Fix the power bands for the Diesel Prototypes!

[maciej908]

In GT5 the description of the Audi R10 TDi '06 in GT5 says: 'very low power band 3000-5000rpm' so why does the car rev up to 6500rpm? Same thing with the Peugeot 908.

In Forza the rev limiter for the 908's and R18's ends on 5000rpm but in GT5 they rev up to 6500? I've never seen a diesel rev that high.

Hopefully they fixed that for GT6 and the new (old) R18 TDi will rev up to normal rpm.

(I don't own an XBOX so don't call me a fanboy of Forza, though their diesels really sound better and rev more realistically)

 

[Tornado]

Hopefully they fix all of the LMP/GT1/Group C cars.




Not sure if I would expect it, though.

 

[wowbaggerBR]

Hopefully they fix all of the LMP/GT1/Group C cars.




Not sure if I would expect it, though.

👍

 

[tinram]

Because Forza is the best reference for rev limits in race cars.

 

[finnracer]

Because Forza is the best reference for rev limits in race cars.

But since most diesels rev to around 5000rpm I'd say its a fair comparison.

 

[KinLM]

But since most diesels rev to around 5000rpm I'd say its a fair comparison.

Because a Peugeot V12 racing engine Diesel definitely is like 'most other diesels'

Most petrol cars rev to 8,000. Most of the Prototype LM petrol cars rev above that.

 

[Tornado]

Because Forza is the best reference for rev limits in race cars.

I'll bite. Why should how they are represented in Forza be discounted as reasoning to think GT5 got them wrong?




And the OP is right anyway.

 

[Cosbuster]

I don't own an XBOX so don't call me a fanboy of Forza

I really wish people would feel comfortable posting their opinion without having to add crap like this at the end.

 

[maciej908]

If apparently the rev limiter for the Peugeot 908 in GT5 is accurate, then the drivers must have been short shifting EVERY TIME they were driving the car, cuz I don't recall it revving above 6500rpm like ever...

 

[Kake Bake]

Forza doesn't make a very good comparison for arguing against GT's absolutely dedicated realism.

I mean, it doesn't arbitrarily withhold ~%80 of its 8-year-old+ content from the player, it lets you paint any car however you'd like and its menus don't require you to complete a CPA certification to navigate.

Forza is arcade and it's always wrong.

 

[maciej908]

Forza doesn't make a very good comparison for arguing against GT's absolutely dedicated realism.

I mean, it doesn't arbitrarily withhold ~%80 of its 8-year-old+ content from the player, it lets you paint any car however you'd like and it's menus don't require you to complete a CPA certification to navigate.

Forza is arcade and it's always wrong.

I'm sorry but that's just pure GT fanboyism. It seems like you treat GT games like the bible and simply fail to take into account faults on Polyphony's behalf in certain parts of the game...

Edit: If above post was sarcastic which I think it might have been, I didn't catch it :/ lol

 

[HighSeasHoMastr]

I'm sorry but that's just pure GT fanboyism. It seems like you treat GT games like the bible and simply fail to take into account faults on Polyphony's behalf in certain parts of the game...

His whole post was sarcasm.

 

[KinLM]

I'll bite. Why should how they are represented in Forza be discounted as reasoning to think GT5 got them wrong?

And the OP is right anyway.

Because first off, every single car in Forza has an idle rev of 800 which immediately throws off the power bands for every single car which doesn't idle at 800.

Most everyday cars idle near that but most race cars, as well as diesels, do not.

I don't see how Forza can be a true comparison for this reason. It may have more realistic rev limiters but that could easily be offset by the false idle revs.

Not saying that GT's are correct (because many of them aren't) but simply that Forza's aren't either.

 

[eSZee]

In GT5 the description of the Audi R10 TDi '06 in GT5 says: 'very low power band 3000-5000rpm' so why does the car rev up to 6500rpm?

You seem to be under the impression that redline=power band, unless I'm reading that wrong?
The redline on the car is 6500 or 6600, that doesn't mean that the "meat" of it's power comes in at 6500.

