Torque Physics (Turbo, VVTi, Vtec)

[TayeezSA]

Found it! Excuse my error in the previous post, about 1000rpm earlier shift point



@karelpipa , that's exactly what I want to see but a more refined version of turbo lag. That so I can utilise the benefits of the different ranges for different tracks and such.

 

[Rdp616]

GT6 has a terrible representation of torque delivery, or the application of boost. For example, sports hard tires, Supra. You're stopped in first gear, floor. The car instantly is bouncing off the rev limiter.. There's no feeling of building power, or turbo lag. Torque in the game is instantaneous and very unrealistic.

 

[stuff1138]

GT6 has a terrible representation of torque delivery, or the application of boost. For example, sports hard tires, Supra. You're stopped in first gear, floor. The car instantly is bouncing off the rev limiter.. There's no feeling of building power, or turbo lag. Torque in the game is instantaneous and very unrealistic.

Okay just quickly. Your first statement about a poor representation of torque delivery and the application of boost in GT isn't wrong. Your example doesn't make sense though. First of all torque itself is not exclusive to turbo. Every motor NA, turbo charged, variable valve timed, whatever makes torque. It has to. It's physics. Second of all most road going cars if you put your foot on the floor in first gear you will hit the rev limiter quite quickly if you don't shift. Lastly torque is instantaneous and you don't have to be moving for torque to be present. Hell a pole in the ground with no outside forces other than gravity acting upon it has torque. In static physics it's called moment but it's the same thing.

 

[TRLWNC7396]

All that that ^^^ boils down to is recognizing the "power band" and representing it well. Understandably difficult, too.

 

[TayeezSA]

Holy Crap balls, PD I think is listening to us

Has anyone noticed in the 1.09 update consisted of elements that were mentioned in the suggestions forum?

Maybe this could be looked at for all we know... I need to bump up my premium Subaru GC8 thread and Legacy B4 RSK

 

[TayeezSA]

All that that ^^^ boils down to is recognizing the "power band" and representing it well. Understandably difficult, too.

Dyno sheets brah

 

[gitslautriv]

Dyno sheets brah

It may be painful, but somebody has to do it...

 

[TayeezSA]

I've just thought of something. I think it will be more likely for PD to experiment and implement more pronounced and close to accurate Torque Physics into the game.

Why you may ask? Simply because of the answer in the Sound Update thread. It leads me to believe that PD is using Dynapacks to aid in recording vehicle audio. So why not kill 2 birds with 1 stone then? Since the Dynapacks are made for the purpose of recording power and torque figures and even showing those figures on graph readings, it would be a lot easier and be a great time to implement better torque physics. Do those in line with the sounds and you'll end up with something pretty unique. However, I'm only expecting this in GT7.

I mean look at this even:



There's potential in this I rate...

 

[TayeezSA]

One last thing, Look at how the boost gauge and boost behaves in this video.



Imagine this being implemented

 

[TRLWNC7396]

That would be a neat addition to the tuning!

 

[nickg07]

No what most people don't get is that turbo lag is not just a steep torque curve it's about how it's slow to pull away but that it takes time to spin up a turbo no matter what rpm you are at, it's just usually more pronounced down low in the rev range.

For example at WOT at 3500rpm you could have multiple different BHP output at the wheels depending on when you put your foot down and went WOT and how laggy the turbo is. Related directly to how much boost pressure is being generated at x rpm.

for instance if you had gone WOT at 3000rpm by 3500rpm let's say the turbo is fully spooled producing max bar pressure your bhp could be (example value) 200 bhp at the wheels. Now had you just been at part throttle and only went WOT at 3400 rpm it's possible the turbo didn't spool up to its peak by the time it gets to 3500rpm so you only had 180bhp at the wheels despite being at the same rpm and same throttle position.

Basically at any given rpm you could be at 0-x bar or psi turbo pressure. At 0.5 bar at the same rpm bhp output will be lower than being at 1 bar. I don't feel that the increase in turbo pressure is slow enough in GT6 as it is in some cars in real life. It just seems to hit 100% boost simultaneously as the throttle is pressed. Possibly less of an issue with modern low pressure low rpm spooling turbos but definitely for older cars and high rpm turbos where the actual lag would be more pronounced.

My question is does PD implement this or does wot at 3500 rpm regardless of spool time produce exactly the same bhp output over and over again? Like an NA car.

btw I think vtec and vvtli is actually not modelled that badly. It could be slightly more pronounced but I can feel like vvtli kicking in at the relevant rpm but maybe not the acoustic change.

