GT5Calc 1.51b

[Litzner]

I couldn't get it to open, gives me some sort of error message, but I see a potential problem in that your formulas can't and don't take into account suspension motion ratios. We can see some cars like the MKIV Supra have extreme front/rear differences in spring rate which correspond roughly to real life rates but have no correlation at all with weight distribution. That these cars handle fine with these springs leads me to conclude that GT does indeed take motion ratios into account somehow. The rest of the math may be rock solid but without this little bit of information we're still left throwing darts.

Motion ratios are actually in my calculations to a point, but as I cannot expect that to be data the user plugs in for every car, I use a generic value I determined considering a lot of cars using these settings will not have extreme motion ratios one way or another, due to the fact they usually lowered to the ground. I also tested messing with the motion ratio, and unless setting it to extremely different values it did not make huge differences in the spring rates.

I also am re-uploading the app, I do think it requires a certain version of the .Net frame work to function though, since it was written in .Net w/ C#.

 

[Litzner]

So I have not been able to sleep, so I decided to throw together my initial build for GTCalc that includes down-force calculations. Enjoy and let me know what you think.

 

[oppositelock]

Motion ratios are actually in my calculations to a point, but as I cannot expect that to be data the user plugs in for every car, I use a generic value I determined considering a lot of cars using these settings will not have extreme motion ratios one way or another, due to the fact they usually lowered to the ground. I also tested messing with the motion ratio, and unless setting it to extremely different values it did not make huge differences in the spring rates.

The only way a generic value could work even close to reasonably well was if the user had a way to enter the type of suspension the car uses. For example, you could assume 1:1 for strut type suspensions and 0.7:1 for multilink/wishbone type suspensions and have a field where the user can input the type independently for front and rear. Even then, there are extremely wide variences in multilink/wishbone ratios which means this method would be inconsistent at best. Motion ratio is also totally independent of ride height. Slamming a car doesn't change the length of the control arms or the location of the shock mounting point. If I were you I'd have a field to input the stock spring rates and then create a formula to compare this against the weight distribution and come up with a rough guesstimate regarding the motion ratios. I think your calculator has a lot of potential if you can find a reliable and consistant work-around. Excellent work so far. 👍

 

[Litzner]

The only way a generic value could work even close to reasonably well was if the user had a way to enter the type of suspension the car uses. For example, you could assume 1:1 for strut type suspensions and 0.7:1 for multilink/wishbone type suspensions and have a field where the user can input the type independently for front and rear. Even then, there are extremely wide variences in multilink/wishbone ratios which means this method would be inconsistent at best. Motion ratio is also totally independent of ride height. Slamming a car doesn't change the length of the control arms or the location of the shock mounting point. If I were you I'd have a field to input the stock spring rates and then create a formula to compare this against the weight distribution and come up with a rough guesstimate regarding the motion ratios. I think your calculator has a lot of potential if you can find a reliable and consistant work-around. Excellent work so far. 👍

After looking more deeply into motion ratios, and messing with the numbers and seeing the results, I agree that to get very accurate calculations I need to include the ability to manually adjust them some how. But I do not see a easy way to do this, as these numbers are not easily obtained.

In general is the motion ratio of the front similar to the motion ratio of the rear of a car?

 

[esoxhntr]

very interesting app. thanks for the work

 

[Litzner]

I just put up 1.3b. I have cleaned up my motion ratio code, and have the ability to easily let the user adjust motion ratios, although at this point in time I think it is better to leave the values static. I am still trying to figure out easy way to deal with motion rations, if anyone has any ideas, please let me know.

 

[calan_svc]

You guys are assuming that PD's suspension model is considering these factors also, which it may not be. In fact, the method used to create the illusion of a dynamic drivable car may hardly resemble a real-life suspension model at all.

As I was doing all the tire testing, I came to the conclusion that when dealing with GT5 physics, it's better to come up with something that works... rather than something that makes sense.

 

[column5]

Thanks for continuing to work on this. Any chance of an iPhone/iPad app?

 

[Litzner]

You guys are assuming that PD's suspension model is considering these factors also, which it may not be. In fact, the method used to create the illusion of a dynamic drivable car may hardly resemble a real-life suspension model at all.

As I was doing all the tire testing, I came to the conclusion that when dealing with GT5 physics, it's better to come up with something that works... rather than something that makes sense.

I completely agree, that is why I need people to tell me what they think about it. I may just modify this to do only real life calculations (which will be easier, since anyone wanting to do those calculations will also have the required information to make them), and make something different for GT5. Although right now, the only thing I have to go on is real life physics

 

[Litzner]

Thanks for continuing to work on this. Any chance of an iPhone/iPad app?

I guess I could. Although I have never made a iApp before, so I would not even know how to start converting it over.

 

[column5]

I guess I could. Although I have never made a iApp before, so I would not even know how to start converting it over.

