Understanding TDUPE - What the Values Mean

[jut703]

I've been searching for quite a while now on a comprehensive guide explaining all the values available to be edited with TDUPE, and sadly there isn't one. So I've decided to try and make one.

 

All info is based on my personal experience, as I've spent around a hundred hours or so tinkering with TDUPE. If there's something wrong in my descriptions, feel free to correct me.

 

First off, I believe that everyone, or the majority at least, wants their physics to be as realistic as possible. So it's natural to gather as much specs as possible from the net (or whatever source) and input them for the desired car in TDUPE. Fields that fall into this nature that affect your car's performance/handling include:

 

• Weight
  
• Drive Type
  
• Engine Position
  
• Brake Horsepower
  
• Torque
  
• Rev Limit
  
• Gear Ratios
  
• Dimensions (length, width, height, wheelbase)
  

Inputting proper values into these fields do not automatically give your car performance and handling similar to real life. Other fields are available to tweak the physics to replicate reality as closely as possible. I believe that sorting out physics is a two-pronged approach: first, you try and get its straight line performance correct, then focus on the car's unique handling characteristics.

 

Straight Line Performance

To guide me towards realism, I research real life statistics for the car, and try to make the TDU car perform similarly. Particularly I research about 0-60 mph/0-100 kph times and top speed, for these are pretty easy to measure with the built in chronograph. For example, an AE86 Trueno goes from 0-60 in about 8.5 seconds, and has a top speed of about 200 kph. Given this, I edit the following values accordingly, using trial and error until I get it to have accurate times.

 

 

• Acceleration - It's pretty straightforward, the higher the value, the quicker your car accelerates and vice versa. Setting this value too high just to achieve the acceleration required to meet the desired 0-60 time usually makes the car reach its top speed too quickly. Hence, other factors must be adjusted as well to give realistic acceleration times. Usual values range from 80-120.
  

 

• Drag - Basically it sets the car's achievable top speed. A higher value lowers top speed and conversely a lower one allows higher top speeds. Keep in mind that even if you have high drag, if your acceleration is too high, the car will still accelerate too quickly then just stop as if it was limited. So it's best to have a little harmony between the two. Oh, and one more thing, this value of drag DOES NOT equate to the real-life drag coefficient of cars. Trying to input real values will result in an econobox reaching 300 kph. Usual values range from 0.25-0.60.
  

 

• Torque Balance - Only applicable to 4WD vehicles, this doesn't seem to have as much effect as the previous two. Basically it just distributes power, though it doesn't have as much effect on traction as the Handling values, which are to be discussed later.
  

 

• Gearbox Inertia - This is a tricky one, yet it's particularly important especially in 0-60 acceleration. From my experience, a lower value of Gearbox Inertia makes the car rev up faster. Having a value too high makes it rev up more than what the traction and the engine can handle, resulting in excessive wheel spin and your car redlining even if it hasn't achieved its maximum speed for that gear. A value too low will result in the car climbing up the revs so slowly that acceleration is reduced (even if the value in "Acceleration" is high). Toying with this will allow you to have quick launch times yet proportional high-end acceleration. Values can range anywhere from 10-120.
  

 

• Engine Inertia - Another tricky one, I guess the best way to describe it is that the higher the value, the longer your revs are maintained. If Engine Inertia is set at a high value, the car takes longer to go down to idle after revving (as said by Dredgy in the tooltip as well). However, I've also noticed that a lower value allows for marginally quicker shifting in Manual and Automatic vehicles (though has no significant difference in Sequential/Semi-Auto). From the stock car physics I've observed, and from custom physics from others as well, this value is usually higher than Gearbox Inertia by around 10-50. However, I've encountered times wherein the only way to make the car behave properly was to make this lower than Gearbox Inertia. Usual values range from 15-150.
  

Handling

Unlike straight line performance, you can't just research a car's handling and find exact values to put in TDUPE and expect the car to behave similar to real life. This is a more subjective thing and it helps if you've driven the cars IRL. I have to admit I find editing straight line performance much easier, but I'll give this one a shot. I won't put usual values because it greatly depends on the car you're editing. A Lexus LS460 and a Nissan 350Z both have stock oversteer values of 100 yet it is obvious that the Lexus tends to understeer much, much ore than the 350Z.

