Fixed that for you.....Only 707 (factory rated) HP required...
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SAE Certified. Just like the Viper.
So you are saying the GM cars are overrated?SAE Certified. Just like the Viper.
SAE Horsepower rating requires very specific test requirements and the manufacturer can't over or underestimate HP by more than 1% of the measured value from the stringent test requirements.
They pull a car off the production line at random and the SAE official observer witnesses the test. Then the manufacturer has the option of rating the car within a range of 1% of the measured value.
Dodge has always selected the low end of the range allowed. They did the same with the Viper.
With high HP cars like this, 1% is a significant swing. If the car tested at 714 HP, Dodge could choose anything between 707 and 721 as the applied rating.
If you apply the statistical 2x Standard Deviation rule, then any Hellcat coming off the line will range in HP from 700-728 HP (if the car tested at 714).
Independent Motor Trend Dyno results confirm the rating...
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"According to K&N's dyno results, the Challenger SRT Hellcat puts down 635 hp and 591 lb-ft of torque at the rear wheels. Assuming a 12-percent drivetrain loss (automatics are getting more efficient each year), that means this Hellcat puts out about 722 hp at the crank."
This is within the range of the SAE testing requirements and not an under-rating by the Factory.
1/4 mile calculations based on the Hellcat track numbers also confirm these results.
Calculated Flywheel HP: Hellcat - 699 HP (a little low likely due to traction loss during launch).
The myth of being underrated by the factory is just that...a myth.
That particular dyno graph is the ZL1 not the ZR1.
I would have to run the gear numbers in order to know what's going on. Even though they both have 8 speeds, the gear ratio in each plus the rear gear ratio could explain it. Down force of the Vette would also add to the equation at the higher speeds.
More great work DdaddySo, I started running gear numbers and dyno comparisons and found something very interesting...and not what I expected at all.
First I compared the gearing numbers for the Hellcat and the Z06 and they are virtually identical...
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Then I looked at the HP curves and found that the Z06 essentially flatlines at 5200 RPM while the Hellcat is still building power (some advantage to the Hellcat in the 1/4 mile with a sustained higher HP to offset the weight difference and keep with the Vette)
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Then I looked at the torque curve of the Z06 and Holy Crap!
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The Z06 drops from 610 lb/ft @3800 RPM to 460 lb/ft @6500 RPM (150 loss / 24%)
The Hellcat only drops from 591 lb/ft @4200 RPM to 540 @6200 RPM (51 loss / 8.6%)
The Z06 is bleeding torque above 4000 RPM at nearly 3 times the rate of the Hellcat!
This is critical to explain the acceleration difference in the 1/4 mile at the top of each shift. At high speed, torque is King to keep the vehicle pushing against the exponentially increasing wind resistance and the Z06 just doesn't have it.
I'm a bit confused. Which images have dropped? I try to keep them hosted on the Forum to keep that from happening.
Your last detailed post apparently had images or graphs in it but all I can see are the little icons that come up when an image doesn't loadI'm a bit confused. Which images have dropped? I try to keep them hosted on the Forum to keep that from happening.
The images still appear for me.
