Drag Transmissions and Gear Ratios

Discussion in 'GT5 Drag Racing' started by ampire, Aug 1, 2011.

  1. Hi guys, I posted this in another thread but figured I would share it here as it took a few minutes to write.

    Here are some thoughts and tips on tuning your car's gearing. I will try and logically construct this in an easy to understand format. This information is simplified and is not technical so I hope no mechanical engineers will come in here and rag on it too much.

    Before you set gearing, you should set up your suspension. This is important. With a rear wheel dive car, I set my rear very high and my front very low. I make my spring rate in the rear very low, my shock absorbers soft but my compression slightly harder than my extension because I want my tires to remain in contact with the ground.

    Final gear is the gear inside your transmission on a rear wheel drive car. It is the last gear before the axles transmit power to the wheels. Each gear ratio dictates how many engine speed (RPMS) to how many rotations of the final gear to finally how many rotations of the wheels of the car.

    The bigger the ratio number, the shorter the gear. So a 4.00 FINAL DRIVE gear ratio means for every 4 rotations of the driveshaft (continuing the rear wheel drive example), the wheels turn 1 time.

    So you could set all of your ratio's excluding the final gear to lower numbers. but set the final drive ratio high (like 4.00) and the car will behave like it has shorter gears (it revs up quicker). If you kept the same ratio's and set the final gear to a lower number, (like 3.00), the car will behave like it has taller gears (it will take longer to rev up).


    Now GT has a setting called Top Speed. This is an auto setting that makes it simpler to tune cars. This will give you a set of ratios that will allow you to reach the top speed (in perfect conditions like if you had perfect aerodynamics).

    The trick with setting drag ratios is you want a really tall (lower number) gear ratio for the first gear and the a slightly less tall gear for the second. Third, fourth, fifth, and sixth should be evenly spaced to allow a smooth acceleration. This is because unlike in real life, you do not have much throttle control nor do you have drag racing tires so you want to minimize wheel spin as much as possible. A tall gear (smaller number) reduces wheel spin because it reduces acceleration.


    Okay so now with that background information, here is my advice on setting a gear ratio.

    Top speed: leave it at default. Otherwise you lose flexibility in setting a tall first gear (small number, the available choices get larger when you mess with the top speed).

    Final gear: lower this to the lowest possible setting. this gives you more flexibility to adjust the individual gears. You may raise this back up later.


    Set the first gear to the lowest possible setting. Then, look at the graph. You want the / diagonal lines to be evenly spaced at the red line. This would show even acceleration and shift points. The slope of the line indicates how fast it reaches that red line shift point.

    So now set the second gear to be tall as well but not the lowest possible number, just a low number that when the car shifts first to second will put you in a nice powerband. Powerband is the area of the power curve graph (in the first tuning screen) where the car makes the most horsepower, think area under the horsepower curve not the peak power.

    Okay so now set the third, fourth, fifth, and sixth ratios to be relatively short (higher gear ratio number) and evenly spaced in that graph I mentioned on the transmission setting screen with nice slopes on the diagonal.


    Test the tune out. You must use MT when testing it out! Do you get wheel spin when you launch in first gear with all driving aids turned off? Remember, you have final gear at the lowest possible number and top speed has not been messed at. Uh oh, you can't make that first gear any taller either because its at its lowest setting. If this applies to you, you will need to launch the car in second. if not, and i hope not, you will be able to launch in first which gives you some advantages like running automatic transmission if you are lazy.

    Okay so you have no wheel spin but the car is too slow off the line. Raise that first gear ratio to a slightly higher number and test it. too much wheel spin, take it back down. Some wheel spin might be okay but you want the minimal amount that still gives you good acceleration. Same applies if you have to start in second gear as described above, just you will need to shift to 2nd before you rev the car up prior to launching it.

    Once you get a nice gear ratio that shifts smoothly into second gear and does not have excessive or any wheel spin, you will need to adjust your second gear so it smoothly accelerates into third. You do not want ANY wheel spin in your second gear (or third if you are starting in second). So play with it a bit by raising or lowering the number until you get a nice acceleration (meaning inside the power band) and a shift point that puts you in the powerband for the third gear.

    Then once you get this worked out, third gear, fourth gear, fifth gear, and sixth gear should be self explanatory. These should be shorter gears (higher numbers). Each gear should put you in the powerband for the next gear when you shift. The last gear should optimize your trap speed (speed reached when you cross the finish line), however a high trap speeds may indicate excess wheel spin when you launch.

    Finally, if you like the spacing of the gears but require more acceleration and wheel spin is not occuring, you may increase the final gear incrementally. This will make all the gear settings above shorter so you may experience wheel spin. If you do, lower it back down.

