GT Sport beta physics discussion

Discussion in 'Gran Turismo Sport' started by z06fun, Mar 30, 2017.

  1. z06fun

    United States Northeast :(
    PSN:z06fun, z06fun1

    So I though I would start a physics discussion thread for the beta. These are my thoughts so far, I've had a lot of driving & tuning time with it at this point. Many of of you know my background, years of sim experience, years of real experience competing with and suspension tuning many many different cars yada yada yada...

    Also check out praiano63's findings with the beta, he has been looking at tuning responses quite a bit:

    EDK posted some good tuning related info he found here:

    I've used many different cars at this point, mid RWD, F/R RWD, FWD, and the AWD cars. I've mostly used a G29 so far, I mention this because using Assetto Corsa on PS4, the T300 gives much more detailed and correct FFB vs the G29. See T300 beta comments down near the bottom.

    The beta tire model feels much more correct to me vs GT6. The tires no longer immediately overheat and experience a huge grip drop from a little bit of sliding, unlike GT6. The tires seem to feel fairly correct around their peak grip slip angle, as far as how the grip changes when you are above and below the peak grip slip angle. However its hard to really tell what the tire model is like because of the physics problems listed below.

    A physics issue in GT6 that seems to be fixed is the delayed RWD tire spin. In GT6 you could slam the gas down in a situation the should cause immediate wheel spin, but oddly the wheel spin would not happen until AFTER the weight seemed be shifted to the rear. Very messed up and incorrect, but that delay seems to be gone now and feels more correct now:tup:

    FFB feels more correct compared to GT6, also more detailed. But it is not at the level of realism you get in AC on PS4. Although the beta (and GT6 too actually) has less of a center FFB deadzone with the G29, compared to Assetto Corsa. The curbs seem to give FFB impacts relative to their size, very good! I need to try more FFB setting variations here, so far I've mostly been running ~2 or 3 for both FFB settings. I need to get access to a track with bumps too (vs just curbs), hopefully the ring will come back.

    The more Major Physics Problems/incorrectness I've found so far:

    1) Balance of RWD does not change properly when going from complete throttle lift to partial throttle. Doing this should add some rear grip, and help straighten/correct the car if the rear is mildly sliding, it doesn't seem to though. The issue of this not working correctly is more obvious on a mid engine car like the Evora. In real life a mid engine car will tend to experience a big shift of balance (to less oversteer/more understeer) when going from full lift to partial throttle due to the close distance of the CG to the rear wheels, compared to say a 50/50 weight RWD car. I feel like the reverse of this physics issue is also true, lifting mid corner does not seem change the balance towards more front grip the way it should, and at times causes the opposite to happen where it actually adds understeer. These physics issues were also present in GT6, however it is probably somehow tied to the next issue.

    2) There is also a behind the scenes "driving aid"/physics incorrectness that will sometimes cause the front of a car to lose grip if the rear starts sliding a bit. This can be seen if you have a fairly balanced car, and you are in a long turn and you lift off the throttle and the rear starts to slide a bit, it basically takes the front with it rather than adding front grip from the weight shift and helping rotation like it should. Very noticeable/obvious on the Evora because it has a bit of oversteer by default. This effect is super frustrating. This is by far my biggest upset with the beta as it REALLY takes away from the driving experience for me. Others I've talked to have echoed similar feelings about it. I actually made a post on the official beta feedback forum just about this issue, but my guess is that won't change anything. Why not put this behind the scenes "driving aid" only on with the "Brake/Steering" driving assist, or with skid force recovery if it is included? There is also optional stability control for those who may want that help. Or make this aid only on for the controller users maybe?

    3) I'm sure there are still other little behind the scenes "driving aids" happening too. In general the driving experience is more correct and generally much better than GT6, but is still a bit filtered, simplified, and less involved compared to what it could/should feel like, and compared to AC on PS4.

    Proper tuning responses rely on proper physics modeling, past GT versions have been known to not respond to tuning properly in some ways. This is what I have found so far:

    I have not seen much balance change from sway bar or spring changes. Seems like the can be used for fine tuning only. Need to investigate more though.

