The definitive GT5 transmission tuning guide.

[grenadeshark]

We should a gear off. Lol

Choose a car. Preferably leave it stock other transmission and we all create ratios. See which produces fastest lap time.

Gotta have a parts challenge as well if you are having a gear challenge . Set a PP and weight restrictions and I am in!

 

[grenadeshark]

Yay, more to pick apart.

My "amazing setup" works consistently for me. For obvious reasons I vary it depending on the car in question. Low power needs a shorter first to get the correct launch behavior, mad power needs it to be even longer, etc etc etc. There will always be variables but I find this route to work well. You can make the maximum 1st gear stretch further by making the needed top gear ratio be close to the shortest possible rather than longest possible, leading to narrower gears, or lessen it by doing roughly what you did.

I tend to (as mentioned) set my cars up to just barely break the tires loose (and keep them spinning to avoid bogging) after a redline WOT clutch dump and rarely, if ever, spin once underway. Ratios get set as close as is useful. The setup currently sitting on my RX-7 (slight power choke for slightly nicer performance in 535pp rooms) sees me use 1st through 4th at Tsukuba while still maintaining a theoretical top speed above 300 km/h... I make proper use of my ratios rather than wasting the early gears to wheelspin.

Edit:

Urgh. Shift sooner, problem solved. Running that car out to redline is such a massive waste of power I can't even begin to explain it. Same for the extremely power-choked example you have now edited in, shifting at lower RPM will result in faster acceleration. But it'd be even faster for whatever PP it has with fewer power parts and less power choke. Oh, wait, I'm going completely off topic again aren't I... Eyup.

There is nothing wrong with your setups. But, I got the feeling you were claiming your setup was the only way to do it. I was pointing out the flaws in only doing it your way by the book.

You made a very valid point. Each car requires specific tuning. That's what I tried to cover in my guide.

I agree it will be faster with fewer power parts up to a point. That's a whole different guide I want to cover which you are already keen to. Basically in summary, chocking off power where the shift points in the car drop RPMs to right below the flat HP curve is ideal.

If you HP curve is flat beyond the usable levels of gearing and RPMs, you are basically chocking it too much. I spend 2 hours on almost every car testing every part and its effect on the power curve.

Notable conclusions. Small and medium turbos are useless (in actual in game racing and chocking the engine).

Stage 2 upgrades are always the worst. Med turbo, med exhaust,med stage 2 upgrade all add large amounts of torque down low and basically nothing up top.

Running a N/A or stock power adder almost always results in better acceleration at a given PP level where power restrictions are in place.

I am sure you are aware of most of these if not all.

I have a few cars that I feel are tuning achievements. I challenge anyone to build a faster 240 RS (83) than me at 450 pp. I realize this is kind of a specific challenge, but I am up giving out a reward to anyone who can.

By faster I mean acceleration and top speed in a given set of time/distance.

 

[Rotary Junkie]

Sadly I would be unable to participate as my PS3 is currently downed. Or I could maybe spend an hour or so at the neighbor's leeching their PS3 doing a parts set and gearing... Although honestly I'd rather have an already set parts list etc for all to be clear who can gear the car best... Beyond that it may as well be another tuning competition.

Edit: Lower level turbos do have their uses when building for the lulz, to see how fast a car can be, or for pure driving entertainment.

Also, less choke is ALWAYS better as long as you can hold the car near as possible to peak power at all times. Hence why I only run something like an 8% choke on my RX-7; my ratios are so close that I'm always at my peak ~38xhp anyway. There's a lot to be said on that subject really...

 

[grenadeshark]

Sadly I would be unable to participate as my PS3 is currently downed. Or I could maybe spend an hour or so at the neighbor's leeching their PS3 doing a parts set and gearing... Although honestly I'd rather have an already set parts list etc for all to be clear who can gear the car best... Beyond that it may as well be another tuning competition.

Edit: Lower level turbos do have their uses when building for the lulz, to see how fast a car can be, or for pure driving entertainment.

Also, less choke is ALWAYS better as long as you can hold the car near as possible to peak power at all times. Hence why I only run something like an 8% choke on my RX-7; my ratios are so close that I'm always at my peak ~38xhp anyway. There's a lot to be said on that subject really...

