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Gearing question
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(42 posts, started )
Gearing question
I'm trying to set up my gearing. I did a search of the forum and found a few things and I've also read a few articles and I'm still not clear on how to go about setting up my gearing.

In one post Bob said he always has his highest gear set at 1:1. Why is this? I'm also assuming then that you adjust the final drive to make the highest gear work effectively?

Then in first gear, I've read you want it to be as tall as possible without wheel spin? What exactly does this mean? No wheel spin from a standing start or no wheel spin with the engine revved for a drag start?

Finally all the gears in the middle, I've see where you should evenly space them, then adjust them for each corner. Bob's Vehicle Analyzer has three ways to set the gear spacing but I don't understand when I would use one method vs the others.

Talking about the highest gear again, I think the only thing I understand about gearing is that I want to be between 150 and 300 RMS above max power when I hit the end of the longest straight.

Can you guys clear some of this up for me please?
1:1 is just an easy number, and many top gears are close to this in real life.

Then set final drive so you are at peak power rpm at the end of the longest straight. As you get better at the track you'll find you rev beyond this, which is okay as long as it's only a few hundred rpm more, but starting at max is a good place.

Then look at the lowest gear you plan on using in the race - usually second gear. Set this so on the exit of the slowest corner you are a little bit below peak torque rpm.

Then set the in-between gears until you have fairy even spacing, but smaller spaces in higher gears. If you want to be clever, you can then slightly adjust each gear to suit a corner or complex, but don't overdo it because you'll lose out elsewhere.

Finally set 1st gear. I set it so it's just a decent drop into 2nd, and don't worry about wheelspin from the start (it's quicker in LFS!). But you could make a really tall first gear that simply won't spin the wheels if you wanted. I would hope this exploit gets fixed when setup options are reduced in resolution.
Quote from tristancliffe :But you could make a really tall first gear that simply won't spin the wheels if you wanted.

(But don't complain when your clutch melts after a full throttle start then )
The only reason I can think of for a 1:1 top gear is to make it easy to figure out the total ratio when you include the final drive. With lower top gear ratios, you need higher final drive ratios, and in LFS, this means a higher pitched final drive gear whine.
When you say " Then set the in-between gears until you have fairy even spacing, but smaller spaces in higher gears." how do you go about this? Do you just take the difference between 1 and 6th gear, divide by four and increment each gear by that?
No, that would be linear/equal spacing, which is very bad. Linear or equal spacing means that every gear has the same speed gain, so it would be

Gear: 1st - 2nd - 3rd - 4th - 5th
km/h: 40 - 80 - 120 - 160 - 200
Diff: 40 - 40 - 40 - 40 - 40

However, since drag (wind resistance) increases by speed squared, the for example 4th gear would have a much harder time going from 120 to 160, than the 2nd one going from 40 to 80, even though both increase the speed by the same amount.

Therefore you want to space the gears in an sort-of exponential curve, with the higher gears giving less and less additional speed than the previous one. Something like this would be far more preferable:

Gear: 1st - 2nd - 3rd - 4th - 5th
km/h: 50 - 95 - 135 - 170 - 200
Diff: 50 - 45 - 40 - 35 - 30

E: That's probably not a very good example either, I hope you understand, though.
So I imagine that there is also a peak RPM you want to drop into when you go to the next gear right? Say from 7000 to 5500? How do I figure out where I want to drop the RPMs to for the next gear?
What he said.

With the gear sliders in game, rather than having a straight line between bottom and top have a nice curve

E.g.

1st ..........|
2nd .......|..
3rd .....|....
4th ...|......
5th ..|.......

Behold my amazing ASCII art that probably won't work on different computers

The rev drop will just be a function of the gearing, so if your gear spacing is good, and you're not running out of revs on the straights, or over/under revving in the slowest corners, then it's okay. To work out where to shift just watch the little red shift light in LFS. In real life it's a slightly more complex process and you have to know torque curves (or power curves).
Quote from tristancliffe :What he said.

With the gear sliders in game, rather than having a straight line between bottom and top have a nice curve

E.g.

1st ..........|
2nd .......|..
3rd .....|....
4th ...|......
5th ..|.......

