The Torque Thread. And other little things you might find useful...

Discussion in 'GT6 Tuning' started by yannagas, Mar 7, 2014.

  1. TurnLeft

    TurnLeft

    Messages:
    1,370
    Location:
    Canada
    Hi there, real great info even though I must admit that more than half of what you say sounds more like jibber-jabber for me right now, but I'm working on it. I've been trying to see how to power up a car to have it go as fast as possible on a given track, too much torque or to much Hp is not the way to go, there seems to be a sort of balance you have to achieve including the weight. No I haven't figured that one out (sorry), but I've been testing with some different combinations of weight/Hp/torque to see if I could come up with a formula that would help determine what would be best. One thing I haven't been taking into account is the RPM, sometimes on the cars data sheet it gives you the torque at a certain RPM, but not all the time, I've seen the graph on the the bottom left hand side with info on torque/Hp/Rpm but I don't know how to use it. If you could help me in any way possible it would be most appreciated. I've included a link to the data sheet of some tests I've been working on, if you could take a look at it and tell me how I could make those tests better that would be great. It's really great to have people share their knowledge to elevate the rest of us.
    Have a good day, and thanks for this great thread.:tup::tup::tup:....:cheers:
    Power/Limiter/Weight Tests
     
    yannagas likes this.
  2. DaBomm4

    DaBomm4

    Messages:
    1,337
    Location:
    United States
    To get more accurate hp @ rpm and torque @ rpm, go to your main garage. I do this all the time when I'm tuning.
     
    yannagas and TurnLeft like this.
  3. Wide Boy

    Wide Boy

    Messages:
    292
    Nice article however I think the comparison between the 2 engines is no surprise & ignores design criteria.

    Cup car is heavy & is mainly running at high speeds on ovals with the odd circuit race, Torque is therefore important most of the time. Mercedes as a fast Autobahn cruiser would be a comparison I suppose.
    F1 car is light & runs exclusvly on circuits so a mixed range of speeds. At the slower end of the scale it probably strugles to transfer the torque it has already to the road, more would not help. Caterham 7 or a sports motorbike as a comparison.

    Capacity has always been the easy way to go if you want torque & hence a flexible easy to drive motor with a wide band of usable power.
    The reason for this as I understand it (I am no expert) is that it becomes increasingly harder to flow fuel & air efficently as you increase the RPM.
    Inertia also starts to become a real issue, hence 4 smaller valves etc to aid flow & stop bounce.

    I doubt the Cup engine could turn many more RPM if it was not restricted.
    Both are good engines but both have been built within the restrictions imposed to serve in the chassis they were intended for.
     
    muzzed_235 likes this.
  4. muzzed_235

    muzzed_235

    Messages:
    6
     
    FussyFez likes this.
  5. meek

    meek

    Messages:
    443
    Interesting thread @yannagas

    I have a few simple questions for your bright minds:

    Peak torque on a car is at 7,000 RPM. Save for starts, I rarely happen to be at that RPM, instead floating in the 8,000/9,200 range.
    Peak HP is at 9,000 RPM.


    Would it be better to have gears start at that 7,000 RPM point when shifting, instead of ~8,000 ?

    If I'm looking for best top speed, should I be at 9,000 RPM or closer to redline (~9,300) at end of straight?

    In other words, should an engine preferrably be revving between its peak torque's RPM and peak power's RPM for optimal performance (acceleration and speed) ?
     
  6. MrGrado

    MrGrado

    Messages:
    1,198
    It's a juggling act. If your looking for top speed at the end of the straight, you want the RPM not more than where max HP is at (but not less either). Don't be too afraid to use much less rpm range in top gear than the other gears, as in, you can go down most of the straight in 5th if you like, as long as your not over revving the engine for no good reason.

    If you want fastest lap speed, you might want your top gear just fractionally shorter. Your top speed at the end of the straight might be less, but you be will accelerating faster earlier along the straight. This gear will be better also on any shorter straights where your in top gear.

    If you do some testing and your not sure which gear ratio to use, use whichever will give you the higher top speed on the longest straight. Your only going to lose 0.010's of a second anyway (at the most), while driver inputs and other tuning settings are going to cost you many 0.100's of seconds per lap (for any regular track).
     
