The definitive GT5 transmission tuning guide.
- Thread starter grenadeshark
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TT3AZ
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- tt3_az
- TT3AZ
Okay, here are my detailed torque graph, not that nice, but it is a beggining though.
And heres my table:
Anything usefull that can be read here, considering my other graphs and info i have given? *2nd gear, at 5900rpm, the output torque should be 1433*
Well, lets se how much rpm i drop when i change gears:
I rev to 7900rpm in all gears.
1-2 gear - 5750rpm. Rpm loss = 2150rpm
2-3 gear - 6250rpm. Rpm loss = 1650rpm
3-4 gear - 6500rpm. Rpm loss = 1400rpm
4-5 gear - 6500rpm. Rpm loss = 1400rpm
4-5 gear - 6750rpm. Rpm loss = 1150rpm
This are the rpm i land on, when i rev to 7900 in one gear, and change to another gear.
And heres my table:
Anything usefull that can be read here, considering my other graphs and info i have given? *2nd gear, at 5900rpm, the output torque should be 1433*
Well, lets se how much rpm i drop when i change gears:
I rev to 7900rpm in all gears.
1-2 gear - 5750rpm. Rpm loss = 2150rpm
2-3 gear - 6250rpm. Rpm loss = 1650rpm
3-4 gear - 6500rpm. Rpm loss = 1400rpm
4-5 gear - 6500rpm. Rpm loss = 1400rpm
4-5 gear - 6750rpm. Rpm loss = 1150rpm
This are the rpm i land on, when i rev to 7900 in one gear, and change to another gear.
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- 567
- aGrenadeShark
- aGrenadeShark
I am taking an exerpt from Drive to Win by Carroll Smith. Most of what I know about tuning theory comes from this man.
I reread the entire chapter on RPM and HP curves and I found where most people are getting their 200 RPM past peak HP. Problem is, you guys are quoting him WRONG.
The information below is what he used to come to his conclusion.
Straight from the horses mouth. Power in the engine exists past peak HP. But, due to reliability concerns, he is very conservative. In this game, reliability is a mute point.
So much of the information out there is ignoring the fact that he clearly states "Depending on the shape of the curve and the gear splits". That is so important. He was not playing a video game. Most curves were highly peaky in his time and his ability to change transmission gearing on the fly was basically nonexistent. We have more tools.
The reason we look at tq output to the wheels is because we have the ability to not only change the final drive ratio, but also the transmission gearing ratios! With these tools, we can extrapolate even more use out of the power curve then ever existed before.
I reread the entire chapter on RPM and HP curves and I found where most people are getting their 200 RPM past peak HP. Problem is, you guys are quoting him WRONG.
The information below is what he used to come to his conclusion.
Straight from the horses mouth. Power in the engine exists past peak HP. But, due to reliability concerns, he is very conservative. In this game, reliability is a mute point.
So much of the information out there is ignoring the fact that he clearly states "Depending on the shape of the curve and the gear splits". That is so important. He was not playing a video game. Most curves were highly peaky in his time and his ability to change transmission gearing on the fly was basically nonexistent. We have more tools.
The reason we look at tq output to the wheels is because we have the ability to not only change the final drive ratio, but also the transmission gearing ratios! With these tools, we can extrapolate even more use out of the power curve then ever existed before.
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- 567
- aGrenadeShark
- aGrenadeShark
TT3AZ
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- tt3_az
- TT3AZ
Okay, look at my post above to see how much rpm i lose while shifting gears. If anybody have a better idea to make a more exact torque/hp graph, feel free to fill in. One strange thing, is also that the graph states 88.3 kgfm as peak torque, and in the description of the car, it states 87kgfm as peak torque. Well i think, even if the graps i have made has flaws,
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- 567
- aGrenadeShark
- aGrenadeShark
using RPM * (gear2ratio/gear1ratio) to get rpm drop
we get 7900 * (2.33/3.241) = 5679rpm
so from 7900 in 1st we drop to 5680 in 2nd.
