optimum gear ratios found

[nitrorustler41]

no matter the car these ratios will not bog your turbo, and will give you beautiful top end speed. these ratios are optimum for 5-6 speed transmissions, and the 4 speeds may require the use of an overdrive 4th gear.

1st: 2.56
2nd: 1.8
3rd: 1.3
4th: 1
5th: .8
6th: between .7 and .6 usually try .660, and go from there.

no the rear end is a complete change in every car. in my viper I ran a 3.07
in my smaller higher revving cars i ran 4.56 or 4.88 if the track is really tight.

try some of these: 2.83, 3.07, 3.42, 3.73, 4.10, 4.56, 4.88, 5.13

these are the most common ones I use.

hope you like my advise

 

[Leonidae]

What about Chaparrals? what kind of gearing I should use for them?

 

[Parnelli Bone]

I don't think you can say one single set of gear ratios will be good for any car in any situation on any track. There are too many variables at risk.

 

[sucahyo]

I don't think you can say one single set of gear ratios will be good for any car in any situation on any track. There are too many variables at risk.

Agree. The top rpm of cars in GT4 can be different, the tire diameter too. Different tire diameter or top rpm may change the car top speed even with the same gear ratio and final drive. Also there is wind drag, the need to avoid changing gear in the middle of corner, etc.....

 

[nitrorustler41]

in order to just change the speeds of the gears, and compensate for bigger tires, make the rear end different.

you don't have to touch the gears. these work great, I'm teeling you if you have to make the rear end gear bigger or smaller compared to what you need

change the freakin rear end!!!!!!!!!!

 

[Scaff]

in order to just change the speeds of the gears, and compensate for bigger tires, make the rear end different.

you don't have to touch the gears. these work great, I'm teeling you if you have to make the rear end gear bigger or smaller compared to what you need

change the freakin rear end!!!!!!!!!!

I think you will find that all the people who have replied in your thread are more than aware that changing the final drive will effect all the individual gear ratios, this is not exactly news.

The overall gear ratio for each gear is after all simply the given gear ratio multiplied by the final drive ratio (well to be 100% accurate the driven wheel size also needs to be accounted for), so its rather logical that a change to the final drive will effect the gearing overall.

The main issue I see here is that you appear to be offering this as a one size fits all solution, and I have to agree with those that say this simply is not the case. Too many variables exist here for this to provide an optimum (your words remember) set of ratios.

What you have offered here could be described as a reasonable starting point for a descent cross section of cars; but an optimum set-up for everything from a TVR Speed 12 at the 'ring, to a AZ-1 at Motorsport land to a WRC Evo at the Grand Canyon? Sorry but simply tweaking the final drive ratio is not enough when you look at that range of situations.

Think about it this way, you are claiming to have the optimal set-up for 700 cars and over 50 tracks combinations, simply requiring a change of final drive ratio!!!! Sorry but hundreds of tuning set-up in GT lead me to think otherwise.


Regards

Scaff

 

[sukerkin]

Another thing to consider is that once you fit an LSD to the car then changing the Final Drive ratio also has an impact on how the Diff behaves and thus influences the overall handling of the car.

It's good that you wished to contribute positively, nitrorustler41, a thing to be encouraged without doubt, but you have to bear in mind that there are bound to be a number of people amongst a membership of tens of thousands who might have a different take on matters than your own.

 

[sucahyo]

you don't have to touch the gears. these work great, I'm teeling you if you have to make the rear end gear bigger or smaller compared to what you need

change the freakin rear end!!!!!!!!!!

That is the opposite of what I usually do. Except for drifting, I always attempt to use the smallest final drive, on any car .

Besides, setting the same gear for different car can be a lot harder to do than just using the auto gearing, which usually give the same speed on many car, more consistent. Although there is some exception where the auto gearing give weird result (Hyundai Coupe?).

Another thing to consider is that once you fit an LSD to the car then changing the Final Drive ratio also has an impact on how the Diff behaves and thus influences the overall handling of the car.

Increased lock when using lower final drive or the opposite?

 

[nitrorustler41]

omg.

you guys just don't quit.