 

[CarBastard]

While they're at it, they should fix LMPs altogether as Tornado said.

The R10 TDi is the perfect representation of what GT5 is to me. When I first saw it in a trailer, racing alongside the 787B I couldn't believe it and could barely hold my excitement becauset it's one of my favourite cars ever. But then, when I bought it and took it for a spin I was really disappointed. And to this day, I rarely touch it because not only it's not very well done but because I was expecting so much more of it.

It's a shame. The model for the car is one of the best in GT5 and the car looks absolutely stunning. Everything else is done poorly.

 

[Vegard]

You seem to be under the impression that redline=power band, unless I'm reading that wrong?
The redline on the car is 6500 or 6600, that doesn't mean that the "meat" of it's power comes in at 6500.

Have you even looked at the curves before making this statement?

Both the 908 HDi and R10 TDi have comepletely absurd powerbands.
I did some research on this some time ago and both cars are "done by 5500 rpm" (IRL).
Drivers would shift somewhere between 5000 and 5500 depending on circumstances.

Another absurd aspect of this issue is when tuning engines.
Basically all engines keep their torque and power-curve profiles
no matter how high the specific output. (The exception being Turbo and Supercharger tuning, although there are some really absurd examples of those as well).

 

[maciej908]

You seem to be under the impression that redline=power band, unless I'm reading that wrong?
The redline on the car is 6500 or 6600, that doesn't mean that the "meat" of it's power comes in at 6500.

I know that redline doesn't = power band. What I mean is most of the power in the Audi or the Peugeot in the game comes on at the end of the rev limiter which is not the case IRL.

What bothers me the most is that in IRL their shifting seems very short which would indicate one of two things: most power available at low rpm or very short gear ratios (unlikely since they reached above 210mph IRL). Something that PD hasn't replicated correctly in the game. :/

 

[GTV0819]

As the redline of the two diesel Le Mans racers, the R10 TDI and the 908 HDi, is high at 6500RPM, that's not the case IRL. Even the Tank Car, despite not being a diesel in game, has a lower redline at 3000+RPM but this is due to the large displacement of the engine.

What's worse is that the peak torque of the R10 TDI and 908 HDi, are generated at high diesel RPMs like about 3500RPM, which is totally unrealistic when a typical diesel's peak torque are generated mostly about 1500-2500RPM.

The only diesel car in the game that has the proper powerband for a diesel car is the BMW 120d. It generates peak HP at 4000RPM and peak torque at 2000RPM. IMO, these ratings are already high for a diesel engined car but is still acceptable.

 

[daan]

In GT5 the description of the Audi R10 TDi '06 in GT5 says: 'very low power band 3000-5000rpm' so why does the car rev up to 6500rpm? Same thing with the Peugeot 908.

Now, I'm not saying that PD have it right or wrong, but it would seem that Audi don't say what the R10 revs up to. It may be 5500. It may be 6500. We just don't know.

Also "power band" and a rev limit are 2 entirely different things.

IIRC there is a Skyline that revs to about 9000rpm but it does nothing above about 6000. Just because it can get there, doesn't mean it should be taken there.

 

[finnracer]

Because a Peugeot V12 racing engine Diesel definitely is like 'most other diesels'

Most petrol cars rev to 8,000. Most of the Prototype LM petrol cars rev above that.

Most petrol cars rev to 6-7000, and yes LM cars rev higher, but the diesels are Turbocharged and more getting more power from said engines is usually by adding boost and creating a fatter powerband, rather than one that revs higher. Plus the charictaristics of a diesel engine make it harder to make them rev much beyond 5-5500rpm.

http://www.dieselpowermag.com/news/0512dp_audi_r10/

This article states that the 'usable powerband' of an R10 is 3-5000rpm, so it is reasonable to assume the limiter/redline is not swt that far above this level.

 

[Vegard]

Now, I'm not saying that PD have it right or wrong, but it would seem that Audi don't say what the R10 revs up to. It may be 5500. It may be 6500. We just don't know.

