Non-Drag Racing Transmission tuning guide

[Otaliema]

@OdeFinn @Rotary Junkie please take this discussion down a couple notches it's starting to get a little warm. I'd prefer not to have an inferno in here.

You both have vaild points and unquie opinions on the matters at hand and I don't think any amount of arguing is going to sway one to the other side. It has been a good debate and I encourage that. So please continue its good info or at least I think so. So let's not start poking soft spots.

 

[OdeFinn]

@Otaliema fine with that, just getting boring to "fight" ... Normal discussion partners can ask/answer freely questions, say when they were wrong and you right and opposite way.

The only ratio that matters in terms of effective gear ratio is the overall (i.e gear * final), and that the lower you can set the final while maintaining the same overall ratios in each gear, the vehicle will accelerate noticeably quicker in side-by-side testing.

Proven wrong.

The ratios are identical, they should act the same. Certainly vehicle speed at any given RPM in whatever gear is identical. Thing is, the lower final accelerates harder every single time. I've tested this in every GT game since GT4, there has never been a change in that.

Proven wrong.

The amount of deceleration from engine braking is fixed for any given RPM and is multiplied by the overall gear ratio. If it reversed as you say, engine braking would be several times stronger in higher gears, which is not the case.

Assumptions based on own mind.

Complete throttle lift is where decel lock will be strongest, under braking it becomes slightly weaker

Weird understandings how differential lock works.

If the overall gear ratio is 3:1, the effect of engine braking at the tires will be triple what it is at the crankshaft, not 1:3. However, the effect of brakes being applied against the engine will be 1:3, that is my point here.

Opponent doesn't have capability count how torque multiply is happening to even admit it, or see how gear ratio works and where is stressed joints with friction surfaces.

Oh, wait. Funny thing, big angry cams have slightly weaker engine braking... They also pull less vacuum at idle, I wonder if the two could possibly be related?

I really hope at this is just joke.



Ready to continue conversation, hopefully in mature way.


Edit: one more carrot, test stock BMW, alter only triple clutch and carbon propeller shaft, adjust custom LSD to 60/60/60 and install first American racing vintage thrust wheels on it, then do testing Tsukuba, drive like a stolen, then change wheels to ENKEI RC-T2 and try again. If you feel nothing, install more power to it.

 

[Rotary Junkie]

@Otaliema fine with that, just getting boring to "fight" ... Normal discussion partners can ask/answer freely questions, say when they were wrong and you right and opposite way.

In the cases where I have actually been wrong, I have had no problem admitting such.

Proven wrong.

Actually still stands for straight-line testing. Your 2002 example was indeed slower around Tsukuba due to traction issues on both entry and exit that were aggravated by the exact thing that makes the lower final faster in a straight line. I also already said as much.

Proven wrong.

See above. If you would like to show me an example with both testing repeatability and even overall gear ratios where a high final is indeed faster in a straight line, be my guest. So far, you have not.

Assumptions based on own mind.

As well as basic math and having dealt with a car or two in my time.

Weird understandings how differential lock works.

Funny thing, it works.

Opponent doesn't have capability count how torque multiply is happening to even admit it, or see how gear ratio works and where is stressed joints with friction surfaces.

Positive number x positive number x positive number = bigger positive number.
Negative number x positive number x positive number = bigger negative number.

Simple, easy math. Torque direction does not reverse torque multiplication. Two locations for possible slippage, clutch and tires. If clutch can hold under acceleration, it can hold under deceleration.

I really hope at this is just joke.

A little tongue-in cheek, yes, but not a joke. Maybe you'll get it, maybe you won't, but it's thoroughly irrelevant to this discussion or Gran Turismo in general.

Edit: one more carrot, test stock BMW, alter only triple clutch and carbon propeller shaft, adjust custom LSD to 60/60/60 and install first American racing vintage thrust wheels on it, then do testing Tsukuba, drive like a stolen, then change wheels to ENKEI RC-T2 and try again. If you feel nothing, install more power to it.

Since I'm quite lazy and have better, more profitable things to do than do your testing for you and report back, feel free to enlighten us on what you're actually trying to show here.

If PD modeled wheel weight I'm gonna giggle. Torque Thrusts aren't exactly known for being lightweight.

 

[OdeFinn]

Positive number x positive number x positive number = bigger positive number.
Negative number x positive number x positive number = bigger negative number.

Simple, easy math. Torque direction does not reverse torque multiplication. Two locations for possible slippage, clutch and tires. If clutch can hold under acceleration, it can hold under deceleration.

