I need help with transmission tuning, please!!!

Stigsblkcousin · May 26, 2011

Every time I race online everyone is quicker than me out of the turns. While tuner garage's suspension set ups are beyond terrific, the numbers for the gear ratio are a bit off(they will say to turn the gears down to a number below the gears limit). Is there something I don't know about when reading those numbers?

Better yet, could someone give me a extremely dumbed down explanation for gear tuning? Any help would mean a lot.

No_OBsT33R · May 26, 2011

I'm putting together a gear tuner app (excel spreadsheet) that will tune the gears based off power band, top speed, and a few other engine specs..

I'm working on including a adjuster for individual gear speeds (adjust how fast you can go in 2nd for example) so you can fine tune for specific tracks.

Keep an eye out for it in the next day or so. I'm just finishing it up, I don't have much free time.

Basilea · May 26, 2011

You can find helpful things here: Tuning link collection

AlphaGnomeo · May 26, 2011

Stigsblkcousin
Every time I race online everyone is quicker than me out of the turns. While tuner garage's suspension set ups are beyond terrific, the numbers for the gear ratio are a bit off(they will say to turn the gears down to a number below the gears limit). Is there something I don't know about when reading those numbers?

Better yet, could someone give me a extremely dumbed down explanation for gear tuning? Any help would mean a lot.

What you are experiencing has more to do with the track than the tune. The default tune is generally pretty good and some of the modified tunes can be pretty bad for a particular track.

The most important thing is to make sure that the max speed on the tune is close to the top speed on the track. There are probably even some people who will give up a teensy bit of top speed for a little bit better performance on the turns.

One trick that you can use to put the gears closer together is to set the final gear at the highest value and then slide the speed slider all the way down so that GT5 thinks it has to cram all those gears into a small speed band. Then raise the speed back up to the max speed for the track by reducing the final gear. The gears will stay close together as the speed increases. This will make your first gear performance worse, but should help once you get up to speed, especially if the min speed on the track is relatively high. The downside is that if the car has a 7 speed tranny, the driver's arm could fall off from shifting so much. (Make sure you have made the drive train improvements to your car. They don't change your PP, but they should increase your shift speed.)

You can also get a clue to what is going on by looking at your RPM in the corners. Review at the perfomance chart and note the RPM range with the best performance. As you are accelerating around the last part of the corner, you should ideally be in this RPM range. You can adjust individual gears to fix this, but be aware that doing so might screw up your performance in another corner.

Rotary Junkie · May 26, 2011

AlphaGnomeo
What you are experiencing has more to do with the track than the tune. The default tune is generally pretty good and some of the modified tunes can be pretty bad for a particular track.

Default is usually crap with a few exceptions. I've met very few cars that can't easily enough shave a second from the change from default to a proper tune on the average track.

AlphaGnomeo
The most important thing is to make sure that the max speed on the tune is close to the top speed on the track. There are probably even some people who will give up a teensy bit of top speed for a little bit better performance on the turns.

Ah-ah-ah! No. You do want to gear the car to be just past peak power in top gear at the end of the longest straight provided the speed range is wide enough to need it. Gearing is only somewhat track-specific really; there's only so much first gear you can effectively run (in terms of multiplication) at any given power level and you can only run so narrow of ratios. Generally you can find a happy medium where 1st is right on the edge of traction and top gear sees you hitting your absolute maximum speed right at peak power. Certain tracks will require some adjustment in gear spacing to make the car "happy" through a certain corner but it's fairly easy to get it close enough to not worry about.

AlphaGnomeo
One trick that you can use to put the gears closer together is to set the final gear at the highest value and then slide the speed slider all the way down so that GT5 thinks it has to cram all those gears into a small speed band. Then raise the speed back up to the max speed for the track by reducing the final gear. The gears will stay close together as the speed increases. This will make your first gear performance worse, but should help once you get up to speed, especially if the min speed on the track is relatively high. The downside is that if the car has a 7 speed tranny, the driver's arm could fall off from shifting so much. (Make sure you have made the drive train improvements to your car. They don't change your PP, but they should increase your shift speed.)