    Last edited: May 18, 2014
    meek likes this.
  7. jlmcmillan1978

    jlmcmillan1978

    Messages:
    262
    Location:
    Australia
    This is the best and most interesting thread I've ever stumbled upon at GTPlanet, thank you! :)

    Love the comparison between the F1 and NASCAR engines. It isn't obvious to most people how impressive NASCAR is in general, or there would be less idiots bashing it with stupid comments about only turning left, etc.
     
    fordracer likes this.
  8. Otaliema

    Otaliema

    Messages:
    5,489
    Location:
    United States
    It's also a balancing act based on the torque and power curves for the engine. How fast does the torque drop off compared to the how fast does the power rise. When i'm setting up a transmission I set most gears to start just before the torque and power cross over so that I'm not over torquing the tires when shifting, and I can short shift a car to get the torque to pull me through a corner with out spinning the tires out from too much power. with peak power and red line so close to each other red line shifting is the best bet for this engine. and making progressively shorter gears to use more power and less torque will keep the speed up.
    I guess thats the long winded way of saying
    Torque=lower speeds
    Power= Higher Speeds.
    Power+Torque=Top speed.
    Don't make the gears too long. or the power loss will eat up the torque gain at speed.
     
    xande1959 and meek like this.
  9. sgr

    sgr

    Messages:
    23
    Location:
    United States
    So Ive been recently experimenting with torque on the latest seasonal. The xbow on ascari. I max out all the settings and limited the engine to 60 percent to get the pp. I thought since the huge gains in torque to less loss in hp i would get quicker lap times. Not the case. The car was to much for corners and the ghost would catch up in the straights. I thought sense ascari doesnt have a long straight torque would matter. I was wrong. When does torque matter and how much hp is lost to put gain in torque? I know i shoulda tuned suspension better to accomidate the snap torque gives outta corners but it seems hp always wins in getting better times. So what would b the best ratio to torque and hp for the latest ascari seasonal?
     
  10. meek

    meek

    Messages:
    443
    Please proof read yourself and/or space out the text in the future, that post is a bit of a mess but it's got some interesting questions.
    I think torque is screwed up in this game. I'm no expert but, to me, torque is basically acceleration, and more often than not in this game where accel/torque should be in use, it's actually HP that is.

    Don't hesitate to check your car's powerband, and acknowledge an important thing, the graphs are off! Torque=HP at 5252 RPM, so where both graphs meet is really 5252 RPM, you would think on some cars/graphs it's 2000 (:rolleyes: PDI).

    Try lowering your initial torque and accel LSD settings to very low figures (even 5/5), the car should handle much better out of turns. If it still doesn't, add some rear toe, unless it's already at +0.60 lol.

    Have you tried adding 200kg to the Xbow? which model you use, Street or R?
     
  11. sgr

    sgr

    Messages:
    23
    Location:
    United States
    I shoulda added more comas. Sorry. Its the R. I will try that. I just wanted to get to the perfect ratio of torque to hp. So I could get a better time. But Its a little confusing. Thanks for ur input.
     
  12. Lionheart2113

    Lionheart2113

    Messages:
    1,485
    Location:
    United Kingdom
    It is very confusing!:lol: @meek is correct, the 2 lines on the graph should cross each other at (or very close to) the 5252rpm mark and some cars are off. I've never seen as far off as 2000....yikes!:scared: There are so many variations that can be used, but if you are talking about torque/rpm, like I mentioned on the other thread a flatter line for torque is good, or trying to keep the rpm/torque lines as close to "parallel" to each other as possible is another. I was halfway into trying to test these things when I pulled out to enter the camber debate. But I would suggest @praiano63 thread. If he doesn't have a tune for a crossbow, his understanding of transmissions and the necessity of torque is amazing. I'm sure you can find more answers there as well as here.
    Link
     
    meek and sgr like this.
  13. sgr

    sgr

    Messages:
    23
    Location:
    United States
    Why does the torque drop off 1/3 but the hp drops off by half, when running max settings at 50 percent power? I take that its an error by pd? youd think ud get a performance gain with this but i guess not. So what im interpreting by the recent posts is that equal parts torque to equal parts hp is the ideal setting. example 500 ft. lbs. torque 500 hp Not more torque or more hp. example 90000 ft. lbs of torque 500 hp.
     
