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Hi guys, I posted this in another thread but figured I would share it here as it took a few minutes to write.
Here are some thoughts and tips on tuning your car's gearing. I will try and logically construct this in an easy to understand format. This information is simplified and is not technical so I hope no mechanical engineers will come in here and rag on it too much.
Before you set gearing, you should set up your suspension. This is important. With a rear wheel dive car, I set my rear very high and my front very low. I make my spring rate in the rear very low, my shock absorbers soft but my compression slightly harder than my extension because I want my tires to remain in contact with the ground.
Final gear is the gear inside your transmission on a rear wheel drive car. It is the last gear before the axles transmit power to the wheels. Each gear ratio dictates how many engine speed (RPMS) to how many rotations of the final gear to finally how many rotations of the wheels of the car.
The bigger the ratio number, the shorter the gear. So a 4.00 FINAL DRIVE gear ratio means for every 4 rotations of the driveshaft (continuing the rear wheel drive example), the wheels turn 1 time.
So you could set all of your ratio's excluding the final gear to lower numbers. but set the final drive ratio high (like 4.00) and the car will behave like it has shorter gears (it revs up quicker). If you kept the same ratio's and set the final gear to a lower number, (like 3.00), the car will behave like it has taller gears (it will take longer to rev up).
Now GT has a setting called Top Speed. This is an auto setting that makes it simpler to tune cars. This will give you a set of ratios that will allow you to reach the top speed (in perfect conditions like if you had perfect aerodynamics).
The trick with setting drag ratios is you want a really tall (lower number) gear ratio for the first gear and the a slightly less tall gear for the second. Third, fourth, fifth, and sixth should be evenly spaced to allow a smooth acceleration. This is because unlike in real life, you do not have much throttle control nor do you have drag racing tires so you want to minimize wheel spin as much as possible. A tall gear (smaller number) reduces wheel spin because it reduces acceleration.
Okay so now with that background information, here is my advice on setting a gear ratio.
Top speed: leave it at default. Otherwise you lose flexibility in setting a tall first gear (small number, the available choices get larger when you mess with the top speed).
Final gear: lower this to the lowest possible setting. this gives you more flexibility to adjust the individual gears. You may raise this back up later.
Set the first gear to the lowest possible setting. Then, look at the graph. You want the / diagonal lines to be evenly spaced at the red line. This would show even acceleration and shift points. The slope of the line indicates how fast it reaches that red line shift point.
So now set the second gear to be tall as well but not the lowest possible number, just a low number that when the car shifts first to second will put you in a nice powerband. Powerband is the area of the power curve graph (in the first tuning screen) where the car makes the most horsepower, think area under the horsepower curve not the peak power.
Okay so now set the third, fourth, fifth, and sixth ratios to be relatively short (higher gear ratio number) and evenly spaced in that graph I mentioned on the transmission setting screen with nice slopes on the diagonal.
Test the tune out. You must use MT when testing it out! Do you get wheel spin when you launch in first gear with all driving aids turned off? Remember, you have final gear at the lowest possible number and top speed has not been messed at. Uh oh, you can't make that first gear any taller either because its at its lowest setting. If this applies to you, you will need to launch the car in second. if not, and i hope not, you will be able to launch in first which gives you some advantages like running automatic transmission if you are lazy.
Okay so you have no wheel spin but the car is too slow off the line. Raise that first gear ratio to a slightly higher number and test it. too much wheel spin, take it back down. Some wheel spin might be okay but you want the minimal amount that still gives you good acceleration. Same applies if you have to start in second gear as described above, just you will need to shift to 2nd before you rev the car up prior to launching it.
Once you get a nice gear ratio that shifts smoothly into second gear and does not have excessive or any wheel spin, you will need to adjust your second gear so it smoothly accelerates into third. You do not want ANY wheel spin in your second gear (or third if you are starting in second). So play with it a bit by raising or lowering the number until you get a nice acceleration (meaning inside the power band) and a shift point that puts you in the powerband for the third gear.
Then once you get this worked out, third gear, fourth gear, fifth gear, and sixth gear should be self explanatory. These should be shorter gears (higher numbers). Each gear should put you in the powerband for the next gear when you shift. The last gear should optimize your trap speed (speed reached when you cross the finish line), however a high trap speeds may indicate excess wheel spin when you launch.
Finally, if you like the spacing of the gears but require more acceleration and wheel spin is not occuring, you may increase the final gear incrementally. This will make all the gear settings above shorter so you may experience wheel spin. If you do, lower it back down.
