lot of factors such as weight, suspension type and the length and positioning of the spring/dampers. I don't think you would be able to find two cars of similar enough design to draw comparison unfortunately.

For tuning purposes I'd say treat them as sliders, if you are intending to build replicas and need to know what translates and what doesn't then you might need to talk to one of the many specialists in the tuning forum.

 

[ALB123]

Frankly, I think the OP's question is redundant, although I don't think he intended it to be. Of course editing the spring value is similar to moving a slider from 0% to 100% because whatever the lowest available value is will result in the least amount of available resistance while the highest value available for a particular car's suspension will result in the stiffest amount of resistance possible with that particular spring.

If one car offered values of 5.0 to 12.0 and another car offered values of 8.0 to 15.0, no I do not think that 10.0 would result in the same amount of stiffness on both cars. Other factors come into play like @DolHaus mentioned, such as weight distribution and even vehicle weight.

However, I say all of this IF Gran Turismo 6 is replicating real life. If it's not, then everything I just said is probably incorrect. Therefore, I would suggest doing exactly what DolHaus suggested and talk to the respected tuners on GTPlanet. They have all spent vast amounts of time investigating these matters. In the mean time, in accordance with DolHaus's suggestion, I would continue to think of each car's spring rate value as a slider like you proposed, offering a linear degree of increasing resistance.

I think this is probably the biggest conundrum when it comes to tuning in Gran Turismo. There is no GT Manual that explains any of their physics implementations. For example, if you ask 5 people on this website their opinion on how tires "work" in terms of providing grip level, you undoubtedly will get 5 different answers because PD has never provided any meaningful information on how they implement their tire model. It is beyond frustrating.

 

[ACGreen86]

Thanks for the help guys. I was going to see if I could make some ratios with the Weight, Weight Distribution and Spring settings to make one car handle like another car, but if it's just a percent slider then that complicates things a bit. I'll ask on the tuning forum as well and see what they've got to say about it. Again, thanks for your help!

 

[Bluesman81977]

Thanks for the help guys. I was going to see if I could make some ratios with the Weight, Weight Distribution and Spring settings to make one car handle like another car, but if it's just a percent slider then that complicates things a bit. I'll ask on the tuning forum as well and see what they've got to say about it. Again, thanks for your help!

I don't know if I tune the right way but when I buy a customizable suspension for any given car I always adjust the slider to about one third of the space of the scale. Usually put the dampers at about 4. So the spring rate is about equal to the dampers. Suspension tuning always confused me.

 

[ACGreen86]

Well believe it or not, my initial testing with tuning based on the numbers being the important part are looking pretty good! It seems that GT6 really DOES emulate real life to a certain extent. It's confusing sometimes because certain cars have different limits (like lambos having crazy high minimum spring rates for example), however it seems that if you set your cars to have the same "ratio" of spring rate per their weight it really does handle (almost) the same.

For reference I tuned a Celica XX and a Superbird. After giving both cars the same "HP vs Rear weight" ratio, and the same "Spring Rate vs Weight Front/Rear", the two cars handle almost exactly the same. All other settings were exactly the same between both cars. The only different settings were Spring Rate and HP, which were set using ratios vs weight.

 

[DolHaus]

Thanks for the help guys. I was going to see if I could make some ratios with the Weight, Weight Distribution and Spring settings to make one car handle like another car, but if it's just a percent slider then that complicates things a bit. I'll ask on the tuning forum as well and see what they've got to say about it. Again, thanks for your help!

For those purposes the numbers are accurate enough. All cars in GT use the same basic weight distribution physics, some cars have hidden values so it won't be 100% accurate but for your purposes they should suffice

 

[Bluesman81977]

Well believe it or not, my initial testing with tuning based on the numbers being the important part are looking pretty good! It seems that GT6 really DOES emulate real life to a certain extent. It's confusing sometimes because certain cars have different limits (like lambos having crazy high minimum spring rates for example), however it seems that if you set your cars to have the same "ratio" of spring rate per their weight it really does handle (almost) the same.

For reference I tuned a Celica XX and a Superbird. After giving both cars the same "HP vs Rear weight" ratio, and the same "Spring Rate vs Weight Front/Rear", the two cars handle almost exactly the same. All other settings were exactly the same between both cars. The only different settings were Spring Rate and HP, which were set using ratios vs weight.

Wow that wasca lot of info to digest at once. Lol! I need a basic tutorial or something.

 

[GTP_CargoRatt]

Frankly, I think the OP's question is redundant, although I don't think he intended it to be. Of course editing the spring value is similar to moving a slider from 0% to 100% because whatever the lowest available value is will result in the least amount of available resistance while the highest value available for a particular car's suspension will result in the stiffest amount of resistance possible with that particular spring.

If one car offered values of 5.0 to 12.0 and another car offered values of 8.0 to 15.0, no I do not think that 10.0 would result in the same amount of stiffness on both cars. Other factors come into play like @DolHaus mentioned, such as weight distribution and even vehicle weight.

However, I say all of this IF Gran Turismo 6 is replicating real life. If it's not, then everything I just said is probably incorrect. Therefore, I would suggest doing exactly what DolHaus suggested and talk to the respected tuners on GTPlanet. They have all spent vast amounts of time investigating these matters. In the mean time, in accordance with DolHaus's suggestion, I would continue to think of each car's spring rate value as a slider like you proposed, offering a linear degree of increasing resistance.

