Quote from Scawen :

That's interesting. Do you know how resistant to rotation they are? E.g. how many degrees they can "give" when transmitting the engine's maximum torque. LFS does have something like this but if I had some real life figures I could compare them with the LFS version of it.

This is exciting to read. I don't have any figures, but I can imagine that introducing an accurate drive-train flex will add hugely to the sim. Tyre physics would also be affected, though, if introducing driveshaft flex. I've broken a driveshaft or two myself by accelerating uphill over a bumpy surface.. the driveshaft twisted a good many degrees, wheels bounced, caught again.. driveshafts snapped as the tyres caught and the engine torque went straight into twisting the shafts.

Here are some probs that i have noticed in X33. i don't know if it is posted before.

AI:

AI doesent overtake. did an 16hour test race wit UFR 30%restriction XFR 25%restriction and LX4 0% restriction. but they just don't overtake. they step all the time on the brake when they make a move to pass. also Did GTR test on KY Oval, when AI is faster they just don't pass even on straights. they jump on the brakes and make abrubt steering moves. also they enter the pitlane to fast at KY oval so they get a drivetrough all the time. but i see that its fixed in X35?

Car handling:

i've noticed that the cars are verry bumpy now. specially on cerbs. almost out of controll.

Setups:

All the car setups are gone. but the files are still in the map settings and i put them in map Setups. Only the lx4 still has all the setups.

i hope you can use the information.

gtrz
henrico-20-

p.s. the FBM drives great

Quote from henrico-20- :

Setups:

All the car setups are gone. but the files are still in the map settings and i put them in map Setups. Only the lx4 still has all the setups.

That's because the setups follow a different naming scheme now. You can get a batch-renaming tool here.

Just wanting to pursue this drivetrain thing for a moment.. (we need Bob or Tod Wasson or someone).. in my old Audi 90 (1.9L 5cyl), I could let the clutch off sharply, the clutch would bite fully, the car would lunge forward, the engine would *not* stall, the tyres would *not* skid, and the flex in the drivetrain (and suspension) would get the car moving. So, I'm guessing there's potentially a LOT of flex in there.

[edit] I'm such an amateur bar-stool engineer ... points of flex would also include engine mountings (rubber blocks.. broken them before, too), driveshaft, chassis flex, longtitudinal tyre rubber flex.. prolly a number of other points too.

You have to change setup filenames: for example Formula XR -> FOX and so on... Very useful programs, meant to do exactly that, were posted in unofficial addons section

Edit: beaten by Android

Don't know about XF GTI and RC but all cars have much better clutch heating simulation in X35 than in X33 when going on tarmac.

Hope clutch heating won't be increased to X33 levels ever again because it's horrible and X35's clutch acts more like the real in terms of heating and you can heat it when you're really trying (when going on tarmac that is).

Ok this post won't be easy for me. I should have taken the technical english course at the uni. In one of my current lectures (car construction I) we talked about clutches. When you talked about the stiffness of the drivetrain another point came to my mind.

Do you simulate torsional springs in a clutch at the moment scawen? Watch my attached pic, i marked it with a orange square. In roadcars clutches do not have a 100% stiff connection between drive side and the other (dont know the right english name). Even if they are fully engaged, all the tourque goes through these torsional springs. They are mainly one of the dozen methods to reduce engine vibrations in the drive shaft and to get rid off high tourque peaks.

Did you get what i tried to say/ask?

Greetings

Quote from SamH :

Just wanting to pursue this drivetrain thing for a moment.. (we need Bob or Tod Wasson or someone).. in my old Audi 90 (1.9L 5cyl), I could let the clutch off sharply, the clutch would bite fully, the car would lunge forward, the engine would *not* stall, the tyres would *not* skid, and the flex in the drivetrain (and suspension) would get the car moving. So, I'm guessing there's potentially a LOT of flex in there.

Engine mounts do flex quite a bit, also suspension movement helps a bit, don't know if either one of these is in LFS yet.