    Camber seems to have a big impact on grip, much more than real life, much more than GT6. Luckily it at least changes grip in the correct direction when you change it. I have not tested the impact of excessive negative camber etc yet.

    Rear toe, seems to mostly affect power lay down. You should be able to toe out the rear and have the car turn better from the affect of rear steering that it gives, but that only seems happen by a small amount on FWD the cars where you really need. I think it's just that there is not enough toe out range to really help FWD, because I certainly feel the rear steering on the more balanced cars when you have ~0.50 rear toe out. In real life rear toe out is often used to help a FWD or AWD car turn when class rules prohibit staggered wheel/tire sizes.

    LSD change seems to give a response similar to GT6, its still a very good tuning knob. One issue I see, if you lower the accel setting enough to get inside wheels spin on the pavement, you should easily get wheel spin if only one drive wheel is in the grass, but you don't if you are going straight. This is another "driving aid" I'm guessing. The grass is very slippery here, as it should be. You get lots of wheel spin if both drive wheels are in the grass.

    Dampers seem to work properly, affecting the balance change rate as they should, but again hard to tell for sure with the physics problems noted above getting in the way.

    So what things are you all noticing with physics?
    Maybe we'll also get a few others with real car experience that can add their thoughts too.
    :cheers: to PD for the early use of GTS!

    EDIT/Updates: I just drove the ring with the SLS for a hour. The LSD will spin 1 wheel when its up on, or partially on some curbs, if you have a low accel setting. Lots of bumps coming through the FFB here too (G29). Car gets loose even under mild throttle in places. Much more involved driving experience compared to Brands Hatch or Tokyo. Still feel the tire model is fairly decent (these were race hards).

    More general observations, I now have 2 mid engine cars, the stock Evora and the Audi R8 LMS. Neither one feels like it puts down power better than the F/R cars in the game. GT6 had this same issue, like weight on the drive wheels doesn't translate to a higher peak force that the tire can generate :confused:

    Also, like GT5 & GT6, all cars lose most of their acceleration ability while turning. This is way over done from how it should be but not a huge annoyance.

    Tried the T300, I definitely like it more than the G29. Curbs feel great on it, the FFB gives a good sense of how big they are etc. But I haven't tried it on the ring so more testing is needed when the ring comes back. One downside is the ratio is slower than the G29, and the built in degrees of rotation setting it has does not change anything in the beta.
    UPDATE: tried the T300 on the ring, its nice. If anyone is deciding on T300 vs G29 for this game I would definitely go T300. More details seem to come though on the FFB, feels much better around the center area too.

    Willow springs real shows this odd physics thing I mentioned in #2 above. With RWD and AWD the long turns really show this bizzare effect where, if you lift in one of the long turns, you will usually push way off line, vs not lifting which keeps the car turning better. Its very strange, makes it harder to drive because you often can't tuck in the front by lifting.

    Mar 5 Update: I originally posted here that I found the Gr. 4 GTR to feel very different between Arcade mode and Sport time trial at Brands Hatch. I've now tried this with a few other cars and see no difference in the 2 modes so maybe an odd thing with the GTR only. Needs a bit more investigation.[/URL]
    Last edited: Apr 10, 2017
    SW__10, ebelen92, msgt-sd and 27 others like this.
  2. sems4arsenal

    Online Now!
    Contributing Writer
    Egypt Cairo, Egypt

    Thanks for starting the thread, would love to hear more impressions and comparisons to AC and PCARS.
    SlimCharles and LeoStrop like this.
  3. yes i agree with most what you said ,i also felt when you should be able feather the gas when your just starting to get rear end slide to control it felt like someother than me was driving lol . i also noticed that on gt3 car when you hammer the gas there was no feeling of the car jumping up to speed like in ac or pcars .
  4. z06fun

    United States Northeast :(
    PSN:z06fun, z06fun1

    I spent a lot of time with Pcars on the PS4 before AC came out. I liked the physics mostly but they had some odd issues at times. But the FFB never seemed real correct to me, even with 20 different adjustments available. But I only used it with a G29.
  5. i dont have wheel for ps4 yet prolly get t150 as its cheapest good one but i found some cars on pc to be bit slick on ds4 and the ac cobra on ac with ds4 is almost undrivable .

