Tuning Garage Links & FITT Physics Discussions

Discussion in 'GT6 Tuning' started by Motor City Hami, Nov 30, 2013.

  1. Motor City Hami

    Motor City Hami

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    I had this happen before 1.02 but only on one car. When I was first tuning the Acura NSX '91 the rear was sliding quite a bit. I spun the tires a few times in a row and they went red, then stayed yellow for a few laps. The tune badly needed adjustment. Once I tuned to add more rear grip, it solved the issue.
     
    Zuel likes this.
  2. Motor City Hami

    Motor City Hami

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    So I just drove the Honda CR-Z '10. I bought it to use in the EV events. I hated the CR-Z in GT5. No matter what I tried, I could not reduce the understeer enough to make it even fun to drive. In GT5, I could barely get it around the track. So, I thought I would try one out in GT6. Plus I just refuse to drive a Prius and can't stand most of the other EVs under 400PP. So I bought the CR-Z. I could not afford any parts after the purchase so I just drove it right out of the dealership and into the EV events (no oil change, no nothin').

    Why am I on about the CR-Z? Well, it was actually fun to drive in GT-6. It still pushes without any tuning, but it leads me to think that there is hope for this car. To me, every car that I have driven in GT6 is much more fun than the GT5 counterpart. So much so that I cannot ever see loading GT5 ever again.

    The way the game physics drive is one thing... props to PD for making the driving experience better. But, on the flip side, we still do not have much in the way of data to help guide what the cars need. Tuning is still a bit of a big guessing game. And, setting just do too little. You should be able to adjust a single setting and easily see improvement or decline. I want tire temps across the tire. I want the seven post rig that was mentioned. I want corner speed and g-force data.

    Anyone else having this same feeling? I feel like GT6 is a great game, but it still is not what it could be.
     
  3. D_M

    D_M

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    Motor City Hami,

    I just want the tire/suspension load circles back. Hopefully it will return in a future update. Do you compare the cars using a DS3 and wheel? Are there any differences between the two control methods? Are you faster using a wheel or a controller?
     
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  4. DigitalBaka

    DigitalBaka Premium

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    Yep! I want ALL of the telemetry. At least what we had in GT5 and then some. I want the speed test back, the load indicators, skid pad, I want to easily chart my cornering speeds, tire temp, I want to see what my contact patch looks like, wind tunnel, dyno...all the things that the magazines, tuning shops and review sites have access to for their work. Hell, give me all the stuff the F1 and other pro racing teams have.

    Overload me with the amount of data I can see so I can choose what I want to focus on and what I want to discard. If you want to hide it in an "advanced tuning" menu so be it but give me the options.
     
  5. iainoflo85

    iainoflo85

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    Yeah, I've noticed that FF cars feel a lot better stock in GT6. I'm seriously in love with the Scirocco - on comfort softs it's still really good, I refuse to put sports tires on it. I used it to beat M3s in the Scharzwald League.
     
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  6. Zuel

    Zuel (Banned)

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    I agree with you @Motor City Hami that GT6 is great but it's still missing so much, one item that should have been from day one is the 7 post. Which I'm very eager use in GT6 because I've used them in the pass. The Data Logger should have returned as well. I used the logger to compare the changes in my tunes from stock to what every class I was tuning for that wasn't running at a major de-tuned state and I got some outstanding results.

    I'm very, very impressed with with PD for teaming up with KW and Yokohama and whom ever else they teamed up with to bring us what we have today. I bout every car I owned in my life time to date and every car handled just as my real cars did which gave me chills of excitement. For the first time I'm looking forward to drive more street cars in GT6, more than I ever did in GT5. In fact I'm taking my copy of GT5 and resealing it along with putting it back in the collectors box.
     
  7. Zuel

    Zuel (Banned)

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    I'm hopping the software graphs are the same, or close, if the information is going to be in its entirety or a portion of the information. Pending on what information we get through the KW 7 post the level of suspension tuning will elevate, along with more developments. I'm really excited to see what will come of the in racing, how in depth will it will get for tuners, driver, teams and so on. SO for we got somewhat of a handle on things some more than others but I know sure it will only get better, the track is the ocean and the car is your vessel. Develop your vessel to beat the ocean don't let the ocean beat you.
     
  8. elevensixty

    elevensixty

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    this! plus one
    I will add:
    simply a graph for power band and gear ratios!
     
  9. Johnnypenso

    Johnnypenso Premium

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    IIRC from the News Forum, the 7 post rig will be used to analyze replay data only so if you're using it to tune your cars it'll be a rather unwieldy process.
     
