Torque Converter Lockup Questions

Just curious, thought I would ask.

So torque converters are set to lock up shortly after it changes gear, but it is really violent in a lot of cases, as such -



You can see as it goes into 3rd gear it jolts the car.
Is there a setting in the jbeam that can customize how long after a gear change the torque converter will lock? Devs? Maybe?

 

Check this page: https://wiki.beamng.com/TorqueConverter

 

I've checked that, and the vehicle controller and automatic transmission pages

 

It's a bug, in the next hotfix it will be fixed. It's because there is power being applied during the shift. The throttle should be closed to avoid the jolt.

 

Still present in latest update. Every 4 speed auto locks the torque converter every time it goes into 3rd gear.

The devs should do it like this: in most transmissions in real life, it will lock the torque converter if it is sustaining a speed above usually 42-46 MPH, usually in 4th gear (OD) but sometimes on a hill it could lock up in 3rd gear (especially if you turn off OD manually). You can also usually give the car a little bit of gas while 4th gear is locked up, and it'll unlock 4th gear but remain in 4th gear, so in a way it almost gives you like a 3.5 gear. In the old versions when it was working better, it would always lock up 4th gear but I didn't mind that as much.

 

Bump, it's been a year now and automatic transmissions still aren't working correctly.

Every auto is locking up the torque converter in 3rd gear, every time. This needs to be fixed (like it was before) so 3rd is unlocked (unless 3rd is sustained) and 4th starts unlocked and locks after a second.

Please fix this, this affects automatic transmissions more than you'd think. It causes some major gear hunting on hills because 3rd gear locked is often too low of an RPM

 

agree.. i have a mod that does this, but it's pretty much impossible without lua to have it 'correct' ive got 1c-2c-3c-3l-4l working on a mod (just remembered, forgot to upload it ) but it's all to eager to jump from 3rd gear slipping to 2nd without slip, but ive tuned it so that with 4.10 gearing (3.55 is too sluggish for my taste) at high speed like 60.. put your foot down and you get circa 160hp in 3rd as the torque converter unlocks, then it re-locks at around 75mph before the torque converter is a drag... to do this i have basically made it so that above 60mph you can have your foot flat on the floor and have it still in 3rd, so you manually have to go to 2nd if you want an epic overtake...

What needs to happen is torqueConverterHighLockRPM and torqueConverterLowLockRPM for both high and low throttle positions.. that would be optimal

 

I agree, I think more advanced TC behavior would be great. TC lock by gear, high and low TC lockup points, or at the very least, throttle cut by gear so the gavril 6 speed shifts normally.

 

TC lock up RPM by gear is a good idea. The "torqueconveterLockupRPM": [0,0,2100,1500] would be great. A very simple way to remedy the "RPM hunting" is to use throttle cut during upshift.
The problem about the Gavril automatic is that both 4AT and 6AT use the same TC that lockup in 3rd, making the 4AT TC lockup in 4TH and 6AT TC lockup an 5TH is practical, easy to implement(you can mode them right now) and realistic(throttle cut in old hydromechanical is not possible). Personally I dislike unlock by throttle but not downshift (3.5 gear) because this will make hypermiling impossible. In hypermiling you upshift early(using M mode) to lower RPM(thus lower friction) and apply high throttle(low throttling/pumping loss). If you do this in the "torqueConverterLowLockRPM for high throttle position" the TC will unlock, losing transmission efficiency

 

I think @Diamondback has said no to this twice already, but if we keep asking he'll give in eventually, right? But I really want at least throttle cut by gear so you can have a transmission with multiple unlocked and locked gears, and have both shift properly. The Gavril 6 speed is a particularly bad example, it surges a ton in the higher gears.

 

Oh no, he will just get angery, you would need to give some concrete solid evidence that clearly shows the need and benefits over any hurdles there could be.

 

I'm sure me, Michealflat, and probably a few other people would gladly write an essay on why better TC lockup behavior would improve the game. Whether diamondback agrees is a completely different problem, however.

 

No, I wish the Devs could solve this problem first, TL;DR try parallel park the eSBR.