    Hope this helps. Each car is different and each driver is different.
     
  2. DLR

    DLR
    (Banned)
    United States Under the Hood
    PSN:iWinYouLooz

    1. Wheel spin isn't bad. My Enzo spins until 95mph and has good acceleration.

    2. You never mentioned launching from 2nd or 3rd. Especially in RWD and some AWD cars this is very important.

    3. Gear ratios should be close enough together that there is no lag when shifting. This is extremely important in the first few gears as this is where you are accelerating the most.

    :tup:
     
  3. CSLACR

    United States
    PSN:GTP_CSL

    Wheel spin is only beneficial when the friction coefficient of the tires while spinning is greater than the engine's power, so in an Enzo, maybe off the line, (when RPM's would be very low) and that's it.
     
  4. DLR

    DLR
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    PSN:iWinYouLooz

    RPM's are at 8 - 9 thousand. I am redlining it :)

    I agree that when it comes to wheelspin, PD screwed up big time. In real life you want as little wheelspin as possible but in GT5 it isn't that big of a factor.
     
  5. Gotcha, all good points. I mentioned launching in 2nd gear if you can't get a tall enough first gear to launch with minimal wheel spin.

    I also have my 1st gear set up to spin in my ACR and win a decent number of races, even with AT on when Im lazy, the 60 foot is actually better with some spin on this car.
     
  6. DLR

    DLR
    (Banned)
    United States Under the Hood
    PSN:iWinYouLooz

    ACR launch in 1st?!? I can barley manage 2nd. Where you dragging?
     
  7. TT3AZ

    (Banned)
    Sweden
    PSN:tt3_az

    I launch my ACR in first as well, but its for ssr7. If i would race on indy, i would probably make my 2nd gear as long as my first gear, and accelerate from 2nd to 5th or 6th gear...i dont know, havent drag tuned a ACR for Indy yet....

    Im still waiting on my zo6, which a certain person owns me.....:indiff:

    Second, while this guide helps alot, each car is individual, and you cant apply one basic rule for all cars, since they all have different tq/hp curve. That also determines how long last gear should be. Some times its good to test your car out with others to see if you can do any changes.

    What we still need, is drag suspension for rwd, 4wd and ff to be written down, according to real life technics. I have mine, but i will release them once others have done it as well, so we can get a discussion going on.
     
  8. I drag on indy. I'm no drag pro, I figured this could shed some light on drag tuning since everyone is so secretive, and I think its good that people don't want to share set ups, otherwise every race would be boring because of cookie-cutter builds.
     
  9. dr_slump

    Premium
    Switzerland Switzerland
    PSN:the_dr_slump / GTP_dr_slump

    Hmm, some people share their setups if you ask them. Of course, they won't give you the best one. But even a basic or old tune should be helpful.
    And if they don't do this, the most of them give at least some tips.
     
  10. DLR

    DLR
    (Banned)
    United States Under the Hood
    PSN:iWinYouLooz

    I might start a thread about the basics at Indy. Them maybe maf or cooldude could help me give the basics at SSR7. Not giving out all our secrets but enough to get people in the right direction :tup:

    All this when I get back of course. :)
     
  11. d24689

    Australia Australia,SA
    PSN:d24689

    yours is tuned for indy tho of course it will spin till 95mph :sly:
     
  12. DLR

    DLR
    (Banned)
    United States Under the Hood
    PSN:iWinYouLooz

    Yea knowing that your gears are longer and you have different suspension setups you probably don't have so much problem with wheelspin as you are more focused on top speed rather than acceleration ;)
     
  13. TT3AZ

    (Banned)
    Sweden
    PSN:tt3_az

    Well, the first gear is the same on my ssr7 and indy cars. Thats is because i dont want that much wheelspin when i launch. The suspension is also the same, but on ssr7 cars the front is a litle bit higher (so i can hit higher top speed, and then shorten my gears even more). Thats it baby...You want to jump of the line regardles of how long you are racing. The launch and acceleration is as important on ssr7 as on indy...trust me.
     
  14. DLR

    DLR
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    PSN:iWinYouLooz

    But still the majority of passing at SSR7 occurs at speeds of 170+ which is the top end speeds at Indy. In your opinion, is the GTR good at SSR7? Never tried it.
     
  15. TT3AZ

    (Banned)
    Sweden
    PSN:tt3_az

    As i have written before, the concept of 1/4 mile and ssr7 is the same, only thing is you are making the gears longer for ssr7 to hit a decent and competitive speed, while beeing able to come there in a short ammount of time. And all cars can be used for indy and ssr7, as long as you are racing equal cars. The only thing is that, those cars that has good acceleration or 4wd will have a huge advantage at a short straight, because the other one will just keep spinning...The GTR is good i guess, i use all kind of cars. You should try to make tunes for ssr7 as well, so you get a little bit of variation.

