Bring back realistic engine tuning!

[seinfeld]

yes I preferred GT3 as opposed to GT4 , GT5 P is however an improvement, without tuning in the real sense in GT5 can't make an accurate comparison, but GT4 was a flop in terms of physics. And we all know it was. So I think GT5 will be a improvment, we can only hope anyway.

I loved the Skylines in GT3 they were laggy as hell, and fast. my mate loved the R34 stage 4, expanded Bore

I loved the R32 , that had a lot more torque then the R34 when fully tuned, still laggy as hell, but I had it tuned so well with gears every time I changed gear watching from my mates screen, the car would squat and just take off, he would shake his head in disbelief as we had similar power, I just had well tuned torque curve, I don't know if you remember that you could watch the power curve while adjusting the boost, everyone used to go flat out on the boost, but I would go a couple notches back because it made the torque very flat and better throughout the rev range, as opposed to all out. The torque would peak early and drop off.

 

[digitalwolf]

I can't remember how many cars i ruined in GT2 (i think i was in 3rd or 4th grade at the time), but i read all the descriptions and tried really hard to figure it all out. Later moving on to GT4 i really enjoy the more simple settings, as well as the test field to try it out on.

Thing is, its really time consuming having to frequently leave the stage, tune, come back, find an issue, tune, try a different track for hours on end(including loading times). This is something i pretty much had to do for most cars to suit my driving style. getting every part to make sure i had everything right, and spending extensive time with my mustangs, and mini coppers

If the approach was more stream lined, to where you could eliminate time between tuning and driving(its not realistic, but its more engaging). then a more complex engine tuning system would be excellent, it would also mean more people would be open to it aswell.

I didn't have long enough time with gt5p to really mess with the tuning settings...i only rented it :\

 

[shirakawaa]

I don't remember GT2 settings being more complicated than GT4.
GT2 and GT1 did have that extra stabilizer component you could buy (not sure about GT2).
GT1 also had a boost setting, and that's it.

Maybe various additional engine settings could be made available in a "professional" setttings set-up mode, while the standard one would retain the slider seen in GT5P. Adjusting it would adjust torque/power curves for more low-end torque or more high end power depending on the available components.

The only additional difficulty compared to GT4 of a more realistic engine tuning system (not the settings, just its double-edged characteristics. The more power the user wants from his engine, the harder it will become to drive, basically) would be that once the user has decided how he wants the torque/power delivery to be, he'd have also to properly adjust gear ratios in order to better use the resulting narrower/wider powerband. This is the case in GT5P too, though.

In GT4 most of the time the user just had to make gears globally taller, not closer one to each other (or taller, in some cases), as torque delivery hardly changed after increasing maximum power.

In this previously posted image (from GT5P) for example you can see that after reducing maximum power in order to gain more mid- and low-end torque, essentially power delivery from 3500 to 7500 rpm is almost a flatline. Gears could be made taller and less close relatively to each other (So that after changing gears at 7500 rpm the engine falls at about 3500 rpm or slightly above) in order to reduce the number of gear changes needed while affecting only marginally car performance. Again, in GT3 and GT4 the user almost never had to think about how torque delivery changed. In GT1/2, yes.

 

[GDII]

I liked the Boost gauge in GT2. Although it didn't make much sense because it didn't have any numbers and oddly spaced dashes it seemed to work better than the new gauges in GT4 and GT5P.

GT2s boost gauge seemed to show lower boost levels for less powerful cars and less tuned cars. But when you tune a car with lots of power and a big turbo the guage would go much higher.

One car I remember was the Nissan Skyline R34 GT-R. The gauge would almost go back on itself when it was fully tuned. But less powerful cars with similar or bigger engines wouldn't go so high.

The new GT4/GT5P gauge seems to just scale the boost range for that car over the whole gauge.

It would be nice to have control over the boost level and see a number go with it ie PSI or bar pressures. Even if it may not be exact to the real life engine as I know many things depend on what boost pressure makes what power.

I guess it is hard to make a game made for everyone that has basic and advanced tuning. I myself don't know heaps about engine tuning but I have a basic understanding of what happens when you do something.

I like GTs tuning in the way that when you do buy a part or make a setting change it will change how the car drives. Some games don't feel like tuning has much affect on the car.

I'm looking forward to November and the more indepth tuning that Kaz has said to be in GT5.

 

[Griffith500]

I decided to check out the options for tuning and modding in GT2, because quite frankly I didn't remember it that well - and I was intrigued by this extra stabiliser you mentioned...