I think this is probably the biggest conundrum when it comes to tuning in Gran Turismo. There is no GT Manual that explains any of their physics implementations. For example, if you ask 5 people on this website their opinion on how tires "work" in terms of providing grip level, you undoubtedly will get 5 different answers because PD has never provided any meaningful information on how they implement their tire model. It is beyond frustrating.

This has been my biggest frustration also.

 

[ALB123]

This has been my biggest frustration also.

What amazes me is, a site like GTPlanet is obviously well respected by at least some of the people in PD. We know that because of the communications Jordan has had in the past. You would think that at least a couple of employees would peruse the bigger fan sites, like GTPlanet, from time to time to see what the users are talking about. After all, if you're in the software business you want your software to sell/be successful. What better way to do "market research" than go into the forums of the world's biggest Gran Turismo user websites and see what the people are talking about.

If you've never been on GTPlanet before, I would think that within an hour or two, at the very most, you would discover that a great majority of Gran Turismo players are very unsatisfied with having no information regarding the tires or suspension physics implementation.

I'm not suggesting that a PD employee should be hanging out on GTPlanet hitting refresh every hour to check the pulse of the community, but I know if I were running a software shop there would be some people who are hitting the forums to gather feedback. Now, I'm a relatively new Gran Turismo player - but it seems like this information has never been made available and since they change their tire model, suspension model and general physics implementation from this version to that version, it would be nice to just give a general overview of how these things really work in Gran Turismo world. Especially because they're calling themselves a SIM and not an Arcade Game.

 

[oranjoos]

Well believe it or not, my initial testing with tuning based on the numbers being the important part are looking pretty good! It seems that GT6 really DOES emulate real life to a certain extent. It's confusing sometimes because certain cars have different limits (like lambos having crazy high minimum spring rates for example), however it seems that if you set your cars to have the same "ratio" of spring rate per their weight it really does handle (almost) the same.

For reference I tuned a Celica XX and a Superbird. After giving both cars the same "HP vs Rear weight" ratio, and the same "Spring Rate vs Weight Front/Rear", the two cars handle almost exactly the same. All other settings were exactly the same between both cars. The only different settings were Spring Rate and HP, which were set using ratios vs weight.

hey man, i'd really love to know what kind of ratios you use so that i would be able to try and replicate them, just how you ratio the front springs and rear springs with the weight distribution. thanks a lot in advance!

 

[332i]

Springs are solely meant for supporting vehicle weight and load. Everything else needs to be adjusted accordingly. Anything else is a compromise or adjusted for purposes of accomodation specific track.

 

[ACGreen86]

hey man, i'd really love to know what kind of ratios you use so that i would be able to try and replicate them, just how you ratio the front springs and rear springs with the weight distribution. thanks a lot in advance!

Honestly, I just used the ratios from my favorite car. I'm sure you've got that one car that feels amazing right? Just come up with your own ratios from it, and use those. It's really not that hard and I'll even show you how. Take the total weight of the car, multiply it by the percentage of weight from front/rear to find how much weight is over the front/rear. Divide the numbers by the spring rate from your favorite car, and boom you've got the ratio.

Example:
Car total weight: 1200
Car weight balance: 55/45
Spring rate Front/Rear: 8.00/6.00 <-- These are made up and not actual spring numbers for any car
1200 * .55 = 660 <-- Weight over the front wheels
1200 * .45 = 540 <-- Weight over the rear wheels
660 / 8.00 = 82.5 <-- Front Spring Ratio
540 / 6.00 = 90.0 <-- Rear Spring Ratio

Then, you just do the same process with a different car. When you get the front and rear weights, divide them by the appropriate ratio to get the spring rate you want.

This is an example of how you can make your own spring rate ratios. Note that it doesn't work for every car due to different models having different levels of grip, and cars that naturally have down-force will also handle differently. Your mileage may vary.

As for my specific ratios... Well, we all have secrets right?

 

[oranjoos]

Honestly, I just used the ratios from my favorite car. I'm sure you've got that one car that feels amazing right? Just come up with your own ratios from it, and use those. It's really not that hard and I'll even show you how. Take the total weight of the car, multiply it by the percentage of weight from front/rear to find how much weight is over the front/rear. Divide the numbers by the spring rate from your favorite car, and boom you've got the ratio.

Example:
Car total weight: 1200
Car weight balance: 55/45
Spring rate Front/Rear: 8.00/6.00 <-- These are made up and not actual spring numbers for any car
1200 * .55 = 660 <-- Weight over the front wheels
1200 * .45 = 540 <-- Weight over the rear wheels
660 / 8.00 = 82.5 <-- Front Spring Ratio
540 / 6.00 = 90.0 <-- Rear Spring Ratio

Then, you just do the same process with a different car. When you get the front and rear weights, divide them by the appropriate ratio to get the spring rate you want.

This is an example of how you can make your own spring rate ratios. Note that it doesn't work for every car due to different models having different levels of grip, and cars that naturally have down-force will also handle differently. Your mileage may vary.

As for my specific ratios... Well, we all have secrets right?

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