  14. Wide Boy

    Wide Boy

    Messages:
    292
    Did you read the posts, restricting power impacts far more on the HP than the torque the way PD has set it up.
    This normally gives you a performance gain due to better acceleration, however to much torque for the cars chassis to handle makes it harder to drive needing good throttle control or use of a higher gear in slow speed corners.
    The restrictor also flattens the torque curve making it wider, wide torque curves are good in that you can be a lazy driver the car will pull well & hence accelerate hard over a wide rev range so gear changes are less crucial.
    If its to wide & overpowering the car selecting a higher gear to minimise the torque becomes difficult because you still land in the high part of the torque curve so its all down to throttle control.

    The Xbow is a very light car so delivering the power is hard, all other things being equal the heavier the car the more torque it can put on the road. But of course it needs to as its shifting more weight.

    Hence the reason the engine comparison in this thread is not really valid.
    The F1 car produces less torque because its lighter & cant use any more yet it accelerates far quicker.
    You want as much torque as is usable for maximum acceleration & a gearbox set up so you can short shift & use less torque in the lower gears if needed to stop wheel spin.
     
    Last edited: Jul 4, 2014
    sgr and meek like this.
  15. Otaliema

    Otaliema

    Messages:
    5,489
    Location:
    United States
    I've found during tuning most cars that are around 1k kg will do well with a balanced chassis to power, with a maxed rpm upgrades on the engine and power limited to about 80-85%, the reason is it flattens the power and torque bands at about the rpm range that a mid/min transmission will be putting the rpm with red line shifting so it works for AT and MT transmissions and doesn't over power the chassis. I'm no place close to my ps3 right now a in can't get in and look at it and see exactly what the % would be, but you can find it easily by doing the following,
    Remove all power upgrades and set PL to 100%, remove all ballast.
    Reduce the engine power till the HP is a flattened right before normal maximum power or the torque and hp meet which comes second.
    Add power upgrades to maximize rpm and torque gains to pp target.
    Check ptwr.
    Add power and ballast keeping the ptwr with in 0.10 of the original number.
    Set transmission at half way point of the final drive/gear
    Set TS slide as low as it will go.
    Set each gear to allow for smooth shifting.
     
    sgr and Lionheart2113 like this.
  16. sgr

    sgr

    Messages:
    23
    Location:
    United States
    Thank You. I will try that out on multiple cars and see if I get better lap times. So far I get good results with 4wd cars wth max rpm upgrades at around 50 percent power limit. whatever the power limit is to maintain original pp. And I get better times on shorter tracks with shorter straights. or at least similar times with no upgrades at 100 percent power. Im just trying to utilize the original posts, showing that max upgrades and reduced power retain minimal torque lost. for example. gtr touring car stock 623pp 687 hp 551ft lb torque. now stage 3 engine tuning mid rpm turbo 66.1 percent power limit. still 623pp. but 631 hp and 764ft lb. minimal hp lost and huge torque gains.
     
  17. meek

    meek

    Messages:
    443
    can you reformulate that? second part mostly

    what are your lap time differences? I'm wondering cos I never set a car looking at torque, always looking for best (=lowest) kg/HP ratio, might need to change my approach!
     
    Last edited: Jul 6, 2014
  18. Otaliema

    Otaliema

    Messages:
    5,489
    Location:
    United States
    Basily if the torque peak and the hp peak are noticeibly different say 4.2k peak torque and 6.3k peak power flatten the power to the torque point if they are close say 5.3k torque and 6.2k hp than flatten to just prior of max hp so 6k as an example, this keeps the gearing in range to utilize the maximum power and torque with out much impact to the actual power of the car.
    I was in a big of rush when I first posted so did word it well, sorry bout that
     
    meek and sgr like this.
  19. sgr

    sgr

    Messages:
    23
    Location:
    United States
    I was just elaborating that with any given car u can gain huge torque numbers and minimal hp loss, by maxing the engine upgrades and limiting the engine power to the original pp you were aiming at. like the original post. But what im getting from the replies are that when you do that the power band drops in the torque range too much for it to benefit the hp. On the power graph, you notice that the hp line flat lines mid rpm and the torque line plummets in low rpm. So your only gains would be in very low rpm. So far the only good results I get using this method is on very very short windy or bumpy tracks with a very very short straight. Example. tuskuba or matterhorn or eiger. And I would shift well before the red line to use all the very low end power. I get the best results with 4wd cars using this method but only on tracks like tuskuba or matterhorn. For me, The time differences are at least 1 sec off best lap times. Times that match the pp with 100 percent power limiter and no engine upgrades.
     