I agree and disagree at the same time. I like to choke any car who doesn't have a relatively flat power band a bit more then others. As long as the choke doesn't go beyond the optimal RPM range of the gear you are using, it can be a good thing.

That's why I want to have both a gearing and tuning competition. Because I spend loads of time on both ends. Theory comes to reality when testing and I have load of testing. Here is my silvia for example. Enough choke IMO, but not too much. Still more then you are advocating. For my gearing techniques, that is almost a perfect power curve. The drop off at the end is unavoidable unless you want to really choke the engine even more.

 

[Rotary Junkie]

That looks to be about the right width of powerband to me (which is what I go for most of the time), choke % is mostly irrelevant. I just prefer to keep it absolutely as low as possible for obvious reasons.

 

[articzap]

Sadly I would be unable to participate as my PS3 is currently downed. Or I could maybe spend an hour or so at the neighbor's leeching their PS3 doing a parts set and gearing... Although honestly I'd rather have an already set parts list etc for all to be clear who can gear the car best... Beyond that it may as well be another tuning competition.

Agreed. Set list. I'd just like to see who's gear set is best. Test it on three tracks. Gear sets for the typical user should be universal, as best as possible.

 

[drivehard]

I got really excited when I read step one: adjust first gear so that you get a small amount of tire spin but mostly forward progress. Nice and simple. Practical and instructional. The we went off into nano mechanics. I really hope this gets broken down into a simpler form for the know nothings.

 

[grenadeshark]

Agreed. Set list. I'd just like to see who's gear set is best. Test it on three tracks. Gear sets for the typical user should be universal, as best as possible.

I never claimed my gear sets were the best for track performance. I claimed they would promote the best acceleration up to a top speed. Granted, that translates directly to track performance, but its not always the same thing.

 

[articzap]

I never claimed my gear sets were the best for track performance. I claimed they would promote the best acceleration up to a top speed. Granted, that translates directly to track performance, but its not always the same thing.

So you wanna do a drag?

 

[grenadeshark]

So you wanna do a drag?

Sure. ss7.

 

[Adrenaline]

The Nissan OPTION Stream Z '04 would provide a much better canvas for this test, I think

 

[grenadeshark]

The Nissan OPTION Stream Z '04 would provide a much better canvas for this test, I think

In my opinion, tuning a low horsepower car to get the most out of it shows tuner input more than a higher output car.

Same with tires. The crappier the tires we use, the more tuning has to factor into the speed at which the car accelerates.

I would prefer to do a car with Sport Soft or crappier tires. Race tires just allow too much room for tuning error.

Also an engine with a non-exemplary power band will show tuning expertise as well.

Does the clutch in this game still allow faster shifting?

 

[GT5SER]

What I want to know is, when do you use a low geared tranny with high final or high tranny gears with low final?

- Jeramy

 

[articzap]

Sure. ss7.

Done deal. Name the car and tuning restrictions.

 

[articzap]

What I want to know is, when do you use a low geared tranny with high final or high tranny gears with low final?

- Jeramy

The net gear reduction will always be the same if you achieve the same exact top speed. I feel that a transmission that does not exceed 1.00 on 6th gear might be a hair quicker.

 

[Adrenaline]

Done deal. Name the car and tuning restrictions.

Everything should have to be the exact same, with the only exception being the transmission.

 

[articzap]

Everything should have to be the exact same, with the only exception being the transmission.

Exactly. By restriction I meant the exact parts to be used. I love to keep things fair for this. Same suspension and LSD setup. Only the gears will be different.

 

[TT3AZ]

Haha, seriously, you are ging to drag, with exactly the same settings, but transmission. The pointof drag tuning is to have different tuning overall, because everything affects. Then I really hope you are using a "tree", so no one jumps.

And i also have one question, to measure output torque to the wheels, you are multiplying the peak torque with the gear ratio, for example 629x3.241 = 2039, which was my old setup on my supra. My new ratio for first gear is 629x3.300 = 2076. The question is which of these gear ratios give me most output torque to the wheels, since i used final gear ratio 2.279 for my first setup, and now i using final gear ratio 2.150.

