Bring back realistic engine tuning!

[shirakawaa]

Has anybody noticed that in GT1 and GT2 engine tuning was far more realistic than in newer games in the franchise?

Components that increased high-end power basically reduced low end torque. In the case of NA tuning that was because they were shifting the powerband to higher rpms in order to achieve more power.
In the case of Turbocharged engines, with tuning the much higher torque at medium and high rpms was counterbalanced by losses (huge if big turbo kit were used) at low rpms caused by lower engine compression needed, higher turbo lag, wilder cams (probably), turbos not able to produce enough pressure at low rpms. Anybody who tuned their cars in real-life can tell that this is how most engines respond to modifications.

The result was that tuning was far more realistic. You couldn't fit a Stage 4 NA kit/Turbo kit and drive your car as you would if it were stock, just with more power. Basically with too much tuning most cars turned into undrivable mess ideally only suitable for high speed races/drag races/top speed tests. Modifications actually made sense!

In GT3 and 4 PD for some reason simplified everything. Most cars (there were very few exceptions) with tuning just gained power and torque more and more, with no drawback.

Don't you think GT should go back to its roots regarding tuning (and possibly expanding it with more technical/advanced options) ? As time passed I feel they dumbed it down, personally. I hope it will become more realistic again in GT5.

 

[reece22345]

They dumbed it down, probably because most of us aren't mechanics or know much about the whole thing. Don't forget, GT5 is for a very wide demographic, I was like 12 years old playing GT4 and didn't understand the options then completely, but thankfully I still had fun because they weren't waaaay over my head.

Hell I don't even understand some of the suspension settings or downforce settings to this day. If they are to make it more realistic, they better supply a very large manual that teaches you how to tune your car.

Maybe they should have a toggle tuning setting of like Simplified -> Realistic. That way it doesn't alienate consumers such as myself that are in it more for the racing and driving experience and don't want to spend ages setting up a car just to get it to go around a track.

 

[Smoke&Slide]

Well KY said the cars will act the same as their real life counterparts, so should be more real than GT1.Obviously GT5 being more realistic, there should be more options to play with.The settings should be as accurate as a new pin.

 

[CoolColJ]

Sliding the power up in GT5 Prologue reduces bottom end torque and vice versa. You can see it in the graph

 

[shirakawaa]

Sliding the power up in GT5 Prologue reduces bottom end torque and vice versa. You can see it in the graph

Well, I don't have GT5 Prologue so I didn't know that. So it looks that PD are at least aware of the problem.
But are you sure that low-end torque is actually reduced and not only visually lower on the graph because high-end power becomes higher? Can the torque loss be actually felt?

Maybe they should have a toggle tuning setting of like Simplified -> Realistic. That way it doesn't alienate consumers such as myself that are in it more for the racing and driving experience and don't want to spend ages setting up a car just to get it to go around a track.

Yes, that's the key! PD should make it optionally (very) realistic and technical.

 

[Sprite]

PD should give players the option to choose. Those who want heavy and in depth tuning should get it. Those who want to stick a big turbo can do this but in a simple and diluted way. The only thing that should stay consistent is the characteristics of the car after said modifications. Then players who use the diluted options will inevitably switch to the detailed options and tweak the cars to make them more balanced.

I would trade more detail in this area for anything else.

 

[GDII]

The Lancia Delta in GT5P really suffers with the power slider pushed right up. It's good on faster tracks but when it's off boost in the low revs it's very slow. PD have done well with the tuning so far. The Mines BNR34 needs to be reved past redline to get the most out of it with a full tune.

 

[CoolColJ]

Well, I don't have GT5 Prologue so I didn't know that. So it looks that PD are at least aware of the problem.
But are you sure that low-end torque is actually reduced and not only visually lower on the graph because high-end power becomes higher? Can the torque loss be actually felt?

Yeah acceleration is slower and less traction problems

That's why the Amuse S2000 GT1 is slower than the Tuned Ford GTwhen accelerating, even though it has just as much power. A 600hp 2 litre Turbo 4 is no match for a big V8 as far as low end torque goes, and so the Ford GT accelerates faster.
But on sustained highspeed runs like you do on an oval, the Amuse can be just as fast if not faster

Obviously PD use a formula to drive power and torque values for a give engine size and dimensions, and tune level. Probably like the kind of formulas used in engine tuning prediction software.

