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Old 12-26-2009, 09:11 PM
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Join Date: Dec 2009
Location: Colorado
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Vehicle: 2004 Dodge Ram RC 4x4
Trim Level: SLT Sport
Color: Silver
Engine: 2003-2008 345ci (5.7L) Hemi V8 345hp 375lb/ft
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Quote:
Originally Posted by HEMI5150 View Post
wow, thats very misleading of dodge... they should be more specific how they got those numbers..!!!!
Most of us engine builders know that hp/trq at the crank dont meen sh*t...
its what gets to the ground is whats important

Oh well, i like my 2010 RT pretty good so far... BUT it does have ALOT of noise issues that i dont like (tranny noise issues)
How is that misleading? All auto manufactures rate their vehicles HP at the crank, which is BHP. This also does not include the accessories that the engine turns, e.g. alternators, A/C compressors, etc.

Now, we as the consumer test the said HP via a chassis dyno, which reads at the tires and use somewhat of a broad range or % to determine the amount of loss there is between the flywheel and what it is actually putting to the ground. Manual transmissions eat up less power than automatics, so, depending on the setup, you can lose anywhere from 12-20% through the drivetrain.

All we care is about what it makes to the ground along with the correction factors and conditions in which the vehicle was dynoed in. Most stock 09 HEMI rams rated at 390hp will put down around 300-310 stock at the wheels. Now, these numbers can also vary with what dyno you're using. Mustang or inertia dynos tend to be a little lower than the more common dynos, like a dyno jet.

Dyno's are best for tuning and ensuring everything like timing, air to fuel ratios, etc are safe. The real test to see what power you are making is at the track. Trap speed based of weight of vehicle is a good indication of HP, the E.T. is the indication of how well and efficiently it puts it to the ground.
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