I think the 07s are rated 230 at the crank for the 4.7 non-HOs and 260 for the HOs. I am not sure on the whp, I would guess 10-15% less than the crank, so 195.5-207whp for non-HOs and 221-234whp for the HOs
Vehicle: '06 Dak Laramie QC 4x4 4.7HO 2" level and 1.5" rear block. 265/65/17 Hankook Dynapro AT/M
Location: Arizona
Posts: 159
hmm...I remember seeing all the differences the HO engine has as compared to the 'regular' 4.7. Not sure if it was this board or another. I will have to see if I can find it. I think I remember different cams though.
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If it aint broke...take it apart anyways to see how it works! - '06 Dak Laramie QC 4x4 4.7HO - 2" leveling w/ 1.5" blocks - 3.91 lmtd slip - 180 t-stat - 265/65/17 Hankook AT/M
**1986 Seaswirl Topaz 20' w/ Chevy 305**
Was the only difference in the HO headwork? I looked up cams, and they are identical part numbers. Same with intake manifolds.
I guess the Cams could be the same part number with different grinds.
I guess what I am asking is, where is the extra 30 HP coming from. (I have to believe its cams.)
Engine differences from the 4.7l to the 4.7l H.O. (taken from wjjeeps.com):
Block: Detonation sensor bosses in the valley
Camshaft: Custom profile lobes (designed for increased performance)
Connecting rods: Modified, with floating wrist pins (vs pressed-fit pins in standard 4.7)
Crankshaft: Forged steel (vs cast iron in standard 4.7)
Crankshaft damper: unique to H.O.
Cylinder heads: different shaped combustion chambers (for improved airflow). The letters "H.O." are cast on the front end of the heads.
Fuel injectors: higher flow (+3.3 lb/hr)
Intake manifold: modified (shorter runners)
Intake: low-restriction intake system (different resonator, air filter, air filter hose and housing)
Knock sensors: two, stereo
Main bearings: tri-metal (vs bi-metal in standard 4.7, designed specifically for the HO engine)
PCM calibration : unique programming
Pistons: dome shaped for increased compression ratio
Spark plugs: platinum tipped
Valves: unique exhaust valves (same lift as standard 4.7)
Valve springs: upgraded valve springs (intake & exhaust. Larger diameter wire and more coils)
Keep in mind that this list is compiled for the 4.7HO used in the Jeep Grand Cherokee's and there may be some differences in ours. I would expect it to mostly be the same though.
Well those other differences would also help the HO accept more power adders without changing the internals. Put it this way: I wouldn't want to try running the amount of boost Blown is running on my non-HO without upgrading the internals.
Billy, I've been reading that about 20% of the horsepower is lost, due to the automatic trans, and the drivetrain length... so you're looking at more like, 165hp at the wheels...
I put down, 197 in mine, and that was just with the intake and no mufflers... and that's with the manual... I know you're not putting down manual numbers with a dodge's automatic transmission...
There is NO way that's happening...
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Quote:
Originally Posted by osufans
you can think of the economy as the "g-spot", and congress just spent $790 Billion on a huge vibrator...
[Red Truck Club #11][Lower Class Club #23][Manual Truck Club #3]
Billy, I've been reading that about 20% of the horsepower is lost, due to the automatic trans, and the drivetrain length... so you're looking at more like, 165hp at the wheels...
I put down, 197 in mine, and that was just with the intake and no mufflers... and that's with the manual... I know you're not putting down manual numbers with a dodge's automatic transmission...
There is NO way that's happening...
Let's say it is 20%. Then....
Frenchy we need to get you a math tutor son... a 20% reduction to 230 is not 165 hp, its 184 hp. I'll tell ya this summer what shes getting. I plan on Dynoing it with and without the tuner. All thats been done is the intake and the exhaust. So we will see... in the mean time study hard
I dont think that our gens HO is the same as that. I know for a fact our intake manifolds are identical. they have the same same stamping and part numbers. there is no way they are different.
that may have been the case for the previous gens 4.7 but if you were to go to KRC or Airram and look at the most current intake manifolds, they are the same. the new 4.7 has shorter runners though.
