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Discussion Starter #1
We recently bought a boat, and have been towing it with my 06 4.7.

Now, I am Coming from a nissan 4 cylinder(drove for 15 years), so I feel like the V8 does "just fine" :) JUst NO oomph when accelerating at highway speed...maybe I expected too much?

Towing MPG is pretty dismal(12.5), but thats life really...

Are there any tips/tricks to better make it NOTICEABLY better?

I was thinking one of those cold air intakes would help a bit, and a better flowin muffler....?

Id like more guts, but i wont trade towing MPG's for it...bad enough already LOL

any advice/recommendations? :D
 

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We recently bought a boat, and have been towing it with my 06 4.7.

Now, I am Coming from a nissan 4 cylinder(drove for 15 years), so I feel like the V8 does "just fine" :) JUst NO oomph when accelerating at highway speed...maybe I expected too much?
Yes you could say that. These days with emission requirements the V8's are really toned down.

What size is the boat? If it's a aluminum fishing boat with a light trailer,
you shouldn't be seeing much difference in power between no tow and
towing, but a cabin cruiser cruiser with a class II? hitch adds weight
and chances are you are not getting into O/D that much, so if you are
towing the boat in 3rd gear on the automatic a lot, the gas mileage will not be that great..
but...
Towing MPG is pretty dismal(12.5), but thats life really...
That isn't very good on flat ground. I can see if you were in the hills
and the transmission was dropping into 2nd and 3rd. What is the
normal MPG?

Are there any tips/tricks to better make it NOTICEABLY better?

I was thinking one of those cold air intakes would help a bit, and a better flowin muffler....?

Id like more guts, but i wont trade towing MPG's for it...bad enough already LOL
To get more h/p out of that engine, you really need a different cams,
a performance cams actually and different manifolds. The HO version of that engine would be what you are probably seeking, but not sure about the gas mileage.

Here's all the extras on the 4.7L HO (High Output) V8...
http://www.wjjeeps.com/ho_engine.htm

The HO engine was discontinued in the Grand Cherokee at the end of the 2004 model year. The all-new 2005 model Grand Cherokee's offered the new 3.7 V6, the standard 4.7, the 5.7 Hemi and the new 6.1L Hemi SRT engines.

Starting at the end of the 2005 model year, the 4.7 HO engine became availble in the Dodge Dakota.

Quite a few Dodge truck owners have successfully installed the manifold and cams into their standard 4.7 engines without any major problems.
Most have reported horsepower gains from 5% to 15%, varying at different RPM's. Anyone interested in doing this upgrade or learning more about it should visit the message boards at DodgeDakotas.com and search through the HO related posts.
The Mopar Manifold/Cams kit is available from Multitronics ("Kolak")

Ok, putting aside the hundreds required to upgrade the standard 4.7 on the Dakota to get more power out of it with new manifolds and cams,
which is a BIG rebuild job as well.... what can be done with the standard mediocre factory 4.7 to get more "oomph out of it but retain the current fuel mileage.. (without towing stuff off course)

1. Install a K&N air filter (a better filter than the standard paper filter),
ok a cold air intake kit
2. Better plugs (platinum NGK)
3. Try a better grade of fuel (mid grade) midgrade has more octane than the
standard 85 octane fuel and should develop more power in the engine
While mid-grade may cost a few cents more, in fuel grades, you do get
what you pay for.
4. If you are going for a low restriction muffler though, as a certain amount of
backpressure is required in the exhaust and you still want to have
the cat on to pass emissions.

But the factory 4.7L is detuned on purpose, so even with all the above
you would only probably see a marginal improvement in power after
installing all the above..you really need to change the timing curves for
the ignition and injectors to get that extra power out of it.

5. If you don't live in the state of California, you could also consider installing a performance Chip upgrade ( like Jet Stage 2 performance module) or others
described on this board.

