General Tuning Guide (Updated 1.09)

Discussion in 'GT6 Tuning' started by DolHaus, Jan 16, 2014.

  1. Death2508

    Death2508

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    I'm too lazy and afraid of weird handling cars to have even thought of any of these. Thanks for the info mate
     
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  2. DolHaus

    DolHaus

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    But why start at one extreme? Max/Max won't give maximum rotation, the job of ARBs in GT is sharing the load between inside and outside wheel so setting it to max is just ensuring that the inside wheel extends equal to the compression of the outside wheel during cornering load. This is fine if you've got grip to spare but you will quickly exceed traction limits if you're trying to work within the constraints of the tyres. The same is true of minimum values where you will be effectively putting 90% of the load on the outside wheel rather than splitting it, this again puts you at risk of quickly exceeding grip limits.
    By starting in the middle and working from there you stand a much better chance of efficiently finding where the suspension performs best. Weight distribution (more weight = more roll) and the associated roll axis of the car plays a big part in how to best utilise your ARBs as you are effectively equalising or influencing how much one end of the car rolls under load relative to the other, its quite complicated to explain the whole process but from a practical point of view there are two ways to go about it depending on drivetrain and weight distribution. The first way is the conventional method where you are trying to maximise the efficiency of load on both ends of the car to influence rotation characteristics (better for RWD) and the second works by maximising the grip at the front wheels and using a combination of excess roll and inertia at the rear to generate extra rotation via controlled oversteer (better for FWD), 4WD cars can utilise either depending on the temperament of the car. The conventional method works as you'd expect, stiffening the rear or softening the front is going to improve rotation by adjusting the grip balance to give the front end more traction relative to the rear, the second method works by using the sloppy rear end like a pendulum to push the front end towards the apex on corner entry, the downside of this method is that it can become a handful at high speed and you have a high chance of doing a 180 if you go in too hot (think early Porsche 911s).

    The basic rules regarding a traditional set up are explained here:


    These work well but because of GT's unwillingness to let a car roll over you can exploit the second method to your advantage but only if rear grip is negligible or well within tolerances.

    Your method is sort of right but you are ignoring a large span of possibilities by starting at the extremes, you risk exceeding the capabilities of the tyre before even getting started with adjusting the balance therefore are adding more potential problem than you are likely to solve. P:censored:g into the wind as it were, making things more difficult than they need to be :tup:
     
  3. Otaliema

    Otaliema

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    @DolHaus i never said it made sense nor do I understand why it works that way. But having the ARBs set with one at Min or Max and then adjusting one to change the grip on that end of the car works very well in the game. I know IRL it's stupid to do but in the game it's a good way to get the car to do what you want, especially in TT's.
     
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  4. DolHaus

    DolHaus

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    It does work more or less but it strikes me as a gross simplification of what's actually going on, good for a quick fix but may prevent you reaching the full potential of the suspension in a similar fashion to how you can use rake to overcome a lot of problems quickly but you'll find a better balance by manipulating other components to reach the same result. One size fits all solutions are fine in a pinch but a properly engineered solution will always outperform them :tup:
     
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  5. speedy turtle

    speedy turtle

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    Yes @Otaliema, few days ago I tried to race with Pozzi Camaro RS without be bitten by it :lol:, and its default gearbox was very savage. Before anything else, I had to modify the gearbox, following your indications, to get the wheels transmit the power correctly to the asphalt.

    I've modified a little the Miata and got an easier but faster car :tup:. I've reduced only 5mm the front RH to don't mask other modifications deficiencies, the rear BB to 5/4 and added rear ballast (90/+25) to obtain 50/50 weight distribution. Obviously I added a few HP to mantain PP. Maybe I wouldn't add ballast till we tune a more powerful car and you teach me all its implications... I don't know. But in this case it seems to work.

    The light oversteer that converts the Miata in a little funny car has disappeared, but instead I've discovered a more consistent and confident car. And with less effort I've gotten a 2 tenth faster lap.