 

I said to diamondback when the agression factor automatic first came in about how you need to measure the acceleration of the accelerator pedal (so if you stomp on the accelerator, it builds the agression quickly, but lightly depress the accelerator, it slowly reacts) i remember him saying that acceleration code would be complex and that it would likely not be implemented.. 2 versions or so later (hotfixes i think) it's in the changelog

i'm not advocating we pester diamondback until he finally gives in and adds these features.. but those features would be nice..

Find attached the best i could do with the pickup transmission (passing mod approval, but if you want you can have it now) (drop in mods folder) - kickdown transmission works best, but there is an NA (no agression) and a non kickdown transmission (so you can floor it at above 60mph and it will unlock in 3rd and just steadily build up speed)
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True, but it will be set so that up to about max torque available it will be locked, then unlock when more throttle is commanded (whilst the engine is at max torque)... (thus you could have your max torque, right up until you want to boot it and the torque converter unlocks to get the revs up to get more power)..

locking stratergy is this: accelerate with tcc unlocked, until the speed of that gear with the transmission locked can deliver the horsepower at the wheels (so engine power - 20hp or so) (find this data using the torque curve) and once it is available, and there is more than 15-20nm torque headroom (at that powerpoint on the graph), then lock the torque converter

ALSO some GM cars actually have a PWM torque converter lockup clutch http://www.fuelly.com/forums/f16/how-a-pwm-controlled-tcc-torque-converter-clutch-works-10720.html, which has 100 states of lockup, so if we were to be completely realistic nah lets not do this

 

I found a small problem with your agressioned kickdown AT, is that if you increase throttle to unlock the TC it will also downshift ofter half a second, i.e unable to maintain that 3.5gear unless the throttle is controlled very presicely. IRL I had driven this kind of vehicles I can tell there's significant margin to maintain 3.5 before downshift

 

Yup. Both of my Japanese and American 4 speed autos in real life behave this way. The computer is smart enough to determine whether or not to use the "3.5 gear" (aka 4th gear TCC unlocked) or downshift to 3rd. It doesn't affect hypermiling because, if programmed correctly, you can modulate the throttle enough to do what you want.

 

I think why diamondback hasn't implemented it is because maybe the cars they have been testing it with (6-speed BMW autos and 8 speed autos) don't need to have as complex torque converter logic, most of the time it is just 1c-2c-2l and then all locked from there on in, as when you want more throttle, the tcu can just drop a gear as the difference is quite small, instead of slipping the torque converter..

However even on a 5 speed mercedes transmission (5 is a little low speeds i know) there is 4.5gear (on the motorway it's setup so 5th gear is 2500rpm at 70mph, put your foot down it unlocks and revs rise to 2900rpm any further it goes to 4L (4 locked)..

 

Nice computer. Looks like that's my vehicle's problem. Instead of P R N D D(OD-off) 2 1, my 4AT uses PRNDM and the TCC will unlock even in M4.
That's nothing to complain about it because I had driven cars that handle even worse, much much worse. It's a German car with 7DCT and when I drive it out of a underground parking lot it use half-clutch 2nd gear instead of 1st to go uphill, no wonder the transmission overheat in traffic jams all over the world. That car company really need to learn from ETK.

 

Well, even most basic of lockup TC equipped box TH200R4 is hard to get working well as it does not have any kind of logic really, it is hydromechanic thing, with cable making kick down and TC lockup being cut off by brake and quite small amount of throttle.

Also TC lockup happens only above certain speed (I think lockup turned on something like 85kph and above which I remember needed some bit of speeding, but opening was around 65kph, I remember it was pretty close to idle rpm) and only on top gear, when gear selector is in OD position, no lockup on D position.

Haven't figured out how to get that to behave realistic way in game, well not without some rewriting, but haven't attempted in latest versions either.

 

You can make a 5-speed and use the same ratio in 4th and 5th and program the TC to lock up in 5th. This will behave like a 4AT in 1c 2c 3c 4c 4l. Watch the file in #14.
In terms of speed drive the car at 65km/h or whatever you want and use the PowertrainVisualization app move your mouse over the TC icon and readout the RPM of the output shaft, use this RPM in shiftupRPM from 4th to 5th.

EDIT: put the attachment to the mods folder and select 4.5 automatic and torque converter.
The Pickup will lock the TC at about 85km/h with low throttle, with 40% throttle it will lockup at about 110km/h.
Apply 45-50% throttle with TC already locked will unlock and it'll eventually downshift if the throttle is 60% or above.