Thank you for best laugh of this year.

If PD modeled wheel weight I'm gonna giggle. Torque Thrusts aren't exactly known for being lightweight.

Guess what, PD knows that too.

 

[Rotary Junkie]

You do realize the differential rotates at wheel speed, not driveshaft speed right?

 

[OdeFinn]

You do realize the differential rotates at wheel speed, not driveshaft speed right?

What a surprise, how is this now changing things? Do you know at power of engine is used to move over 1000kg object called car, btw have you realised at when engine is not accelerating that object, object turns to power source for Drivetrain, powering it from other end, rolling tires.

 

[Otaliema]

@OdeFinn @Rotary Junkie
Alright you two cut it out. You have crossed the line on personal vs debate. This is the last warning before reports start getting sent.

 

[Rotary Junkie]

Taken to PM.

 

[JaseScott]

Taken to PM.

Awww, was hoping to hear your response

 

[Otaliema]

Awww, was hoping to hear your response

He did the wise move. Thier convo was deep in the grey area of the AUP and just crossed it. I will not let this thread go south to the point of needing mod intervention and clean up. I've seen it happen too much in good threads.
I would have this debate keep running but it started to heat up too much. If they can keep it cool they can pick it back up. Healthy debate about the game revolving around the more subtal points of transmission and drive train is just fine.

 

[Rotary Junkie]

There is one area where the less violent response and engine braking may be of help; high power FWD. My old approach to FWD suspension worked minty in GT4 (though some cars wound up with slightly insane power-oversteer) as front downforce could be added, okay in GT5, and so far in GT6 it's been strongly car-dependent.

Will report back after doing some testing, there still remains the question of balancing the more "stable" response versus straightaway speed as well. 1-2mph peak down every straight isn't much but it is enough that it needs to be accounted for.

Edit: Results thoroughly inconclusive. Short (numerically high) FD seems easier to drive and speedometer claims it's quicker through high speed corners, clock says "I dunno lol", with both posting somewhere around the same average lap time, despite my driving being more accurate with the short FD. Also somewhat easier to get down to apex with tall FD in the slow corners.

 

[OdeFinn]

If there is someone who's truly interested to open GT6 physics he should try above mentioned wheels on BMW.
Once again tested on online lobby, all real, no tyre wear to ensure grip staying same on all laps, no damage, time fixed to keep testing equal. Both cars with different wheels directly from dealership, never wrecked on any walls or objects. Online because you can switch cars on fly to avoid long break between different wheels.
Testing with open differential thru whole power and weight scale, with and without clutch+flywheel and carbon propeller upgrades. No ABS. You may test with LSD also.
During testing you should lap above 4 laps on Tsukuba, tires aren't working before, too cold or something, they start to grip after 4 laps.

As @Rotary Junkie said for American vintage torque thrust wheels, effects what you'll find are supporting that.

Lapping around 10+ (or any amount when you're familiar with car) and then switching to another wheels you'll see how much you have to adapt on your driving style between those.
Guys who always wants pictures or time and stuff like that can go and take them, maybe taking pictures from 5-10 meter longer skid marks from other wheel than other, checking those .500 sec differences between wheels, but when doing so you should preferably be tested thru whole power/weight/addons scale with notes, you'll see when heavier is better and when lighter.

I'm not gonna start proving anything for any queries, because you can test it your self and get all answers from those tests. After you have tested and found something I might have much more to reveal.

 

[TheInfamousJEW6]

So I came back to do some re-reading, as I'm still trying to get all I can out the transmission tuning in this game, and I noticed the image links are broken... Just an fyi @Otaliema

 

[Otaliema]

So I came back to do some re-reading, as I'm still trying to get all I can out the transmission tuning in this game, and I noticed the image links are broken... Just an fyi @Otaliema

so very odd they were all uploaded here. I wonder if the images expired on the server.
No biggie I'll fetch them from storage and reupload. Ty on the catch

 

[Lionheart2113]

Is that transmission spreadsheet from 🤬 helping at all? I'm working on a revised version. Much more user friendly!

 

[Otaliema]

Is that transmission spreadsheet from 🤬 helping at all? I'm working on a revised version. Much more user friendly!

TBH I haven't had time to try it -_-
I'll see what I can do about pulling it up and giving it a spin in the next couple days.

 

[speedy turtle]

Hello Otaliema.

Mr. DolHaus introduced me your thread. I’d like to thank you your effort and to share your knowledge with the community.