    I'll keep experimenting to see what I keep discovering. :cheers:

    Thank you
     
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  6. DolHaus

    DolHaus

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    Apologies for the lack of replies, I've been very busy with helping my friend get ready for his wedding all week but that's all over and done now so I should be much more prompt with my tuition from now on.

    Unfortunately adjusting the ballast screws up your springs rates and I was hoping to cover that later. Your spring rates are a direct result of the weight pushing down on them and by adjusting the ballast you've changed the amount of static load that is acting upon the front/rear springs. By adding weight you've effectively made your car more softly sprung, the opposite happens when you add the weight reduction option because by removing weight you are effectively making the springs stiffer.

    If we imagine a car that weighs 1000kg and has a weight distribution of F60/R40, the front springs are carrying a static load of 600kg and the rear springs are carrying 400kg. In order to balance this load the front end needs to be more stiffly sprung than the rear to stop it compressing under static load. If the car has a weight distribution of F50/R50 then the front and rear springs are carrying an equal static load of 500kg and therefore the spring rates should be more or less equal to support the weight. In reality the rear springs should be a touch stiffer than the front because when the car is moving its no longer a static load, you have to take into account the fact that the mass of the object is always resisting change so will be acting in the opposite direction to the direction of travel (accelerating forwards = weight transfer backwards / turn right = weight transfers left etc.).

    This would explain why you've needed to raise the rear ride height in order to counteract the oversteer, while this is a perfectly good solution in some scenarios I would always look at the springs first because I'd want to keep the option of raising the front ride height to improve front end grip and hopefully cornering speed. My basic mentality is to avoid doing anything to add understeer if I can get away with it, some cars really need reigning in to make them consistently fast but this shouldn't really be the case with the Miata.

    There is a useful equation that was first brought to my attention by @Lionheart2113 which can be helpful for finding ideal spring rates, doesn't work perfectly on every car (seems to work better on standards than premiums) but its always worth checking. We will use our 1000kg 60/40 example car for illustration:

    (Weight X gravity) divided by weight distribution = spring rate

    F: (1000 x 9.81) x 0.60 = 5886
    R: (1000 x 9.81) x 0.40 = 3924

    Now we just need to put a decimal point in there and round the number up or down to translate it into a usable figure:

    F: 5.89 kgfm
    R: 3.92 kgfm

    Now because the car will be moving forwards (therefore weight going backwards) for most of the time we need to adjust the rear spring rate to take this into account, usually its only a small amount but by keeping a record of our original number we can easily test all the possibilities.

    3924 x 1.1 = 4316.4
    3924 x 1.2 = 4708.8
    3924 x 1.3 = 5101.2
    3924 x 1.4 = 5493.6

    You need to test these until you find which one suits your car, once you've found the right ratio it will make further modifications regarding ballast much easier. Lets say we have found that the 1.3xR fits our car best and imagine that we are now going to change the weight distribution to 50/50.

    F: (1000 x 9.81) x 0.50 = 4905
    R: ((1000 x 9.81) x 0.50) x 1.3 = 6376

    F: 4.91 kgfm
    R: 6.38 kgfm

    It should be mentioned that finding your starting point isn't an exact science, I generally start by trying to find the right number to multiply the front spring rate to get it reasonably close to the stock value and then go from there, as long as I keep the same ratio throughout the testing stage I should be able to avoid upsetting the F/R grip balance no matter how much I move the ballast around. :tup:



    You asked my to discuss wheel alignment before so I will quickly run though that, it can have a big effect on the stability of the car and can help you squeeze a little more traction out of the front end of the car on entry or during mid corner.