 

[Rdp616]

Okay just quickly. Your first statement about a poor representation of torque delivery and the application of boost in GT isn't wrong. Your example doesn't make sense though. First of all torque itself is not exclusive to turbo. Every motor NA, turbo charged, variable valve timed, whatever makes torque. It has to. It's physics. Second of all most road going cars if you put your foot on the floor in first gear you will hit the rev limiter quite quickly if you don't shift. Lastly torque is instantaneous and you don't have to be moving for torque to be present. Hell a pole in the ground with no outside forces other than gravity acting upon it has torque. In static physics it's called moment but it's the same thing.

I understand what you mean. But when i say instantly, i mean instantly, it's a half second from not moving to wheels spinning hitting off the limiter. Though the tire model has a lot to do with this is well. The representation of traction in the game is also way off.

But that's not what i'm getting at with that post. I'm basically just using the turbo motor as an example of the lack of realism with torque delivery and turbo lag in the game.

If anything, a Supra with a largo turbo should be very laggy. Meaning from a roll of say 10mph, when you go full throttle, there is a fairly large amount of lag with a couple seconds until power comes on. I would say the Escudo and HPA R32 are probably 2 of the closest representations of turbo lag in the game.

But you have this problem all across the board in GT. NA, Turbo, Supercharged. It's almost as if every car has a super lightweight flywheel.

 

[BrodieBoi94]

I honestly believe that gt4 had better engine sounds (that is across the whole range of vehicles, some sound better in gt6) and i remember there being legitimate turbo lag. Take for instance, the 1JZ Supra. My experience with turbo lag came from installing the biggest turbo. Upon starting from a low enough rpm the car was very "laggy", and as rpms would build naturally so would the boost, but at a certain point the lag was subdued and the results were of course redlining wheel spin. Why this doesnt seem to be as prominent in gt6.... ???

 

[djslofstra]

There is absolutely no spooling time implemented in GT6. When you are in the powerband of a turbocharged vehicle and hit the throttle, the turbo immediately gives pressure in GT6 without a any spooling time.

 

[TayeezSA]

But you have this problem all across the board in GT. NA, Turbo, Supercharged. It's almost as if every car has a super lightweight flywheel.

So what you're also saying is that the cars need to show more weight/torque? I agree with that as well.

There is absolutely no spooling time implemented in GT6. When you are in the powerband of a turbocharged vehicle and hit the throttle, the turbo immediately gives pressure in GT6 without a any spooling time.

The 97T shows some turbo lag but it's almost non existant.

Welp, since we've said something it should get looked at then.

 

[djslofstra]

The 97T shows some turbo lag but it's almost non existant.

Welp, since we've said something it should get looked at then.

Watch this video: Every time when he approaches a slow corner holding his foot of the gas and then accelerates after a corner, the turbo is almost spooled up immediately.

Also when you're in the powerband, the turbo has to spool up again after lifting the gas for a longer time. This is not good implemented in GT6, also not with the 97T.
The annoying turbo spooling time should be better implemented in GT6. That would reconsider people putting a enormous single turbo on their car.

 

[Robbks]

Problem with the above post is this,

that engine never drops under ~7000rpm
that is still an ENORMOUS amount of airflow through the engine, exhaust and exhaust housing of the turbo even with a closed throttle.

As such, the turbo will still maintain a very fast shaft speed and suck in a huge amount of air even with a closed throttle.
You'd probably be suprised at teh pressure build up between the turbo compressor outlet and the throttle plate
Most road cars will have a BOV/BPV to release that pressure, but it simply re-circulates back into the pre-turbo intake.
So the turbo is still flowing a huge amount of air.
As soon as you go WOT again, the turbo speeds up again and pressurises the intake manifold/ cylinders again.

 

[Speedster911]

My mate and I were talking car jargon the other day and the topic of GT6 came up. What he said actually blew my mind.

Torque Physics. How is torque recorded into the game's vehicle physics?

Now when I speak of torque physics, I'll put it into perspective. Simply put it's the slam you get in your seat when your turbo reaches boost, Vtec kicks in and or an LS1 motor vs 4AGE.

At the moment I can't really tell that much when a turbo spools or when I've felt Vtec kick, even the feeling of how Twin Turbos feel.

To prove what I'm saying, I performed a real life comparison of a Factory GT6 Blob Eye WRX STI vs a Factory Real Life Blob Eye STI with bad Zambian fuel (Don't ask why about the fuel).

With the Real Life STI I felt and knew when the turbo spooled and when the turbo lagged with the RPM involved (Sound also plays an important role here as well *wink wink)

In the Gran Turismo 6 STI, I couldn't really feel when the turbo spool or lag happened. Same goes for Vtec. Even when I slapped on turbos of different ranges I couldn't really tell the difference.