 

[Rotary Junkie]

That is the opposite of what I usually do. Except for drifting, I always attempt to use the smallest final drive, on any car .

Besides, setting the same gear for different car can be a lot harder to do than just using the auto gearing, which usually give the same speed on many car, more consistent. Although there is some exception where the auto gearing give weird result (Hyundai Coupe?).

This is new to me, increased lock when using lower final drive or the opposite?

Huh. I do the opposite. I usually run about a 4.10 ratio for most tracks, and I almost always run

2.320/1.690/1.290/1.000/.800/.622 gears. It does work for me, but I am not exactly picky about ratios, so long as the car can keep moving.

Why? Less of a transmission ratio is easier on parts than a big trans ratio and a tall final.

 

[sucahyo]

Why? Less of a transmission ratio is easier on parts than a big trans ratio and a tall final.

I see. In my case I use smallest final drive because it give faster 1000m time for sub 500hp cars, faster straight acceleration, compared to high final drive.

Scaff even did some experiment for this:

I've been testing this one out with an SLR running on R3 tyres, an FC box and a racing flywheel.

Looked at 0-1000m times with the FC G.box set to auto 13 and then at FD 2.00, FD 2.647 (FC default value), FD 5.00, and then FD 2.647 with the flywheel.

Results are (all averages of 6 runs)

FD 2.00 (No R.Flywheel) - 20.06

FD 2.647 (No R.Flywheel) - 20.11

FD 5.00 (No R.Flywheel) - 20.33

FD 2.647 (With R.Flywheel) - 19.90

So the 0-1000m runs with the lowest FD setting do see to have a similar effect to using a lighter flywheel (but not as great).

However is this down to the lower FD values or the higher individual gear ratios? Tnats the question I want to answer.

Have to do some more testing on this one as it will have an impact if you change the individual gear ratios.

The main thing is the benifit of using the lower FD/Higher gear ratios is not as great as the advantage of using a racing flywheel (but of course you can always do both).

More here

 

[Famine]

omg.

you guys just don't quit.

Generally speaking, no. But then again, we encourage discussion here.

Nevertheless, I agree that no single set of gear ratios will suit every car. The purpose of gears is to multiply torque and there is no universal solution for every car, regardless of how much torque they have and where they have it. If there was, all car manufacturers would use the same gear ratios.

So, please, demonstrate to us why your gearings suit, perfectly, turbocharged cars, supercharged cars, VTEC/VVTi cars, diesel cars and hybrid cars. Examples of your gearings outperforming any other car-specific gearings would be helpful.

 

[Duke]

omg.

you guys just don't quit.

If we quit questioning everything, lots and lots and lots of poorly researched, inaccurate, and just plain wrong information would get passed around like Gospel between people who just don't know any better yet.

I see. In my case I use smallest final drive because it give faster 1000m time for sub 500hp cars, faster straight acceleration, compared to high final drive.

Scaff even did some experiment for this: More here

I think you're reading too much into that simple experiment. I don't believe it demonstrates that a smaller final drive ratio gives the best acceleration.

The bigger the final drive number, the more the torque is multiplied, but the faster the engine reaches redline. This is known as "shorter" gearing. If the final drive ratio is smaller, the less the torque is multiplied, but the longer it takes to reach redline. This is known as "taller" gearing.

Shorter gearing will definitely give you better acceleration, up to a point where the engine reaches redline too quickly to remain in a given gear very long. At this point, acceleration is traded for pulling power, but that's another story.

I believe that Scaff's 3-step demonstration went past that limit with the 5.00 final drive. Mostly likely, the radically short FD ratio forced an additional shift in the 1000m run, lengthening the ET by a few tenths of a second. It's entirely possible that the car was moving faster in terms of trap speed on that run than on the run with the lower ET.

The 2.00 FD is clearly too tall for the best acceleration, and cost a few tenths of a second. HOWEVER, I strongly suspect that there is a FD ratio a little shorter than the stock 2.647 (but not as short as 5.00) that would yield the best ET in a 1000m run. It would be a matter of making repeated runs, and progressively shortening the FD until the car was just hitting the rev limiter at the 1000m mark without requiring an additional upshift over the stock FD setting. This FD value would yield the best acceleration and ET for an arbitrary 1000m run.