    We will be mostly using Toe because for what ever reason camber has never worked in GT6 for gaining traction, cambers only real use is a controlled reduction in grip to prevent a nervous car from getting twitchy. This kind behaviour is mostly encountered on cars running racing tyres where there is tons of grip initially but as soon as you go beyond the limit the car lets go dramatically which can lead to a spin and adding a bit of camber can smooth the transition between gripping and sliding making it more manageable. In this instance the time penalty that camber gives is potentially less than you would encounter by either driving cautiously or having a crash, in either case I would always advise running less than 1.0 degrees of camber for race tyres and 0.5 degrees on sports/comfort tyres on either end to keep losses to a minimum.

    I have copy/pasted my original summation on toe because its fairly self explanatory and there is little point in me discussing real life elements such as tyre scrub and vectored thrust because you don't really need to know them.


    Toe settings -



    Front toe in (+ Slider to the right)


    Pros: Improved straight line stability. Increased mid corner grip

    Cons: Reduced grip on turn in



    Front toe out (- Slider to the left)


    Pros: Increased grip on turn in

    Cons: Less stable at speed. Reduced mid corner grip.



    Rear toe in (+ Slider to the right)


    Pros: Increased stability

    Cons: Increased understeer



    Rear toe out (- Slider to the left)


    Pros: increased manoeuvrability

    Cons: increased lift off/power oversteer



    An important thing to remember is that adding Toe increases the rolling resistance of the car which will have a negative effect on acceleration and top speed so its always a case of using the least amount necessary to overcome what ever troubles you're having elsewhere. The stock 0.60 amount of rear toe is frankly ridiculous, it adds so much understeer and drag to every car hence why I asked you originally to zero the camber and Toe, it's much harder to find the balance of the car when Toe is having such an influence on it.


    Toe out on the rear end is only really something that should be used on FF's and occasionally on 4WDs, in any kind of RWD the oversteer will be extremely hard to manage and the car will become a real handful, rarely worth trying unless you've got a really understeery car. On the front end its always worth trying both ends of the scale and noting the effects, I rarely use above 0.30 in either direction as I find the drawbacks begin to outweigh the gains by that point.

    When using an FF car you can utilise equal amounts of rear Toe out and front Toe in to dramatically improve rotation but be careful as it can make the car feel quite unnatural and twitchy if you use too much. You can also use a bit of rear camber on FF's to make the rear wheels less resistant to rotation allowing you to chuck the car into corners like you were driving on gravel or other loose surfaces, doesn't always work out but its worth experimenting with.
     
    Last edited: Oct 30, 2016
  7. Lionheart2113

    Lionheart2113

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    Brilliant math there, my friend!:bowdown: I still find the base spring rate the same way, but I do % increments from there... 10% initially (pending on car/track), but I usually have to re-adjust in smaller %'s back down. Puts me about the same numbers as you would get. But your multiplying method is quicker to do and easier to remember. Writing that one down in the notes!:tup:
    :cheers:
     
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  8. DolHaus

    DolHaus

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    It's a really good method for some cars, I used percentages for a while but after trying the simple multiplication and finding it put me in a similar place results wise I decided it was probably the more efficient method and stuck with it. Never found it to work well with premium cars that have raked default suspension but its always worth a go :tup:

    I believe @Thorin Cain had a similar method that involved ride height as well but because of the early results I had using your method I rarely felt the need to further complicate things. Both methods work in the sense that they give you base values that can be easily adjusted to suit changes to the defining characteristics of the car, no idea how its programmed but they both allow you to study specific changes while keeping the overall grip and balance the same
     
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  9. Lionheart2113

    Lionheart2113

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    Yes, I've tried to use the ride height as well, but like you said, standard vs premiums.:crazy: I did better adjusting them separately. The spreadsheet I created still has that formula within it, as well as RH changes when spoilers are used. But I haven't gotten confident in that one though.
    IMG_5667.JPG
     
  10. Thorin Cain

    Thorin Cain Premium

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    You believe correctly :). But I can't remember exactly how it goes :(, been quite some time since I used that one. I developed a new, even more complicated set based on targeting specific ride frequencies which I feel gives a better starting point than the other one.