I tested with another supra that had exactly the same setup as I do and 725 hp, but different transmission setup, and our conclusion was that my new transmission setup was a little bit faster, since i got more output tourque to the wheels over all. When you are multiplying peak torque with the gear ratio, are you suppose to take the final gear in count aswell?

For example:
Old setup: 629x3.241x2.279 = 4646
New setup: 629x3.300x2.150 = 4463

As you can see, the new setup, while taking the final gear into count, actually gives less output torque to the wheels, but still im accelerationg faster, and reach a little bit higher top speed. Any one have a good explenation for this, and does the final gear has a effect in output torque? Both setups was made to be close geared, losing approx 1500 rpm between the gears while shifting. You can examine my old setup here, since its public. My new setup i cant make it public .

Do you get any information from this drag setup? Its for full tunnel ssr7.

Max hp: 725@6900rpm
Max torque: 629 ftlb@4900rpm

Old
1st Gear - 3.241 - Output Torque @4900rpm: 2039
2nd Gear - 2.330 - Output Torque @4900rpm: 1447
3rd Gear - 1.824 - Output Torque @4900rpm: 1147
4th Gear - 1.473 - Output Torque @4900rpm: 926
5th Gear - 1.222 - Output Torque @4900rpm: 769
6th Gear - 1.037 - Output Torque @4900rpm: 652
Final Gear - 2.279 (Not taking this into count)
Max Speed: 300 km/h (Actuall top speed 400 km/h). At the end of the tunnel im hitting 365-366 km/h

New
1st Gear - 3.300 - Output Torque @4900rpm: 2076
2nd Gear - *.*** - Output Torque @4900rpm: Higher than "old" setup
3rd Gear - *.*** - Output Torque @4900rpm: Higher than "old" setup
4th Gear - *.*** - Output Torque @4900rpm: Higher than "old" setup
5th Gear - *.*** - Output Torque @4900rpm: Higher than "old" setup
6th Gear - *.*** - Output Torque @4900rpm: Higher than "old" setup
Final Gear - 2.150 (Not taking this into count)
Max Speed: *** km/h (Actuall top speed *** km/h) At the end of the tunnel im hitting 366-367 km/h

To accelerate fast and avoid lagging, i need to rev to 7900rpm, and that is just before the rev limiter bumps off.

The Torque/HP graph:

The gearing graph:

"Old"

"New"

 

[esoxhntr]

are you suppose to take the final gear in count aswell?

yes. engine torque * gear ratio * final drive

however, to figure out shift points you don't need to include final drive since it is a constant in every gear.

 

[TT3AZ]

yes. engine torque * gear ratio * final drive

however, to figure out shift points you don't need to include final drive since it is a constant in every gear.

Okay, but how do you explain that the "new" setup is faster then then old one, even though we had exactly the same settings on both our supras, and the transmission was set up in a siminal manner? The main issue here is what gear ratio and final drive you should set to get maximum output torque to the wheels, still able to have the gears long enough and reduce wheelspin.

With your statement, the "new" setup has less output torque to the wheels, and that is less wheelspin, which can explain the faster accceleration, but this new setup still pulling hard comparing to the "old" one, even after the wheels has stopped spinning. For dragracing, we need to understand this. Lets focus on the Toyota Supra RZ as an example, since i have given both theoretical and practical examples.

 

[esoxhntr]

define "faster" -- more top speed or quicker accel off the line.

you didn't include all your ratios so it's impossible to say

 

[grenadeshark]

Haha, seriously, you are ging to drag, with exactly the same settings, but transmission. The pointof drag tuning is to have different tuning overall, because everything affects. Then I really hope you are using a "tree", so no one jumps.

And i also have one question, to measure output torque to the wheels, you are multiplying the peak torque with the gear ratio, for example 629x3.241 = 2039, which was my old setup on my supra. My new ratio for first gear is 629x3.300 = 2076. The question is which of these gear ratios give me most output torque to the wheels, since i used final gear ratio 2.279 for my first setup, and now i using final gear ratio 2.150.

