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Cadillac puts "truck engine" in CT4-V


MY93SHO

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4 hours ago, Fgts said:

 It's a diesel and there similar engine outputs from GM and Ram, still don't take from the fact Germans underrated their engine outputs in their luxury cars these days.

What happens to hp if you take an engine that makes 375 hp and 400 lb/ft and you move the peak torque (same 400 lb/ft) to a lower rpm for better off the line performance?

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10 hours ago, akirby said:

What happens to hp if you take an engine that makes 375 hp and 400 lb/ft and you move the peak torque (same 400 lb/ft) to a lower rpm for better off the line performance?

It could increase, decrease, or stay the same. All depends on the specific tuning applied to achieve the revised torque curve.

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14 minutes ago, rperez817 said:

It could increase, decrease, or stay the same. All depends on the specific tuning applied to achieve the revised torque curve.

Wrong.  It HAS to decrease if the torque curve moves lower in the rpm band because it’s a simple mathematic formula.  Diesels produce their power at very low rpm which is why their hp ratings are so much lower than their torque ratings.

hp = torque * rpm / 5252

 

The point is that it’s not necessarily underrating HP just because it’s lower than before.  It could just be the way they tuned it.  And lower hp doesn’t necessarily mean lower performance especially if the torque remains the same.

The Germans have been known to understate power.  But not GM and especially not when they’re competing with Lincoln.

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46 minutes ago, akirby said:

Wrong.  It HAS to decrease if the torque curve moves lower in the rpm band because it’s a simple mathematic formula.  Diesels produce their power at very low rpm which is why their hp ratings are so much lower than their torque ratings.

hp = torque * rpm / 5252

 

The point is that it’s not necessarily underrating HP just because it’s lower than before.  It could just be the way they tuned it.  And lower hp doesn’t necessarily mean lower performance especially if the torque remains the same.

The Germans have been known to understate power.  But not GM and especially not when they’re competing with Lincoln.

My misinterpretation about what you meant by "power". The formula says power at peak torque rpm will decrease if the torque curve is modified as you described. But peak power (which is usually at a different rpm than peak torque) can increase, decrease, or stay the same. All depends on the specific tuning of the engine as I mentioned previously.

We'll have to wait until the CT4-V and CT5-V come out and multiple third party firms do some dyno tests to find out if their power ratings are understated. But GM has done it before. One of the most dramatic example of understated power ratings in automotive history was the legendary L88 427 big block Chevy engine. More recently, a dyno test done on the Cadillac ATS-V LF4 twin turbo suggests it is understated. But at least one additional dyno test by a different firm would be needed to confirm. https://jalopnik.com/here-s-how-much-horsepower-the-cadillac-ats-v-really-ma-1786968718

What makes you think CT4-V is competing with Lincoln? 

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