I was wondering if I could make you some questions about the transmission configuration that I don’t understand, my level of English isn’t very good and sometimes I don’t perceive the real meaning or the explanations.

In any case, again thank you for share it.


ST70

 

[Otaliema]

Hello Otaliema.

Mr. DolHaus introduced me your thread. I’d like to thank you your effort and to share your knowledge with the community.

I was wondering if I could make you some questions about the transmission configuration that I don’t understand, my level of English isn’t very good and sometimes I don’t perceive the real meaning or the explanations.

In any case, again thank you for share it.


ST70

You're most welcome.
Ask away. I'll answer best I can. Some of the finer things I may not be able to answer as my game has died.

 

[speedy turtle]

Hello Otaliema:

I've found your "Silver Dragon Tuning" thread and it clarifies me very much. Anyway, thank you for your offer, I'll consider it for upcoming questions.

Sorry if you introduce it on this thread but I haven't had time to read it all yet.

Can I ask you in either thread or prefer one in particular?


Thanks again. 👍

ST70

 

[Otaliema]

Hello Otaliema:

I've found your "Silver Dragon Tuning" thread and it clarifies me very much. Anyway, thank you for your offer, I'll consider it for upcoming questions.

Sorry if you introduce it on this thread but I haven't had time to read it all yet.

Can I ask you in either thread or prefer one in particular?


Thanks again. 👍

ST70

I would prefer this thread as it's the main transmission thread now. The Silver Dragon Garage has been closed for a couple years. And with my game tanking the Bronze Dragon garage has been closed for new tunes or test updates

 

[speedy turtle]

Thank you Otaliema:

I've been reading and testing your explanations about gearbox tuning in Silver Dragon thread and I've improve a lot, it is very clear.

In any case, if I'd have new doubts I'll ask you by this one. I have much to learn yet, I have to study this thread and it has a little more difficult English for me.


Thanks again.

ST70

 

[Otaliema]

Thank you Otaliema:

I've been reading and testing your explanations about gearbox tuning in Silver Dragon thread and I've improve a lot, it is very clear.

In any case, if I'd have new doubts I'll ask you by this one. I have much to learn yet, I have to study this thread and it has a little more difficult English for me.


Thanks again.

ST70

Good to hear the old guide is helping. Yeah th A one is far more in depth so if English is not your first langue it could be kinda hard to figure out.

 

[speedy turtle]

Looking at your “old guide” and following their indications, I tuned the MX5 1.6 and I realized the differences between the two principal gearboxes, acceleration and top speed. Then I tried to translate those indications to a 6 gear gearbox, and extrapolated results to percentages, but I don’t know if I can do it, if I never must do it, or if I can do it sometimes. I found these results to the max acceleration gearbox:

1st gear: 5% - 8%
2nd gear: 17% - 20%
3rd gear: 42% - 45%
4th gear: 54% - 55%
5th gear: 70% - 70%
6th gear: 100% - 100%

Extrapolating your 5 gear gearbox we obtain these percentages:

1st gear: 5%
2nd gear: 23%
3rd gear: 58%
4th gear: 64%
5th gear: 100%

I would like to know if I can do this or it isn’t a good practice.


Another question, in that same example, the “final” final gear goes to the minimum value. If I find that value don’t allow me to reach a good max speed and I rebound to redline on a specific circuit. What do you recommend me? Start with a shorter (greater value) "initial" final gear?


Thank you.

 

[Otaliema]

Looking at your “old guide” and following their indications, I tuned the MX5 1.6 and I realized the differences between the two principal gearboxes, acceleration and top speed. Then I tried to translate those indications to a 6 gear gearbox, and extrapolated results to percentages, but I don’t know if I can do it, if I never must do it, or if I can do it sometimes. I found these results to the max acceleration gearbox:

1st gear: 5% - 8%
2nd gear: 17% - 20%
3rd gear: 42% - 45%
4th gear: 54% - 55%
5th gear: 70% - 70%
6th gear: 100% - 100%

Extrapolating your 5 gear gearbox we obtain these percentages:

1st gear: 5%
2nd gear: 23%
3rd gear: 58%
4th gear: 64%
5th gear: 100%

I would like to know if I can do this or it isn’t a good practice.


Another question, in that same example, the “final” final gear goes to the minimum value. If I find that value don’t allow me to reach a good max speed and I rebound to redline on a specific circuit. What do you recommend me? Start with a shorter (greater value) "initial" final gear?


Thank you.