Behold my amazing ASCII art that probably won't work on different computers

The rev drop will just be a function of the gearing, so if your gear spacing is good, and you're not running out of revs on the straights, or over/under revving in the slowest corners, then it's okay. To work out where to shift just watch the little red shift light in LFS. In real life it's a slightly more complex process and you have to know torque curves (or power curves).

Hm, I thought the gearing tab on Bob's tool would tell me what to set my gearing at rather than just guessing. I thought the red light was the rev limiter is that really the shift light?
Quote from jarmenia :Hm, I thought the gearing tab on Bob's tool would tell me what to set my gearing at rather than just guessing. I thought the red light was the rev limiter is that really the shift light?

Bob's tool will optimise it within certain constraints, but whether or not it's right for you is a different matter. You might find that with the gearing Bob's tool suggests you are having to change up right on the exit of a corner (or use the next gear up, which might be too much).

Bob's tool can only tell you an initial estimate, but it doesn't know YOUR apex speeds, or YOUR throttle application methods etc.

The little red light is the optimum shifting point - i.e. where the torque curves cross in each gear. Some will say shift a bit after it to cope with the speed loss, but I think it's pretty negligable - you'll have have a bit less torque before or after the shift depending on the speed of it, and I think it cancels out.

As far as I can remember ALL the cars have it - the outermost lights on the BF1 for example as it's 'optimum' shift lights (which occurs at too high an rpm iirc). I'm hoping that along with restrictions on the gear ratios and spring selection (we have a near infinite amount between the limits) that Scawen also removes or dumbs down the shift light (so it's configurable in the garage to work at a specific RPM perhaps), and include more data to work out the optimums oneself).
Quote from tristancliffe :Bob's tool will optimise it within certain constraints, but whether or not it's right for you is a different matter. You might find that with the gearing Bob's tool suggests you are having to change up right on the exit of a corner (or use the next gear up, which might be too much).

Bob's tool can only tell you an initial estimate, but it doesn't know YOUR apex speeds, or YOUR throttle application methods etc.

The little red light is the optimum shifting point - i.e. where the torque curves cross in each gear. Some will say shift a bit after it to cope with the speed loss, but I think it's pretty negligable - you'll have have a bit less torque before or after the shift depending on the speed of it, and I think it cancels out.

As far as I can remember ALL the cars have it - the outermost lights on the BF1 for example as it's 'optimum' shift lights (which occurs at too high an rpm iirc). I'm hoping that along with restrictions on the gear ratios and spring selection (we have a near infinite amount between the limits) that Scawen also removes or dumbs down the shift light (so it's configurable in the garage to work at a specific RPM perhaps), and include more data to work out the optimums oneself).

Great info. Would you mind walking me through Bob's tool on how to use it to configure my gearing? As I know that as I move the sliders back and forth the graphs change. How do I know what is good vs bad?
If I had time I'd love to, and I'd write a little tutorial. But time is not something I'm gifted with at the moment. I'd suggest PMing Bob himself, as it's his tool and he knows it best.

If, next week, you still haven't sussed it I'll try and help. Until then I can only really offer advice to specific questions...

Once you have a top gear and a bottom gear set in it, can't you click a button to optimise spacing or something, which I think spaces them on a simple exponential scale?
Quote from tristancliffe :If I had time I'd love to, and I'd write a little tutorial. But time is not something I'm gifted with at the moment. I'd suggest PMing Bob himself, as it's his tool and he knows it best.

If, next week, you still haven't sussed it I'll try and help. Until then I can only really offer advice to specific questions...

Once you have a top gear and a bottom gear set in it, can't you click a button to optimise spacing or something, which I think spaces them on a simple exponential scale?

I appreciate all the help you've given me already. I've learned a ton from you guys in the short time I've been working on this.

Yes, I can put in the top and bottom gears and let it auto space but there are three options and I don't understand what the different auto space options are for.
I think you're putting a bit too much weight on the importance of the gearing. It's really just a very rough thing and there's not a lot to optimize.