This is exactly the transmission tuning process to use in adjusting a car to each particular road course. Once you have the individual gears adjusted for good, even ratio coverage, you adjust the final drive ratio to the shortest possible setting where the car just reaches the rev limiter in the top gear at the braking point of the longest straight. For tighter courses this is a higher final drive due to the lower top speed achievable in the shorter straights. For longer courses with big straights, this will be a lower FD for more top speed.

 

[Scaff]

I believe that Scaff's 3-step demonstration went past that limit with the 5.00 final drive. Mostly likely, the radically short FD ratio forced an additional shift in the 1000m run, lengthening the ET by a few tenths of a second. It's entirely possible that the car was moving faster in terms of trap speed on that run than on the run with the lower ET.

Quite right, and I do believe that more is bein read into a rather quick test I put together, that I quite clearly say doesn't reach any definitive conclusions.

It certainly wasn't meant too be taken any other way.

omg.

you guys just don't quit.

Sorry to sound a bit blunt, but what else did you expect?

If you simple expected people to fall down with fawning praise that I'm happy we disappointed. Even a quick look around the tuning and setting forum will quickly and clearly show that robust and in-depth discussion and analysis are the order of the day here. To post a thread claiming to have found the optimum gear ratios is going to draw people in like moths to a flame, but moths who are not simply going to agree with you simply because you say something.

To back up Duke's point about the reason we question things, I have personally lost count of the number of posts I have had to dismiss because from a technical point of view they were simply wrong. Without this kind of robust questioning and debate GTP would not be the place it is. The vast majority of the info you find here is strongly peer reviewed, tested, checked and discussed to the nth degree, and its all the better for it.

Now don't get me wrong, please by all means post up discussions and join in, just be aware that a good number of us know a bit about the subjects in question and we have our own opinions as well. That said we don't bite, so please don't be put off.


Regards

Scaff

 

[Parnelli Bone]

The main issue I see here is that you appear to be offering this as a one size fits all solution, and I have to agree with those that say this simply is not the case. Too many variables exist here for this to provide an optimum (your words remember) set of ratios.

Regards

Scaff

...exactly....​

in order to just change the speeds of the gears, and compensate for bigger tires, make the rear end different.

you don't have to touch the gears. these work great, I'm teeling you if you have to make the rear end gear bigger or smaller compared to what you need

change the freakin rear end!!!!!!!!!!

For some reason i have a real problem taking advice (even car-tuning advice) from someone who can't spell the word "telling". call me crazy...

 

[Dark Elite]

Or from someone who can't use grammar or punctuation correctly, which is, after all, something they agreed to do when they signed up.

Anyway...
Optiumum gear ratios, eh? What if I want to do over 373mph in a road car, are these settings still perfect for that?

DE

 

[sucahyo]

I believe that Scaff's 3-step demonstration went past that limit with the 5.00 final drive. Mostly likely, the radically short FD ratio forced an additional shift in the 1000m run, lengthening the ET by a few tenths of a second. It's entirely possible that the car was moving faster in terms of trap speed on that run than on the run with the lower ET.

The 2.00 FD is clearly too tall for the best acceleration, and cost a few tenths of a second. HOWEVER, I strongly suspect that there is a FD ratio a little shorter than the stock 2.647 (but not as short as 5.00) that would yield the best ET in a 1000m run. It would be a matter of making repeated runs, and progressively shortening the FD until the car was just hitting the rev limiter at the 1000m mark without requiring an additional upshift over the stock FD setting. This FD value would yield the best acceleration and ET for an arbitrary 1000m run.

It's not that simple. The other gear is changed too when we change auto gearing. It's a less known fact of auto gearing. On a same car, auto gear will give the same car speed no matter what final drive we currently use. A confinient tool. Although unlike in GT2, in GT4 you need to change auto gearing number to other number first if you intend to use the same auto gear number.