 

 

• Suspension - As the tooltip says, the higher the value, the firmer the suspension. Of course, taut suspension usually gives superior handling, but there are just some cars (luxury cars for example), that shouldn't have very hard suspensions.
  

 

• Oversteer - A value too low will result in understeer, but having a high value does not cause the usual drift-inducing oversteer one would expect. Instead, when Oversteer is set at a high value, the car just becomes edgier in the sense that a merely having 1 tire on the side walk causes you to spin out of control.
  

 

• Grip - This is the missing value in the formula to induce oversteer. Keep it low enough so that the car breaks traction when pushed to its limits, yet high enough to ensure driveability. I find it just arcade-y and unrealistic if no matter what you do, and no matter how quickly you take a turn, your car just maintains grip.
  

 

• Steering Sharpness - From what I've tested, this is dependent on your oversteer value. If it's quite low compared to Oversteer, it results in even the simplest of flicks of the steering wheel inducing tail wag. However, if it's way too low, it just makes your car refuse to turn at all. A value a tad too high results in unrealistic precision. How much you set this depends on how fast you usually drive. If you're the all out racing type, this should be quite high as to have controllable steering at high speeds with the tradeoff that even at low speeds, a simple 30 degree turn of the steering wheel allows you to take a tight corner already. For cruisers like me, I prefer keeping it a wee bit lower to allow for great maneuverability when driving at normal city speeds at the expense of twitchy steering at high speeds.
  

 

• Braking - I guess this is a special factor, because TDU's braking physics just sucks. It sucks in the sense that a mere tap on the brake gives stopping power unacceptably near to when you mash the brakes full on. Hence, to have realistic braking in everyday conditions (where you don't usually step on the brakes all the way down), its best to lower whatever default braking value to what feels just right when you step on the pedal. Keep in mind though that while this feels just right in slow driving, once you try to do a 60-0 test with the chronograph, you'll see that your car stops around 5-10 meters longer than it should. Blame the physics engine.
  

 

• Suspension Length - Honestly I don't tinker with this much since I don't see much difference. Perhaps some kind soul can enlighten me as to how I can use this properly.
  

 

• Suspension Rate - It supposedly makes your car softer at lower values, but editing the Suspension value gives more significant results. Again another of the values I don't play with too much.
  

 

• Damping Rate - This is weird because the Suspension Rate above supposedly makes your Shock Absorbers softer or harder, and Damper is merely a synonym for shock absorbers. So I find this one redundant, and like the previous value, provides unnoticeable changes. Either I'm not keen enough or I'm using it incorrectly. Enlightenment would be greatly appreciated.
  

 

• Center of Gravity (X-Axis) - Oddly, this has the potential to affect your car in so many ways. A high value would actually give your car much more grip, yet in doing so it reduces the ability to accelerate at high speeds (as if it affected Drag value). It also makes your car have less body roll with higher values. Because of its encompassing nature, I usually avoid editing it unless the car is too unrealistic no matter how I edit the other settings. Keeping it unchanged allows most cars to still have realistic handling anyway.
  

 

• Handling - Oddly enough, this value does nothing to affect your handling.
  

 

• Downforce - I haven't encountered a scenario where I've had to edit this just to get the car to drive properly, so I wouldn't really know.
  

 

• Ride Height - While it's listed at Aesthetic Value, it actually affects your handling and straight-line performance as well. When this value is set high (as is required for SUV mods), the car has reduced grip resulting in wheel spin even at high gears (it feels as if you're hydroplaning). Furthermore, it also induces body roll to the car. The few times that I've had to change Center of Gravity settings was when I had Ride Height set too high and I had to offset it.
  

 

So basically that's it. Armed with info on what those tools do, it is now possible to adjust them to your liking. There is however one very important note to keep in mind:

 

 

• If for example you have custom physics for car A. Using the exact same values for car B will most likely not result in identical behavior of cars A and B. This is because the values in each field are relative only to the specific car. Hence, a gear inertia of 50 might be appropriate for car A, but cause too much wheel spin for car B, ceteris paribus. It also applies in handling - a Grip value of 900 may be sufficient for car A but cause car B to spin out at every opportunity.
  