But for a start do this:
- Set your highest gear to 1.0

- Adjust final drive so that the highest gear's top speed matches the maximum speed achievable on the track (watch a WR lap or something to find this out)

- Set the first gear ratio to a value that produces a usable first gear top speed. Aim for a speed between 40 and 80 km/h (25 and 50mph), depending on how powerful the car is (more power = longer first gear)

- Click on "Auto space gearing" and select a method that produces a nice looking curve. Progressive to zero linear/exponential might actually be a bit too harsh, try using the adjustable one and generate a curve that is roughly in between the "progressive to zero linear" and "equally spaced" one.

This is really only a rough base, and you can only find out what to adjust when actually driving on the track. Bob's VHPA can only tell you the optimal gearing for a certain distance on a perfectly flat piece of road, which isn't going to help you much outside of drag races

Seriously though, the time lost or gained due to non-perfect gearing is insignificant unless you can consistently drive in the 103% WR region or faster.
Quote from AndroidXP :I think you're putting a bit too much weight on the importance of the gearing. It's really just a very rough thing and there's not a lot to optimize.

But for a start do this:
- Set your highest gear to 1.0
- Adjust final drive so that the highest gear's top speed matches the maximum speed achievable on the track (watch a WR lap or something to find this out)
- Set the first gear ratio to a value that produces a usable first gear top speed. Aim for a speed between 40 and 80 km/h (25 and 50mph), depending on how powerful the car is (more power = longer first gear)
- Click on "Auto space gearing" and select a method that produces a nice looking curve. Progressive to zero linear/exponential might actually be a bit too harsh, try using the adjustable one and generate a curve that is roughly in between the "progressive to zero linear" and "equally spaced" one.

This is really only a rough base, and you can only find out what to adjust when actually driving on the track. Bob's VHPA can only tell you the optimal gearing for a certain distance on a perfectly flat piece of road, which isn't going to help you much outside of drag races

Seriously though, the time lost or gained due to non-perfect gearing is insignificant unless you can consistently drive in the 103% WR region or faster.

Maybe I am, but I've read several articles that say gearing is often over looked so I figured I better take a closer look at it.
Yes, but as soon as you've set up the gearing to have a sensible first gear, a last gear that tops out on the end of the longest straight and not completely screwed up gears in between, you already took enough precaution up to the point where you start coming close to WR speeds.

Maybe tweak it if the gearing is really badly spaced for an important corner, or the way power is distributed makes it unnecessarily hard to navigate one section of the track, but that's about it.

Once it's roughly set up, it's better to invest your time into analysing suspension, differential and most importantly your driving style, as most time is lost in the latter.
^^whs

Regarding the different auto-spacing options in VHPA, they were all just made from playing around in excel one evening to create a nice looking spread of gearing. The last in the list, selected by default, is probably best and certainly most flexible, but it is not perfect. So, feel free to play around with the numbers they chuck out, or ignore them completely. Probably not what you wanted to hear.

I would like to add an "optimal" setting that maximises the area under the torque curves for a given first and top, but that's a load of maths and just as much time, which I don't have atm but, like most things I've work on, I'm always planning to get around to them at some point.
Here's a good example of why I asked the question. I started running some laps at Kyto GP Long last night to start practicing for the next event in the OWRL. I left my gearing the way I had it set for Blackwood. This "seemed" ok to me in that I was just beginning to redline at the end of the real long straight. The problem for me was that my lap time was 15 seconds behind the WR.

So I downloaded the WR and watched what he was doing. One thing I noticed was he was going almost 15 KPH faster than me at the end of the longest straight. I knew there had to be something wrong with the car (I'm not THAT bad am I?). I went into Bob's tool and changed the final to 3.2 (kept tweaking until I got the speed I wanted), then hit the auto adjust button. Now my top speed was much faster (still a few KPH below but that is because of the driver).

So, had I not looked at the WR and saw his top speed I would have never thought there was a problem. Is they only way to find something like that by watching the WR or is there something in Bob's tool that I should have seen telling me there was more speed available if I had better gearing?
And how much difference did the gearing change actually make? Half a second?
How much difference did watching where the WR brakes and accelerates make? 10 seconds?
How much difference did the rest of the setup changes make?