 

[sp0rk]

I remember in the earlier GT games each tuning option had a somewhat lengthy explanation as to what exactly you're toying with and how it affects the car.

As long as that is included, I don't see a problem with this. I doubt PD expects anyone to be a mechanic to play their game.

 

[shirakawaa]

The Lancia Delta in GT5P really suffers with the power slider pushed right up. It's good on faster tracks but when it's off boost in the low revs it's very slow. PD have done well with the tuning so far. The Mines BNR34 needs to be reved past redline to get the most out of it with a full tune.

As I wrote, as I don't have the game I didn't know that in GT5P tuning was more realistic, I just assumed that the engine quicktune there worked like the same thing in the GT4 arcade mode (+/-xx% power at all rpms).

Personally, though, I wouldn't mind have that behavior even more expanded. It would be nice if in the final game we'll be able (in an advanced mode so that new/inexperienced players wouldn't be overwhelmed by option) for example to select cams/exhaust manifold types/etc in order to tweak the power/torque curves realistically, a bit like what happens with desktop dyno software (if you've ever seen one in action).

 

[Ascari_Gruppe]

I'd love to be able to fiddle with the air/fuel ratio and place tape over air vents to keep engine and brake temps in the optimum, stuff like that and if I completely cock it up my engine will seize resulting in a financial loss.

But it won't happen

 

[shirakawaa]

Sliding the power up in GT5 Prologue reduces bottom end torque and vice versa. You can see it in the graph

By the way, could you post some screenshots/photos/http links showing how torque curves there change according to the slider setting? I'm curious.

I'd love to be able to fiddle with the air/fuel ratio and place tape over air vents to keep engine and brake temps in the optimum, stuff like that and if I completely cock it up my engine will seize resulting in a financial loss.

But it won't happen

PD could use a system similar to GT4 where the chassis gets damaged over time, and then you have the chance to refresh it for quite some money.
In GT5, engine damage, if enabled, could be caused by different things (overtuning, improper use, etc).
With a more realistic tuning system with damage enabled players could opt to have more conservative settings in order to keep reliability high, even in case of engine mistreatment (stock engines simply can get much more abuse than tuned ones before they start showing problems).

 

[PAPPACLART]

One thing that has always bugged me with NA tuning in GT is the fact that big power/torque gains can be made without an increase in rpms.

On average to achieve, 100bp per litre a car would need to produce peak power at approximately 7000rpm. This varies slightly depending on the capacity of the engine and the amount of cylinders /cylinder size and bore and stroke. but generally 6500/7500rpm is required. So, a 2000cc engine without a turbo making 400bhp would need to be able to rev anywhere between 13000rpm/15000rpm. Put simply, If you want to double the power than you have to double the RPMS.


Equally, it is more or less impossible to produce 100 lb/ft per litre for an NA engine. No matter how much power an NA engine makes, 100lb/ft per litre will not be reached. Perhaps the most exotic engine like F1 etc. can touch 100 lb/ft.

Current 2400cc F1 engines make approx 700bhp and approx 220 lb/ft of torque.

So, what I don't want to see in GT5 after tuning, is a 2000cc NA engine make 350bhp @ 6500rpm and 230/ft/lb of torque at 5000rpm because it is impossible.

It should look more like this.

NA 2000cc 4 cylinder - 350bhp @ 10800rpm and 175/ft @ 8500rpm (Peak power at a particialr RPM will vary from engine to engine dependent on spec)

 

[shirakawaa]

100 lb/ft (135.58 Nm) per litre might be attainable by extremely tuned and advanced NA engines. To reach those levels they would have to exploit fluid dynamics to the limit. So probably only Formula 1 engines are able to go there. So you're right.

Production cars however have managed to reach close values in certain cases. For example the 1988 Opel Kadett 2.0 GSI attained an insane (for a stock street car) 114 Nm/l (84 lbft/l). The current Ferrari 458 Italia reaches 120 Nm/l.

As you write, NA tuning in GT3 and GT4 was not realistic at all. Too much torque increase with no powerband shift to higher rpms. I 100% agree with what you wrote.

Turbo engine tuning wasn't very realistic either (no loss of low-end torque due to engine decompression and bigger turbos, negligible lag in all situations, etc) but that's another story...

 

[Vincent Viceroy]

I'm not a tuner/mechanic/whatever so a lot of this stuff is completely over my head. I've looked at SCAFF's tuning guide (two of them) and it's too much information. Are there any 'For Dummies' guides out there or will a new one be made for GT5?