What this means: If you are downloading custom physics for a particular mod, but have the mod installed in a slot that is not the slot for which the custom physics is intended, you will most likely not have the realistic behavior you desire.

 

Oh, and one more thing. If you are making physics for a car that has higher rpm limit than what the car you are replacing has, the following occurs: the car will still rev to its limit, however, past the original car's rev limit, the revs will go up much slower and acceleration will greatly be decreased. For example, the Farboud has a rev limiter at 7500 rpm. However, replacing it with a Carrera GT mod and making realistic physics means that the rev limit will then be set at 8400 rpm (CGT's redline). Sadly, doing this will make 7500-8400 a very, very slow climb. Hence, it is most advisable to replace a car with a mod that has a redline less than or equal to the original car's redline. Or, another alternative which I find quite useful is getting the ratio of the max rpm hp and max torque hp to the redline, then lowering the redline to the original car's redline and adjusting the max torque and hp rpm accordingly (i.e. 8000 @ 8400 will become 7142 @ 7500).

 

I hope I've been of help, and pardon me if I haven't had a full grasp of everything TDUPE offers, after all I'm still learning.

 

Thanks to Dredgy for coming up with such a great tool, you've helped make TDU more realistic than ever. Thanks as well to all the modders out there, you guys continue to make TDU interesting. :thumbsup:

[dredgy]

All info is based on my personal experience, as I've spent around a hundred hours or so tinkering with TDUPE.

 

About 80 hours more than me, congratulations :P

 

Nice guide too, very comprehensive.

[jut703]

Thanks.

 

Ok I just realized 100 is pushing it too much, around 60 is more realistic. It's just that there were times when I didn't notice it was dawn already as I was too busy figuring how it works. Perhaps 80% of the time was spent trying to figure out why I can't get the car to have the physics I want it to have.

[iLLusion]

No doubt, impressive. ;) +rep

[Kurgan777]

The biggest thing that Downforce effects is how long your car stays on the air off of jumps or large bumps in the road. The higher the number, the quicker your car hits the road, the lower the number, the higher the jump.

 

Setting it very low will make you jump at less than 35mph......setting it high glues your car to the ground, this works great for the Formula 1 mod.

 

Damping Rate, this is how fast or slow the shock moves up and down in it's travel, at least that's how it is in real life, whether or not the game works properly remains to be seen. In real cars, if the damping rate is too slow, the ride gets rougher and harder to handle because the suspension can't react to the bumps fast enough. If it's too fast, the suspension bounces off the pavement, the proper balance must be achieved to keep the tires on the ground at all times.

[jut703]

Oh. Thanks Kurgan. So if I increase downforce on all my cars, the only difference I'll notice is the jumpiness? I've long hated the fact that going up and down bridges and other uneven roads causes my car to fly.

 

As for damping. I've tried playing around with it but it doesn't seem to change how quickly the suspension reacts. Have you noticed any noticeable difference?

[willhub]

When when I increase the BHP does the revs always stay at nearly max when I start the car? Also using the clutch the revs go up instead of down!!

[Kurgan777]

When when I increase the BHP does the revs always stay at nearly max when I start the car? Also using the clutch the revs go up instead of down!!

Sounds like more of a BTRQ error than a physics error.

[zo6dude]

Wow nice work. Thanks for taking the time to do this.

[willhub]

Sounds like more of a BTRQ error than a physics error.

 

BTRQ?

[jut703]

Wow nice work. Thanks for taking the time to do this.

 

Thanks. I wanted to help out everyone who was clueless about TDUPE (as I was before) and at the same time help me remember the settings better.

 

 

BTRQ?

BTRQ is a file inside the car's exterior BNK (i.e. SKYGTR.bnk) which contains information about the car. I'm not entirely sure as to what it contains, but am certain that one of which is the redline limit. For example, let's take an Audi TT which has a rev limiter of 6500 rpm. Say, you decided to replace it with a Ferrari 458 Italia that revs up to 9000 rpm. Naturally, you'd edit the physics so as to make the TT (now an Italia) have a 9000 rpm redline. However, once you do drive the car, you would notice that it would rev properly to about 6500-7000 rpm properly, and past that, it would rev very slowly and when you actually reach 9000 it doesn't have the "bouncing off" effect on the limit but rather just stays there. This is because the BTRQ of the TT BNK was unchanged and still limited the car to 6500 rpm.