    I like @Lionheart2113, also use 5% and 10% increments for fine tuning after establishing a base :tup:.
     
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  11. Thorin Cain

    Thorin Cain Premium

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    Sorry for the double post :guilty:. But I thought as it was brought up, I'd link the post which explains the weight/ride height equation mentioned above.

    https://www.gtplanet.net/forum/thre...values-vs-custom-values.319779/#post-10235180

    The link is to the thread OP Sorry, on phone and can't figure out how to quote the post itself :banghead:. Further down the page also explains how Downforce is integrated when applicable :tup:.

    Thanks to @Lionheart2113 for jogging the old memory :cheers:.


    Edit: Link fixed :).
     
    Last edited: Nov 2, 2016
  12. danbojte

    danbojte

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    Touch and hold on the date/time bellow your name and choose "copy link address". :cheers:
     
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  13. Thorin Cain

    Thorin Cain Premium

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    Ah! :idea: Thank you my good friend :cheers:.
     
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  14. DolHaus

    DolHaus

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    You can multiply by any percentage without having to alter the sum using my method, just change the 1.xx (ie. 157% = X1.57)to the desired percentage and away you go :tup: I generally don't bother going below 5% increments as the gains rarely match the effort required to test
     
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  15. speedy turtle

    speedy turtle

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    Hi Dolhaus:

    Ok, I'll go back to my last configuration and wait for your indications about the use of ballast, maybe in another more powerful car.

    In relation with the ecuations you use to calculate the spring rate, I have a question:

    Reading other threads, I've "heard" that the stiffness or softness of the springs depends on the type of tires the car uses. Then we can break the blue bar into 9 sections to know, more or less, the "exact point" where to start to test the car on track.

    On the equations I can't see any relation with the tire type, must we assume that this equations are for sport hard tyres or what compound?

    About the use of toe, I'll reread your initial indications and will go to track to try different angles.

    Excuse me to make so many questions in one post (#537), I'd have understood that you'll talk about them later, and in the same fashion... one at a time.
     
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  16. DolHaus

    DolHaus

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    The general rule is that the more grip the tyre has, the stiffer your springs can be. You can't really say that a specific tyre will fit a specific range of the blue bar, or rather you can but only on a case by case basis and even then it'll just be vaguely in the right area to make the tyre work. The definition of soft or stiff springs depends entirely on who's describing it and what they're describing, its all relative and can get a bit confusing without perspective so try not to get too hung up on it.

    If you've stuck a stickier set of tyres on the car than what it either came with or has been tuned with then you are most likely going to be moving the spring rates to the right a bit, the bigger the grip change the bigger the adjustment but that change might be 0.5kgfm or 5.0kgfm depending on the car. If the car came with comfort hards and now its running racing softs then you're spring rates are likely to be somewhere in the last 3rd of the bar but if the car came with sports softs from the dealership then it might be closer to the middle of the bar. In either case your approach must be the same as we have been practising on our Miata: - Test-Evaluate-Modify-Repeat.

    Now as for the equation I discussed a few posts back, that is basically a cheat sheet that allows you to find and adjust the balance of your spring rates and then maintain that same balance while changing other key parameters. It does have more of a numeric pattern in relation to tyre type but you won't find any solution that fits everything, every time.


    I get the feeling you're done with the Miata so its probably best if we move on to something else, pick a range of cars you'd be interested in tuning and make a list, I will need to see this list just in case you've inadvertently chosen a really difficult car but you otherwise choose what you like. This will allow us to show the equation in action and give us opertunity to discuss ballast and other things. I don't know if they run seasonal time trials any more or if you participate in them but that could be an idea to give the project more focus? :tup:
     
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  17. speedy turtle

    speedy turtle

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    Ok, you are the master, if you think I can learn more changing the car now, let’s go.