    i think the one thing the physics so far for gtsport is it could translate into fun .

    driving the c7 at nurb in ac is heartpounding concentration which for me is fun but i understand that it wont be fun for avg gamer were gtsport should be .

    as side note pc2 is supposed be easier to drive on a pad .

    and did kaz not say he didnt want wheel users to have a advantage over pad users ?
  6. z06fun

    United States Northeast :(
    PSN:z06fun, z06fun1

    But the whole point of the driving aids are to help make the game accessible to the average user. The beta also has introduced more available driving aids vs GT6 with this "steering and brake assist" , to help those who may want them.
    sumukhavegito2 likes this.
  7. JDMKING13

    United States Edison NJ

    @ZO6 what tires are you using when testing the lotus Evora?
  8. after more play i think the two things i would add are more steering imput adjustment and brake pressure adjustment .

    one a side note anyone else get the feeling the wheel lock automatically adjusts itself . i dont mean a racing wheel but on the cars them selves in the game
  9. polizei

    United States Raleigh, NC

    I agree with your thoughts on the "behind-the-scenes" driver aids. GT has always had that feeling though. IMO, this is due to the majority of people playing with sticks instead of wheels. They have to make a million compromises to make the game enjoyable and comparable with both. I don't have a ps4 compatible wheel right now, so i was forced to use the controller and found the balance of the Focus ST was pretty good and i was able to use throttle inputs to get around corners faster. I did feel that push on off-throttle-medium throttle inputs you describe.

    I also share your concerns with the thoughts on the suspension adjustments not emulating real-world adjustments. That was one thing that ruined the competitive online for me was the spreadsheet geeks that spent hours tweaking the suspension in ways that would never work in the real world but gave them a huge benefit in the game.

    I also noticed today that some people were posted sub 1 minute lap times on willow springs when i was running 1:30's. I logged on later in the day and there was a message saying they scrubbed all the data. So i hope they test the tracks out and make the penalty system work.
    z06fun likes this.
  10. hankolerd

    United States Seattle, WA

    I think in certain situations that may be true, but I think in most cases the best you will do is catch and balance the slide to keep it from getting worse. If the rears are already slipping, applying just a little more torque to them if anything is just going to make them slip that little bit more. But, the shift of weight toward the rear of the car should help counteract the extra torque to the wheels, and this should allow you to catch the slide. I would think the only way you are going to straighten it back out is to add a little to the steering angle (counter), or waiting for the tread blocks on the tire to pull the car back toward straight.

    Overall I agree with your impressions. GT Sport is a nice improvement over GT6, and you can really feel the car moving around and the suspension working. Like you I have found that spring rates and anti-roll bars don't seem to have as drastic of consequences as you would expect them to. I ran the Evora on full soft springs and full hard springs, and expected a noticeable difference in body roll and the way the car responds, but for the most part it felt the same. In GT Sport it just seems that the lower and stiffer will almost always be faster.

    I have found that the softer the tire compound, the greater the camber can be set to achieve higher cornering speeds. As a rule of thumb set to ~0.5° for comfort tires, 1-1.5° for sport tires, and 2-3° for racing tires, and then tune from there. If I try to add too high camber setting it seems the tire is not able to produce enough grip to stand the tire up during cornering, and it ultimately reduces the grip level and cornering speeds.

    I have noticed this too, especially turn 2 at Willow Springs. In the Evora, I can get the car set in the turn with full steering angle and full throttle in 5th gear, and it will just continue to slow and slow, by the 3/4 point I will have slowed enough that I can shift down to 4th, and then there is enough torque to start accelerating again. You would think with a wheel it would be a little easier to limit this by taking off just a degree or two of steering angle to avoid the tires scrubbing. But I am not sure GT Sport has a sophisticated enough tire model to accomplish this. It seems backing off just the slightest will cause you to start running wide. Project CARS modeled this pretty well, as full steering angle always produces scrub (slowing the car and producing understeer), and you have to back off to find the sweet spot in order to get the fastest cornering speed.
    bremics, z06fun and Grippy like this.
  11. azrilnazli


    Compare sls with iRacing version if you can.