 

I'm not particularly sure, but what I did in a situation like that (forgot which car, CLS55 I think which I replaced with C63), was to replace the BTRQ of the car with the BTRQ of another car that I knew had a much higher RPM limit. :)

[Kurgan777]

Inside every mod there's a BTRQ file, it's stored in the car's exterior file, the one without the _I in the filename.

 

That BTRQ file can drastically effect the revving of the engine if the wrong one is used, and it can even stop the engine from revving high enough to shift gears. It can also allow an engine to rev way up and stay there.

 

The best way to fix these problems is to substitute an original TDU BTRQ file from the car slot you modded.

 

Let's say you put a car mod onto the Skyline GTR and are having problems. You need to extract the BTRQ file from the original TDU Skyline and put it into the new car mod. If you put a mod onto the Ferrari F40 slot, you'd need to find the original F-40 BTRQ file.

 

This is done with TDU Modding Tools and the File Manager in that program.

[willhub]

I've not changed the revs, all I did was change one single thing from stock, the BHP to 550, and now it holds the revs and takes forever to go down.

[Guest Aussie.Guy]

I've been searching for quite a while now on a comprehensive guide explaining all the values available to be edited with TDUPE, and sadly there isn't one. So I've decided to try and make one.

 

All info is based on my personal experience, as I've spent around a hundred hours or so tinkering with TDUPE. If there's something wrong in my descriptions, feel free to correct me.

 

First off, I believe that everyone, or the majority at least, wants their physics to be as realistic as possible. So it's natural to gather as much specs as possible from the net (or whatever source) and input them for the desired car in TDUPE. Fields that fall into this nature that affect your car's performance/handling include:

 

• Weight
  
• Drive Type
  
• Engine Position
  
• Brake Horsepower
  
• Torque
  
• Rev Limit
  
• Gear Ratios
  
• Dimensions (length, width, height, wheelbase)
  

Inputting proper values into these fields do not automatically give your car performance and handling similar to real life. Other fields are available to tweak the physics to replicate reality as closely as possible. I believe that sorting out physics is a two-pronged approach: first, you try and get its straight line performance correct, then focus on the car's unique handling characteristics.

 

Straight Line Performance

To guide me towards realism, I research real life statistics for the car, and try to make the TDU car perform similarly. Particularly I research about 0-60 mph/0-100 kph times and top speed, for these are pretty easy to measure with the built in chronograph. For example, an AE86 Trueno goes from 0-60 in about 8.5 seconds, and has a top speed of about 200 kph. Given this, I edit the following values accordingly, using trial and error until I get it to have accurate times.

 

 

• Acceleration - It's pretty straightforward, the higher the value, the quicker your car accelerates and vice versa. Setting this value too high just to achieve the acceleration required to meet the desired 0-60 time usually makes the car reach its top speed too quickly. Hence, other factors must be adjusted as well to give realistic acceleration times. Usual values range from 80-120.
  

• Drag - Basically it sets the car's achievable top speed. A higher value lowers top speed and conversely a lower one allows higher top speeds. Keep in mind that even if you have high drag, if your acceleration is too high, the car will still accelerate too quickly then just stop as if it was limited. So it's best to have a little harmony between the two. Oh, and one more thing, this value of drag DOES NOT equate to the real-life drag coefficient of cars. Trying to input real values will result in an econobox reaching 300 kph. Usual values range from 0.25-0.60.
  

• Torque Balance - Only applicable to 4WD vehicles, this doesn't seem to have as much effect as the previous two. Basically it just distributes power, though it doesn't have as much effect on traction as the Handling values, which are to be discussed later.
  

• Gearbox Inertia - This is a tricky one, yet it's particularly important especially in 0-60 acceleration. From my experience, a lower value of Gearbox Inertia makes the car rev up faster. Having a value too high makes it rev up more than what the traction and the engine can handle, resulting in excessive wheel spin and your car redlining even if it hasn't achieved its maximum speed for that gear. A value too low will result in the car climbing up the revs so slowly that acceleration is reduced (even if the value in "Acceleration" is high). Toying with this will allow you to have quick launch times yet proportional high-end acceleration. Values can range anywhere from 10-120.
  