Engine mounts can be biggest reason as in Audi 90 there is not much to flex in drivetrain, imo.

Quote from Scawen :

I need to know which cars (if any) suffer more clutch overheating than others, on road or rallycross tracks, so I can hopefully start to see a pattern.

I've just done some races and free practice with the FZR, which is quite hard on the clutch, and I got the feeling that 25% might be a bit too much, I think something like 15-20% would be better.

I did the tests with FZR @ AS3 (the combo I've driven the most) with a DFP and using auto clutch.
Patch X35 on my side and patch X30 on the server.

Quote from Cue-Ball :

How much torque can tires and engine braking possibly cause when driving on dirt and gravel? Letting off the gas while driving over bumpy pavement, or being on the gas after going over a speedbump a bit too fast would be more likely to generate a lot of stress on the drivetrain, and I've never had a clutch slip as a result of those types of actions. Not even in 15 year old beaters.

I think you need to stop and think about how hard we actually drive these things in LFS. (See attachment) When all that mass comes crashing down to earth you can be quite sure there'll be some clutch stress. With all that weight the tires will spin up almost immediately, even on gravel, and a clutch designed for normal road use can't keep up with those kinds of forces.

Of course, your suspension would probably collapse after your first lap IRL, so the clutch heating up would be the least of your worries.

I'm sure Dennis mentioned somethime about axle twist due to inboard brakes on the dp1. Sadly I cannot find in emails/his site where this was mentioned, and I remember the exact figure. I remember it being higher than I thought, over 20 degrees I think (under full braking, that's 1.6gs or so).

Quote from wien :

I think you need to stop and think about how hard we actually drive these things in LFS. (See attachment) When all that mass comes crashing down to earth you can be quite sure there'll be some clutch stress. With all that weight the tires will spin up almost immediately, even on gravel, and a clutch designed for normal road use can't keep up with those kinds of forces.

I think you are seriously underestimating the durability of the average car. I've jumped WAY higher and WAY farther than that in POS beater cars loads of times, on both pavement and dirt (I grew up in Wyoming. There was nothing better to do ). Never broken or burnt out a clutch. Hell, we jumped my friend Dave's Datsun so high that the seats hit the ground when we landed. The windows broke out of the car, but the clutch worked just fine. I've launched my Mustang quite hard on very wide tires without frying my stock clutch. I've had friends launch their cars many times using sticky drag radials, and never broken a clutch (I've seen them slip, but only after repeated abuse like this). Hell, my friend's GTO twisted off THREE driveshafts and broke multiple U-joints, but never had the clutch overheat or massively slip. And that was just a Centerforce "street/strip" clutch, not a racing clutch.

Quote :

Of course, your suspension would probably collapse after your first lap IRL, so the clutch heating up would be the least of your worries.

Nah. Cars are pretty damn tough. Except Hummer H2s.

In order for the clutch to slip, you would have to have enough torque between the tires and the engine that it overpowered the clutch. In general, either the tires don't have enough grip (in the dirt they certainly wouldn't) or the engine doesn't have enough power/engine braking (depending on if you're on the gas or off). The only time I've ever seen a clutch slip and burn up is if it was old, if it had been massively abused (lots of riding/slipping the clutch or hard launches), or if the car had been highly modified but was using a stock clutch. Simply powershifting from first to second should not be enough to slip the clutch.

For the engine mount flex. I haven’t any arithmetic values but I have seen some engines move a lot even with just hard revups in netural. On some dyno runs, I couldn’t believe how much the engine mounts where flexing.

I tried to find some decent videos on youtube about that.
This is a good example of stock engine mounts
http://ie.youtube.com/watch?v=FrK8-fd9cN8
http://ie.youtube.com/watch?v=q7vRSkvmAT8



Sometimes this is a problem because the engine moves so much the gearbox, that you can’t shift a gear fast enough so there comes the need for an engine dumper especially if you have increased its power.
http://ie.youtube.com/watch?v=Yxa8o0Kq83c
http://ie.youtube.com/watch?v=lC4Dr_Mr2gY



And all this flex distortion is way less than axle twist that mentioned above.