If your chart/table are correct I would shorten 2nd (or lengthen 1st since you propably have wheelspin issues)
You know. I forgot you can do that... Very helpful. Thanks! It's all just math and physics. Always an equation for everything and I forgot about it
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NP. It's all here: http://www.allpar.com/eek/hp-vs-torque.html
TT3AZ
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- tt3_az
- TT3AZ
Hmm, it is gettin even more complex, and this is why:using RPM * (gear2ratio/gear1ratio) to get rpm drop
we get 7900 * (2.33/3.241) = 5679rpm
so from 7900 in 1st we drop to 5680 in 2nd.
If your chart/table are correct I would shorten 2nd (or lengthen 1st since you propably have wheelspin issues
1-2 gear - 5750rpm. Rpm loss = 2150rpm
2-3 gear - 6250rpm. Rpm loss = 1650rpm
3-4 gear - 6500rpm. Rpm loss = 1400rpm
4-5 gear - 6500rpm. Rpm loss = 1400rpm
5-6 gear - 6750rpm. Rpm loss = 1150rpm
According to my chart, the "less" rpm i land on after shifting gears, the more output torque i get for that moment. But changing one gear changes the torque output, and will affect the other gear aswell.
After looking at my numbers, it seems that the "new" setup gives higher output torque in 2, 3, 4 gears, while the old one has higher output torque in 1, 5, 6 gears, and that would explain the slightly more wheelspin in 1st gear, but slower acceleration in the gears up to 5 and 6 gear, which gives more output torque and reach top speed faster.
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Right. 
Ignore final drive for now, we are only interested in finding optimum shift points and gears for an engine's power curve - ultimately, it (fd) has no effect on that since it is a constant (same in every gear). Once you figure out the optimum gears/shift point to accelerate they will never change unless the power curve changes (or you want to get uber track specific and tune for a specific corner which would take you out of the optimum everywhere else - but ignore that). You THEN use final drive to adjust your top speed vs RATE of acceleration for each track.
Best way is to create a spreadsheet that looks like this:
Where you plug in your Ratios (column L), Shift Points (Column M) and Torque (Column B) and have the spreadsheet calculate things for you and find the best setup and (possibly) a better place to shift instead of 7900 rpm.
Ignore final drive for now, we are only interested in finding optimum shift points and gears for an engine's power curve - ultimately, it (fd) has no effect on that since it is a constant (same in every gear). Once you figure out the optimum gears/shift point to accelerate they will never change unless the power curve changes (or you want to get uber track specific and tune for a specific corner which would take you out of the optimum everywhere else - but ignore that
). You THEN use final drive to adjust your top speed vs RATE of acceleration for each track.Best way is to create a spreadsheet that looks like this:
Where you plug in your Ratios (column L), Shift Points (Column M) and Torque (Column B) and have the spreadsheet calculate things for you and find the best setup and (possibly) a better place to shift instead of 7900 rpm.
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TT3AZ
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- tt3_az
- TT3AZ
Right.
Ignore final drive for now, we are only interested in finding optimum shift points & ultimately, it has no effect on that since it is a constant (same in every gear). Once you figure out the optimum gears to use to accelerate, you can use Final Drive to adjust your top speed.
Best way is to create a spreadsheet that looks like this:
Where you plug in your Ratios (column L), Shift Points (Column M) and Torque (Column B) and have the spreadsheet calculate things for you and find the best setup and (possibly) a better place to shift instead of 7900 rpm.
Yes, that would be cool, considering you have all this numbers, that are really hard to get hold on from gt5. Read my post above, its the explenation why the "old" and "new" setup differs, it makes sence.
What can we learn? Well specially for drag racing, a spreadsheet would be usefull, only if you have all those variables needed. If you start at 0, dont knowing anything about your car, then you have to spend endless hours trying to figure out a good "base" setup.