• Engine Inertia - Another tricky one, I guess the best way to describe it is that the higher the value, the longer your revs are maintained. If Engine Inertia is set at a high value, the car takes longer to go down to idle after revving (as said by Dredgy in the tooltip as well). However, I've also noticed that a lower value allows for marginally quicker shifting in Manual and Automatic vehicles (though has no significant difference in Sequential/Semi-Auto). From the stock car physics I've observed, and from custom physics from others as well, this value is usually higher than Gearbox Inertia by around 10-50. However, I've encountered times wherein the only way to make the car behave properly was to make this lower than Gearbox Inertia. Usual values range from 15-150.
  

Handling

Unlike straight line performance, you can't just research a car's handling and find exact values to put in TDUPE and expect the car to behave similar to real life. This is a more subjective thing and it helps if you've driven the cars IRL. I have to admit I find editing straight line performance much easier, but I'll give this one a shot. I won't put usual values because it greatly depends on the car you're editing. A Lexus LS460 and a Nissan 350Z both have stock oversteer values of 100 yet it is obvious that the Lexus tends to understeer much, much ore than the 350Z.

 

 

• Suspension - As the tooltip says, the higher the value, the firmer the suspension. Of course, taut suspension usually gives superior handling, but there are just some cars (luxury cars for example), that shouldn't have very hard suspensions.
  

• Oversteer - A value too low will result in understeer, but having a high value does not cause the usual drift-inducing oversteer one would expect. Instead, when Oversteer is set at a high value, the car just becomes edgier in the sense that a merely having 1 tire on the side walk causes you to spin out of control.
  

• Grip - This is the missing value in the formula to induce oversteer. Keep it low enough so that the car breaks traction when pushed to its limits, yet high enough to ensure driveability. I find it just arcade-y and unrealistic if no matter what you do, and no matter how quickly you take a turn, your car just maintains grip.
  

• Steering Sharpness - From what I've tested, this is dependent on your oversteer value. If it's quite low compared to Oversteer, it results in even the simplest of flicks of the steering wheel inducing tail wag. However, if it's way too low, it just makes your car refuse to turn at all. A value a tad too high results in unrealistic precision. How much you set this depends on how fast you usually drive. If you're the all out racing type, this should be quite high as to have controllable steering at high speeds with the tradeoff that even at low speeds, a simple 30 degree turn of the steering wheel allows you to take a tight corner already. For cruisers like me, I prefer keeping it a wee bit lower to allow for great maneuverability when driving at normal city speeds at the expense of twitchy steering at high speeds.
  

• Braking - I guess this is a special factor, because TDU's braking physics just sucks. It sucks in the sense that a mere tap on the brake gives stopping power unacceptably near to when you mash the brakes full on. Hence, to have realistic braking in everyday conditions (where you don't usually step on the brakes all the way down), its best to lower whatever default braking value to what feels just right when you step on the pedal. Keep in mind though that while this feels just right in slow driving, once you try to do a 60-0 test with the chronograph, you'll see that your car stops around 5-10 meters longer than it should. Blame the physics engine.
  

• Suspension Length - Honestly I don't tinker with this much since I don't see much difference. Perhaps some kind soul can enlighten me as to how I can use this properly.
  

• Suspension Rate - It supposedly makes your car softer at lower values, but editing the Suspension value gives more significant results. Again another of the values I don't play with too much.
  

• Damping Rate - This is weird because the Suspension Rate above supposedly makes your Shock Absorbers softer or harder, and Damper is merely a synonym for shock absorbers. So I find this one redundant, and like the previous value, provides unnoticeable changes. Either I'm not keen enough or I'm using it incorrectly. Enlightenment would be greatly appreciated.
  

• Center of Gravity (X-Axis) - Oddly, this has the potential to affect your car in so many ways. A high value would actually give your car much more grip, yet in doing so it reduces the ability to accelerate at high speeds (as if it affected Drag value). It also makes your car have less body roll with higher values. Because of its encompassing nature, I usually avoid editing it unless the car is too unrealistic no matter how I edit the other settings. Keeping it unchanged allows most cars to still have realistic handling anyway.
  

