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Old 05-29-2013, 02:57 PM
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where's the extra 30 or so HP on the 5.7L?

Hi,

I'm sure this has come up before, and I know people hate it when (what I'm fairly certain is a) commonly asked question comes in a slightly different way, but I'd appreciate very much someone taking a minute or two to summarize it. Thanks in advance.

The Hermi in the '12 seems to be down 30 or so HP from other Hemis (e.g. those found in the Ram).

1. What is the reason why, in a nutshell (compression ratio/exhaust/engine computer/etc)?

2. What's the easiest (*) way to get most if not all of it "back"?
(*) By easiest, I mean: most cost effective and least intrusive (e.g. I don't want to install headers or a full exhaust system and I'm not looking to install any serious aftermarket equipment like a supercharger ... you see where I am going with this).

I know the 2nd question above question isn't black and white and opinions will weigh into it, I don't mean to stir up any controversy with the question, just looking for solid numbers and experience.

I have ditched the stock air intake, already, for a K&N cold air kit and have a JET ECM module installed, they each made a small incremental difference in response but I do feel that there should be more from this engine given what it can do in other vehicles.

Thanks in advance.
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Old 05-29-2013, 10:36 PM
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Re: where's the extra 30 or so HP on the 5.7L?

I believe most of the difference is how it's tuned from the factory, intake/exhaust/header routing etc. Intake, exhaust, tuner. Headers would definitely help, but I would dump the JET and go with the Hemifever tune. Do a search, it has canned tunes and then you can datalog and he will customize your Jeep specifically, i.e. for your intake, if you have an exhaust, etc. Do a search, I remember seeing a Ram vs Jeep Hemi thread on here too. Search for the Hemifever too...I'll be doing it for my charger as the wife doesn't want me messing too much with her Jeep, she said the intake was enough...party pooper
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Old 05-29-2013, 11:43 PM
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Re: where's the extra 30 or so HP on the 5.7L?

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Originally Posted by joenjulie View Post
I believe most of the difference is how it's tuned from the factory, intake/exhaust/header routing etc. Intake, exhaust, tuner. Headers would definitely help, but I would dump the JET and go with the Hemifever tune. Do a search, it has canned tunes and then you can datalog and he will customize your Jeep specifically, i.e. for your intake, if you have an exhaust, etc. Do a search, I remember seeing a Ram vs Jeep Hemi thread on here too. Search for the Hemifever too...I'll be doing it for my charger as the wife doesn't want me messing too much with her Jeep, she said the intake was enough...party pooper
Hi,
Thanks. I've read something about this but honestly it seems a bit far fetched that the header is the much different. I have both a ram and a JGC both with the hemi and it just doesn't seem plausible when you remove the covers and look at both that there could be that much difference. It seems that many responses are speculative around is topic, how can we get to a more definitive answer?
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Old 05-30-2013, 09:25 AM
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Re: where's the extra 30 or so HP on the 5.7L?

I don't think we'll get a straight one from Fiat...I drove a Ram quad/4x4/hemi 2 weeks ago and it seemed to just have more power. I remember driving an 09 commander that seemed to have a lot more ass than my jeep. I realize the Jeep has gotten heavier over time, but with my 3.73 axle, the power it has it should MOVE OUT, I can't see the four wheel drive sapping that much power vs a 2 wheel drive truck. Oh well, my new charger r/t seems to have all 370hp/395tq when I stomp it, so another example of same motor, different power, and reacts totally different when whipped in the behind.
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Old 06-01-2013, 04:05 PM
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Re: where's the extra 30 or so HP on the 5.7L?

Hi,

Everyone keeps talking about hemiever tunes, but, it seems that it's just a modified Diablo program.... is there really a difference between that and the standard diablo tune?
Thanks.
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Old 06-02-2013, 12:28 AM
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I recently purchased the diablo I-1000 for my '05 limited grand, combined with a BBK 85mm tb & Airraid cai I think she's got a little more pull off the line & into the red! It's a great setup I highly recommend looking into simple bolt on's or plug in's like these.
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Old 06-03-2013, 09:49 AM
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Re: where's the extra 30 or so HP on the 5.7L?

The Hemifever sends you basically a Diablo, then you data log and send it back to him and he'll modifiy it and write a "custom" tune for you based on the data. Also, if you have a CAI/Exhaust/etc he can tune for that as well. Much better than just a canned tune. I'm going to look into it, but now with the new charger, it's getting "done up" first.
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Old 06-03-2013, 12:31 PM
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Re: where's the extra 30 or so HP on the 5.7L?

its basically the intake manifold on the Rams are different. Jeep went with a lower profile intake manifold due to hood clearance and it cost them some horsepower.
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Old 06-04-2013, 08:30 PM
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Re: where's the extra 30 or so HP on the 5.7L?

Hi,

Help me understand the real increase of the hemifever tune compared to the regular i-1000-dcx diablo tuner? The i-1000-dcx costs $400 brand new on autoanything.com and the hemifever option is 490$. I can't find anything that points to any discrete differences.... is it really worth the extra 90 bucks on a '12 JGC?
I am running 89 octane with no real ambition to go to anything better...
Thanks
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Old 06-05-2013, 07:12 AM
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Re: where's the extra 30 or so HP on the 5.7L?

Quote:
Originally Posted by Scottina06 View Post
its basically the intake manifold on the Rams are different. Jeep went with a lower profile intake manifold due to hood clearance and it cost them some horsepower.
Hi

How can the bigger srt engine make the same power as the other applications (challenger, 300, etc) but the smaller 5.7 be a victim of size constraints? This just doesn't make sense to me.
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Old 06-05-2013, 11:06 PM
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Re: where's the extra 30 or so HP on the 5.7L?

Quote:
Originally Posted by Scottina06 View Post
its basically the intake manifold on the Rams are different. Jeep went with a lower profile intake manifold due to hood clearance and it cost them some horsepower.
Correct.

The pickup intake is huge and has a big tuning valve inside. The tuning for this would be different obviously. The cam is different accordingly.

Some years there are up to 6 differnt cams, tune and HP rating depending on application.



Mikeoz- part of the reason the SRT engine went from 6.1 to 6.4 is due to the truck 5.7 making almost the same power.
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Old 06-22-2013, 01:19 PM
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Quote:
Originally Posted by Scottina06 View Post
its basically the intake manifold on the Rams are different. Jeep went with a lower profile intake manifold due to hood clearance and it cost them some horsepower.
If there is so many clearance issues why are guys able to put intake spacers, adapters & 6.1L intake manifolds which obviously sit way higher than the plastic oem 5.7L intake that everyone hates including myself... Stupid plastic crap needs to go!
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