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Inside Tire Wobbling Out Of Control. WHY??

Discussion in 'rFactor' started by rsmithdrift, Feb 11, 2012.

  1. Ok so I am a drift fanatic and obsessed with realistic drift physics... I have even been redoing the physics for the drift mods to be more realistic and have been doing a damn fine job if i do say so myself.. I have been changing primarily the hdv values as well as a tire set i created that rocks. But now I've finally decided to start delving into the world or suspension PM file editing and I've come across a problem. One I found before with another mod and fixed it by using a PM file from the same car in a different mod.

    But now I'm starting to find that when I rebuild the suspension to mimic the real thing all the cars get this wheel flipping out and going absolutely crazy at very high steering angles (like 50* or more) I can't figure out what's causing this either... I've tried everything I can think of moving the steering arms around even putting them in unrealistic places, moving the suspension arms farther in or making them have a smaller footprint (moving the inside of the arms closer together) and making all sorts of different things but nothing fixes it.

    Even the aasbo supra mod does it at full lock and I can't fix it their either it just wonks out the car rises up and the wheel spazzes out vibrating from lock to lock at an incredibly high rate of speed filling the air with smoke even.

    And only the inside wheel does it because of the ackerman in the steering. If I reverse the ackerman the outside wheel will start doing it instead of the inside wheel because if you know about ackerman that's the wheel that's turning the farthest. WIth 0 ackerman BOTH wheels start doing it simultaneously.... Which leads me to believe that it has nothing to do with the steering arms and everything to do with something interfering with the wheel keeping it from going at any higher of an angle and the games physics basically go insane in that situation

    I've thought maybe the steering arm is interfering with the lower suspension arm and locking out or maybe the steering arm is reversing at high angle (happens to real cars too) or maybe the inner points are too far forward and too far out toward the wheel and the wheel is hitting the arm or maybe it has something to do with caster and camber gain going too far IDK anymore i just can't seem to fix it.

    Does anybody know how to fix this?? Or better yet what causes it?? I'm so lost here... I'm frustrated out of my mind cause I FINALLY figured out how to almost perfectly mimic McPherson suspension geometry and I imputted the data from my person 240sx exactly with the only diff being the way I learned to make double a arms work in a mcpherson kind of way.. but everytime it causes this crazy vibrating wheel problem at close to full lock. The car feels so good with factory lock and has no problems and handles nearly perfect but go to 50* or so (easily acheiveable with spacers on a 240sx) and things get bad and I want to fix it for real. Please help
     
    • Like Like x 1
  2. What steering ratio and how many degrees of rotation are you using ?
     
  3. Well the aasbo supra that does it has 62* of steering lock and it starts doing it at 61.5* If you read the post, with ackerman the inside tire does it, with opposite ackerman the outside tire does it and with 0 ackerman ie parallel steering both tires do it simultaneously.

    And my wheel goes to 900* but this has absolutely nothing to do with the problem the problem happens virtually and is in the physics in the design of the suspension. And the REAL CAR that the suspension was blueprinted from literally and perfectly has 65* of steering lock.

    On the other cars Im making to have mcpherson replica suspension the steering lock is 55* and it starts happening around 52* or so. I've only done a AE86 and s13 so far but they both do it at about the same point and the ae86 suspension even has perfectly level lower inner points no anti dive or anything just straight a arm perfctly level and in line with one another the only diff between the two points is the z direction. (front/rear) so that rules out camber gain and twisting theories I had.
     
  4. 900deg of rotation with 50+ steering lock !? It's waaaaaaay too much, you don't need as much for drifting :S
     
  5. Knut Omdal Tveito

    Knut Omdal Tveito
    Premium Member

    It seems like the suspension is mathematically "undefined" after a certain steering arm movement (several possible wheel angles, no unique solution). But I would expect it to disappear if you make a simple equal-length parallel arm suspension (set bumbsteer, cambergain, antidive etc to zero) and make the steering arm parallel to the A-arms and zero ackermann. But it seems like you already tried this so I'm not quite sure what the problem is. Did you also set the in-game caster setting to zero?

    I would recommend using something like Kangaloosh! carFactory to visualize the suspension to make sure there is no mistakes.

    You can also check out this mod with another drift version for the Supra:
    http://www.racedepartment.com/forum...-supra-mkiv-drift-released.42819/#post-974200
     
  6. Bahahaha... that link IS the Aasbo MKIV drift supra i was talking about. Cut the wheel to full lock a few times and watch what happens to your inside front tire LMAO.

    And btw to William Lavesque, it has 62* of steering lock and he recomends 720 rotation. THE REAL CAR HAS 65* OF LOCK AND 720 ROTATION BUT THAT WASNT POSSIBLE DUE TO THE WOBBLY WHEEL ISSUE!!!. And the suspensiion of the real car was blue printed into the game meaning ABSOLUTELY every part of it is in the right place in the pm file. So thier is no logical explanation for this.

    And the in game caster setting is set to the fsm spec of the real car.

    I was able to solve in my AE86 and 180sx via ajusting the steering arms just shorter by 5mm than the rotation axis of the spindle (ie very low akerman) but that doesn't solve the prob with the supra. Even with perfectly parallel steering both wheels wobble at full lock just before 62* :confused: I need to eventually get the supra to 70* of lock (this is what the real car now has with new custom made spindles for 2012 season)

    And I don't use kangaloosh it doesnt seem to work for me... I use suspension editer v2 which shows graphically the changes you are makin to the pm and works VERY well. But it doesn't give you percentages of caster or akerman or scrub or anything like that... Just shows visually the suspension and the wheels and fuel tank and pushrods all together so you can see what your changing.
     