    You asked me about a list of cars I’d like to tune… I don’t know how many cars to choice, there are plenty of them I would like to drive, I don’t like to abuse your trust. I’ve tried to select different powers and weights and finally I made the following list:

    FR
    Chevrolet Corvette ZR1 (C6) '09
    SRT Viper GTS '13
    Ferrari 599 '06
    Shelby Cobra 427 '66
    Mercedes SL 55 AMG (R320) '02
    TVR Cerbera Speed 6 '97
    Ferrari 365 GTB4 '71

    MR
    Ford GT LM Pace Car Spec II
    McLaren F1 '94
    Ferrari Enzo '02
    Ferrari 458 Italia '09
    Ferrari GTO '84
    Lamborghini Miura P400 '67
    Lancia Stratos '73

    RR
    Ruf BTR '86

    4WD
    Bugatti Veyron 16.4 '13
    Lamborghini Aventador LP 700-4 '11
    Tommykaira ZZII '00

    MR Racing
    Toyota 7 '70
    Mercedes Sauber C9 '89
    BMW V12 LMR '99
    Pagani Zonda R '09

    Yes, I know... too many cars :nervous:

    Sorry, you asked me if I run time trials... Yes, I run them. Now there are two different types of trials: One, you alone against chrono and you win the trophy and credits only once. And another one, where you race against others and you obtain the prizes any time you run.

    I try every one but obviously have troubles with some expert ones.


    Thank you
     
    Last edited: Nov 8, 2016
  18. DolHaus

    DolHaus

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    The reason I asked you about seasonal time trial is because that is where you'll find the most advantage to tuning, you shouldn't really need much tuning to beat the AI drivers in any race because they're not fast or smart, occasionally underhanded but not smart. Driving against other human drivers is where you start to see the advantages, whether this be in a race scenario or in a time trial every bit of speed you can extract from the car is important and may make the difference between finishing first and last.

    Does the current time trial appeal to you? If so we can use it as a back drop for the tuning exercise and use your ranking as motivation, if not we can just continue as before but I feel that without a goal it is easy to lose focus. I wouldn't pile several hundred miles into a car without good reason and I shouldn't expect the you to do it either, its a shame there isn't a FITT event running at the moment otherwise I would suggest you sign up there, competition really helps sharpen the mind
     
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  19. speedy turtle

    speedy turtle

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    Sorry, in my last post I’ve forgotten the expression “Seassonal events” and I wouldn’t know how to explain the differences between them and “Time trial”. :dunce:

    Hmmm, or are you talking about "on-line events"?

    Yes, I like the time trials, but the current one is for 700PP. Is it not very much to start? I tried it last weekend and I got the silver. :O

    I don't know if I have the skills to beat others on track in "on-line events", maybe by now, I prefer to fight against myself in time trials.

    All of me is a big and listening ear. When do we start?
     
    Last edited: Nov 8, 2016
  20. DolHaus

    DolHaus

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    The ranked time trial events were the ones I was talking about but if there is only a 700pp event available then that's probably not the best place to start.

    I suppose the Chevrolet Corvette ZR1 (C6) '09 is the easiest place to start, if you are happy to proceed with that one then please copy the stock settings into the sheet below:

    Wheel / Joypad:
    Power:
    x BHP @ x Rpm / x kgfm @ x Rpm
    Weight: x kg
    Performance Points: x PP
    Wheels: Standard Size
    Fitted parts: x
    Tires: x
    Weight Distribution: x:x

    Suspension : (Height-Adjustable, Fully-Customisable Suspension)

    Ride Height: Front: x Rear: x
    Spring Rate: Front: x kg Rear: x kg
    Dampers (Compression):Front: x Rear: x
    Dampers (Extension): Front: x Rear: x
    Anti-Roll Bars: Front: x Rear: x
    Camber Angle (-): Front: 0.0° Rear: 0.0°
    Toe Angle: Front: 0.00° Rear: 0.00°
    Brakes : F: 5 R: 5




    Differential Gear: Fully Customisable Mechanical Limited-Slip Diff

    Initial Torque: R= x
    Acceleration Sensitivity: R= x
    Braking Sensitivity: R= x