Anyway, the parts break down like this:

• Muffler
  • Muffler and Air cleaner
    • Sports, Semi Racing and Racing
• Brakes
  • Brakes
  • Brake Balance Controller
• Engine
  • Computer
  • Engine Balancing
  • Port and Polish
  • NA tune-up
    • Stages 1, 2 and 3
  • Displacement
• Drivetrain
  • Transmission
    • Sports, Semi-Racing and Full Racing
  • Clutch
    • Heavy Duty Single, Twin and Triple
  • Flywheel
    • Sports, Semi-Racing and Racing
  • Driveshaft
  • For Professionals
    • 2 way, 1.5 way, 1 way and Fully Adjustable LSDs
• Turbo
  • Turbo Kits
    • Stages 1, 2, 3 and 4
  • Intercooler
    • Sports, Racing
• Tyres
  • Sports
  • Racing Slick
    • Racing Hard, Medium, Soft and Super Soft
  • Dirt
  • For Professionals ("Simulation" i.e. normal)
• Others
  • Weight Reduction
    • Stages 1, 2 and 3
  • Race Modification
  • For Professionals
    • Yaw Control, Active Stability Control, TCS Controller

......................... The tuning menu ............................. The NA modifications and power / torque curves

The turbo kits have a similar difference in curve shape, whilst all other engine mods merely scale both curves without changing their shape.

 

[Tornado]

The different mufflers on some cars would throw around the torque curves quite a bit, as I recall.

 

[shirakawaa]

I think in GT1 the torque redistribution side-effect of modifications was more pronounced than in GT2, where cars weren't losing as much low-end torque as in the previous game as the NA or Turbo Kit level increased. I remember too, as Toronado mentioned, that in GT1, mufflers would not only increase maximum power, but also shift a bit torque toward higher rpms. GT1 also has the really nice gear chart graph that got lost in GT2.

EDIT:

this

 

[Tornado]

I also remember as Toronado mentioned, that there, mufflers would not only increase maximum power, but also shift a bit torque to higher rpms.

Also, on turbocharged cars, while the Sports muffler would generally shift the torque curve to the right, the Semi-Racing and Racing mufflers would actually sometimes shift it back to the left.

 

[GT_Prologue5]

I think in GT1 the torque redistribution side-effect of modifications was more pronounced than in GT2, where cars weren't losing as much low-end torque as in the previous game as the NA or Turbo Kit level increased. I remember too, as Toronado mentioned, that in GT1, mufflers would not only increase maximum power, but also shift a bit torque toward higher rpms. GT1 also has the really nice gear chart graph that got lost in GT2.

Isn't that what mufflers do? Shift to a higher revving rpm? And yes, who doesn't love the GT1 charts?

 

[Anathema]

I believe that is part of the point of the Apex magazine/book that comes with the CE and SE editions, correct me if I am wrong.

That's part of what the Apex manual is. I know some things about tuning and stuff, since I've studied it to find info about the GT4 tuning.
I hope I can get a better understanding from the Apex manual.

 

[shirakawaa]

Isn't that what mufflers do? Shift to a higher revving rpm? And yes, who doesn't love the GT1 charts?

Well, that really depends on what the muffler (or better, the whole exhaust system, including the exhaust manifold) is for.
Certain complete exhaust systems will optimize all-around torque without bringing excessive gains. Other ones might increase high-end power while sacrificing low-end torque. Naturally aspirated engines are usually very sensitive to changes in exhaust tuning (often it's easier to do more harm - not actually damage - than good to the engine drivability), while many turbocharged ones will benefit all-around from fitting free-flowing exhausts. Etc...

So it's not that "simple" . That depends on your needs, what you buy, and your engine. I hope to see that complexity in GT5, with "complexity" meaning "many choices available" rather than "difficult to understand".

 

[CoolColJ]

re the exhausts, that's what stock, sports, sem-racing and racing do
Stock and sports offer the best responce and torque, from the greater back pressure. Semi-racing and racing more top end power from the better flow

 

[shirakawaa]

re the exhausts, that's what stock, sports, sem-racing and racing do
Stock and sports offer the best responce and torque, from the greater back pressure. Semi-racing and racing more top end power from the better flow

Not necessarily so, however (and also, not in GT4 of course). You can have a free-flowing (and noisy) exhaust which increases mainly low-end torque. That depends on how it's tuned. Two-stroke engine exhausts/mufflers are the extremization of this concept as their geometry affects much torque and power more than flow.