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  7. It's ridiculous... 720° with 65 lock is good for a 5.5:1 steering ratio, a F1 has ~10:1...

    Are you sure it's not more like 32.5 ? rFactor's steering lock takes only one side, not both, so you have to divide by 2.
     
  8. http://blog.cardomain.com/2009/04/01/cool-build-fredric-aasbos-new-drift-supra/

    I'm quite positive since that is the real aasbo supra drift car lolz

    Drifting 101 I NEEDZ MOAR LOCKS!!! XD For real same with rally. And F1 uses very low steering angles for more precision, it's not a very good compairo lol. Drift and rally like to have as much lock as possible with as little steering movement as possible. Gives you more control over flicking the car quickly and holding it at high angles.

    FYI My 240sx in stock form has 37* of lock at 900 rotation and with spacers 50* is acheived with shortened steering knuckles over 60* is easily possible with a ratio that is shortened depending on how much the arm is shortened. The actual rack ratio can stay the same but the steering ratio still changes greatly. 62* and 720 lock to lock is easily possible with it before you hit the lca. 70+ is acheivable by reinventing the cars geometry just for pro drifting.

    Here just for good measure. I believe you'll see how common this is.. It aint nothin but a drift thang baby =P
    http://www.wreckedmagazine.com/blog...-steering-angle-in-the-2010-chevrolet-camaro/

    http://canibeatlizerd.tumblr.com/post/7207664233/sooper-crazy-steering-angle-pbm-ftmfw

    http://canibeatlizerd.tumblr.com/post/7207664233/sooper-crazy-steering-angle-pbm-ftmfw

    http://zilvia.net/f/tech-talk/29672...ngle-modification-thread-108.html#post4292786

    Even a 350z can do it haha
    http://my350z.com/forum/7355882-post7.html
     
  9. Ridiculous :confused:

    Must be undrivable !
     
  10. Steering is very heavy so it self centers fairly easily and takes a heavy push/pull to turn the car and you just gotta be very precise and aware of where your steering is. When drifting you can just flick it back and forth and get sideways and just let go of the wheel when going from lock to lock and catch it when the car comes to it's balance point. I love having shorter steering ratio's I drive a normal car I feel like I'm driving a freaking school bus now haha.

    But in a game it might be a bit harder if your ffb isn't 100% realfeel and strong enough like in the tutorial in this forum.

    Undriveable is pressing select/r3/r1 and locking the wheel into 200* rotation with it at such high lock hahaha. I do that sometimes to drift at night without waking up my parents with my loud a$$ DFP. THATS when it's hard to hold straight XD
     
  11. Still no verdict on this huh?? Come on... somebodies got to know something...
     
  12. Knut Omdal Tveito

    Knut Omdal Tveito
    Premium Member

    I don't have any more ideas unfortunately. It's not easy to find the problem if I can't look at the real files. I you could send me your mod, I can have a look at it and try to find the issue.
     
  13. All you have to do is download the Aasbo Supra MKIV Drift mod v1.1 from rfc or many other sources one even listed and edit the max steering lock in the hdv to go to 70*, I'm sure you know how to do that... It'll happen sometimes even at 62* but it needs to be able to go to 70*
     
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  14. Knut Omdal Tveito

    Knut Omdal Tveito
    Premium Member


    I had a quick look at the default Drift mod and the same happened to as you said. I did the following changes in the .hdv file:
    These changes means that rFactor does not modify the suspension in the .pm file when it loads the car (track, wheelbase, etc. comes from .pm file instead of .hdv file now). The first correction above relates to rideheight adjustments (now the inner pick-up points does not move when you change the rideheight, as it should be) and made the biggest difference. These changes brings the maximum lock up to 87.92 degrees for me.
     
  15. Wait, why shouldn't the pick up point change when ride hieght is changed?? -1 moves the cars hight up or down when the ride hieght is moved up or down (as a real car would)... Seems making the height of the car fixed no matter the setup would be the unreal option, as though someone were to lower the chasis of the car without lowering the body of the car wich would require removing the body from the car and installing/removing spacers to lift/lower the body to keep it at the same height every time in real life... and that just isn't so...

    And align wheels... isn't that just a graphical thing so that the wheels look to be aligned with the chasis??

    ... I was kinda hoping to find a solution in the pm file without having to sacrifice the realism of the hdv... :/
     
  16. Ok well for the supra it turned out I needed to make the wheelbase/track width call from the pm not the hdv and I found out the value for corrected inner suspension hieght is 0.085.... And seeing as the bottom of the car is at 0.1381 above the lowest part of the inner suspension that means that part of the suspension is attached 0.0531 below the reference plane/skid plate... and the body is .05 below the reference plane... So since the suspension was all from blueprints and the car does sit high... I'm betting the inner susp points are all 0.0531 too low... Or the skid plate is that far too high... Because it would make sense that if the real car can only get to 70* with correct geometry, then the game car should only be able to get that far before becoming "undefined" basically the steering arm is maxxing out and reversing it's pull as it would in real life beyond its max range (happens to a stock susp 240sx at 52*).

    So yea that's the verdict. I learned something... correctedinnersuspheight isn't the wheel/fender gap its the hieght correction for the susp geometry... That's good to know haha.