    Clutch & Flywheel:
    x
    Propeller Shaft: x


    Power

    Oil Change:
    x
    Power Limiter: x %
    Engine Tuning: Stage x
    Computer: x
    Exhaust: x
    Exhaust Manifold: x
    Catalytic Converter: x
    Intake Tuning: x
    Turbo Kit: Stage: x
    Nitrous Oxide (N2O): x

    Body

    Body Rigidity Improvement:
    x
    Downforce: F: x R: x
    Weight Reduction: x
    Bonnet: x
    Windows: x
    Ballast: x kg
    Ballast position: x%


    Please choose a track you would like to tune it for and we will decide a specification to build the car to, we will discuss the best strategies for modifications and how to go about finding them :tup:
     
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  21. pretend racer

    pretend racer

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    There is also a 400pp TT at Tsukuba as well. The fastest car to use seems to be the Suzuki gsx-r....

    The 700pp TT is at apricot hill. The c60 pescarolo is the car of choice...
     
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  22. DolHaus

    DolHaus

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    It's always the GSX-R at 400pp... :lol:

    Thank you for the information :tup:

    @speedy turtle does that event sound like something you'd be interested in?
     
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  23. speedy turtle

    speedy turtle

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    Well, I'm interesed into learn.

    The TT at Tsukuba only admits Confort Hard tyres... it is another learning path, I'm open to everything that teaches me. I've already won the gold, but with a very poor time... yes, the GSX-R too but without wings.

    Ok, we can take advantage of this TT now and leave the ZR1 (C6) for later.

    The configuration that I used wasn't a good tune, but I started with the minimal effort to see if I was able to win the gold with the minimum time investment because I was trying to dedícate all my time and effort to the Miata:

    GSX-R
    ==========
    PR: 400
    HP: 94
    Kg: 700 (50/50)
    Tyres: CH
    -------------------
    RH: 75/85
    SR: 6'00/5'30
    DC: 3/4
    DE: 4/3
    ARB: 4/2
    Camber: 0'00/0'00
    Toe: 0'00/0'20
    BB: 5/3 (normal brakes)
    ------------------
    LSD: 9/11/15
    Clutch: double
    Shaft: standard
    -----------------
    Pot: 53'9%
    Parts: All standard
    -----------------
    Ballast: 60/-20%
    Reduction: All standard

    Please don't scream, I told you, I invest very little time :guilty:

    I can't tell you my time because I have problems now with the PSN connection, but if I remember correctly, only 1 or 2 tenths below the gold limit.
     
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  24. DolHaus

    DolHaus

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    Hmmmm.... considering that we'd be limited in our tuning options and working in a very specific way to get the GSX-R to go faster I feel we would be limited in our learning opportunities.

    (From the look of the tune I'm guessing it's quite stable but understeer prone. The rear ride height being higher that the front, relatively stiff front springs and front ARB higher than rear are all methods typically used to increase stability/predictability by ensuring that the front end lets go before the rear resulting in understeer rather than oversteer, I suspect the tune was intended for a novice driver and is meant to be manageable rather than capable)



    Lets go back to the Corvette and go from there :tup:
     
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  25. speedy turtle

    speedy turtle

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    They aren’t the cars, they aren’t the tunes, it’s my driving style, I don’t know if I push the throttle too early and always the car oversteer, I always discovered myself looking for the stability that I rarely find, and finally I have to extend the coasting time on every turn and I lost the theory of “brake early to throttle early”. Any suggestion or advice to be able to accelerate more softly, more “analogically” and not so “digitally”…

    Chevrolet Corvette ZR1 (C6) ‘09

    Wheel / Joypad: DS3
    Power: 660 BHP
    Weight: 1206 kg
    Performance Points: 593 PP
    Wheels: Standard Size
    Fitted parts: none
    Tires: SH
    Weight Distribution: 49:51