  10. Zuel

    Zuel (Banned)

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    Has anyone had any success with the way the diff is acting? I've been setting my diff pretty high, higher than normal with great success. I've been work with the GT-R GT3 race car and it has picky torque band, I didn't bother stretching out the gears to combat that. The current diff set I'm running is 28-35-38 which is working well so far but it can be a bear when the weight hasn't shifted correctly which will get the tires speeding kinking out the rear. I've got the weight transfer almost nailed down for AP Hill forward and reverse along with Le Mas with out adding ballast. To get a better handle on things I may have to start using some math to make sure I can get the best out of a set over a long distance race.
     
  11. Zuel

    Zuel (Banned)

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    Why do you think it would be unwieldy; difficult @Johnnypenso? I don't believe they would have made it to overwhelming, lengthy maybe but not overwhelming. It could also tighten up the racing even more than it already has once everyone better understand it. Plus there are already a few members that has had hand on experience with a 7 post. I'm sure they'll be happy to help out lead every one in the right path.
     
  12. Motor City Hami

    Motor City Hami

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    @Johnnypenso - I have been looking all over for that 7 post rig in the replay data. When is it going to finally get here. :nervous:

    @Zuel - LSD. I am noticing that I can run higher values on Initial Torque and Decel. Many cars in the game seem to need added stability under braking (higher decel). Some need a little help on exit to solve oversteer (initial torque). But LSD Accel seems to be pretty close to GT5, maybe a little higher. I have seen moves from like 12 to 14 on accel from cars in GT5 vs GT6. For your GT-R GT3, try putting on sport hard tires and mashing it off the corners. If the outside rear tire spins first, the LSD accel is too high.
     
  13. rsergio007

    rsergio007

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    I did the following test on the Willow Springs skidpad.
    Go around as fast and steady as possible. For each run, watch replay and record the average lap speed, lateral acceleration indicator value and the lap time.
    My initial objective was to see how the weight increase for a certain car would affect traction and lateral acceleration. To understand the linearity of tyre response to vertical loads.

    I recorded the data below. Anyone wanting to help interpret the data is more than welcome to do so.
    The formulas I used were taken from the book "How to Make Your Car Handle
    by Fred Puhn" available online here: http://books.google.pt/books?id=cr4...onepage&q=car weigh cornering g force&f=false

    The conclusions I get from this data:

    - adding ballast weight to a car, and consequently increasing total tyre vertical load results in a linear increase in lateral acceleration. IRL, as you keep increasing vertical load on a tyre you start getting decreased lateral acceleration benefits. GT6 seems to use a constant relationship between vertical load and lateral acceleration generated.

    - the GT6 onboard lateral G gauge, shows values consistent with the lateral acceleration calculated based on time. This means that, whatever physics model PD is using, regardless of car, tyres, aero load, or concepts such as sprung and unsprung weight, the values displayed are apparently correct.

    - the difference in values between the calculations for lateral acceleration based on weight and based on time puzzles me. I can't really explain why they are different. Both these calculations are supposed to be universal and apply to cars as much as anything else relevant. The fact that a car is subject to additional vertical forces, rolls on rubber tyres, etc, might be the reason. But I can't really explain it logically.

    - aero load variations, as measured with the Z4 GT3 run, at 80km/h, do not affect run times. This seems to be consistent with reality were only at higher speeds you start getting relevant downforce from aero components


    skidpad test 1.jpg


    I'd really appreciate any opinions on both the data and conclusions. Feel free to ask for additional test details or simply crush my approach. Also, any insights regarding using the skidpad for testing are also quite welcome.

    Thanks
     
  14. Motor City Hami

    Motor City Hami

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    @rsergio007 - Great approach! Help me to understand the changes that you made between tests. Ballast increments, but always in the zero position? And on the Z4 looks like aero change.

    It is a little concerning that the speeds are all nearly identical between changes. I love this approach. Maybe PD did not program much change between individual settings?
     
  15. rsergio007

    rsergio007

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    Hi. Well, I just added ballast in 100kg increments in the 0 position.
    On the Z4 just tried the extremes for aero load.
    All cars are stock.
    In the case of the Caterham the percentual weight increase is huge, but, as for the heavier cars, still no lap times changes.
     
  16. MrGrado

    MrGrado

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    I always assumed lateral acceleration would be the force a driver would feel, so it's going to be based only on corner radius and speed. Your radius and speed are constant for each car, so your lateral acceleration is constant. The higher speed cars also have higher lateral acceleration.
     
  17. Johnnypenso

    Johnnypenso Premium

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    Unwieldy, not overwhelming. Because if I read it correctly, it only works with replays, not live data. Every time you make a change to the car and want to evaluate, you have to run a race or hotlap, record the replay, leave the lobby/practice area, go to Gallery or 7 Post Rig area, run analysis and then repeat.
     
