Eliminating exit turn oversteer

Discussion in 'FM4 Tuning' started by Melting Brains, Jan 5, 2012.

  1. Melting Brains

    Melting Brains

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    I just posted in another thread where I mentioned exit turn oversteer and how I learned to deal with it, but I was wondering how you guys think it's best to eliminate it through tuning?

    I mainly try to reduce it by loosening the rear sway bar, but I never seem to be able to get rid of it completely. I'm, of course, talking about rear wheel drive cars here. In real life, I think the problem is less prominent. From my experience in driving a Corvette on a track, I think it's easier in real life to step on the gas halfway through a corner without too much oversteer or the tail kicking out immediately.
     
  2. ChadSpeed

    ChadSpeed

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    668
    You should also play with the rear to, try .02 to .04 negative rear toe. This does help stabilize the rear through sweepers and allows earlier throttle application, however throttle control is still key.
     
  3. imported_Tiddy

    imported_Tiddy

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    Best way to do this (most noticeable anyway) is by buying the race differential and reducing the accel setting down to around 40% or less. This makes the car understeer a little bit more but allows you to put the power on sooner without being scared that the car will swap ends.

    I to be honest don't like using toe settings because if you go too far it starts to feel like the car has shopping trolley style wheels at the back :lol:
     
  4. grayPhantom47

    grayPhantom47

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    6
    As Tiddy said, I use the race differential and lower the accel percentage. But I don't go as low as 40% very often. Default is 75% accel and 75% Decel. I like to start around 65% accel and 50 to 55% decel ( front engine/rear drive). Then lower both in 5% increments until it feels better on turn exit. Also in the adjustable shocks, I will lower the front rebound a couple of clicks, and raise the rear bump a couple of clicks. This seems to plant the rear end when you hit the throttle coming out of a turn...lets you get on the throttle a little earlier. In theory it will give quicker weight transfer to the rear on acceleration. Of course, good throttle control is a must.
     
  5. MuchoJimbo

    MuchoJimbo

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    Don't mind me, just tagging so I can refer back to this thread for tips and insight.
     
  6. Melting Brains

    Melting Brains

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    Thanks for the replies guys. I've tried to lower the accel rating on the diff and set it to 50% and lowered it by 5% after each lap to see the effect. I now have it at 85% front, 35% rear and it works much better!

    I also fiddled with the bump and rebound settings, but I don't want to screw up my spring ratings too much :S

    Thanks again and I'm still going to see if I can get better results and post it here for your information.
     
  7. Luminis

    Luminis

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    Softening the ARBs helps to reduce corner exit oversteer, as does reducing the accell-setting of the differential and increasing rear toe-in, as has been mentioned.

    Reducing the camber on the rear wheels might also help, you've got to be careful, though. It's best to just check the telemitry screen and make sure that your rear wheels are set to a value where you've always got some negative camber on them, but basically the smallest amount possible.

    Softening the rear springs, ARBs or shocks too much might also have the opposite effect on your car. If they're too soft, the car will exhibit too much body roll, which in turn will, again, cause oversteer.

    I highly recommend reading this tuning guide over at forzamotorsport.net.
     
  8. imported_Calico

    imported_Calico

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    Why dont you just subscribe to the thread under thread tools at the top of the thread.
     
  9. MuchoJimbo

    MuchoJimbo

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    Well if I did that I would be 1 post shy of what I have now, duh!

    For real though, I did not know of this, thanks for the future tip. I will be sure to utilize this feature!
     
  10. H1GHD3FF

    H1GHD3FF

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    Adjust rear toe, rear sway bar, and front and rear rebound settings.
     
  11. HBR-Roadhog

    HBR-Roadhog

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    For exit oversteer issues I generally will either lower the Accel on the rear diff and/or widen the gap between the front and rear dampers making the rear a bit stronger and/or the front a bit softer. The damper settings will have a double effect in that this will make the car turn in more while reducing the oversteer on exit. Assumign of course that the oversteer is not power induced in which case the diff setting would be the key.

    The problem with using the ARB, Springs or Toe is that these will also reduce your turn in ability which may cause entry understeer and may not be the best solution.

    The bottom line is that every thing has to be balanced properly so that it all works together to give you the best turn in, exit and strait line stability as well as speed and accel.
     
  12. Spagetti69

    Spagetti69 Premium

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    10,403
    When tuning the rear Diff have the grip telemetry up on screen.
    Look for the rear inside wheel to be losing grip first. Try lowering the diff until the inside rear doesn't brake traction before the outer.
     
  13. imported_Calico

    imported_Calico

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    No worries glad to be of help.
     
  14. Wiggs

    Wiggs

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    1,380
    Well said. :tup: I usually only make small adjustments to ARB, springs, and toe myself. In many situations the race diff is a lifesaver.
     
  15. viper2788

    viper2788

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    I generally stick to lightweight cars with relatively low torque.
     
  16. hennessey86

    hennessey86

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    1,470
    If n tune is working for you then it is your driving , you need to be in the right gear for the corner for a start, next you need to have good progressive throttle control and your steering angle must be right.
     
  17. Melting Brains

    Melting Brains

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    I agree hennessey, but when I raced ghosts of people using the same car, I notice how some of them are able to accelerate sooner and faster out of a corner without oversteer (and not using any assists either'.

    But any way, this was waaay back before I learned how to properly tune a car ;-) and I don´t have the problem anymore with most cars. If I experience exit oversteer it can usually be solved by adjusting the rear ARB setting or the front-to-rear damper ratio.
     
  18. Pcaola

    Pcaola

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    Great thread guys. So glad I stumbled across it today. Was looking for any tuning guides ( as there are dozens in the GT5 section ). Taking a break from GT5 and thoroughly enjoying F4 :-). Speakers and subwoofer turned way up! I've been buying some tunes but have realized having a locked tune doesn't help me at all. I always need to make personal adjustments and I figure most people do too. Spending 0-5K on a tune doesn't kill me, but having no idea what kind of tune I'm buying is frustrating. So I've been tuning myself a bit. 75% of the time my #1 goal is to tune down exit oversteer. I am learning throttle control, progressively squeezing my R2 but when the car in front of me is putting distance between us in a hurry I tend to lean in figuring "I gotta go!" Which results in me letting off the throttle to get the ass end backin line ( and that's if I'm not busy doing a left right dance shuffle ).
    My go-to has been the Race Dif... Then gearing. Trying to find a sweet spot for a good acceleration without a ton of tire slip. OhHH, and fatter rear tires too.

    Thanks for good tips guys. I'll be trying the other tricks tonight ,

    Paul
     
    Last edited: Nov 6, 2013
  19. mister dog

    mister dog (Banned)

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    Just came from tuning some R3 race cars, man if you go for sim steering and TCS off the stock tunes are impossible!
    You need to spend a bit of time playing around with all the settings on each R class race car before you can stop spinning on exit.

    Throttle control is key indeed, but it's way exaggerated seeing how bad those stock tunes are. I guess the stock tunes were put in for the general FM4 public that drives with normal steering and aids on no?

    Anyway once you get it right, the physics feel great.