A chassis-dyno measures HP at the wheels using (usually) a rotating drum.....to get actual engine HP on a GM RWD vehicle you multiply that number by 117% (GM's 4L60-e tranny has a 17% driveline loss...20-22% on the 4L80-e) to get actual engine HP

h777's lower numbers are corrected numbers, what that means is: On a dyno they measure the power at the wheels, this would be the raw numbers. The numbers are then SAE corrected to a set temperature/elevation setting. On a cold day at sea level, the raw numbers would most likely be corrected downwards, since the reading will be high. On a hot day, the the raw numbers would be lower, so they are corrected upwards. corrected numbers are the REAL dyno numbers

 

Dodge is supposed to release a new computer for these hemi engines, like $1200 but comes with a new set of injectors. I know 1/4 mile wise when my truck shifts at 5800 out of 2nd into 3rd, it goes down to 3700 and barely gets to 4 grand, you can feel the bog and more than likely being drive by wire with that electronic throttle bullshit I would imagine that is not opening up. This truck runs totally different from 50mph and up vs a dead stop. The computer limits it big time.


Talking about the design of the engine, the heads on this hemi flow just as good as yalls LS6 heads. if dodge would have used a MAF and LS1 style computer things would be very very fun

 

That's what I say, but most car/truck people say that the speed density set up is easier to tune the the MAF set up....go figure.

 

I have heard that too and looked into it, to me on paper that is right. You can basically tune speed density for anything, you just keep playing with it, at some point to reach the max of the maf and what it will do, then its time for some upgrades. But the LS1 style computer set up appears to do what 90% of the owners wanted, handle 400, 500 and 600hp with someone that knows how to tune. The computer is the biggest thing I hate about the Dodge stuff know, I owned an f body, and damn was it easy to mod and get results

 

The dyno numbers KB got are pretty normal for stock Hemi motors. Yes, there is a HUGE powertrain loss and we owners went thru hell trying to figure out why. We even sent a petition to DC, begged, pleaded, offered sacrifices, etc. DC remained mum. 265 rwhp, 300 rwtq is about the norm for most everyone. Again, this is bone stock. KB also did an engine dyno test that came out very close to the factory numbers ( 340 hp 365 trq vs DC 345 hp 375 trq ).
H777 also pointed out the tranny for the Hemi engines, it is different than the regular motors. It is a 5spd tranny built by Mercedes-Benz that has proven very reliable so far, especially compared to the previous Dodge offerings.
Overall, yes there is a larger than normal drivetrain loss on the Hemi equipped vehicles. Engine management is mostly to blame. 1/4 mile performance is improved by removing the torque management system for an immediate 0.3 seconds. This is not realized by a dyno. Also, the 5 spd tranny is hard to get good dyno readings on due to the close ratios. 2nd is too low, 3rd is a little high.
H777 has put a lot of time and work to improve 1/4 times and overall power increases. We just have to go about it a little differently than the GenIII crowd.