  18. Zuel

    Zuel (Banned)

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    Just read the data? That's nuts.
     
  19. bread82

    bread82

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    @rsergio007: I think the discrepancy between the G force calculated from the weight and time formulae come down to how accurately you can measure the time of a lap. The time is written to the nearest second, and with times around 10 seconds, the difference between 10s and 11s is quite a lot (10%).

    Since you know the average speed of the car to the nearest 0.1 mph and the corner radius accurately you can calculate the time more accurately, which removes the discrepancy.

    eg the first "caterham" line:

    speed = 44.1 mph
    radius =108.26772 ft
    circumference = 2*pi*rad = 680.27 ft = 226.76 yd = 0.1288 miles

    time = distance/speed = 0.1288 miles/44.1 mph = 0.00292 hours

    convert to seconds (multiply by 3600) gives 10.5 seconds, rather than the 10 seconds used originally.

    putting 10.5 seconds into formula 3:

    lat accel = 1.226 * 108.26772/(10.5^2) = 132.736/110.25 = 1.20 g QED.

    I'm not sure why the PD displayed gauge is closer to the 1.33 g though :s

    With regard to potential benefits from suspension tuning, check this out:
    http://performance-suspension.eibach.com/performance_testing

    Max G was increased from 0.90 to 0.93g, with lowering springs and upgraded ARB. Would anyone with RL experience (Hami?) care to comment on whether this sort of improvement looks reasonable? And is it achievable on GT6 with just suspension tuning?!?

    Great thread by the way guys.

    Cheers,

    Bread
     
    Last edited: Dec 20, 2013
  20. Motor City Hami

    Motor City Hami

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    My data logger isn't that sophisticated. I rely more on full lap time, segment splits and video. GT6 needs more segments splits, like 10 to 15 per track. That would help a ton. In GT5 I used the Top Gear Test Track for tuning because it had nice airport lines across the track in lots of areas. I split the track into segments using those and would log replays of fast lap to compare tunes. With TGTT now gone from GT6, I haven't found a replacement yet. Just haven't looked hard enough yet.
     
  21. rsergio007

    rsergio007

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    That may be right indeed. But I was expecting, with the increased total weight on tyres, an overall decrease of traction, with a slight degradation of lap times.

    That might be the case. But maybe not on the time side. The lap times shown are indeed as exact as possible. When I write 10 seconds, it's because the time was literally dead on 10 secs. It was just a coincidence that times were so dead on whole seconds. But as you say, timing this type of lap is very tricky. I used a manual stopwatch and tried to perfectly hit the start/stop cone marker, but it's a process quite prone to inaccuracy.

    Even trickier is when you try to measure the average speed of a lap. To me, was almost impossible to keep the exact same speed during the whole lap. But I did try to average it as well as I could.

    Also prone to error is the corner radius. You can try my measurement. Was done using Google Earth, measuring from the centre of the circle to about the point where the middle of the car goes, if you drive a couple of feet from the line.
     
  22. RAZRr1275

    RAZRr1275

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    Are any of you noticing differences driving in 1.02 vs 1.01? I'm seeing some other people saying that there are some and I'm curious to know what the tuning crowd thinks.
     
  23. jtqmopar

    jtqmopar

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    Spring testing:
    Track: Nurburgring GP/D

    Car:
    BMW M3 Coupe '07 - 500PP - Sports: Hard
    428hp/ 301ft-lb
    1505kg
    50:50 weight dist.

    Aero/Wheels:
    Front Aero - Type A
    Rear Wing - Custom Type A
    OZ Racing Superforgiata; size +1"

    Parts:
    Fully Customizable Suspension
    Fully Customizable Transmission
    Fully Cuastomisable Mech. LSD
    Twin-Plate Clutch Kit
    Carbon Driveshaft
    Engine St.1
    Weight St.1

    Power Limiter: 100%
    Downforce: 0/ 10
    Ballast: 33kg @ 0

    Suspension:
    Ride Height: 100/ 100
    Spring Rate: x.xx/ x.xx
    Dampers (C): 3/ 3
    Dampers (E): 3/ 3
    Anti-Roll Bars: 3/ 3
    Camber Angle: 0.00
    Angle of Toes: 0.00/ 0.20

    Brakes:
    Standard: 5/ 5

    Transmission:
    Set in order (I might have done final gear at 3.93 first, try this if you can't get these numbers)
    Top Speed: 205mph
    1st: 3.12
    2nd: 2.28
    3rd: 1.74
    4th: 1.38
    5th: 1.12
    6th: 0.95
    Final: 4.10

    LSD:
    7/ 30/ 15
    *I added the adj. LSD, but retained "stock" (PD universal) settings

    Stock Times (3.86/ 7.04):
    didn't log, but third (fastest) lap was: 1:42.626

    Note: 7.50kg/mm is just a number I picked at random!