Using percentages is good way to coarse tune a transmission. It gets you close to what you're looking for for that build than just fine tune it in.

As for your question about bouncing the rev limiter, you can approach it two ways. Use a higher initial final with a minimum top speed or use the same initial final gear and increase top speed settings.
For a 5 gear car
Adjusting the initial final. Consider the following, will you need drafting room, is it rapid bouncing meaning it's not trying to maintain the speed or is just bouncing.
If it's rapid bouncing (three or more per second is my rule for this) increase your final by 0.500-0.900 and test again.
If it's slow or just bouncing. Increase by no more than 0.500.
If you need draft room add 0.300 to adjustment for rev bouncing.
For each gear past 5 add 0.150 to adjustments.
If you choose to adjust top speed.
Rapid bounce 2 or 3 clicks.
Slow bounce 1 or 2 clicks.
Add one click for drafting.
Add one click for 7-8 gear cars.

 

[speedy turtle]

Using percentages is good way to coarse tune a transmission. It gets you close to what you're looking for for that build than just fine tune it in.

As for your question about bouncing the rev limiter, you can approach it two ways. Use a higher initial final with a minimum top speed or use the same initial final gear and increase top speed settings.
For a 5 gear car
Adjusting the initial final. Consider the following, will you need drafting room, is it rapid bouncing meaning it's not trying to maintain the speed or is just bouncing.
If it's rapid bouncing (three or more per second is my rule for this) increase your final by 0.500-0.900 and test again.
If it's slow or just bouncing. Increase by no more than 0.500.
If you need draft room add 0.300 to adjustment for rev bouncing.
For each gear past 5 add 0.150 to adjustments.
If you choose to adjust top speed.
Rapid bounce 2 or 3 clicks.
Slow bounce 1 or 2 clicks.
Add one click for drafting.
Add one click for 7-8 gear cars.

Thank you. I'll test it. 👍

 

[speedy turtle]

Excuse me, one question: If I use a higher initial final value. Am I not configuring a worse acceleration gearbox?

Thank you.

 

[Otaliema]

Excuse me, one question: If I use a higher initial final value. Am I not configuring a worse acceleration gearbox?

Thank you.

Yes you do reduce the acceleration of the car but you gain top speed.
It's a trade off, but you can also adjust the final shorter after it's built for shorter tracks so you gain the acceleration back on the tracks it's needed.
There is a third option for dealing with a bouncing tachometer.
Make your last gear longer. As long as you keep it in the power band your over all acceleration in that gear will not be hurt by much.
In this guide read the acceleration top speed gear box how to, and build it. It's a best of both worlds set up, you sacrifice a little acceleration and a little bit of top speed but end up right in the middle with a car that pulls hard and still makes a respectable top speed on 95% of the tracks.
Locations like Nordschilfe, Sarth and Spa generally need their own transmissions.

 

[speedy turtle]

Thank you Otaliema.

Reading the beginnings of this thread, there is a topic you call: “Setting up your transmission” where you breaks every gear into short, medium, large, … (post #3) and it confuses me.



I understand this:

But I think it would be this way:

Could you clear it up to me, please?

Thank you.

 

[Otaliema]

Thank you Otaliema.

Reading the beginnings of this thread, there is a topic you call: “Setting up your transmission” where you breaks every gear into short, medium, large, … (post #3) and it confuses me.



I understand this:
View attachment 591423
But I think it would be this way:
View attachment 591424
Could you clear it up to me, please?

Thank you.

The way you have the second image is the way I had it in my head when I wrote it. So if it's not coning across that way I need to rewrite it.

 

[speedy turtle]

If you think the image can help, you can use it. 👍


One question:

I’m trying to define the power band of a low powered car racing on Indy circuit and using the data logger. You recommend SR X, but to a low powered car maybe it’d be a very long circuit.

You told we can define the power band looking where the car "shows a notable increase in speed gains at a particular rpm, and where shows a notable drop in speed gains at particular rpm".

Well, I understand the theory, but when I go to “practice”… I don’t see, I don’t feel those increases or drops in speed gains. Neither on circuit nor data logger.

I don’t know if is difficult to “feel” these concepts on low powered cars, or it’s only that I don’t know how to read them.

One more doubt:

When you said "Hit the track, Come to total stop on the track. Make sure you’re in 1st gear for low powered cars, 2nd gear for mid power 3rd gear for high power and 4th gear for very high powered cars".

I don't understand; if the car is stopped, how will I be able to put it in motion on 3rd or 4th gear...


Thank you