    Suspension: (All standard values)
    Ride Height: Front: 80 Rear: 80
    Spring Rate: Front: 11’14 kg Rear: 12’77 kg
    Dampers (Compression): Front: 3 Rear: 3
    Dampers (Extension): Front: 3 Rear: 3
    Anti-Roll Bars: Front: 3 Rear: 3
    Camber Angle (-): Front: 0.0° Rear: 0.0°
    Toe Angle: Front: 0.00° Rear: 0.00°
    Brakes: F: 5 R: 5

    Differential Gear: Fully Customisable Mechanical Limited-Slip Diff
    Initial Torque: R= 10
    Acceleration Sensitivity: R= 15
    Braking Sensitivity: R= 20
    Clutch & Flywheel: Double
    Propeller Shaft: Carbon

    Power (All standard values)
    Oil Change: no
    Power Limiter: 100 %
    Engine Tuning: Std
    Computer: Std
    Exhaust: Std
    Exhaust Manifold: Std
    Catalytic Converter: Std
    Intake Tuning: Std
    Turbo Kit: Stage: Std
    Nitrous Oxide (N2O): Std

    Body
    Body Rigidity Improvement:
    No
    Downforce: F: - R: -
    Weight Reduction: Stage 3
    Bonnet: Carbon
    Windows: Light
    Ballast: 0 kg
    Ballast position: 0 %

    Now is the moment to know if I have to add any power part or leave it standard, although I think it is well powered.

    Deep Forest makes me a bit dizzy, I was thinking to test the Corvette on Grand Valley Speedway. What do you think?
    I ran 2 or 3 laps to start to know the car focusing on LSD and initially with Accel. at 40 it is undrivable for me. I lowered Accel. to 15 and I was able to finish a lap without trample the grass. I view that the car doesn’t pitch with its standard configuration, only rolls a little.

    Must I start in the same Miata’s way or are you going to define another path?

    Thank you.
     
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  26. mustangxr

    mustangxr

    Messages:
    250
    Location:
    Canada
    Hey Guys,
    This is off topic but I just discovered that Praianos tunes are no longer accessible when you click on them. WTF over?
    Cheers, Pete
     
  27. speedy turtle

    speedy turtle

    Messages:
    108
    Yesterday I tried again the 700PP Apricot Hill TT, this time with a tune for a Pescarolo I found in another thread, and I won the gold at first attempt with 5 tenths of margin. It's not fantastic, but I got it.

    What I'm trying to set forth is that I can do it with a tuned machine, but I like to learn to tune machines. I like to learn to know what to do when I push the throttle of a very "bunny" 400PP FR car starts to oversteer, when in other cases I control perfectly a 600PP car.

    Yesterday I was wondering when tuning the Pescarolo with relative soft springs and very low dampers, the car let me to obtain that margin.
     
  28. DolHaus

    DolHaus

    Messages:
    3,865
    Location:
    England
    Apologies for the delay, my monitor crapped out just as I was about to post this and I've only just sourced a replacement :tup:

    Well you can tune a car to compensate for driving style but care should be taken not to use tuning as an excuse not to improve your abilities as a driver. In terms of throttle application on exit its a hard issue to tackle because I don't know the cause, if the LSD is badly set up (which they usually are from the dealership) then you are going to be at an immediate disadvantage and judging by your actions on the corvette you already have grasped the solution. Any RWD car with a high Accel is going to be a handful on corner exit, I would always drop the accel to around 15 as a starting point, its not so bad in a 4WD or a FWD for various reasons but in a RWD you want the Accel fairly low. In terms of driving technique it can come down to a range of things from controller set up to driving line and I'm not really sure where to begin.

    I guess in the meantime we can discuss the best options for modifications, I can see that you have already applied the weight reduction modifications which is a good first step. In GT6 performance is far more biased towards low weight than it is towards high power, the aerodynamic resistance modelling seems to be a bit off and as a result low powered cars can keep accelerating to higher speeds than they otherwise should be capable of, as a result the usual advantage that higher powered cars have in terms of acceleration past a certain speed is more or less nullified. All this means in terms of modifications is that you should always remove weight unless the car is already super light (less than 900kg) to begin with.