I was thinking that it would make it convenient to be able to look up car specs and run the calcs while sitting in front of the PS3. 👍

 

[Thomas K]

Where shall i put the numbers in so i can calculate what settings the car shall have? :-)

 

[Litzner]

Where shall i put the numbers in so i can calculate what settings the car shall have? :-)

There is a app you can download at the bottom of the first post. You need WinRar to decompress it.

 

[Thomas K]

Are this virus?????

 

[kamisaya]

uhh... exe file. i'm not opening that.

QFT. I've seen first hand what opening an .exe files can do when a keylogger is binded together with it.

 

[A e r o]

In general is the motion ratio of the front similar to the motion ratio of the rear of a car?

In general, no. Sometimes it can be similar, but when different suspension geometries are employed the motion ratios can be quite different from front to rear.

Performance tuning is centered around tire behavior. It seems to me that the tire modeling in GT5 isn't very accurate, so my guess is that the application of any real-world mechanics/dynamics to GT5 will have mixed results.

My $0.02.

 

[Litzner]

Are this virus?????

I say its not, but I wrote it, so my word may be bias

 

[Litzner]

Would people be interested having some other information displayed with the spring settings?

Like the figures on how much weight is being generated at the front and rear axel at speed, including aero?

The ability to see the spring settings in lbs/in?

Or anything else any one has any ideas for?

 

[Litzner]

GT5Calc 1.4b is up

I added to ability for the user to change the overall suspension stiffness, still keeping the oscillation of the suspension in tune.

 

[budious]

I'm not entirely sure the game uses a universal suspension spring ratio, some cars behave like they have linkage spring ratios in place. Since I lean towards the tuning aspect of the game, I've tried a number of factors to attempt to pre-determine spring ratios for a car as a pre-tune method to get a faster start... sometimes it's close, other times it is way off. Also, weight reduction upgrades appear to change the weight distributions of cars, so it's still very much a voodoo art form, imo. I haven't tried your application but I'd like to know the formulas you are attempting to use to get these results... and perhaps offer some feedback on them.

 

[Litzner]

Released 1.5b

Added some basic calculations for dampers based off the spring rate and car drive-train. These are by no means perfect, but should get someone who does not understand dampers near where they should be.

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I am also wondering if I this thread should be moved to the tuning forum?

 

[column5]

Thanks for the 1.5b update! Very nice!

One small request...how difficult would it be to add a button to export our results to a text file? Maybe add a field so we can type in a label for the "tune" as well.

Thanks again!

 

[Litzner]

Thanks for the 1.5b update! Very nice!

One small request...how difficult would it be to add a button to export our results to a text file? Maybe add a field so we can type in a label for the "tune" as well.

Thanks again!

Not too difficult, I will considering this while I am working on the next update. I am planning to change the UI to look more like the GT5 tuning screen. That may not be for awhile though.

Actually that just game me a idea. Let you save each individual tune to a database within the GT5Calc, but that would be way down the road, as I have no idea how to do that yet.

 

[column5]

Sounds great!

 

[Litzner]

1.51b Uploaded

After some testing, I adjusted the shock calculations a bit for FR vehicles.

 

[ScionPower]

Not too difficult, I will considering this while I am working on the next update. I am planning to change the UI to look more like the GT5 tuning screen. That may not be for awhile though.

Actually that just game me a idea. Let you save each individual tune to a database within the GT5Calc, but that would be way down the road, as I have no idea how to do that yet.

It's actually pretty easy with SQL, just need to learn how to create the proper database, and then link it. I did something similar for my senior project, but storing class information instead, storing the updates to your account in a database.

If you need help, let me know, I can try to help you out remotely, or show you how to do it, but that would require the source, obviously.

Also, I've been tinkering with creating android applications lately, so if you need to outsource the app work, I'd be more than happy to do that also

Again, source needed for the apps if you wish to divulge, etc....

I just downloaded it, but haven't used it yet. Looks like it will be very useful in getting a base tune (since i suck at tuning myself outside of gear ratios because I had math for that in GT4 )

 

[column5]

Last night I tuned 4-5 of my favorite cars with the latest version of GTCalc. I think you have it really nicely dialed in now. Taking the SLS AMG and my fully-upgraded 69 vettes around the Cape Ring was a blast.

Donation incoming. 👍

 

[Litzner]

Last night I tuned 4-5 of my favorite cars with the latest version of GTCalc. I think you have it really nicely dialed in now. Taking the SLS AMG and my fully-upgraded 69 vettes around the Cape Ring was a blast.

Donation incoming. 👍

Thanks, first one!

Yeah it works fairly well for most cars. I have found one that does not agree with it at all. 1965 Shelby GT500, you have to put the weight distribution at around 75% front to keep the rear end under it, at least with the weight reductions I had done to it.

I have also noticed most cars are a bit fast with a higher stiffness rating, around 21-24 depending on the car track.

 

[Thomas K]

Can you make iPhone App??

 

[djustiz]

Just tried your app tonight on my '89 Eunos Roadster, and I am properly impressed! I turned the stiffness to 26 before I felt the car was just right - but man - I thought I had a good tune before, but your app really helped make it even better. 👍