I tested with another supra that had exactly the same setup as I do and 725 hp, but different transmission setup, and our conclusion was that my new transmission setup was a little bit faster, since i got more output tourque to the wheels over all. When you are multiplying peak torque with the gear ratio, are you suppose to take the final gear in count aswell?

For example:
Old setup: 629x3.241x2.279 = 4646
New setup: 629x3.300x2.150 = 4463

As you can see, the new setup, while taking the final gear into count, actually gives less output torque to the wheels, but still im accelerationg faster, and reach a little bit higher top speed. Any one have a good explenation for this, and does the final gear has a effect in output torque? Both setups was made to be close geared, losing approx 1500 rpm between the gears while shifting. You can examine my old setup here, since its public. My new setup i cant make it public .

Do you get any information from this drag setup? Its for full tunnel ssr7.

Max hp: 725@6900rpm
Max torque: 629 ftlb@4900rpm

Old
1st Gear - 3.241 - Output Torque @4900rpm: 2039
2nd Gear - 2.330 - Output Torque @4900rpm: 1447
3rd Gear - 1.824 - Output Torque @4900rpm: 1147
4th Gear - 1.473 - Output Torque @4900rpm: 926
5th Gear - 1.222 - Output Torque @4900rpm: 769
6th Gear - 1.037 - Output Torque @4900rpm: 652
Final Gear - 2.279 (Not taking this into count)
Max Speed: 300 km/h (Actuall top speed 400 km/h). At the end of the tunnel im hitting 365-366 km/h

New
1st Gear - 3.300 - Output Torque @4900rpm: 2076
2nd Gear - *.*** - Output Torque @4900rpm: Higher than "old" setup
3rd Gear - *.*** - Output Torque @4900rpm: Higher than "old" setup
4th Gear - *.*** - Output Torque @4900rpm: Higher than "old" setup
5th Gear - *.*** - Output Torque @4900rpm: Higher than "old" setup
6th Gear - *.*** - Output Torque @4900rpm: Higher than "old" setup
Final Gear - 2.150 (Not taking this into count)
Max Speed: *** km/h (Actuall top speed *** km/h) At the end of the tunnel im hitting 366-367 km/h

To accelerate fast and avoid lagging, i need to rev to 7900rpm, and that is just before the rev limiter bumps off.

To figure out why your setups are producing skewed results, I would need to test to see where the explanation lies. It is probably in the power range of the engine. Although your old setup produced more tq to the wheels at Max power, it doesn't account for the rest of the RPM range within that gear.

That might be the reason the oddity exists. Maybe not though.

 

[grenadeshark]

Done deal. Name the car and tuning restrictions.

I would say you name them since I am calling out challengers. My personal preferences would be no cars with tunes already listed.

New cars only since used cars produce awkward results sometimes due to mileage.

Less then 350 hp. Sport Soft or worse tires. Default settings on suspension or customized suspension with no modifications.

Again, I can adjust to anything really. Before we make this decision, we have got to find a way to limit time investment in this endeavor. I can always make a car a bit better by spending another hour with it. Give me 10 hours, and I can generally find another second.

How should we go about this?

 

[TT3AZ]

To figure out why your setups are producing skewed results, I would need to test to see where the explanation lies. It is probably in the power range of the engine. Although your old setup produced more tq to the wheels at Max power, it doesn't account for the rest of the RPM range within that gear.

That might be the reason the oddity exists. Maybe not though.

Well that could be the explanation, the "old" setup had higher torque at the end, but the time to achieve those numbers took longer times, hence reaching enough torque at a faster time = faster acceleration. Fast for me is relative good acceleration and top speed, since i running full tunnel on ssr7.

Take a look at my post above, there are some more details.

 

[Xr3CaRstI]

The net gear reduction will always be the same if you achieve the same exact top speed. I feel that a transmission that does not exceed 1.00 on 6th gear might be a hair quicker.

Quicker acceleration & less top speed. Or slower acceleration & high top speed. Everything is a compromise between acceleration & top speed.