  20. Exorcet

    Exorcet

    Messages:
    7,037
    I'm a bit confused, what would you gain by looking at torque? Like you said HP, torque, and RPM are all related so in essence looking at the HP curve gives you the torque curve.
    Accelerating fast comes down to producing as much energy as you can in as little time as possible since energy is equivalent to speed. Power is rate of energy production. Two cars with the same weight, gearing, condition, etc will accelerate at the same rate if they have the same effective power curve no matter what the torque curve is. I just don't see why you would look at torque.

    Let's say we're deciding on engines based on the 8 graphs you made with the Audi in various states of tune. What info is the torque curve giving us to decide on a configuration and what is the HP curve not telling us?

    What it comes down to is max tuning and then using 50% limiter is probably a bad idea because it kills your acceleration by giving you a uselessly wide powerband with a low peak power.
     
  21. sgr

    sgr

    Messages:
    23
    Location:
    United States
    Theres a theory behind how much torque to hp to use and it all comes down to the track ur running. I agree that 50 percent limiter is a bad idea on most tracks and on most cars. But there are variables and infinite combinations that produce infinite results.
     
  22. Lionheart2113

    Lionheart2113

    Messages:
    1,485
    Location:
    United Kingdom
    Think about torque and horsepower this way... Torque is a body builder and horsepower is a sprint runner. If they ran 100 meters (the sprint runner runs it in 10 secs and the bodybuilder in 15 secs) now throw 150lbs to their back and run it again. The sprinter will be severely slowed down, but the body builder will run it in the same amount of time as his first run because he's built for the power not speed.
    Same can be said about your 2 car scenario. The one with a better torque curve will access that power (torque) sooner and will pull away from the other.
    I've seen this more and more with some of the more knowledgable tuners. I used to think that power/weight ratio was best until I started testing some other tunes that utilised the torque knowledge. A little bit more torque coming out of a turn onto a long straight can easily mean a few tenths per lap.
     
    sgr likes this.
  23. meek

    meek

    Messages:
    443
    I asked you about your lap times, and Otaliema to reformulate, my fault for quoting 2 persons in the same post lol.
    So you're saying what you did doesn't work except on Tsukuba or Matterhorn?

    the following isn't for you to reply to :sly:

    Not a good analogy, there aren't 2 cars (runners) in this case, there's only one car, whose weight doesn't change, and it doesn't do two races (two runners each doing 100m run 200m total, a car runs one lap in the span of... one lap).

    I see it simply: under 5252 RPM, torque is more important, over 5252, power is. At exactly 5252 RPM --which is where the graphs cross, nevermind Polyphony's weird scaling-- power=torque.
    Even when taking into account flattened or modified graphs thanks to power limiter or parts added, the principle holds true.

    If you're most of your lap under 5252 RPM, let's say 5000 for simplicity, you want to look at the torque graph and be equiped with Type 1 turbo upgrade. Are you sure that slow turn you're taking isn't above 5252 RPM? wanna short shift to next gear if so to use torque for a better exit...

    If you're high revving most of the lap, say 5500 or above, don't bother looking at the torque graph, just care about the power graph and your HP (or weight/power ratio).
    Data Logger can come in handy here.
     
  24. Exorcet

    Exorcet

    Messages:
    7,037
    Right. Basically you want to maximize average power over the portion of the track where you're accelerating. You need to look at more than the engine to figure out your average power because whenever you shift your wheels are getting 0 HP.

    In general, higher peak power is better because your gearing allows you to sustain that power. This is why some sports cars have terrible low end, it doesn't matter because hypothetically, with proper gearing they will never need to come out of the powerband.

    Imagine a car that produces 1 HP at all RPM except at exactly 5000 RPM. At 5000 RPM, and only at 5000 RPM is makes 1000 HP. A second car wants to race. It makes 250 HP at all times. Who wins? There is not enough information. If both of these cars have traditional gearboxes, the 250 HP car wins by a land slide because it's making ~245 (less than 250 because non zero shift times) average HP vs .95 (less than 1 because non zero shift times) average HP for the other car. However if they both have perfect CVT's the 1000 HP car wins by a land slide because it's making 1000 average HP compared to 250 average.

    In GT, you want to consider the RPM width of your gearing and how long it takes you to shift/how often you will need to shift to properly gear your car. This should almost never lead you to make a totally flat powerband unless your car takes literally 5 seconds to change gear.