My 6-speed RX-7 runs through 4 gears between turns 1 and 2 of Tsukuba. It then carries on to a top speed over 180mph. First is at the limit of traction on cold tires. The only time you can say you're "shifting too much" is when the car has an extremely flat peak power area that allows you to run wide gearing without ever dropping out of said powerband. An extra shift never hurts more than time off peak power.

AlphaGnomeo
You can also get a clue to what is going on by looking at your RPM in the corners. Review at the perfomance chart and note the RPM range with the best performance. As you are accelerating around the last part of the corner, you should ideally be in this RPM range. You can adjust individual gears to fix this, but be aware that doing so might screw up your performance in another corner.

This is right. You want to be putting down as much power as you can at a given speed as long as it doesn't cause wheelspin.

On another note I've found a stronger LSD accel to result in stronger apex-to-exit acceleration as long as 1. you don't overstress the tires and cause the tail to slide and 2. you don't run into excessive understeer.

zodicus · May 26, 2011

the reason you cant get the numbers they do in each gears is the "top speed" setting. adjust this untill you can get the numbers they want in each gear.

Rotary Junkie · May 27, 2011

zodicus
the reason you cant get the numbers they do in each gears is the "top speed" setting. adjust this untill you can get the numbers they want in each gear.

Actually it's generally because they have different engine mods that change the transmission settings available through a given autoset. Basically, learn to listen to the spec sheet.

zodicus · May 27, 2011

yes but if the tuner has the topspeed setting at say 249 then goes and adjust his gears the way he wants. (may or may not hit 249 anymore) then post his tune with the individual gear settings but dosnt mention where the topspeed settings where. when user X tryes to match the settings, if he has it set at say 160, he will not be bale to match those numbers. no matter what mods hes done.

Rotary Junkie · May 27, 2011

zodicus
yes but if the tuner has the topspeed setting at say 249 then goes and adjust his gears the way he wants. (may or may not hit 249 anymore) then post his tune with the individual gear settings but dosnt mention where the topspeed settings where. when user X tryes to match the settings, if he has it set at say 160, he will not be bale to match those numbers. no matter what mods hes done.

That'd be foolish for a tuner to do. Most don't.

AlphaGnomeo · May 27, 2011

Rotary Junkie
Default is usually crap with a few exceptions. I've met very few cars that can't easily enough shave a second from the change from default to a proper tune on the average track.

Do you mind sharing one of your tunes? I put together a spreadsheet that computes the "area under the curve" and would be curious to see if your tune generates a larger total area - and of course, to try it out.

Regarding too many shifts, I meant that in the context of a setting where you narrow the spacing between gears. If you have 7 gears, you probably don't need that trick since that would increase the likelihood that you will be shifting while accelerating around a corner.

dr_slump · May 27, 2011

AlphaGnomeo
Do you mind sharing one of your tunes? (Rotary Junkie)

Seriously?

@OP my transmissions are set this way: 1. default, 2. max speed, 3. final, 4. single gear ratios.
The most tuners set it like this.

shirakawaa · May 27, 2011

I usually perform this way:

Reset to default
Max speed to the minimum
Final gear to the maximum
Set again Max speed to the minimum
Set the final gear to a meaningful value
Adjust gears individually as needed.

The first four steps make gears close together, with a limited rpm drop. They also enable, by setting a tall final gear (low values), to have a long first gear, while other gears remain close together. These steps are necessary because for some reason programmers at PD thought it would be "cool" to limit the selectable gear range for each gear. Those limits however aren't realistic and do not make sense. The above described workaround mitigates this problem.

I usually set the first gear tall enough so that under full throttle the car will accelerate at its grip limit and will be able to do standing starts properly. On cars with low low-end torque often a compromise is needed. In general I aim to have a usable first gear. With default gearing, the first gear is most of the time useless as it's too short.

