Please close this useless thread so it doesn't get bumped in another 3 years

[AnnDee4444]

Thought this was interesting, especially below 2500 RPM. The Alfa has roughly double the torque at 1000 RPM? CSV files are attached.

*edit: THESE CURVES HAVE BEEN ESTIMATED BY SOME UNKNOWN SOFTWARE USING UNKNOWN DATA.

Sponsored

 

[FUHL]

The Giulia doesn't have big heavy tires to get moving.

 

[AnnDee4444]

The Giulia doesn't have big heavy tires to get moving.

This is power at the crankshaft.

 

[beaups]

Where are those files/graph from? Those can't be actual Dyno numbers, they are never that flat/consistent.

 

[AnnDee4444]

Where are those files/graph from? Those can't be actual Dyno numbers, they are never that flat/consistent.

Sorry, forgot to cite my source in the original post: https://www.automobile-catalog.com/

They say: "The Horspower / Torque Curve below was generated by the ProfessCars™ software, based on the factory data:"

 

[beaups]

Sorry, forgot to cite my source in the original post: https://www.automobile-catalog.com/

They say: "The Horspower / Torque Curve below was generated by the ProfessCars™ software, based on the factory data:"

Ah, I'd take that data with a huge grain of salt.

 

[DadJokes]

While I’d find it an interesting comparison I don’t find that curve familiar for Giulia. You could find something at Eurocompulsion and a couple of others iirc and work at superimposing them if you could verify, at least, a same model dyno. Not many can dyno the Giulia is my understanding as the car freaks out for lack of exact knowledge.

 

[AnnDee4444]

Unfortunately, this is probably the best data we're going to see for a while. As far as I know, manufactures don't release engine dyno charts like these anymore, and only a release peak HP & torque range (sometimes). If anyone has anything more accurate, please feel free to add to this thread. I don't know what data automobile-catalog.com is using, so I can't verify the accuracy of their data.

FWIW: I can confirm the entire flat portion of the torque curve and one data point at peak HP on the Alfa (per the manufacturer's spec). By extension, this confirms the flat portion of the HP curve, and the torque at peak HP. The JL's specs don't give the torque range, however I think it is safe to assume that the Cherokee's specs are probably identical. I can also determine an absolute maximum that the torque could be at all RPMs above peak torque, which I think gives a very good indication of what the curve will look like.

Here's an updated graph with all these exceptions factored in:

Again, if anyone has anything more accurate, please feel free to add to this thread.

 

[beaups]

That data is pretty useless. As stated earlier, the Giulia dyno looks nothing like reality.

 

[AnnDee4444]

That data is pretty useless. As stated earlier, the Giulia dyno looks nothing like reality.

Thanks for your input. Can you please point me in the direction of realities engine dyno data?

 

[beaups]

Thanks for your input. Can you please point me in the direction of realities engine dyno data?

As mentioned earlier in thread, you can find giulia dynos on eurocompulsion. I also believe burger Motorsports and madness autoworks also have some Dyno data.

 

[AnnDee4444]

As mentioned earlier in thread, you can find giulia dynos on eurocompulsion. I also believe burger Motorsports and madness autoworks also have some Dyno data.

Do you have any links? Everything I am finding at Eurocompulsion, Berger Motersports, and Madness Autoworks is measuring the power with a chassis dynamometer, and no recorded data below 2000 RPM. Also, as I mentioned earlier in the thread, the charts I posted are crankshaft or engine power, so comparing them to wheel power isn't accurate (unless you are concerned with calculating drive-train loss).

 

[beaups]

Do you have any links? Everything I am finding at Eurocompulsion, Berger Motersports, and Madness Autoworks is measuring the power with a chassis dynamometer, and no recorded data below 2000 RPM. Also, as I mentioned earlier in the thread, the charts I posted are crankshaft or engine power, so comparing them to wheel power isn't accurate (unless you are concerned with calculating drive-train loss).

Pretty much nobody does a crank dyno except the MFR. You can infer crank hp from wheel HP. Either way the wheel dyno curves are relevant and show that the computer Dyno data you linked to is not very useful. No engine on earth, especially boosted, has curves that flat. Something else to consider is that the giulia is rated for 91+ fuel only. Since the Jeep is rated to use 87, it's possible they backed timing and/or boost off low in the rpm range to accommodate that.

 

[AnnDee4444]

Pretty much nobody does a crank dyno except the MFR.

Which is exactly what this thread was about from the beginning: Comparing crankshaft HP of the different GME 2.0 variants.

You can infer crank hp from wheel HP.

If you know the drive-train loss, and the testing conditions of the chassis dyno. If you are going to infer data for crankshaft power, why not start with the data the Manufacturer has actually provided?

Either way the wheel dyno curves are relevant and show that the computer Dyno data you linked to is not very useful.

I disagree, I find motor dyno information very useful, even if it is estimated from manufacturer's data. How else would you attempt to calculate drivetrain loss? It takes both motor power and wheel power. Comparing motor HP as measured from different chassis dynos, by different operators, with different fuel, while adjusting for their different drivetrain losses... too much room for error. If only there was a way to isolate just the motor's output.

No engine on earth, especially boosted, has curves that flat.

I don't disagree. This is based off of the manufacture's quoted specifications, which is a generalization of how that motor will perform. I doubt they took one specific motor and actually got it to run exactly as the chart shows, with exactly 400 Nm of torque from 3000-4500 RPM.

Something else to consider is that the giulia is rated for 91+ fuel only. Since the Jeep is rated to use 87, it's possible they backed timing and/or boost off low in the rpm range to accommodate that.

There are many differences between the Jeep & Alfa's 2.0 that lead to their power difference. I'm not arguing this at all.


Here's are the power specifications, direct from the manufacturer:

And here are those same numbers, but in a graph:

Adding in some useless data that may or may not be partially or fully estimated from software:

Full circle, back at post #1!

 

[beaups]

If you want to compare a bunch of fake Dyno charts, so be it. I'm just pointing out that you are looking at a wild guess and somehow putting more validity in to it than actual dyno graphs. What you are looking at aren't crank Dyno charts, they are wild guesses that don't resemble any real dyno result. While you have to account for DT loss in a chassis dyno, it's still better than make believe in my opinion.

I'm quite familiar with the Alfa motor and all the differences. I have a giulia with with the 2.9. I've followed the 2.0 tuning scene quite closely, which is partly why I pointed out that the curves you posted don't resemble reality.

I don't see the point in taking known-bad data, sprinkling assumptions on it, and trying to use that to reach some sort of conslusion.

In your fake Dyno data, is that with 87 octane or 91? What are the ambient conditions? How about the DA?

Sponsored