Is there anyway that this aspect can be improved upon? Maybe even working with companies like Borg Warner Turbochargers or Garrett to determine the behaviour of turbos and Honda on Vtec transition?

What a novel idea! PD should consider working with manufacturers to get these performance and audio characteristics right. Hiring the expertise of pro drivers or outsourcing certain aspects (winky winky) to research companies or motorsport schools, could pay big time.

Apart from this, I'm out of suggestions. I'm just weary!

 

[Speedster911]

GT6 has a terrible representation of torque delivery, or the application of boost. For example, sports hard tires, Supra. You're stopped in first gear, floor. The car instantly is bouncing off the rev limiter.. There's no feeling of building power, or turbo lag. Torque in the game is instantaneous and very unrealistic.

I'm positive these elements are going to be addressed in GT on PS4. They better put something on the table. It's about time.

 

[Speedster911]

Sorry, double post. How do I delete?

 

[djslofstra]

Sorry, double post. How do I delete?

You can't.

 

[TayeezSA]

This is why I believe companies like Borg Warner Turbochargers and HKS should come on board because they understand this stuff very well. I mean look at the drastic improvements with the new handling engine.

 

[TRLWNC7396]

Good idea, hope it happens!

 

[TayeezSA]

It would also be interesting to see an Anti-Lag model in place. This particularly for Rally cars.

The most prominent Anti-Lag system would be the Umlift System on the Audi Quattro S1 Rally Car. Anti-Lag on that car is brutal in real life.

 

[Robbks]

It would also be interesting to see an Anti-Lag model in place.

ANti-lag on EVERYTHING...
Although the sound would need to be top-notch first

 

[fizzer]

ANti-lag on EVERYTHING...
Although the sound would need to be top-notch first

All turbo cars effectively have Anti-lag, just doesn't sound like it.

Even the 97T has no lag, just a narrow power band.

It's like all the turbos have zero-friction bearings, mass-less turbines and compressors, and magically compress air with zero energy expenditure.

Turbos just aren't modeled, all they do is add torque in a small rpm range depending on how much torque they add. The more torque, the smaller the range which gives the impression of lag.

Torque "physics" are actually modeled pretty well in gt6. The question to Kaz should be: "do you plan to add realistic turbo physics into the torque modelling of turbocharged engines?"

 

[TayeezSA]

All turbo cars effectively have Anti-lag, just doesn't sound like it.

Even the 97T has no lag, just a narrow power band.

It's like all the turbos have zero-friction bearings, mass-less turbines and compressors, and magically compress air with zero energy expenditure.

Turbos just aren't modeled, all they do is add torque in a small rpm range depending on how much torque they add. The more torque, the smaller the range which gives the impression of lag.

Torque "physics" are actually modeled pretty well in gt6. The question to Kaz should be: "do you plan to add realistic turbo physics into the torque modelling of turbocharged engines?"

Not just turbocharged but also NA cars as well.

I did an experiment driving a Ford Figo (Fiesta essentially) with a 1.4 Duratec engine. Now in that car, the torque is within the lower rev range of the car. As soon you hit over 5000rpm the torque just says, "Peace out brah" and the car becomes sluggish. In a VW Polo Vivo (Predecessor Polo essentially) the torque is in the mid range. The point of this is that it affects the way I drive, I want to drive in such a way that I want to utilize the way the car's engine behaves to my advantage. Also to affect my races as well.

Mind you this isn't done via Butt dyno.... Well some of it was but only some. GT has linear powerbands for me with some cars displaying lag and loss of torque. Heck why not add NA mods that will affect how torque and powerband behaves?

One thing I would like also is if we get the opportunity to add twin turbos or modify factory twin turbos would be to adjust the boost pressure for each individual turbo. I think that would be quite interesting.

 

[Speedster911]

This is exactly what happens when you're stuck in a race to smack in as many cars as possible in ONE game.

 

[TayeezSA]

I was mucking about with the HPA R32 and I have this to say

However I don't remember lag being THAT terrible though I really like the surge in RPM. Now if only they got the sound correct then it will seal the deal kinda. Why can't the low RPM turbos just lose puff really? I tried one out on the Evo 4 and the engine still sings all the way to the redline instead of losing breath after a certain RPM.

I can tell when the turbo spools just by listening.





Let's not forget some Vtec and 4AGE




I think all PD would have to do is make a separate model just for turbos/torque or what have you. Once that's done Bob's your uncle.

 

[TayeezSA]

Another 2 examples





Lastly an NA car, change in powerband



Notice the change in powerbands just from the turbo spooling