    7.50/ 7.50:
    1:43.325
    1:41.843
    1:41.574

    Baseline/ Baseline (hereafter known as BL)
    With the springs like this, the car didn't hold the line mid-corner as well, but that was balanced by it braking faster at lower speeds, and not being as fussy about braking into a turn. It also exited corners smoother.

    7.50/ 10.75:
    1:41.994
    1:41.644
    1:41.179

    BL/ +50%BL
    Handling changes: more understeer, but with closer laptimes. I don't think I'd leave the settings like this. Yes, I got a better time, but I attribute some of that to understeer on the 2nd lap, last turn causing me get on throttle further back on the straight, which gave me an automatic advantage, but is an evil trick for laptimes. This might be manageable with some ARB and toe settings.

    5.62/ 10.75:
    1:41.656
    1:41.467
    1:40.841 - Hard braking before chicane, lucky I didn't smack the barrier

    -25% front BL/ +50% rear BL
    More entry understeer, and now with the added bonus of massive corner exit oversteer. The front is obviously too soft compared to the rear, and sliders are about even.

    5.62/ 7.50:

    1:41.335
    1:41.351
    1:41.747
    -somehow before a restart I got a 1:41.186 as well. Not the best, but manageable.

    -25% / BL
    Way, way, way too unpredictable. It never took a corner the same and I put about 5-6 laps in instead of the usual 3. More oversteer on corner entry, but that was coupled with minor oversteer on exit, unfortunately it was only minor, but the level of wheelspin wasn't. I would NOT recommend these spring rates.

    9.38/ 10.75:
    1:41.639
    1:41.727
    1:41.117

    +25% BL/ +50% BL
    Okay, this would be great with a wheel, but with DS3 I tend to be more aggressive than these settings require. The 3rd lap I just did nice and easy, except one! corner or this might've been in the 1:40.xxx range. Unfortunately as the first two laps show, it's not the best. This car switched from over- to under- steer really quickly through different turns.

    7.50/ 9.38:
    1:41.7xx
    1:41.6xx
    1:41.247

    BL/ +25% BL
    NOPE! Too much oversteer, but I did pull off a decent time. Not gonna lie, I did restart as I got a bad 3rd lap start on the first session, but I don't really like the way it handles.

    5.62/ 9.38
    1:40.747
    1:40.324
    offtrack :(

    -25% BL/ +25% BL
    THE MAGIC NUMBERS!!! Okay, so I might have gotten a bit ansy on the last lap and gone off track, but still. To get two 40's in a row! Amazing.
    These settings even beat out my base-tuned Elise at the same PL/tires by .114s
     
    Last edited: Dec 21, 2013
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  24. jtqmopar

    jtqmopar

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    MR cars apparently are mostly fixed. The only one I drove pre-1.02 was the Diablo GT at max power (bad idea)

    Post-1.02 I have driven the 15th Anni Renault, and Lotus Elise '11 and have had no problems besides the Lotus being a bumper car to the AI.
     
  25. RAZRr1275

    RAZRr1275

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    That's too bad. I liked them wild. I'm not sure I notice a difference though. I didn't have a problem with the Lotus or Renault pre patch and I got into the Diablo yesterday and it was still pretty crazy.

    Also is the whole rims going up in size changing handling thing true as well? I'm going to test this today myself
     
  26. jtqmopar

    jtqmopar

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    I don't know about wheel sizes, but I'm not going to implent that into my spring rates. I posted at 1:22 and it's now 3:03 and I still have a few more settings I want to try, but, I want to make some tunes as well! I can't believe all this is because of the last championship in Nat-A
     
  27. ace004

    ace004

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    Last edited: Dec 21, 2013
  28. Zuel

    Zuel (Banned)

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    This wheel trouble is with any car that has staggered wheel size. I check my Rx7 and the rear tires are the same size as the fronts.

    There are cars in the lower classes that have staggered wheel sets as well @ace004. Gues the wheels are just for drifting, pictures, and stance.
     
    Last edited: Dec 21, 2013
  29. ace004

    ace004

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    Yeah, I guess I didn't say that correctly. The trick is to know what cars come staggered. But since I don't know, there isn't a list, and I don't see me taking the time to check everyone I just decided to return all my cars back to stock wheels until it's hopefully patched. But it has become a tuning headache having to modify many of my tunes. I noticed at lower PP where wheel spin isn't much of a problem, cars can be just as quick with tuning. It seems to me that once you pass that 500PP mark that the extra grip really starts to help.
     
  30. MrGrado

    MrGrado

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    No driving differences offline in my opinion. Online, I couldn't say.