1. Auto gear set to 13, when using FD 2.000. 20.06 1000m time
1st gear: 5.016    x 2.000 = 10.032
2nd gear: 3.084    x 2.000 =  6.168
3rd gear: 2.119    x 2.000 =  4.238
4th gear: 1.548    x 2.000 =  3.096
5th gear: 1.202    x 2.000 =  2.404

2. Auto gear set to 13, when using FD 2.647. 20.11 1000m time
1st gear: 3.789    x 2.647 = 10.029483
2nd gear: 2.330    x 2.647 =  6.167510
3rd gear: 1.601    x 2.647 =  4.237847
4th gear: 1.169    x 2.647 =  3.094343
5th gear: 0.908    x 2.647 =  2.403476

3. Auto gear set to 13, when using FD 5.000. 20.33 1000m time
1st gear: 2.006    x 5.000 = 10.030
2nd gear: 1.233    x 5.000 =  6.165
3rd gear: 0.847    x 5.000 =  4.235
4th gear: 0.619    x 5.000 =  3.095
5th gear: 0.481    x 5.000 =  2.405

All of them have almost the same ratio.

 

[Orion]

So, please, demonstrate to us why your gearings suit, perfectly, turbocharged cars, supercharged cars, VTEC/VVTi cars, diesel cars and hybrid cars. Examples of your gearings outperforming any other car-specific gearings would be helpful.

I have to agree with Famine.

A punk ass Civic can have the same ratios as a Plymouth Barracuda, and they both will be making optimum use of thier powerbands, with the same ratios dialed in?

An average american muscle car has the power curve falling off around 2/3's of thier way to the redline, while an average high performance japanese car has the power curve that keeps gaining HP, until it reaches very close to redline.

Using the same ratios will limit the Plymouth Barracuda's top speed in GT4, and ability to pick up speed, because of it's powerband. The Powerband of it makes it harder to reach it's top speed, and also NEEDS a manual transmission because of it's powerband.

While the Civic on the other hand can just use automatic in GT4, because the redline, or even a bit past the redline is where you get maximum performance. You will need to make use of all/most of the gears, because you want maximum power when you are trying to reach the top speed in a car. The Barracuda can get away with using only 3 gears with a full custom transmission, because it has the HP and the Torque to pull it through, but it would still be recommended to use a manual for a typical muscle car, got to keep the power up if you want to let the speed pick up.

Cars are like human beings, not one of them are exactly the same. You can't slap on the same clothes on each person, as not everyone wears the same size. You can't slap on a Mini Cooper body kit on a Lamborghini, because they are not the same.

There is no such thing as optimum ratios for every car, it depends on what track you are using it on, depends if you want to have longer gears for better gas mileage, etc.

 

[Rotary Junkie]

Interesting about the "lower" tranny ratios/higher final drive (High numeric ratios in the trans, low in the rearend) giving better pull on the top end than my style... Actually, the tall trans gears with the stiff rear ratio will twist the car up on launch worse. And the driveshaft/u-joints get stressed worse. Think about it: on a solid axle car, you've got usually twice the torque going into a rearend that is half as willing to move as the other way around. The pinion gear will not want to move, and the axle will want to twist.

So if I've got 650 ft/lbs of torque going into my transmission, I don't want my driveshaft to have to deal with 2600ft/lbs; I'd rather have 1500 ft/lbs going through it and running a lower rear gear.

510: The gas mileage thing? Give me narrow gear spreads that I can keep the engine at peak EFFICIENCY at all times. It's gonna be floored anyways.

 

[Parnelli Bone]

I have to agree with Famine.

A punk ass Civic can have the same ratios as a Plymouth Barracuda, and they both will be making optimum use of thier powerbands, with the same ratios dialed in?

An average american muscle car has the power curve falling off around 2/3's of thier way to the redline, while an average high performance japanese car has the power curve that keeps gaining HP, until it reaches very close to redline.

Using the same ratios will limit the Plymouth Barracuda's top speed in GT4, and ability to pick up speed, because of it's powerband. The Powerband of it makes it harder to reach it's top speed, and also NEEDS a manual transmission because of it's powerband.