Stuff like this would really interest me if there was a simple cause and effect narrative. As it stands I tune gear ratio's but that's as far as I go at the moment.

 

[duknuz]

Equally, it is more or less impossible to produce 100 lb/ft per litre for an NA engine. No matter how much power an NA engine makes, 100lb/ft per litre will not be reached. Perhaps the most exotic engine like F1 etc. can touch 100 lb/ft.

Honda S2000, Civic Type R, BMW M3, Integra Type R, Mclaren F1. And those are just off the top of my head.

 

[Raagentreg]

I'm not a tuner/mechanic/whatever so a lot of this stuff is completely over my head. I've looked at SCAFF's tuning guide (two of them) and it's too much information. Are there any 'For Dummies' guides out there or will a new one be made for GT5?

Stuff like this would really interest me if there was a simple cause and effect narrative. As it stands I tune gear ratio's but that's as far as I go at the moment.

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.

 

[Griffith500]

I'd like to be able to shape the power curve according to my needs.

E.g. changing the intake runner length can increase low end torque at the sacrifice of high end power (longer runner) or visa-versa; whilst changing the runner diameter will change the point in the rev range at which the peak horsepower occurs, and affect the torque / power relationship accordingly. Of course, this needs to be balanced with the exhaust and everything else, and there are well-known rules of thumb for precisely these kinds of relationship, assuming everything else is kept equal. Basically, I'd like to use the same engine, get the same usable area under the torque curve but give two completely different engines, e.g. one for sprint races, another for endurance - assuming high engine speeds will be penalised by way of wear and tear in the game.

Arguably, the hard part is cam timing; the "optimum" for which is entirely dependent on the cylinder head in question, as much as the plumbing on the engine. This also guides your hand in setting the other parts of the engine up, in order to make best use of the cam timings.
Another trick is to run different exhaust manifolds according to the circuit / circuit conditions, since it's a very easy way to affect the low-end torque of the engine and avoid hitting the traction limit all the time.

These kinds of possibilities in engine modification would be fantastic, though I imagine it'll be somewhat limited by comparison in GT5.

---------------------------

Regarding specific torque outputs; it's potentially "easier" to achieve such optimal torque numbers at modest engine speeds (i.e. no greater than 10 000 RPM.) The reason F1 cars rev so high is to make the best use of the meagre engine capacity; essentially, the faster it spins the more air it displaces and the more power (being a function of time) it makes, provided the air and fuel can get into the cylinder in the ridiculously short time allowed.

It doesn't require anywhere near as much effort and expertise to get a 10 000 rpm engine to breathe optimally (maximise volumetric efficiency) as it does a 20 000 rpm engine, though it is still quite a challenge. (That Kadett achieved peak torque at a heady 4800 rpm; the 458 at 6000 rpm)
This is why the old-school US tuners will tell you there's no point in revving the nuts off an engine (I suppose it's alright when you've got 400+ cubic inches to play with; mind you, it never stopped NASCAR engines from revving beyond 8-9k - kinda puts to bed the "issues" with cross-plane crank exhaust routing, too)

 

[Ascari_Gruppe]

I'm not a tuner/mechanic/whatever so a lot of this stuff is completely over my head. I've looked at SCAFF's tuning guide (two of them) and it's too much information. Are there any 'For Dummies' guides out there or will a new one be made for GT5?

Stuff like this would really interest me if there was a simple cause and effect narrative. As it stands I tune gear ratio's but that's as far as I go at the moment.

As far as chassis tuning for dummies goes, if the rear of the car slides all over the place, take some grip out of the front. Likewise if there's too much understeer, take some grip away from the back.

In GT5p you could do this easily and quickly with the aerodynamics on the tuned cars but it will only effect the handling over 100km/h.

If you were seriously desperate, you could run R2 tyres at the fron and R3's at the rear and vice versa (but this is a real dodgy way of doing it and a last resort )

 

[shirakawaa]

I'd like to be able to shape the power curve according to my needs.

E.g. changing the intake runner length can increase low end torque at the sacrifice of high end power (longer runner) or visa-versa; whilst changing the runner diameter will change the point in the rev range at which the peak horsepower occurs, and affect the torque / power relationship accordingly. Of course, this needs to be balanced with the exhaust and everything else, and there are well-known rules of thumb for precisely these kinds of relationship, assuming everything else is kept equal. Basically, I'd like to use the same engine, get the same usable area under the torque curve but give two completely different engines, e.g. one for sprint races, another for endurance - assuming high engine speeds will be penalised by way of wear and tear in the game.