- 567
- aGrenadeShark
- aGrenadeShark
Yeah, I have been on that page numerous times. Problem is the guy says a few very misleading things.
"Note - and this is important - the transmission does not amplify power.
Power in = power out, minus losses
(which are low for a manual transmission)."
While he is 100% correct, this gives off the idea that tuning your transmission does not effect acceleration, which is completely wrong.
Gear ratios exist to help reduce the spinning rate of the engine into usable power at the wheels. In this process, more TQ is "created". Obviously, its not created. It is converted. It was always there in one way or another.
Tuning each transmission gear absolutely has an effect on acceleration and in the end, that is what truly matters. The reason these tables work is not because we are assuming the the transmission and final drive are creating more power, its because we are looking how an individual gear changes the way it looks.
Having the right gearset for the right power curve does increase acceleration. And that does matter.
TT3AZ
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- tt3_az
- TT3AZ
That is verry true, an the question is how accurate one can be doing all this calculations?I never think there would be a ultimate setup, considering the transmission is very complex.
- 567
- aGrenadeShark
- aGrenadeShark
As accurate as you can determine the HP values for a given in game power curve graph.
My calculator is almost finished and it takes into account and suggests shift points based on a couple factors.
RPM Drop between gears, HP at any given RPM (based on your inputs), transmission gear ratio.
It then tells you the optimal shift points based on the inputs you have entered.
This guy right here goes a step farther and has created a calculator that takes your power curve and optimizes a gearset to use that power curve given certain parameters of your entering (tire width, aero, track, etc).
http://www.mitchellsoftware.com/prod02.htm
This is the quintessential gearing calculator and I am trying to recreate enough of it to use in game. I don't believe I can ever recreate it until we know more about tire widths and aero in this game.
My calculator is designed to study the power curve of an engine and the gearing of the transmission and tell you when to shift. It will not suggest better gearing ratios as of now.
I have another explanation to cover how work is done in this game. As soon as you understand that gearing only removes load from the engine and does not create power, you can figure out why it actually helps you accelerate.
A bicycle is a good example of gearing and how it works. Lets pretend we are talking about a very lean, non muscular man that has high endurance and very little twitch or power muscle.
You could put your bike in lower numerical gear and as long as you had enough power, you could get up a hill. You could also raise the gear number and it would require less power to get up that same hill, but more rotations.
The amount of work being done is the exact same. BUT, how efficient your body works at the different gear ratios is very important as well. At the lower numbered ratio, you expended much more energy because your body was not tuned to be efficient at high load. Your body is keen to endurance more than it is to high outputs of energy. So, at the top of the hill you will be a lot more tired if you used the lower gear then the higher gear (assuming the fitness levels i quoted).
Engines work the EXACT SAME WAY. Gearing allows us to put the engine in its most efficient "work" zone. When in this efficient work zone, we get the most acceleration for the power invested. Think if that bicycler had a professional create gearing for him to climb a 45* hill based on hundreds of physical tests put on him. He would get up that hill in way better then any generic gearing would have gotten him there.
Think of these gearing tables as not absolute values of power, but more as a description of the efficiency of an engine with a given gearing set. We can see when the engine is more efficient and less efficient by calculating the "tq to the wheels". This is how the shift points are being determined and the gearing ratios are being determined.
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TT3AZ
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- tt3_az
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But if i ask this question:
1. If i change to a specific gear, and i land on for example 6000rpm, which gives me output torque 1500, and i redline at 7900rpm, which reduces the output torque to 1300. I loose 200 output torque from 6000rpm to 7900 right.
2. If i instead change the ratio of a gear, and that makes me land on 7000rpm (shorter gear) after i change gear, which give me output torque 1450 and i rev to 7900rpm which gives me output torque 1380. With the rpm landing on "higher" i get reduced output torque, but at redline i get higher output torque comparing to "1" example.
The question is, should you aim to land at a rpm that gives you the most output torque for the moment, or should you tune your gear ratio, so the outpout torque at the redline (when you change gear) is the highest?
