AnnDee4444
Well-Known Member
- Thread starter
- #16
I realized I made a mistake, fixed it in the chart below. I didn't update the averages, doesn't look like they would have changed much anyway.
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All these graphs represent hp and tq numbers at the rear wheel. Usually, only engine builders are set up for testing on engine stands.Great job Compiling this data. I always thought the factory torque numbers for the 2.0T were underrated. It’s apparent it’s rocking over 300 at the crank.
In your original figures, why does torque decrees at the upper level RPMs?Found another dyno by Holley. Not sure how they "Produced +18 horsepower and +25 lb.ft. of torque with excellent performance across all RPM levels" with just an intake... Someone got creative.
Curve is looking constant, but but this was the lowest output so far.
That's pretty consistent with everyone's dyno.In your original figures, why does torque decrees at the upper level RPMs?
I get that, I was just hoping you could explain, mechanically, why it happens.That's pretty consistent with everyone's dyno.
I'm not 100% sure, but have always assumed it's running out of air due to the turbo sizing.I get that, I was just hoping you could explain, mechanically, why it happens.
That makes perfect sense; thank you!I'm not 100% sure, but have always assumed it's running out of air due to the turbo sizing.
All engines will have this point, where they can't pump as much air through and torque will start to go down. Sometimes that point is so high that other components can't handle the RPM needed to see it.
Torque always goes down in higher RPMs. It's a function of the engines ability to breath efficiently. The faster the engine spins the more difficult it is to evacuate the spent gasses and take in fresh air/fuel. An engine builder can make an engine breath more efficiently in upper rpms, but will sacrifice low rpm breathing efficiency. Cylinder scavenging and valve overlap becomes inefficient and does not work well at low RPM and low air flow rates. Most engines are designed to make torque in the lower RPM range because that's where most people need/use it. So that's where they breath more efficiently. That's where the majority of time is spent on a normal vehicle. The cam pretty much dictates where in the RPM curve will sit. The cam controls when the intake and exhaust valves open, how long they stay open for and how much they open. That's where the breathing occurs.In your original figures, why does torque decrees at the upper level RPMs?