• Handling - Oddly enough, this value does nothing to affect your handling.
  

• Downforce - I haven't encountered a scenario where I've had to edit this just to get the car to drive properly, so I wouldn't really know.
  

• Ride Height - While it's listed at Aesthetic Value, it actually affects your handling and straight-line performance as well. When this value is set high (as is required for SUV mods), the car has reduced grip resulting in wheel spin even at high gears (it feels as if you're hydroplaning). Furthermore, it also induces body roll to the car. The few times that I've had to change Center of Gravity settings was when I had Ride Height set too high and I had to offset it.
  

So basically that's it. Armed with info on what those tools do, it is now possible to adjust them to your liking. There is however one very important note to keep in mind:

 

 

• If for example you have custom physics for car A. Using the exact same values for car B will most likely not result in identical behavior of cars A and B. This is because the values in each field are relative only to the specific car. Hence, a gear inertia of 50 might be appropriate for car A, but cause too much wheel spin for car B, ceteris paribus. It also applies in handling - a Grip value of 900 may be sufficient for car A but cause car B to spin out at every opportunity.
  

What this means: If you are downloading custom physics for a particular mod, but have the mod installed in a slot that is not the slot for which the custom physics is intended, you will most likely not have the realistic behavior you desire.

 

Oh, and one more thing. If you are making physics for a car that has higher rpm limit than what the car you are replacing has, the following occurs: the car will still rev to its limit, however, past the original car's rev limit, the revs will go up much slower and acceleration will greatly be decreased. For example, the Farboud has a rev limiter at 7500 rpm. However, replacing it with a Carrera GT mod and making realistic physics means that the rev limit will then be set at 8400 rpm (CGT's redline). Sadly, doing this will make 7500-8400 a very, very slow climb. Hence, it is most advisable to replace a car with a mod that has a redline less than or equal to the original car's redline. Or, another alternative which I find quite useful is getting the ratio of the max rpm hp and max torque hp to the redline, then lowering the redline to the original car's redline and adjusting the max torque and hp rpm accordingly (i.e. 8000 @ 8400 will become 7142 @ 7500).

 

I hope I've been of help, and pardon me if I haven't had a full grasp of everything TDUPE offers, after all I'm still learning.

 

Thanks to Dredgy for coming up with such a great tool, you've helped make TDU more realistic than ever. Thanks as well to all the modders out there, you guys continue to make TDU interesting. :thumbsup:

 

 

Excellent thread thanks for the info.

[KaKoc]

dudes i know how to work with TDU Perfomance Editor ... u change the value of cars ... audi s6 is 535hp an 697nm torque ... u can change this value ... easy sry for my bad english

[agok]

Oddly enough all the vechicles in the game are suffering from same anomaly,lets take an example: Ferrari f40 stops wheelspin @ around 20-25 mph (35-40 km/h) ,i've installed patch 1.68b but it shouldnt affect the car pysics?

From there on,when-ever i turn the car seems to loose power: like it has torque-sensitive limited differential.In other words,i cannot make car slide/drift.Can i ask for any advice (only update to game is patch) ?

[Sly870]

range from 0.25-0.60.

 

My default SL 65 AMG is " 1.2317 "

[chevroletzr1]

you want your car to do its tires skidding beyond 40km / H.??

as is the case of a real corvette without slipping traction control in 1 (gear) to 80km / h or more

 

maybe your car needs more energy (inertia) in the engine.

 

---------- Post added at 13:25 PM ---------- Previous post was at 13:18 PM ----------

 

I have a physical Corvette ZR1 by myself.

330km / h

0-100km / h 3.3 sec

"real gear ratios" and weight, horsepower, torque, etc.

 

if tdupe put "export current car" and I upload that file so you can install "if they want" in your TDU, that would be legal?

thanks so much

[yocktan]

Really nice thread for tuning in TDU... I made the Viper TT physics, i changed the grip but it just like changed the gravity (it is not tires grip).

now i'm still working on suspension, i wish i could make wheelie, but i can't change the power/torque curve

maybe next TDUPE would add power/torque curve tuning :) Thanks modders.... \o/

[Edgarhighmen]

Do we have a more in depth value tutorial for these and the rest of the settings in tdupe? Google provides no help. Most links on this forum are dead.