Arguably, the hard part is cam timing; the "optimum" for which is entirely dependent on the cylinder head in question, as much as the plumbing on the engine. This also guides your hand in setting the other parts of the engine up, in order to make best use of the cam timings.
Another trick is to run different exhaust manifolds according to the circuit / circuit conditions, since it's a very easy way to affect the low-end torque of the engine and avoid hitting the traction limit all the time.

These kinds of possibilities in engine modification would be fantastic, though I imagine it'll be somewhat limited by comparison in GT5.

Griffith - Burnout Drag Racing Championship, an old drag racing sim for pc, had what you described. It was possible to tune the engine by tweaking various parameters (although some were rather simplified, and in general they were oriented toward american performance engines). Power/torque charts were calculated in real time:

There is more complex software available to simulate engine torque/power charts, however what is probably the best balance between complexity and ease of use probably is Desktop Dyno 5. One still needs to know what he's doing to obtain good results, and in a game like Gran Turismo there would have to be some limits on what is possible to do (possibly depending on the engine, for example american big blocks might be able to be stroked/bored much from their starting values, while smaller european or japanese engines might be more limited). Also some things would have to cost money. Overall, though, it shouldn't be something too hard to add (provided that it will have to remain optional for those who want realism or total control... Sony wouldn't allow the game to be too complicated by default).

PS: ideally I'd want something as comprehensive as Engine Analyzer Pro, that truly allows to tweak everything and see what affects torque and power... but it's essentially an engineer's tool. Probably too complex even for a pc sim.

 

[Griffith500]

Griffith - Burnout Drag Racing Championship, an old drag racing sim for pc, had what you described. It was possible to tune the engine by tweaking various parameters (although some were rather simplified, and in general they were oriented toward american performance engines). Power/torque charts were calculated in real time:

[pic]

There is more complex software available to simulate engine torque/power charts, however what is probably the best balance between complexity and ease of use probably is Desktop Dyno 5. One still needs to know what he's doing to obtain good results, and in a game like Gran Turismo there would have to be some limits on what is possible to do (possibly depending on the engine, for example american big blocks might be able to be stroked/bored much from their starting values, while smaller european or japanese engines might be more limited). Also some things would have to cost money. Overall, though, it shouldn't be something too hard to add (provided that it will have to remain optional for those who want realism or total control... Sony wouldn't allow the game to be too complicated by default).

PS: ideally I'd want something as comprehensive as Engine Analyzer Pro, that truly allows to tweak everything and see what affects torque and power... but it's essentially an engineer's tool. Probably too complex even for a pc sim.

Holy carp! I've been looking for that game for years now (I just couldn't remember its name!)
I love you, man.
It looks as though the IHRA Drag Racing games are some sort of spiritual successor to Burnout / HOT ROD - though I don't know if they have the same features.

By the way, Engine Analyzer Pro is some piece of kit. I don't know if they still do trial versions, but it is very impressive. Real (amateur) tuners use it to establish a baseline before expensive / cumbersome dyno time. And indeed it is very complex, though in the 10-day trial I had of v3.3, I managed to compare exhaust mods for a Z1300, among other things. Cam profiles are most definitely the hardest part to get right.

----------------------------------------

Given that GT has always been about aftermarket parts, off-the-shelf stylee, I doubt this kind of custom tuning will ever be present.

However, having several options of each "level" of upgrade would be a good compromise - e.g. three intake manifolds intended for a given "air flow" (arbitrary horsepower / torque composite "performance" measure), but with their geometry tuned for a specific torque curve shape, with the same overall useful area; three such sets of manifolds could exist for three different "performance" levels. The same would apply for exhausts, cams etc.

All of this would be calculated from base stats on the car and a few fudging factors so that it's not too cumbersome to implement, though it might not be altogether accurate to real world examples.
This multi-layered, multi-tiered system could easily be bypassed by the casual tuner by simply selecting the performance level and a "peaky" or "torquey" (or "neutral") bias "globally", across mods, for a given car. Naturally, I'm assuming the separation of NA tuning into its constituents, so that a separate "cams" menu under "engine" would contain "NA" and "Forced Induction" categories before the different levels of aggressiveness.
I think I remember this being discussed before, now that I've gone off on one...