I set other gears so that the covered speed for each one is more or less constant or slightly decreasing as taller gears are engaged. This can be checked by examining the intersection points between the blue lines and the redline:

I do this process by eye, I don't do fancy calculations. This works pretty well.
The last gear is usually set up so that the car reaches its max speed at peak power rpm on the main straight at the Nuerburgring Nordschleife.
More than often after setting up the last gear for top speed, I quickly adjust intermediate gears in order to maintain the constant or slightly decreasing speed coverage for each gear (excluding the first gear) mentioned previously.

Once gears have been set up in this way, in order to not lose settings, further tweaks are usually performed by adjusting the final gear setting only (and/or the last gear). Using the max speed setting again messes up everything.

* * *

In conclusion, the gear set up screen in GT5 is in general a bug-ridden mess ported over from GT4. To fully adjust gears, users have to use tricks and exploits. The gear graph is close to unusable, has no meaningful scale and shows strange and confusing overlaps. Also the lack (or better: removal) of a function to save custom settings has been a very amateurish move by PD. What the hell have they done?

No_OBsT33R · May 27, 2011

You got a few guides available now, one lengthy, one quick.

Hope that helps yah out.

dr_slump · May 27, 2011

No_OBsT33R
You got a few guides available now, one lengthy, one quick.

Hope that helps yah out.

Hmm, I think we should have a look at the OP.
He didn't ask how to set a good transmission, he asked how to set the tuner's gear ratios.

AlphaGnomeo · May 28, 2011

SHIRAKAWA Akira
I usually perform this way:

The reason this method works is that GT5 apparently uses a table-driven approach to compute the gear spread for each different speed (probably a holdover from older versions). For a selected speed, GT5 computes the final gear based taking into account rpm, final gear ratio, wheel diameter, pi, cake etc. To compute the other gears, GT5 consults a lookup table to determine the appropriate multiplier. For example, on a 5 speed transmission, the 1st gear multiplier at 99 mph is always 2.9834 (or thereabouts). At 199 mph, the multiplier is 3.7738. I have no idea how they came up with these values.

But the important thing is that you can use this information to estimate the top speed in each gear. For example, if the selected speed is 99 mph, 1st gear will take you up to 33.5% of the actual speed. If the selected speed is 199 mph, 1st gear will only take you up to 26.5% of the actual speed.

The other half of this trick is that once you select a speed, the spread is set and changing the final gear only changes the actual speed. The percentages stay the same. For example, if the selected speed is 99 mph and you adjust the final gear to take you to 199 mph (for example, by changing the ratio from 5.0 to 2.5), then the top speed in 1st gear will be 33.5% of 199 mph, or about 67 mph. The percentages for gears 2 through 4 are 47.7%, 64.3% and 82.3%. If you had simply selected 199 mph, the default percentages would have been 26.5%, 41.4%, 58.9% and 79%.

I suppose that if you want to generate the highest values for the intermediate gears, you could compute the highest gear ratio you need by multiplying the lowest gear ratio by the speed you want divided by the minimum speed. The disadvantage is that this prevents you from using the final gear to adjust your speed upward since you are already at the max.

I'm sure that some enterprising soul can make this information more useful by putting it in a handy reference table or incorporating it in their spreadsheet.

Cooldude3007 · Jun 3, 2011

If Your having Trouble with your gears do this
1. Firstly Press defualt
2.Secondly Take Your Final Gear All The Way To The Right
3.Then Adjust Your Top Speed Between 200-390 For Any Car (If It's Already Between This Change It e.g From 290 To 300 Back To 290 JUST RESET THE GEARS)
4. Then Fix Your Final Gear Depending On Which Car It Is
5. Then You Tune Your Gears Indualvaully
6.YOUR DONE

Stigsblkcousin · Jun 4, 2011

Thanks for the tips fellas, Ima have to try some of this out.