 

[CoolColJ]

I'm pretty sure GT4 had sports, semi-racing, and racing exhaust upgrades. Infact it's much the same as GT1 and GT2!

Usually more racey exhausts are just straight though and lack the cats and other muffling devices or the bends through the muffler. It should flow better.

 

[shirakawaa]

Yes, GT4 did have Sports, semi-racing and racing exhaust upgrades, but they didn't affect torque and power differently depending on the model. They worked more like fixed percentages increasing power at all rpm, something like (made-up numbers): sports +2% power, semi-racing +5%, racing +8%.

ADDENDUM:
In the case of four-stroke engine exhausts, there is more than better flow which affects power. Explained very simply, longer headers and shorter exhaust diameters will tend to increase torque and reduce maximum power potential. The opposite tends to increase high-end power at the expense of low-end torque. Collectors gathering headers from all cylinders will also tend to increase power at higher rpms (in the case of 4 cylinder banks, 4 in 1 headers), while those which do that in a more gradual manner (4 headers in 2, then 2 in 1 for example) will tend to give less gains, but at all rpms.
It's true that in many cases just swapping a stock exhaust system with a free-flowing one can be beneficial at all rpms, but it's not always so, especially for modern small engines.

 

[Griffith500]

I checked again in GT2;
There is a subtlety I missed when changing mufflers and the "chip": the amount the curve is scaled by increases with RPM (i.e. total airflow through the engine) so that there is a bias towards higher RPM.

NA tuning resets the rev limiter, and stage 3 with all the bells and whistles takes my Griffith 500 up to a 9000 rpm redline and just shy of 600 bhp at 8500 rpm, 63 kgm at 6100 RPM.
Compared with 343 bhp at 5500 rpm, 49 kgm at 4000 rpm - bone stock with a 7000 rpm redline, though nothing beyond 6000 is of any use.
Bog standard with "racing muffler": 370 bhp at 8000 rpm, 51 kgm at 4000 rpm - 8000 rpm rev-limit, just about useable.

Very strange!

I also missed some options on the tuning menu, due to not fitting certain parts...
Adding a brake controller gives a brakes section between the suspension and gearing whilst the LSD, TCS and ASC all go under "other" at the end of the list, after the aero.

I, too, miss GT1's gear-setup screen; they almost brought it back for 5 Prologue but the scales are unusable! Forget about how to display information and all that data-ink ratio stuff, think about how to show manipulations of that information! We need reference points = more ink!
[ahem]

 

[shirakawaa]

A user from another forum made this video for me:


It's from the Honda Integra Type R in GT5P.
I tried making a chart of three power slider settings (min, mid, max) using the same scale for all of them (it took quite some time to correctly calculate and approximate values from screenshots).

The resulting image shows better how by increasing the slider torque at low RPM is affected in the game.

Here torque doesn't get shifted much to higher RPM. Specific torque probably gets a tad too high. Probably it's because in GT5P the rev limiter isn't affected by the power setting. I personally would expect 300 hp from a 2 liter engine to be obtained at around 9000-9500 rpm. But maybe harder engine modifications would be needed to safely go there. (don't Spoon high-revving engines in various GT games have a shorter stroke compared to the stock models?)

 

[Griffith500]

I'm not sure if they have a shorter stroke. I read that the old 11k rpm Spoon EK9 (Type-R) used, in addition to a heavily braced B16 crank-case, the taller B18C block so it could use longer con-rods for reliability at high rpm - the B18 block has the same bore as the B16, and I assume the B16 crank was used, since it was intended to be compared with a normal Type-R - the interest being what benefit the extra reliable rpm would be on the stock engine. The B16 is fairly over-square anyway (81 x 77.4)
I'm not sure, but I think Spoon did a similar thing with the latest Civic Type-R (FD2; Japanese model).

The norm now seems to be to "stroke" the cars (e.g. a K20 to 2.3 / 2.4 litres) and let them top out at 9000 rpm max. Perhaps that's what we are to assume is happening to that DC5?

Great graph, by the way. 👍

 

[CoolColJ]

You forgot about the power of Vtec

 

[shirakawaa]

Maybe it's getting a bit off-topic, but I found a way to semi-automate the the conversion into spreadsheet data of torque/power curves from GT5P.

This is the Suzuki Cappuccino at +0, +50 and +100 Power:

This is the video I used:



With this I could make a spreadsheet/chart to calculate thrust curves and find out where optimal gear shift points would be.