Hope this helps. Each car is different and each driver is different.
Here are some thoughts and tips on tuning your car's gearing. I will try and logically construct this in an easy to understand format. This information is simplified and is not technical so I hope no mechanical engineers will come in here and rag on it too much.
Before you set gearing, you should set up your suspension. This is important. With a rear wheel dive car, I set my rear very high and my front very low. I make my spring rate in the rear very low, my shock absorbers soft but my compression slightly harder than my extension because I want my tires to remain in contact with the ground.
Final gear is the gear inside your transmission on a rear wheel drive car. It is the last gear before the axles transmit power to the wheels. Each gear ratio dictates how many engine speed (RPMS) to how many rotations of the final gear to finally how many rotations of the wheels of the car.
The bigger the ratio number, the shorter the gear. So a 4.00 FINAL DRIVE gear ratio means for every 4 rotations of the driveshaft (continuing the rear wheel drive example), the wheels turn 1 time.
So you could set all of your ratio's excluding the final gear to lower numbers. but set the final drive ratio high (like 4.00) and the car will behave like it has shorter gears (it revs up quicker). If you kept the same ratio's and set the final gear to a lower number, (like 3.00), the car will behave like it has taller gears (it will take longer to rev up).
Now GT has a setting called Top Speed. This is an auto setting that makes it simpler to tune cars. This will give you a set of ratios that will allow you to reach the top speed (in perfect conditions like if you had perfect aerodynamics).
The trick with setting drag ratios is you want a really tall (lower number) gear ratio for the first gear and the a slightly less tall gear for the second. Third, fourth, fifth, and sixth should be evenly spaced to allow a smooth acceleration. This is because unlike in real life, you do not have much throttle control nor do you have drag racing tires so you want to minimize wheel spin as much as possible. A tall gear (smaller number) reduces wheel spin because it reduces acceleration.
Okay so now with that background information, here is my advice on setting a gear ratio.
Top speed: leave it at default. Otherwise you lose flexibility in setting a tall first gear (small number, the available choices get larger when you mess with the top speed).
Final gear: lower this to the lowest possible setting. this gives you more flexibility to adjust the individual gears. You may raise this back up later.
Set the first gear to the lowest possible setting. Then, look at the graph. You want the / diagonal lines to be evenly spaced at the red line. This would show even acceleration and shift points. The slope of the line indicates how fast it reaches that red line shift point.
So now set the second gear to be tall as well but not the lowest possible number, just a low number that when the car shifts first to second will put you in a nice powerband. Powerband is the area of the power curve graph (in the first tuning screen) where the car makes the most horsepower, think area under the horsepower curve not the peak power.
Okay so now set the third, fourth, fifth, and sixth ratios to be relatively short (higher gear ratio number) and evenly spaced in that graph I mentioned on the transmission setting screen with nice slopes on the diagonal.
Test the tune out. You must use MT when testing it out! Do you get wheel spin when you launch in first gear with all driving aids turned off? Remember, you have final gear at the lowest possible number and top speed has not been messed at. Uh oh, you can't make that first gear any taller either because its at its lowest setting. If this applies to you, you will need to launch the car in second. if not, and i hope not, you will be able to launch in first which gives you some advantages like running automatic transmission if you are lazy.
Okay so you have no wheel spin but the car is too slow off the line. Raise that first gear ratio to a slightly higher number and test it. too much wheel spin, take it back down. Some wheel spin might be okay but you want the minimal amount that still gives you good acceleration. Same applies if you have to start in second gear as described above, just you will need to shift to 2nd before you rev the car up prior to launching it.
Once you get a nice gear ratio that shifts smoothly into second gear and does not have excessive or any wheel spin, you will need to adjust your second gear so it smoothly accelerates into third. You do not want ANY wheel spin in your second gear (or third if you are starting in second). So play with it a bit by raising or lowering the number until you get a nice acceleration (meaning inside the power band) and a shift point that puts you in the powerband for the third gear.
Then once you get this worked out, third gear, fourth gear, fifth gear, and sixth gear should be self explanatory. These should be shorter gears (higher numbers). Each gear should put you in the powerband for the next gear when you shift. The last gear should optimize your trap speed (speed reached when you cross the finish line), however a high trap speeds may indicate excess wheel spin when you launch.
Finally, if you like the spacing of the gears but require more acceleration and wheel spin is not occuring, you may increase the final gear incrementally. This will make all the gear settings above shorter so you may experience wheel spin. If you do, lower it back down.
Hope this helps. Each car is different and each driver is different.