    I have to be honest. I've never seen a HP/torque analogy that I thought made things clearer. One issue is they're made out to be different things, but they aren't. HP is torque times RPM. In your track analogy, the body builder wins the second race because of a better power to weight ratio. The sprinter wins the first race also because of a better power to weight ratio. The sprinter's legs simply move at a higher rate (more RPM) allowing the smaller force at the feet to be applied more rapidly. This leads to higher average power.

    You're sort of correct with the last bit. Cars with more torque tend to have flatter curves or have it available lower in the RPM range, but that doesn't make them faster. The car with no low end torque simply revs to 10000 RPM or something while waiting for the green light and then it's gone as soon as it goes.


    The RPM doesn't matter. HP can be used in place of torque anywhere. The 5252 thing is just an arbitrary number that happens because of units. 600 whatevers of torque does not equal 600 whatevers of power. However, 600 whatevers of torques multiplied by gearing multiplied by level arm does equal the force of 600 whatevers of power divided by velocity as long as the torque and power are measured at the same RPM. In other words, what moves the car is force at the wheels. You can get the force at the wheels by measuring torque, inspecting gears, and ignoring HP or you can get the force at the wheels by measuring power and ignoring torque and gears. The HP way is easier.

    That's not really a good strategy. What you would do is gear your car to use the section of the powerband that allows the highest average HP, within the limits of gear shift time/frequency and maximum speed (number of gears). Now you'll have the best possible acceleration for the track no matter what it looks like.
     
    Stotty, TexasTyme214, Nish and 2 others like this.
  25. meek

    meek

    Messages:
    443
    how do you do that in GT6 and its screwed up graphs?
     
  26. Exorcet

    Exorcet

    Messages:
    7,037
    Sadly it becomes a very imprecise science with a bit of guess and check mixed in.
     
  27. sgr

    sgr

    Messages:
    23
    Location:
    United States
    So I tested the lancer evo x gsr 07 with a g27 wheel on tsukuba. Both setups were identical at 550 pp running on ss tires. Except one setup had 497hp 482ft lb torque and the other setup had 509hp and 438ft lb torque. After 10 laps each the setup with more torque was 3/10s faster at 56.5xx then the setup with more hp 56.8xx. Maybe its just my driving style but short tracks with tight corners help me with more torque. and the 4wd especially helps. I had more rotation gassing it outta the corners. give it a try. Now i bet if i ran the same test on high speed ring id get different results. And I will test it. Again these tests cater to my driving style. I am by no means trying to argue that one way is better than another. There are too many variables. I will perform more tests to see how a more torque heavy power limited engine will increase lap times on certain tracks with certain cars. But I need to rework the transmissions better to give the comparisons an equal chance. at least with the evo test the car didnt need tranny work or suspension work to make it an optimum comparison.
     
  28. Lionheart2113

    Lionheart2113

    Messages:
    1,485
    Location:
    United Kingdom
    You are right, there are too many variables to take into account to say that one is better than the other. I understand that I need hp and torque along with a gear box that takes advantage of both. My scenario was just over the short distance. I mean who's to say that we don't run the body builder/sprinter race again for 1/4 mile? Who wins? This arguement has been debated for decades by people who design engines, crunch the numbers, and who even have put men on the moon. What chance do we have of solving it on a video game chat forum?
     
    Otaliema, sgr and Thorin Cain like this.
  29. Munkee Hunter

    Munkee Hunter

    Messages:
    2
    So I understand torque is what gets you moving, and horsepower is what keeps you going. When is it better to have more torque? What's the trade-off? I'll give an example. I have a '69 Z28 Camaro I've been experimenting with. All 3 setups are 500PP. The first setup has 370hp & 345ft-lb, it picks up good speed down the straights but it feels a bit sluggish to get going. The second setup has 368hp & 355ft-lb, it feels pretty well balanced. The third setup has 363hp & 377ft-lbs, it gets off the line quicker than the other two and is faster coming out of the corners but I think top speed starts to fall off. So I guess the trade-off is acceleration for top speed. Would you trade 10hp for 30ft-lb of torque?
     
  30. Otaliema

    Otaliema

    Messages:
    5,489
    Location:
    United States
    It really depends on the car, pp, tires, track and racing mode for which is the best set up.
    If your going be in aspec off line balanced is best, drag type torque. Short/low speed track torque is preferable to hp, Long/high speed track hp over torque, online porky valences is best over all can goto more tracks and do well.
    Heavy cars need more torque than light cars.