Heh, fair enough. I didn't realise you were speaking from (rather impressive) personal experience. I still think a majority of the complaints people are having are because they don't quite realise how violent they are to the cars though. If you drove real life rallycross with a road car like you do in LFS I don't think a few broken and/or overheated pieces would surprise anyone.

Good job. Tested the clutch again on X35 with FBM, had the same time again.

Im not a car expert at all i tried to read all these posts but it sounds to technical for me. Almost look like 80% here are car-engineers

Anyway Scawen if you need some flat-clutch testing again let me know since my logitech g15 macro is very accurate (on the millisecond).

Don't push yourself to hard Scawen you doing a great job, forget the deadline think about the quality of the game. Think about X-mas etc btw merry xmas to everyone already.

Quote from wien :

If you drove real life rallycross with a road car like you do in LFS I don't think a few broken and/or overheated pieces would surprise anyone.

Oh, I definitely agree that the way people drive in this game would break parts. I just don't think the clutch is likely to be one of them. I've found clutches, even crappy stock ones, to be extremely strong. You usually will blow up the engine, snap a u-joint, or break an axle before you toast the clutch.

The way that people downshift in <=X10 is my biggest gripe. They tend to over-rely on engine braking and the artificially fast speed that LFS downshifts. I think a lot of that will go away now that auto-blip and auto-cut are gone, but the cars are still going to be subject to a lot more [virtual] abuse than they could reasonably withstand.

I'm anxiously awaiting further clutch model improvements and hoping for much improved damage modeling. In due time, I'm sure.

Quote from Bob Smith :

I'm sure Dennis mentioned somethime about axle twist due to inboard brakes on the dp1. Sadly I cannot find in emails/his site where this was mentioned, and I remember the exact figure. I remember it being higher than I thought, over 20 degrees I think (under full braking, that's 1.6gs or so).

Yowzer.. 20 degrees is a huge twist. That's a lot of sim!

Quote from trackah123 :

Don't push yourself to hard Scawen you doing a great job, forget the deadline think about the quality of the game. Think about X-mas etc btw merry xmas to everyone already.

Thanks but I'm thinking about my month after Christmas, Patch Y will be out this week!

Quote from Scawen :

Thanks but I'm thinking about my month after Christmas, Patch Y will be out this week!

Yay! Good news Looking forward to Patch Y!

Just plug out the internet after patch Y release and instruct your slav... *ehm* Victor to handle the remaining unlock requests

Quote from Scawen :

That's interesting. Do you know how resistant to rotation they are? E.g. how many degrees they can "give" when transmitting the engine's maximum torque. LFS does have something like this but if I had some real life figures I could compare them with the LFS version of it.

Just a comment:
The german company SGF produces such couplings and I'm pretty sure they deliver parts to several main south-german automobile companies. They'd propably share information on the torsional rigidity of the coupling and the dampening-coefficient of the used material if you'd ask them nicely.

Speak up if you want someone german-speaking to ask them. I'm sure there are many people around here who'd love to support LFS.

Also, I just looked up something from a lecture at university about vibration-simulation of drive-trains. In the presented model with guideline-values they have a torsional spring with a stiffness of 1*10^3 Nm/rad between engine and clutch (clutch included).

Vain

Scawen will have a happy X-mass, we will have a happy Y-mass

Yes i would love to see engine-damage in a way that somebody could break his gearbox or the engine catches black smoke or a fire Maybe thats something for a LFS S3 version or something. Something that could be developed in the very future when the race-physics has been pretty much finished at that time.

Same goes for the exterior of the car (flying parts, breaking glass, losing a tyre when it breaks off the suspension of the car etc.)