    I use the same technic on both ssr7 and indy, and still i consider my tune to be pretty competitive.

    Why should the first gear be any different for indy and ssr7?
     
  16. CSLACR

    United States
    PSN:GTP_CSL

    Technique.

    A longer first gear helps make quicker later gears, something important when trying to win a longer drag race.
     
  17. DLR

    DLR
    (Banned)
    United States Under the Hood
    PSN:iWinYouLooz


    IMO good launches at SSR7 are important, but not unnecessary. I see plenty of people launch horribly but then reel in their opponents. I may not race at SSR7, but I know that Suspension is way different than from Indy. But still when I get back I will defiantly be spending more time at SSR7. We should get together sometime :tup:

    Well cuz gears at SSR7 are longer, no?
     
  18. TT3AZ

    (Banned)
    Sweden
    PSN:tt3_az

    You all go to think different about gears, you tune your first gear to come quick of the line and reduce wheelspin, this is the same, regardles of which track you are using.

    A to short first gear at ssr7 will generate as much wheelspin as on indy, understand?

    The suspenson cant be that different either, because you want maximum contact with the surface and jump of the line regardles. Weight transferment etc is as important on long and short distances, thats how i see it, explained with real life tuning concepts.

    On which way is the suspension different on indy and ssr7? Take a rwd car as example....

    Technic, technique big deal boy....dont you have anything else to comment on?
     
  19. CSLACR

    United States
    PSN:GTP_CSL

    Cute, not sure which is cuter, the spelling or the defense of it.
    And I did comment on something else, but you missed that along with the built-in spell checker. :sly:
     
  20. TT3AZ

    (Banned)
    Sweden
    PSN:tt3_az

    Okay cool, take it to the tracks and i show you cute....
     
  21. DLR

    DLR
    (Banned)
    United States Under the Hood
    PSN:iWinYouLooz

    On Indy suspension we only have to account for maximum grip at low speeds. But at SSR7 you have to incorporate aerodynamics and many other factors at high speeds.
     
  22. TT3AZ

    (Banned)
    Sweden
    PSN:tt3_az

    We on ssr7 only want maximum grip at launch as well, we want no aerodynamic what so ever. You see, similar....
     
  23. DLR

    DLR
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    PSN:iWinYouLooz

    No, I'm saying if the front is scraping the ground and the rear is high in the air, that's all good at indy but at 200+ you are not going to have the best top speed. If i take my best indy car, alter ONLY the transmission, it will most defiantly lose at SSR7.
     
  24. CSLACR

    United States
    PSN:GTP_CSL

    Technically, lowest possible front and rear should be fastest top speed, but it's not. At least not on all cars.
     
  25. TT3AZ

    (Banned)
    Sweden
    PSN:tt3_az

    Thats why i wrote that i use to make my front a little bit higher for top speed. But the truth is, you maybe gain 1 mph by making your front high..

    The idea that ssr7 and indy settings appart from transmission is different is according to me isnt true.

    Seconds, some times its hard to know which car is faster, these ghost and timing system doesnt work right to be honest. I have come to a point in gt5 dragging, that nothings is gettings better. We need official drag strip and tree.
     
  26. DLR

    DLR
    (Banned)
    United States Under the Hood
    PSN:iWinYouLooz

    +1 enough arguing. PD GIVE US A DRAGSTRIP!!!!!!!!!
     
  27. dr_slump

    Premium
    Switzerland Switzerland
    PSN:the_dr_slump / GTP_dr_slump

    2 Dragstrips please! ;)
     
  28. TT3AZ

    (Banned)
    Sweden
    PSN:tt3_az

    We need 1/4 mile drag strip, and drag strip as long as ssr7 tunnels for longer runs. Problem isnt only the tree/ghost, problem is people jump far to much, even the pros, claiming they "anticipate the time". Lately i have seen more and more "mastakillas" when it comes to drag...
     
  29. d24689

    Australia Australia,SA
    PSN:d24689

    everybody jumps every so often ok its life. People even jump on ghost sometimes . All You can do is line it back up and run again.
     
  30. DLR

    DLR
    (Banned)
    United States Under the Hood
    PSN:iWinYouLooz

    The Forza setup is nice. 1 dragstrip over 2 miles long but with indicators along the way (1/8, 1/4, 1/2...)

    Jump the ghost? 0_o
     
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