    Power parts are relatively simple to apply but we must keep a few things in mind, for example the parts on the left hand side of the tuning window all raise the RPM limit of the engine so these must be added before tuning the transmission (reset after fitting parts). Because horse power is derived from torque and RPM these modifications tend to add more BHP than torque. The parts on the right hand side don't change the RPM limit and focus mainly on adding torque to raise power, you can add and remove these parts without needing to adjust or reset your transmission. As a basic rule you should add BHP if the track is high speed and flat and focus on torque if there are hills, low speed or the car is heavy, there is usually very little difference but having the best power parts for the job can be worth a few tenths and that can be the the difference between first and last so always experiment.
    Making changes to the aspiration by fitting a turbocharger or supercharger changes the shape of the power curve and where the peaks sit. Changing the location of the peaks and shapes of the curve can be useful because depending on the engine, transmission and driving style we find ourselves using a particular span of the RPM range for most of the time and we want to be making the best power within that range. Watch a replay of yourself doing a lap and you'll notice that you never drop below a certain RPM so if your BHP peak is below that point then you are never going to be using maximum power and therefore adding an aspiration change that moves the peak power within this range is only going to help you go faster. Fit each one and look at the change of the curve, look at where it makes its peaks and how sharp/smooth do they rise and fall within the useful range? Do any options appear to give more power throughout the range you are using? Engine tuning options may be a bit limited so when you get the option you should always explore it, might only be worth a tenth or two but every little helps.
    Now, we can't always add an aspiration change but we can cheat the system a little by over powering the car for specification and then using the power limiter to bring it back down, the advantage of this is that the power curve gets flattened out at the top and you can essentially be making peak power throughout the full useful range. This method can work very well regardless of the engine aspiration so be sure to experiment, most of my cars were built for competitions where using a lot of limiter was banned and in these instances I generally used as little limiter as possible because when used in low amounts it does have a negative effect on torque which can lead to the engine feeling a bit gutless.

    Earlier we discussed weight reduction but we didn't mention something important, when we tune a road car it is usually necessary to stiffen the suspension up a little bit because they always come a little bit soft to help deal with speed humps, potholes and uneven surfaces in the real world. However, because spring rate is directly related to weight we need to realise that by making the car lighter we have made the springs relatively stiffer.

    I think we should probably build the car to 600PP running on Sports Soft tyres, please feel free to add some power parts to bring the car up to specification and then hit the track. The softer tyres will likely increase body roll and pitching a bit but we will address that soon. Continue to adjust your Accel by concentrating on your rear tyre temperatures as you exit slow corners, if the car starts to oversteer then look at which wheel is letting go first , if the outside wheel is going red then lower the Accel, if the inside wheel is letting go then increase the Accel
     
    Last edited: Nov 11, 2016
    speedy turtle likes this.
  29. Lionheart2113

    Lionheart2113

    Messages:
    1,485
    Location:
    United Kingdom
    I strongly agree with most of everything you said (especially manipulating the power curve) except the above. Parts on the left do alter RPMs redline limits by adding 0/100/200/300 RPM, which leads to different gear ratios when resetting the transmission. Kids have a hold of the tv, but I found this in my notes....it's on paper so that should show how old it is. I can't even remember what cars they were for.:lol:
    IMG_5670.JPG
    Yes, terrible handwriting I know... it's clear why I switched to notes on the iPad!:dopey:
     
  30. DolHaus

    DolHaus

    Messages:
    3,865
    Location:
    England
    Ahh, I see you've spotted the deliberate mistake :lol: :dunce:

    (fixed)

    I still do all my notes on paper, I don't like touch screens so modern technology is starting to pass me by
     
    speedy turtle and Thorin Cain like this.