Quote from Scawen :

That's interesting. Do you know how resistant to rotation they are? E.g. how many degrees they can "give" when transmitting the engine's maximum torque. LFS does have something like this but if I had some real life figures I could compare them with the LFS version of it.

wow, I think it's cool to see that LFS is modelled on actual real-life figures...

i see that stronger clutch dont slips that much and imho in real life :-) in my skoda felicia :-) 50kW at 5000 rpm if about 106 Nm at 2300 rpm 4 cylinder 8 valve

i have 10 years old clutch and if i go in fifth gear about 120 110 kmh uphill i have about 3500 rpm at 120 km h , very long uphill only i 65kg and felicica 950 kg, over this 1,5 km long hill i must floor it because on top i dont have 120 km/h but only 100 km/h :-)))

on top of the hill aj can smell clutch :-) its very different to smell of engine or brakes :-) (brakes uphill dont smell :-) ) i realy love rev up 6000 rpm and never smell that , i can go 110kmh in third gear to 6000 rpm, and no smell of clutch

sometimes if i have passengers family about 200 kg and me i can sense clutch slips if i go uphil in fifth gear i have about 80 kmh 2800 rpm and if road is bumpy and one bridge uphill is bumpy aj can sense clutch sometimes slip, engine rev s up about 100 rpm and after while it gets down, its just not from disapearing load from front wheels because car jumps over bumpy road, it happens if i go uphill with full load and hill is very steep 12 % , thinking of it because i have high gear low rpm , floored pedal , engine have bigger torque in low rpm , maybe if iam pushing that longer i can get engine stall, but i am not heartless i just downshift, but theoreticaly thinking about it :-))

it maybe happen because clutch is old and worn , today i feel that i can't get car moving just with clutch and no gas, i sense that clutch bites, 3 years ago that clutch was fluid i was standing on cluth on hill and if i gets green i just slowly release clutch and car gets moving uphill (little uphill moving :-) ) , today worn clutch it just bite and engine stop without warning , slowly release pedal and bog stalled engine, today i must get little gas if i want stand on clutch uphill

but you know most time i drive alone, i have som bad habits :-) and dont realize that add 200 kg to 50 kw and its lazy dont help reving :-) it just dont have enought power 1.3

i just want describe that if only one hill can heat clut that i can smell it,than in race with bad shifts flat shifts clutch must heat even more

sometimes i do flat shift (not totaly flat :-) like in lfs, i just hold little gass and if i miss the revs) i get fantastic slip :-)

typicaly on second gear do 5800 6000 rpm about 80 kmh and fast shift to third gear, car literaly skips front for a split second i can feel it in back :-) but in later 2 seconds i can see revs dramaticaly drops 500 rpm ,to 3000rpm because engine dont have enought power and drops to rev where he has enough torque, or something like that :-))

now if i think about that i am confused ever more, because i realize that clutch slips only if its not full released and i do flat shift and have gas pedal under load , and second if i have 5 gear and low rpm about 3000 uphill (engine have max torque 106nm in 2300 rpm ) and uphill car with passengers sometimes clutch slips

but if it slip and clutch pedal is full released clutch slip only tothe point where torqe and rev are matching and gets transfered to the wheels at that point clutch bite and hold

if i recall clutch in race car is hard because it cant slip , you can burn pneu if you floor it, but clutch cant slip its last thing you can get if you want from engine max

i just thinking i have g25 , if i can race like before with auto clutch, auto clutch its just very big advantage over manual, in formula seqentional gearbox you don have to heel toe, but in H pattern i think i just must race with autoclutch i cant think where i can get advantage something good with manual clutch

guys with autoclutch just change gears always same in every type of gearbox like it is sequentional gearbox, they just change gears and break with engine

sorry for bad english its real fight for me:-)) describe, what i feel, just correct me, i understand english way better than i write and speak :-),i want read more about clutch, maybe i am in big mistake with some detail maybe i'm totaly off :-)) and in bad topic