 

[eSZee]

+100power, even +50, is obviously not to be used. You have a 2000rpm span where the TQ drops before picking up again. Either the graph is showing the stats wrong or the tuning specs are done my monkeys.

 

[CoolColJ]

I would wait till GT5 proper, the graphs will probably be much larger

 

[shirakawaa]

+100power, even +50, is obviously not to be used. You have a 2000rpm span where the TQ drops before picking up again. Either the graph is showing the stats wrong or the tuning specs are done my monkeys.

I'm guessing that the first peak at +100 represents the torque curve of the engine working almost naturally aspirated, with essentially close to no boost. Then boost starts building up and torque starts rising up again. The second peak is at higher rpm due to different turbocharger characteristics. I don't think it's a bug, and it's not a graphic error either (I've been fairly accurate this time), it's probably meant to be like that. At +50 the turbocharger was probably giving more boost between 4000 and 6000 rpm, but less above.


By the way, this is from the Corvette Z06 posted on page 3 at -35, +0 and +39 power settings. It looks like there are many losses under 5000 rpm by increasing power (and large gains by decreasing it):

The animation used:

Curves at the maximum setting here become so peaky that I would personally set up gearing this way. The engine would have to be used strictly between 5800 and 7500 rpm. Probably a significant amount time would be lost by changing gear often, though. Also the first gear might be too long because of the relatively (compared to high rpm) lack of torque at low rpm:

Gear ratio used:
1: 2.250; 2: 1.680; 3: 1.320; 4: 1.070; 5: 0.890; 6: 0.750
Final gear: depending on your needs.


Sorry for being OT again, by the way
Maybe I should start a new thread in the GT5 Prologue section? I'm not sure if people would find it useful.

 

[Griffith500]

I've seen thrust charts before, but I never bothered to actually try to read them. So, thanks for that. Is the blue line supposed to be air resistance?

By the way, the +50 Cappuccino is quite good; nice torque plateau for an almost linear power delivery 👍

 

[shirakawaa]

Yes, the blue line is supposed to be air resistance, however it's not necessary to calculate optimal shift points. Actually it's also inaccurate in this case since I just realized I forgot to count in transmission losses (GT5P power/torque charts are at the flywheel).

The red lines are the total torque available for each gear (losses excluded) and refer to the values on the left. Bigger values = greater acceleration, provided that wheels have grip. In this case it's better to shift up at 7500 rpm and down as soon as the engine falls below, on average, 6000 rpm. So that's a very narrow powerband unless you accept losing significant acceleration at each gear change.

By the way, the +50 Cappuccino is quite good; nice torque plateau for an almost linear power delivery

Actually, for best performance, charts like this demonstrate that it's not flat torque that you need, but flat power.
It's not a very intuitive thing, as it's most often not attainable on naturally aspirated engines (where the very best you can aim for when tuning for maximum power in real life, is a flat torque line. Turbocharged engines don't have this kind of "limitation", theoretically).

EDITED to add:

By the way, have a look of the same chart for all Cappuccino power steps I have in my spreadsheet.
It uses the same gear ratios for all of them, but shift points (obviously) change.

Note how with standard gearing, at +0 power, the fourth gear gives almost no benefit to acceleration, and could be safely skipped (by shifting in third gear at higher rpm accordingly). This happens because the power curve is very flat.

 

[Griffith500]

Well, not to be pedantic, but a flat power curve would be a bit pointless, too, given that resistance to acceleration increases with vehicle speed (which is in most cases directly linked to engine speed). In ideality, a constant thrust is desired.

A flat(ish) power curve gives the sense of "wafting" instead of the raw, incessant surge you get with a flat torque curve. The former can be a bit uninspiring, whereas it is the latter which gives Honda's high performance powertrains their purported "addictiveness" - same with the McLaren F1's BMW V12. Nobody would accuse these cars of being slow, given what they are; although plenty of people complain about the low-mid-range torque on Hondas, forgetting the limited displacement of the engine...

Turbo engines are very flexible, as the boost can be adjusted according to almost any measurable parameter, given a suitable ECU - though the wastegate would have to be very good. A common idea is to adjust the maximum boost according to what gear the car is in.
Indeed, NA engines can't obtain a flat torque curve without some sophisticated variability in the valvetrain - for example the latest Clio RenaultSport 200 uses some sort of cam phasing. So, really, there's not much to separate the two regimes in actuality - at least in terms of the ultimate (i.e. irrespective of require "mods") tweakability of torque delivery. A turbo, variable breathing motor with charge bypass (instead of exhaust bypass) might be the ultimate solution with current tech. Lets not forget that all boost does is increase the effective capacity of the engine; e.g. 15 psi of boost on a 2 litre lump effectively makes it a four litre!