Sorry, but unless your gearing was WAY out it wouldn't make that much difference to lap times. I think there are other factors at play.
Quote from tristancliffe :And how much difference did the gearing change actually make? Half a second?
How much difference did watching where the WR brakes and accelerates make? 10 seconds?
How much difference did the rest of the setup changes make?

Sorry, but unless your gearing was WAY out it wouldn't make that much difference to lap times. I think there are other factors at play.

Actually I cut 5 seconds off my lap time after the change. The driver is definitely part of the problem but it appears so was the gearing. It had to be a case where I just wasn't getting enough acceleration out of the corners onto the long straights.
Quote from jarmenia :I left my gearing the way I had it set for Blackwood. This "seemed" ok to me in that I was just beginning to redline at the end of the real long straight.
...
So I downloaded the WR and watched what he was doing.

See, that's why I posted this:
Quote from AndroidXP :- Adjust final drive so that the highest gear's top speed matches the maximum speed achievable on the track (watch a WR lap or something to find this out)

Obviously your judgement of what seems ok and what not is not yet fully tuned in to LFS dynamics/physics, otherwise you'd have noticed the engine struggling due to being over/out of the powerband, not because the top speed in general was reached

Though granted, this also depends on how far the powerband is away from the redline. If the gap between max power and redline is very small, it's easier to notice when you gearing is too short. However if the gap is a bit bigger, then you can miss that you only redlined at the end of the straight because the engine was totally out of power, taking much longer to reach redline.
Quote from AndroidXP :See, that's why I posted this:

Obviously your judgement of what seems ok and what not is not yet fully tuned in to LFS dynamics/physics, otherwise you'd have noticed the engine struggling due to being over/out of the powerband, not because the top speed in general was reached

As you can tell by the many noobish questions I don't really know anything about racing. I'm just determined to figure this all out.

Quote :Though granted, this also depends on how far the powerband is away from the redline. If the gap between max power and redline is very small, it's easier to notice when you gearing is too short. However if the gap is a bit bigger, then you can miss that you only redlined at the end of the straight because the engine was totally out of power, taking much longer to reach redline.

So how do I know where the powerband is and when I want to shift to the next gear or down shift to get max performance? Watching the WR he never waited until the red light when on to shift, he always shifted before which seems to be wrong based on what was said earlier (that the red light was the shift light).
Actually the original wording was wrong, the last gear should not reach redline at the end of the straight, but instead it should reach a value that is a bit beyond the powerband. If you had a car with a powerband from 3k to 5k revs, it wouldn't make any sense to wait for it to redline if that one is at 7k RPM.

The powerband can generally be considered from max torque RPM till a bit over max power RPM, both which can be found out in the garage > info screen (look that the power/torque listing, to the right of them you'll see at which RPM they occur).

The red light is indeed the optimal shift light, however a slight deviation from it doesn't generally make any significant difference. What you need to consider when watching WR replays is, that these people don't use the tacho and speedo gauges at all, they're fully focused on the track and only shifting by sound. If they'd actually divert attention from driving to the shift light, they'd not be driving WR times
Quote from AndroidXP :Actually the original wording was wrong, the last gear should not reach redline at the end of the straight, but instead it should reach a value that is a bit beyond the powerband. If you had a car with a powerband from 3k to 5k revs, it wouldn't make any sense to wait for it to redline if that one is at 7k RPM.

The powerband can generally be considered from max torque RPM till a bit over max power RPM, both which can be found out in the garage > info screen (look that the power/torque listing, to the right of them you'll see at which RPM they occur).

The red light is indeed the optimal shift light, however a slight deviation from it doesn't generally make any significant difference. What you need to consider when watching WR replays is, that these people don't use the tacho and speedo gauges at all, they're fully focused on the track and only shifting by sound. If they'd actually divert attention from driving to the shift light, they'd not be driving WR times

Thanks for the info. So to go a step further. Once I know the powerband, when I shift, I'm going to want the next gear to drop me at the low end of the power band again correct?
Yes, that would be the optimal case, though it might not be always possible for every car and every gearbox. However, that's not a disadvantage, since everybody suffers the same bad car design then
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Gearing question
(42 posts, started )
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