For example
Setup 1:
rpm 5 gear (1.300) Setup 2: rpm 5 gear (1400)
4000 ****** 4000 ********
5000 1600ftlb 5000 1750ftlb
6000 1500ftlb 6000 1600ftlb
7000 1400ftlb 7000 1450ftlb
8000 1300ftlb 8000 1380ftlb
These numbers are fictional, and the reason setup 2 makes more output torque, is due to the shorter gear.
1. If i change to a specific gear, and i land on for example 6000rpm, which gives me output torque 1500, and i redline at 7900rpm, which reduces the output torque to 1300. I loose 200 output torque from 6000rpm to 7900 right.
2. If i instead change the ratio of a gear, and that makes me land on 7000rpm (shorter gear) after i change gear, which give me output torque 1450 and i rev to 7900rpm which gives me output torque 1380. With the rpm landing on "higher" i get reduced output torque, but at redline i get higher output torque comparing to "1" example.
The question is, should you aim to land at a rpm that gives you the most output torque for the moment, or should you tune your gear ratio, so the outpout torque at the redline (when you change gear) is the highest?
For example
Setup 1:
rpm 5 gear (1.300) Setup 2: rpm 5 gear (1400)
4000 ****** 4000 ********
5000 1600ftlb 5000 1750ftlb
6000 1500ftlb 6000 1600ftlb
7000 1400ftlb 7000 1450ftlb
8000 1300ftlb 8000 1380ftlb
These numbers are fictional, and the reason setup 2 makes more output torque, is due to the shorter gear.
- 567
- aGrenadeShark
- aGrenadeShark
You should tune so that the gearing fits perfectly in unison with the power curve of the engine and of course for the track you are racing.
To answer your specific questions, you really need to graph out the values or build an excel table. My tuning calculator is almost done testing and will do most of this work for you. Although, it will not tell you which gearset is better then another, it will tell you how your current gearset is doing.
There are so many factors to consider when gearing... Read my thread for an easy tuning method that works for basically all cars. If you want to get even more accurate, you need to consider time in all your equations.
I find that testing on the track is one of the best ways to figure out how your changes are helping you. If between your gears, when you upshift, if the car land a few hundred rpm before peak HP and your have a relatively decent power curve, you will be maximizing acceleration for the most point.
Again, this is all 100% dependent on the power curve of the car. Cars with spikey curves benefit from shorter gearing while cars with very long power curves benefit from wider gearing.
Also, if you havent read the excerpt from carroll smith that I posted above, you should. It's very insightful.
TT3AZ
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- tt3_az
- TT3AZ
Yes, the torque/hp curve is also important. Thats why some cars have higher top speed with longer gears, because short gears will generate lower "hp" to the wheels. Thats why my supra was a little bit faster with longer gears, because the hp dropped after 7000rpm, so under 7000rpm is to aim for that speficic gear. Im doing some testing, and will post the result if my theory is true.
- 567
- aGrenadeShark
- aGrenadeShark
Seriously... You are trolling at this point. Dyno's do not work in any way like you think...
First gear create higher acceleration then any other gear. Hence, why the tq output on the chart is higher. Please stop posting, I feel like you are derailing this thread.
Everything you have said is so far beyond wrong, its borderline trolling. I can't tell the difference honestly.
I found this online. Maybe this will help you.
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There is so much this and that.
Has a car been agreed upon? (too much to look through)
What is it and the mod restriction/specs etc I want in.
I'll reveal my easy beginners trick when there is one made of these formulas, by the person claiming they are proven best/better than auto tune, for a comparison.
BTW the dyne graph in the game BLOWS....
Has a car been agreed upon? (too much to look through)
What is it and the mod restriction/specs etc I want in.
I'll reveal my easy beginners trick when there is one made of these formulas, by the person claiming they are proven best/better than auto tune, for a comparison.
BTW the dyne graph in the game BLOWS....
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