I'll chime in on shift points because the concept is easy to grasp and it's being extremely over complicated. I won't speak to gear tuning just yet(too many variables for a quick post), but shift points are not to hard to understand if simplified.

Shift Points

Determining best shift point requires calculating the amount of torque you will be making at the rpm you land in after shift. If the torque at current gear peak hp rpm is higher than the the torque at (lower) rpm of next gear while going same speed (speed will be constant between shift) you shift after peak Hp., If the torque is lower you shift before. if equal you **** at peak hp. If you find your matching torque at redline you shift there, if just before red line you shift there.

It's as simple as matching the torque at shift rpm vs torque at rpm drop.

How you do this?

Calculator and a torque graph or simplified torque graph. That's where it gets a Lil complex, I'll go over it later.

 

[TT3AZ]

Quicker acceleration & less top speed. Or slower acceleration & high top speed. Everything is a compromise between acceleration & top speed.

I'll chime in on shift points because the concept is easy to grasp and it's being extremely over complicated. I won't speak to gear tuning just yet(too many variables for a quick post), but shift points are not to hard to understand if simplified.

Shift Points

Determining best shift point requires calculating the amount of torque you will be making at the rpm you land in after shift. If the torque at current gear rpm is higher than the the torque at (lower) rpm of next gear at the at peak hp while going same speed (speed will be constant between shift) you shift after peak Hp., If the torque is lower you shift before.

Yes, shift point is one thing you can think about after you have figured out which kind of gearing you want to have, to achieve your goal (take a look at my graph). Feel free to use my "old" setup and calculate the shift points, all information needed are shown. Okay so next step is to make a torque graph out of the picture to estimate the torque at different rpm.

 

[articzap]

Okay, but how do you explain that the "new" setup is faster then then old one, even though we had exactly the same settings on both our supras, and the transmission was set up in a siminal manner? The main issue here is what gear ratio and final drive you should set to get maximum output torque to the wheels, still able to have the gears long enough and reduce wheelspin.

With your statement, the "new" setup has less output torque to the wheels, and that is less wheelspin, which can explain the faster accceleration, but this new setup still pulling hard comparing to the "old" one, even after the wheels has stopped spinning. For dragracing, we need to understand this. Lets focus on the Toyota Supra RZ as an example, since i have given both theoretical and practical examples.

You guys are multiplying torque by gear ratio. It's the wrong method. Remember, torque increases as your gear ratio, numerical value, drops.

As far as drag challenge, I will be out of town till next Monday. We can discuss when I return.

 

[TT3AZ]

You guys are multiplying torque by gear ratio. It's the wrong method. Remember, torque increases as your gear ratio, numerical value, drops.

As far as drag challenge, I will be out of town till next Monday. We can discuss when I return.

Okay, but look at my graphs i have posted, maybe you can tell something about them. Im currently try to make a hp/torque graph where you can estimate torque at different rpm.

Okay i put it this way, i want good acceleration and good top speed, my goal is to reach topspeed in less amount of time, so you suggest longer gears will be better. I know you have to make your gears longer if you are running full tunnel drag, but still you can shorten them a bit, and feel differance.

When you say "increases" as your gear ratio, as far as i know "higher" gear ratio in numbers = shorter gears. Or do you mean that longer gears (small gear ratio in number) gives more torque since the engine has to work harder?

Regardin my specific setup, in this example, we still havent got an objective answer since some people claim that shorter gears = higher torque output to wheels, and you claim longer gears = higher output torque (to wheels??) since engine has to work harder.

 

[esoxhntr]

shorter gears = higher torque output

THIS. Provided the Final Drive is the same. Let me say it again, torque at wheels = engine torque * gear ratio * final drive - drivetrain losses. We cannot account for drivetrain losses but let's assume they are the same in every gear.

 

[TT3AZ]

THIS. Provided the Final Drive is the same. Let me say it again, torque at wheels = engine torque * gear ratio * final drive - drivetrain losses. We cannot account for drivetrain losses but let's assume they are the same in every gear.

Yes, thats your theory. On the other hand, that "greenman" claimed something else if im not mistaken. Im soon finish with my improved graph, maybe that can help you all out.