It all comes down to what it is you're using the car for, and how you like to drive it in that situation. This is why detailed tuning tools, including thrust maps, would be very useful for perfecting online setups, for example.

EDIT: I still like the +50

 

[shirakawaa]

Well, not to be pedantic, but a flat power curve would be a bit pointless, too, given that resistance to acceleration increases with vehicle speed (which is in most cases directly linked to engine speed). In ideality, a constant thrust is desired.

A flat power curve (for a given maximum power needed) would however increase performance and decrease the need of having many gears to maximize acceleration.
Maybe there's the need of one or more graphs to better show this.

A flat(ish) power curve gives the sense of "wafting" instead of the raw, incessant surge you get with a flat torque curve. The former can be a bit uninspiring, whereas it is the latter which gives Honda's high performance powertrains their purported "addictiveness" - same with the McLaren F1's BMW V12. Nobody would accuse these cars of being slow, given what they are; although plenty of people complain about the low-mid-range torque on Hondas, forgetting the limited displacement of the engine...

Yes, I agree that a flatish power curve (with peak torque at low rpm) wouldn't be as attractive/appealing as an one which gives the sensation of never losing juice until the rev limiter. However, if performance is all what counts, there's simply no match, one should try to maximize average power at all costs rather than only caring of making the torque curve flat.

Turbo engines are very flexible, as the boost can be adjusted according to almost any measurable parameter, given a suitable ECU - though the wastegate would have to be very good. A common idea is to adjust the maximum boost according to what gear the car is in.
Indeed, NA engines can't obtain a flat torque curve without some sophisticated variability in the valvetrain - for example the latest Clio RenaultSport 200 uses some sort of cam phasing. So, really, there's not much to separate the two regimes in actuality - at least in terms of the ultimate (i.e. irrespective of require "mods") tweakability of torque delivery. A turbo, variable breathing motor with charge bypass (instead of exhaust bypass) might be the ultimate solution with current tech. Lets not forget that all boost does is increase the effective capacity of the engine; e.g. 15 psi of boost on a 2 litre lump effectively makes it a four litre!

It all comes down to what it is you're using the car for, and how you like to drive it in that situation. This is why detailed tuning tools, including thrust maps, would be very useful for perfecting online setups, for example.

EDIT: I still like the +50

Thanks for explaining your point of view.
By the way, before you added this post I was going to add this other chart which illustrates where, with standard gearing and shifting points for maximum performance, each engine configuration for the Cappuccino (+0 violet, +50 green, +100 yellowish), accelerates quicker:

 

[Griffith500]

Ah, you're right. I suppose that's what CVTs are for!

And I wasn't suggesting the +50 would be quickest, just to clarify. I just hate dead-spots, it makes the car feel frustrating to drive, even if it is quicker (a bit like diesels three or four years ago). Not sure if that has any significance in competition, although at the end of the day, it is people that have to drive the cars.

Funnily enough, the +0 has the closest to ideal shape (corresponding to a constantly variable gear ratio - CVT - excluding the singularity at zero speed), though it is slower overall, especially if traction is an issue in first gear. I'm trying to get my head around the significance of a [thrust*speed] area, though...

 

[shirakawaa]

I thought that area would better show the differences in thrust especially in a comparison between two or more engines, excluding factors like gear shifting times, turbo lag, etc (I should have removed the area below aero/tire losses though). So in the graph above the default engine configuration is really quicker only in 1st gear and a little bit for a short period of time in 2nd.

It's true that there wasn't much need of a similar graph to illustrate that in this case, but this method would work also in (much) less obvious examples. It's just another tool. Setting up gearing and optimal shifting points isn't an easy task.

 

[Griffith500]

Sorry, what I meant is, I don't know what the area signifies; i.e. what the integral of thrust with respect to speed actually means, since there didn't at first, to me, appear to be that much of a difference between all three cases - at least not to the degree I expected from the torque / power curves themselves. I imagine there's a significant difference in the 0-200 kph or 1/4 mile times, but it's hard to see in the thrust graphs (area, or linear plots equally).

Although, looking at it again, and taking into account the aero and drivetrain losses, I see it better now. I guess the visual representation needs some numerical backup?