    Very good post.
    Lapse likes this.
  12. Grippy


    Far as I can recall this isn't new. Drifting on GT6 with a DS3, the front wheels will constantly correct itself at the limit to not allow such big slip angles on front tyres. Basically a form of permanent traction control exclusively for non-wheel users.

    If GT6 actually attempted to model a proper tyre model, half those gains made by "unrealistic setups" would be cut in half. A big part of those gains was how zero camber lead to strangely better grip and absurdly faster times around corners, almost as if the tyres themselves are solid circles with defined static grip contacts, big flaw in how the tires worked in GT6. Now seeing how improved GTSPORT is, far as we know it is built off the same engine, you may get a few similar quirks in physics but judging from other people and OP, car physics and tyre physics has been altered sufficiently to set itself apart from GT6's tuning style aswell. This is good, HOWEVER I can still see setups playing a big part of GT's top times, just like setups play a big part in the real world racing, so don't think that is going to change in Sport either. Having a solid racing setup is just as important in Sport as it was in GT6.
    Last edited: Apr 1, 2017
    z06fun and Imari like this.
  13. azrilnazli


    Ive read many complaints from controller users that hard to play Assetto Corsa and I think PD will make gtsport much more friendly to them.

    Statistically, 90% of GT users is using DS over Wheels. They are the biggest market
    J24681357 likes this.
  14. z06fun

    United States Northeast :(
    PSN:z06fun, z06fun1

    Great post. Just want to clarify this section. For generally any RWD car, in real life, if the rear is sliding a bit under lift, adding some throttle will add rear grip. The reason is, if you can change the rear wheel torque from drag to accel with similar or less magnitude, this will add grip from the weight shift, always. The mid engine cars exhibit this behavior more because they are generally less likely to spin the rears, all other things being equal. In the beta I get almost no sense of this working properly.

    All of my testing with that car were the tires it comes with, sports hard?

    That's true, they need to make it usable for the controller users, but they can add behind the scenes driving aids for them only. That would be helpful. Plus there are additional aids now in the beta, "driving and streering assist". I can't compare the SLS in Iracing because I don't have it anymore. But nothing in Iracing or AC will really compare well to the beta because of the large general physics differences.
    Last edited: Apr 1, 2017
  15. hankolerd

    United States Seattle, WA

    Ah ok, that make sense. With the Evora, I think I can feel this. Turn 1 at Brands Hatch Indy (N300 Sport Mode race), the backend will start to rotate and slide near the apex while off throttle (deceleration). Add a little throttle and you should be able to catch the slide and start to straighten the car back out. Easier to see it happening in the exterior view. Here is my tune. I was running with all aids off (including ABS).

    Ride Height: Fully lowered both front/rear
    Springs: Fully stiff both front/rear
    Stabilizers: 4 both front/rear
    Dampers: 6 both rebound/compression
    Negative Camber: 1.5° both front/rear
    Toe: -0.20 front, 0.10 rear
    LSD: 7/10/7

    I just got a RWD GR.4 Corvette today, so will have to see how it responds in the same corner.
    Last edited: Apr 2, 2017
    z06fun likes this.
  16. highlifeGT


    Gentleman, I give you this...

    I think many of you mistake the term physics with the controller - steering programming algorithms.
    That being said, it's always good to see that discussion lead to sim racers learning the natural behaviors of cars. In the end, it's up to YOU to set your car up to behave how you want it. Ride height, toe, and the black art of differential adjustment, ALL can drastically change your perception of whether a car feels "real" or whether it's even drivable with a controller.

    *** Check the video out and I think you'll all enjoy it.

    There's several other lengthy discussions and feature streams that had been uploaded on my page, all covering GT Sport Beta. Subscribe if you're interested in all things sim racing. All the GT Sport footage is in 1080p60. (Except one of the TT replay).

  17. polizei

    United States Raleigh, NC

    Does online feel any different to you all than solo? I don't notice a huge difference like gt5/6 but my first race felt very weird through the first few corners.
    hankolerd likes this.
  18. highlifeGT


    That's called performance anxiousness, or butterflies, or "James hunt-ing" because you're "stoked".
    It went away didn't it? ;)
    Good question. Maybe one could see a negative impact on multiplayer only in the case of a very low bandwidth connection or server problems on the other side of the pond.
  19. Fredzy

    United States PA

    I call this proximity lag as it only seems to factor in when near other drivers. GT6 had it pretty severe in certain cases and it seems GTS has it to some degree as well.