Also "power band" and a rev limit are 2 entirely different things.

IIRC there is a Skyline that revs to about 9000rpm but it does nothing above about 6000. Just because it can get there, doesn't mean it should be taken there.

Tom Kristensen: "The best band is 3000–5000 and you can go even a bit over."

http://www.mulsannescorner.com/juhaAudiR10.html

Anyway, you don't need a masters degree in mechanical engineering to know that a 5.5 litre V12 turbodiesel will "choke" long before 6500 rpm.

 

[DCP]

I don't think the Rev limit / counter should be a problem, as the powerband it what counts.
I drive a tdi Cupra, and the powerband is something like 4100rpm, but it's got 6000rpm on the clock.

 

[ImmalovemaGTR]

Take the 908, use racing hards , stay in fifth gear and try to take a corner at full throttle and 150-170 kph... rpms are very low, but you will spin out extremely... I don't think they got the powerband thaaaat wrong...

 

[daan]

Tom Kristensen: "The best band is 3000–5000 and you can go even a bit over."

Yes, I'm fully aware of that, but that is its power band. We know that there is not much point in taking it over 5000, but what if you did? What is it's physical actual limit?

 

[niky]

Early press for the R10 suggested that, if necessary, the engine itself could rev to 8,000 rpm. Eventually, they limited it to less since there was no point in revving it that high, but statements from the team suggest the limit is above 5k rpm.

Telemetry videos for the R18 suggest that the soft limit for that diesel is around 5k, and there's a harder limit at 5.5 and 6k. They also say that without the restrictor and limiter, that engine could do 8k rpm.

 

[eran0004]

Are the R10 and 908 even modeled in Le Mans spec? There are some cars where PD seems to have modeled them without air restrictors (such as those who outputs some 900 BHP, while the real car with air restrictors (as used in Le Mans) stayed in the 600 BHP range).

Anyone have the specs of the real cars as used in Le Mans and can compare them with the specs they have in GT5?

 

[Tornado]

The "PD used their unrestricted power numbers" thing is nothing more than a pet theory. If that was their intent (and I think it's far more likely that it was an ill-advised attempt to artificially balance the cars around deficiencies of the physics engine), they did a horrible job at emulating it. PD took the correct stats (peak torque, peak power) that are usually shown in the car dealership screen and car information and multiplied them by anywhere from 25 to over 50 percent without changing anything else (which means they make those wildly higher and in some cases outright unrealistic numbers at the same RPM with the exact same torque curve as they made with the true numbers, making some of the cars nearly undriveable); just the same as if you were hybriding a car in GT3 or GT5 with the power multiplier. The R10 and 908 are some of the few (along with the 787b. The F1 GTR is somewhat close to how it should be) where PD actually modeled them right.

 

[eSZee]

Have you even looked at the curves before making this statement?

No, just took a sip of scotch and let the knowledge flow through my fingers.

 

[Vegard]

Yes, I'm fully aware of that, but that is its power band. We know that there is not much point in taking it over 5000, but what if you did? What is it's physical actual limit?

For the R10 peak rated RPM is ~5,500. http://www.greencarcongress.com/2006/06/audi_r10_tdi_di.html

It produces peak torque from 3000-4000 rpm.

Based on statements from Tom Kristensen; peak power is more or less constant from 4000 - 5000 rpm, afterwhich it drops before reaching the limit at 5500 rpm.

Kristensen also commented on the reported 6000 rpm peak power of the development Ricardo-Judd Diesel V10; "I am pretty certain that the 6000-rpm of the Ricardo is achieved with a very poor efficiency. Probably more noise and high exhaust temperatures than power. I am not quite sure how to deal with the Ricardo figures. I mean 6000 rpm – with a diesel that has characteristically slow burning fuel?"

There is little information to be found on the 908.

 

[sk8er913]

LMPs go way too fast at Le Mans, the real cars (R18, TS030) went like 205-210 on straightaways and on GT5 a stock LMP can hit 230... Way faster than they should, and they don't handle as well as they should either, to get the 3:21 that Audi gets...