While the Civic on the other hand can just use automatic in GT4, because the redline, or even a bit past the redline is where you get maximum performance. You will need to make use of all/most of the gears, because you want maximum power when you are trying to reach the top speed in a car. The Barracuda can get away with using only 3 gears with a full custom transmission, because it has the HP and the Torque to pull it through, but it would still be recommended to use a manual for a typical muscle car, got to keep the power up if you want to let the speed pick up.

Cars are like human beings, not one of them are exactly the same. You can't slap on the same clothes on each person, as not everyone wears the same size. You can't slap on a Mini Cooper body kit on a Lamborghini, because they are not the same.

There is no such thing as optimum ratios for every car, it depends on what track you are using it on, depends if you want to have longer gears for better gas mileage, etc.

There's alot nitrorustler41 missed when he decided to create this "one size fits all" thread. He clearly didn't think it thru; instead he figured we'd all drop our mouses, rush out of our seats, slam in GT4 only to be saved by these "optimum" gear ratios

...well, we've all made mistakes before!

 

[Orion]

510: The gas mileage thing? Give me narrow gear spreads that I can keep the engine at peak EFFICIENCY at all times. It's gonna be floored anyways.

When you have a car with a long gear, like say the Dodge Vipers 6th gear, or the Corvette Z06s 6th gear, that improves gas mileage, atleast in real life anyways. This is also why the 5th gear on most Lancer Evolutions are deep, because they want to improve highway mileage.

 

[Rotary Junkie]

Yes, but in a RACE, you are almost ALWAYS at WOT, and a tall high gear will usually not improve fuel economy. Mayhaps a slight difference, but coming out of corners, lower ratios will help efficiency as the car does not have to work as hard to pull itself out of the corner. I don't see many courses wit nothing but longass straights and sweeping corners. Not even Sarthe is like that.

 

[Orion]

Yes, but in a RACE, you are almost ALWAYS at WOT, and a tall high gear will usually not improve fuel economy. Mayhaps a slight difference, but coming out of corners, lower ratios will help efficiency as the car does not have to work as hard to pull itself out of the corner. I don't see many courses wit nothing but longass straights and sweeping corners. Not even Sarthe is like that.

True... In a race it is important to know your cars power curve, because sometimes a long gear will be very helpful in a car like say the BMW 120d, which is a turbo diesel. Same goes for the Nismo 400R, for some reason the power falls off very early before redline. Narrow ratios means more shifting, which sometimes can slow you down on a straightaway, especially in a Peugeot 905 Race Car. The Honda S2000 for one, will benefit from a close ratio transmission, which is what it already has, you can fully tune it without needing a FC Transmission, because it's ratios works well, but not on the test course. Sometimes you have to make a car have a very deep gear just to get maximum performance, but most of the time you don't, just check the power curve of the car and adjust the ratios accordingly.

 

[Rotary Junkie]

Oh, power falloff? That's what the manual trans is for.

And a 905 would BENEFIT from closer-together ratios. Less speed difference between each gear=less synchro work.

 

[Orion]

Oh, power falloff? That's what the manual trans is for.

And a 905 would BENEFIT from closer-together ratios. Less speed difference between each gear=less synchro work.

But when you use longer gears, you only have to shift a few times, and the 905 has a decent power band to handle these ratios.

I like the Nissan R92CP more than the Pescarolo, because less shifting is needed. I don't need to downshift/upshift on as many turns as in a Pescarolo, than a R92CP.

Same goes for the Chapparals. Close ratio isn't the best in every case, but it is good in cases that far ratio isn't good in, like exiting corners. On a straightaway, less shifting can either make or break your speed, depending on what car. Compare the stock SLR McLaren to the Pagani Zonda C12S. They have similar Power-Weight ratios, but the McLaren can beat it on some straightaways because of less shifting and great overall power. The Zonda on the other hand has more shifting. This is how the McLaren can beat the Zonda on a straightaway. Also the powerband on the zonda is similar to that of a muscle car, even with manual transmission, the gears make it slow down a bit, despite the closer ratio transmission.