    I feel very little difference between GT6 and GTS physics. I think GTS FFB is improved but it's been a while since I last played GT6. GT tries to keep you on the road and racing straight at all costs. It is most noticeable with a wheel, and once you'd become accustomed to managing all of the intricacy of driving in a real sim. GT gets it 85-90% right but trims off the ragged edges.
    Johnnypenso and z06fun like this.
  20. z06fun

    United States Northeast :(
    PSN:z06fun, z06fun1

    Now that we have ring back for a bit, do any if you feel like some (or all) of the grey curbing (the flat ones beyond the red/white curbs) make the tires some what dirty for a brief period?

    As an example the very first one on the right hander that you go around each time you restart in time trial mode. Driving on that curb and others *seems* to cause some grip loss for the next turn. Am I imagining this? Seems odd because, in real life, inside curbs are usually kept clean from use.
  21. I find it funny (or strange) that the most interesting thread about GTS (imo) has so little feedback or posts in general.Personally I cannot add anything usefull since I dont have access to the beta but I would expect people that do,to post here especially since GTS looks like its going to go head to head with other titles (Pcars 2 for example).
    IMO physics are one of the most important "parts" of a racing game (that wants to be called "sim").Graphics and photos are cool but physics,tire model ext are way more important.
    FakeGangstaDIE, SVX, Wolfe and 3 others like this.
  22. JDMKING13

    United States Edison NJ

    I have every racing game out and I will say GTS is definitely going in the right direction I wish I had a wheel for my Xbox1, Im going to do more testing also but I think AC is still on top for me. GTS is way better than GT6 though. I just stopped playing GT6 a week ago so that game is still fresh to me and GTS is just a lot better. @z06fun doing test with stock cars I would use the comfort tires those sports tires are to grippy for stock IMO
  23. Imari

    Australia Melbourne

    Hmm. I started watching. Basically you seems to be saying that GT feels better because the controller assists give you more help with driving. That isn't really here or there for a simulator. You're giving up true control of the car in order to have the computer do it for you, fundamentally it's just another assist. Albeit one that cannot be turned off, which might be considered a downside for those that do have the manual dexterity to play with a pad unassisted.

    I would say that most simulation drivers would consider a game that modifies your inputs such that you can slam the steering left and right and get smooth and accurate inputs to be less of a simulation, simply because you're not actually driving the car. You're directing the computer which is driving the car for you, and that's not quite the same thing. It certainly make the game accessable, but it also means that what people are using isn't a game that actually gives them the experience of driving, it's more of an ego boost because it's hand-holding to the point where it won't let them make certain types of mistakes.

    You says that other games haven't got it to the point where pad players can keep up with wheel players. This is incorrect. Forza has plenty of leaderboard toppers with pads, or did last time I checked. pCARS and AC probably less so, as their pad support isn't great but I'd still put money on a good player with a pad over a poor player with a wheel. A wheel is not a sudden 5 second a lap advantage if you're unable to drive already. People continue to make a fuss over a pad being an inferior control mechanism, and I suppose technically it is, but it's totally capable of pulling out a single hot lap just as fast as a wheel. It might take a little more practise and control, but it's totally doable for someone who is dedicated.

    And no, pad players do not have a right to additional assists over wheels. Not ones that make them faster anyway. That's a slippery slope, and it means that if anyone is equally good with both input types then they actually have an advantage with a pad. We all remember SRF and how where it was available you pretty much had to use it to be competitive. One could argue that you have to use a wheel to be competitive but you don't. You just have to be able to give the same inputs, which is how it should be. You may find it more difficult with a pad, but many people achieve it.

    I think you're just adapted to the GT style, which many people have, and are assuming that it's superior. In some ways it is, for casual players for example. In others it isn't, like for people who want to have full control of their car without intrusive assists. If it was a toggleable option I'd be all for it. As it stands...meh. It's fine, but it does go against the idea that GTS is a real driving experience, and I dislike it when people minimise that.