 

[reece22345]

Yeah I remember GT4 had a description of what changing bits of the tuning would do to the dynamics of the car but it was frustrating because it one-line side-scrolled at the bottom of your screen. Wasn't very easy to read/user friendly.

I'm sure they'll have something up their sleeves! I too, was under the impression the Apex book had something to do with it, but I doubt they'll keep the large majority of customers out of the loop when they buy the standard game if tuning was a fundamental aspect of it.

 

[E28]

How about if all cars are tuned to a default 'all round' setting, but if you want to go and take your M5 for example and optimise it for the Nurburgring, before tuning making it look the part with (hopefully) some custom rims, race car bodykit and a custom livery, you should be able to.

If you just want to enjoy the cars and scenery however, you can!

 

[Aloha62_2]

but I doubt they'll keep the large majority of customers out of the loop when they buy the standard game if tuning was a fundamental aspect of it.

I think cars should comes to race 'as-is' when it comes to settings so no major fiddling is required make the default settings sensible, but that shouldn't rule out a whole host of very fine tuning options for those of us who want to dive into the fiddly bits.

I would happily spend a evening testing the difference tyre profiles and pressures make to my car around a track, but iam a bit sad like that.

 

[Griffith500]

I think cars should comes to race 'as-is' when it comes to settings so no major fiddling is required make the default settings sensible, but that shouldn't rule out a whole host of very fine tuning options for those of us who want to dive into the fiddly bits.

I would happily spend a evening testing the difference tyre profiles and pressures make to my car around a track, but iam a bit sad like that.

+1 👍

 

[Vincent Viceroy]

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.

It's still going to be overly complicated though...considering it's PD's document.

As far as chassis tuning for dummies goes, if the rear of the car slides all over the place, take some grip out of the front. Likewise if there's too much understeer, take some grip away from the back.

In GT5p you could do this easily and quickly with the aerodynamics on the tuned cars but it will only effect the handling over 100km/h.

If you were seriously desperate, you could run R2 tyres at the fron and R3's at the rear and vice versa (but this is a real dodgy way of doing it and a last resort )

I do understand the basics...much of it is common sense...but it's the technical stuff I want to get on with more.

 

[Spagetti69]

^^ Roll bars are your best friend.

 

[Tornado]

I've wanted the same thing for GT5 in tuning since 2005: The same system that Need For Speed Underground 2 had. Now, I would probably accept a return to the system used in GT1 and GT2, but it would be silly to come up with that after all of the hyperbole Kaz has been talking about in relation to tuning.

In any case, the gimped system used by GT3 and 4 would be unacceptable.

Honda S2000, Civic Type R, BMW M3, Integra Type R, Mclaren F1. And those are just off the top of my head.

All of those have well short of 100 lb/ft per liter. That isn't to say it is impossible, but it certainly hasn't been done before to my knowledge.

 

[Greycap]

Honda S2000, Civic Type R, BMW M3, Integra Type R, Mclaren F1. And those are just off the top of my head.

S2000 (Japanese version): 1997 cc, 161 lb/ft, failed.
Civic Type R (FD2 chassis): 1998 cc, 159 lb/ft, failed.
M3 (E90 chassis): 3999 cc, 295 lb/ft, failed.
Integra Type R (DC5 chassis): 1998 cc, 152 lb/ft, failed.
McLaren F1 road version: 6064 cc, 480 lb/ft, failed.

And your point was?

Well, being honest I believe you confused Nm with lb/ft and all of those engines indeed exceed 100 Nm per litre but they all fail to exceed 100 lb/ft per litre. Even F1 engines can't do it as PAPPACLART pointed out.

 

[shirakawaa]

By the way, speaking of how technical and more realistic GT1 was in certain aspects, does anybody remember how much more detailed and easy to read gear charts and torque/curve charts were there? That's another aspect where there was a definite step down in the last games in the franchise (again, I can't speak for GT5P. Has this been corrected there?). Both charts contain important information for an optimal set-up of the car.

Actually I'd want to see something which combines both charts. It would be useful to set up proper gearing, especially if the engine has a very limited/peaky powerband (again, maybe the guys at PD thought that since power wasn't increasing in a realistic manner in the last games, they dropped detailed gear/dyno charts with helpful grids, intermediate values, etc?).

Something which would show losses would be also useful in determining top speed in advance (here it contains torque at the wheel for each gear. Power would probably be more intuitive for setting up gearing for maximum speed):