Now the Subaru Impreza Type-R Coupe vs. the Subaru Impreza 22B STi vs. the Subaru Impreza VI Sedan vs. the New Subaru WRX STi '03.

22B STi
Great overall power and torque, and very close ratios, as it hits last gear before reaching 100MPH! It shifts way too much, but has stunning acceleration, the long 5th gear gives it some top speed though. It is slower than the STi Sedan, and the STi Type-R Coupe from 0-100MPH

STi Type-R
Great powerband as well as torque, with less shifting and faster 0-100MPH time than the 22B STi.It is a coupe with longer gears, and according to PD, aerodynamic lift. It hits the 5th gear at 111MPH, thus having a higher top speed than a 22B.

Sedan STi VI
Same as the coupe above, but 4 doors and longer ratios. Faster 0-100MPH time than both of the coupes, and the 5th gear is at 132MPH, meaning more speed. The 4th gear is just past 100MPH, so that saves it some time from 0-100MPH.

WRX STi GC '03
Powerband falls off a bit near redline, but has 6 gears. It also has more HP and torque. The ratios are closer, the 5th gear is at 110MPH, and the 4th is at 85MPH. It is tied with the STi Sedan VI posted above from 0-100MPH.

What I'm trying to prove is close ratio is not always the way to go.

Note: I'm not arguing, just having a discussion about transmission.

 

[Dark Elite]

When you have a car with a long gear, like say the Dodge Vipers 6th gear, or the Corvette Z06s 6th gear, that improves gas mileage, atleast in real life anyways. This is also why the 5th gear on most Lancer Evolutions are deep, because they want to improve highway mileage.

Quite true, but this is because it would take less throttle to keep those cars at motorway speeds in their top gears - the Dodge Viper is almost at idle when cruising in its intergalactic 6th gear, turning at 1200rpm at 70mph, and that takes almost no throttle at all - which is about as economical as it gets. If you buried the pedal in the carpet, it would be using just as much fuel as if you did it in 2nd.

DE

 

[Stevisiov]

Oh, power falloff? That's what the manual trans is for.

And a 905 would BENEFIT from closer-together ratios. Less speed difference between each gear=less synchro work.

Really is that what you find, personally I turn my 905 into a 3 speed gearbox, just a little work with you transmission and you have yourself gearing similar to a chapparal. You have the disadvantage of a slow start on races that don't allow rolling starts, and you also will find getting corner exits slightly harder to get right, because you have less gear choice, but lets be honest, the advantage of not having to shift much and still get a respectable top speed, I find makes this car slightly quicker and much less frustrating to drive, this is just my opinion but I find it works a treat on the 905 if set up correctly.

 

[Rotary Junkie]

Well, I was stating what SHOULD happen. I don't presently have a 905. And the shift lag isn't bad. I only upshift on straights.

510: Closer ratios are better.

For a real test, grab a Jag XK or S-type from the dealer, toss R5's on it (To prevent wheelspin for the purpose of this test) and grab an FC tranny. Try it close ratio and wide ratio. see which is quicker. I'll bet on close ratio. (Use the 400m test. That way the close ratio car will not top out.)

I love the Jag's stock trans, but the FC shifts the same anyways... Instantly.

 

[Orion]

Rotary Junkie, you do know when you buy a race tranny for those Jaguars, they don't have seamless shifting anymore?

Not good, trust me, it is only good to change gears for top speed runs. Run these cars head to head one with FC and one with stock tranny, I tried it today with close ratios and the stock tranny one won the "Mulsanne Drag Strip" I made up, even though it is the straight between the two chicanes. Close ratios aren't the one size fits all type of thing.

 

[Scaff]

510: Closer ratios are better.

At what? Fishing?

Without qualification that statement is totally invalid, if you are simply after top speed runs then no, closer ratios are not better at all. If all you are interested in is acceleration then maybe its valid, but again without taking the engine characteristics into account you can't use it as a truism.

Sorry, but I have a huge dislike for this simplistic, formula driving approach to tuning. It rarely works and never gets you to think about things, its almost as bad as when people say 'car x always understeers', what even when going straight or not moving!

Context please or you are adding nothing at all to this.

Regards

Scaff