    Simulators are by design sort of elitist in the same vein that something like Dark Souls is. You learn to drive properly or you don't. If you fail, go back and start again until you get it right. A sim won't hold your hand much, ultimately you have to be able to perform with the physics that the game gives you, but it's therefore a rewarding experience to actually develop skill. If you're just memorising braking points and turn in speeds it becomes little more than a rhythm game, which isn't at all what real racing is like. No doubt some people like yourself enjoy that, but I think it's a bit misleading to describe that as an accurate representation of driving.
    Sick Lenny, bremics, Pete05 and 11 others like this.
  24. Actually his point is that GTS is more for the casual player game and not anything like iRacing or AC or Pcars.From that point of view,its a good thing that playing with the pad works that way.
  25. z06fun

    United States Northeast :(
    PSN:z06fun, z06fun1

    Ive used Forza6 (and 4 way back when) and found the same thing. It was generally easier to go fast with a controller vs a wheel because of the various aids you got on the controller. That made me much less interested in the game. Although the Forza tire model is THE worst, ugg. Once you go past the point of peak grip the coerfficient of friction seems to drop in half and you dont stop sliding until you find a wall.

    Controller aids can be a slippery slope like you say.

    I actually did the same thing! For base line I got out the PS3 and drove several different cars right before I started using the beta. It really helped show the differences in general feel and FFB details.

    Its true the sports hards are grippy, but in real life that doesn't really change the balance changes that happen with throttle change etc. Although grippy race oriented tires will tend to be more knife edged because they have more of an adhesive component vs simple pure friction of something like an grippy street tire.

    The more I use the beta, the more I really like it vs. GT6. Sure its not like AC where you get all this feedback (not just FFB, but also sound, car reaction etc) about exactly what is going on with car all the time, but certainly more feedback than GT6.

    I have to say this again because its one thing I really like, the tire model really feels better to me than GT6 in the situation where you slide the rear tire a little with weight on it. In GT6, when using most any RWD car, if you got the rear slightly loose with a little too much throttle, the tires would immediately over heat and grip would massively drop off. That just doesn't happen that way in real life. In the beta, this situation of a little too much throttle feels soooo much more correct, where can counter steer a bit and stabilize the car. That feels very much like real life to me.:cheers:
    Last edited: Apr 3, 2017
  26. Seanspeed

    United Kingdom London, UK

    I've had a very different experience. Maybe we're just driving different cars or something, but slides are easily recoverable for me in Forza(and in GT). Too much so if we're judging by realism. Beyond just the extra limits of grip they provide, that extra forgiveness when pushing a car beyond the limit is actually a big reason these games are considered sim-lites rather than full-on simulators. Neither of them punish poor driving like they should.
  27. Imari

    Australia Melbourne

    Certainly. But it's not necessarily good for a game that wants to establish itself as a real motorsport. I mean, DotA isn't exactly the most user friendly game in the world but it doesn't seem to slow it down.
    JulesDennis and Wolfe like this.
  28. Ledbetter

    United States California

    If they put in hidden aids for controller users, they should disable them for wheel users.
    Lord Protector likes this.
  29. ImaRobot

    Online Now!
    United States San Gabriel, CA

    I've found that to be quiet wrong to be honest. While it is easier to be fast with a controller, it also restricts with things like turn-in at speed. Its a double edged sword, because while it is easier, a wheel should be faster in the long run, if the person has the skill to do it.

    Forza's tire model is actually a bit ahead of GT from what I've heard. As for breaking peak grip, I think you're massively over-exaggerating the situation. I've found most instances rather easy to correct, that is, unless you're going full speed into a 90 degree turn, slamming your brakes last minute, going into the turn sideways.
    BoneSawTX, Fat Tyre, Imari and 2 others like this.
  30. TeamCZRRacing

    United States FL, USA, Earth, Sol, Local Bubble, Milky Way

    Unless you're in a prototype (which is what I race most often) or an equivalent or faster car. They have a thoroughly ridiculous amount of grip/downforce.

    Not complaining, because that makes them more fun, but still.
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