These are easily installed onto the PCM.
However with that extra performance, your MPG WILL also drop...it's the other side of the coin unfortunately. You mention that you are already in the high fuel consumption (12.5 mpg)category, so you don't want to drop too much below that
either when towing.

http://www.autoanything.com/performance-chips/61A1777A0A0.aspx
 

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A superchips tuner may help with towing. There is a 'Tow Tune' program that can be loaded, as well as other tunes that come along with it. Our 4.7's use the Superchips 3865 programmer, or Cortex 3950 (same as the SC 3865 with a warranty). I have the SC 3865 and it really wakes up the engine.

Superchips (It's cheaper on other sites, such as Amazon.)

Another option is a gear change, either 3.92, 4.10, or 4.56, but this will negatively affect you MPG's.
 

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Discussion Starter #4
right on...

few things in response:

boat is about 2000 lbs and it was a little hilly. I'm getting 15-16 ish average mpg. no tow.
I use 87 fuel, and Iowa could give two $hits less about emissions LOL

So not interested in rebuilding the motor(cams) for more power....

My thinking was: free up intake and exhaust, like I do on quads...maybe less throttle needed to get torque.....figured it was a long shot. Power kills efficiency, i get it.

Aside from better spark plugs, and maybe air filter, Ill Probably stay stock, but....figured Id ask.

thanks again folks!
 

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right on...

boat is about 2000 lbs and it was a little hilly. I'm getting 15-16 ish average mpg. no tow.
I use 87 fuel, and Iowa could give two $hits less about emissions LOL
So not interested in rebuilding the motor(cams) for more power....
full story on the 4.7L here..
http://www.allpar.com/mopar/47.html

In 2005, these were estimated between 14 city/18 highway..but this kind
of mileage would be under ideal conditions..not on hills and with the 0/D
in. I'm getting about the same with my 5.2L previous generation Magnum,
so these engines were never designed as terribly fuel efficient in the first
place. Coupled up to a 3 speed automatic, in the city, you can expect
less than 14 mpg because you never get into O/D long enough to drop
the rpms down.

My thinking was: free up intake and exhaust, like I do on quads...maybe less throttle needed to get torque.....figured it was a long shot. Power kills efficiency, i get it.
IMO, you can spend a hell of a lot of money to squeeze out 1 or 2 extra
MPG with these old tech engines. In the end, you have to ask yourself..
was the <hundreds I spent on tuning, exhaust etc> really worth the extra
horsepower I gained or the little bit of gas that I saved?

If you are interested in more efficient engines, then you need to look
at the newer design trucks, where the engines are designed for better
fuel economy and power...Like the RAM 1500 5.7L Hemis with MDS technology V8 that switch from 4 cylinders to 6 to 8.
http://www.chryslercanada.ca/en/tech_hemimds.php

Aside from better spark plugs, and maybe air filter, Ill Probably stay stock, but....figured Id ask.
That's what I would do.

Others may disagree with my opinion here..but..
I think with that older design V8, you are going to have to "squeeze it" a LOT
to get any more HP out of it, yet maintain even the fuel economy you have now.

It's just not cost effective to spend that kind of money on it,IMO.
Better to trade it in on one of the newer models that do have more power and better fuel efficiency as well.
The compression ratio (9.5 to 1) and the rpms that you need to wind it up
to get any reasonable power out of it (230hp at 4600rpm!), the fuel injector program curves and the design of the combustion chamber just doesn't make this a good candidate for spending a lot of money on...even with Superchips.

Other than spark plugs and air filter, there really isn't much more you can
do to these engines to make them "haul".
You can't fiddle with anything on these without changing the stock PCM programming..
and even if you did, that would still require a lot of trial and error to get "it right". :D
 

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Discussion Starter #6
much obliged for that very informative response. :)


"IMO, you can spend a hell of a lot of money to squeeze out 1 or 2 extra
MPG with these old tech engines. In the end, you have to ask yourself..
was the <hundreds I spent on tuning, exhaust etc> really worth the extra
horsepower I gained or the little bit of gas that I saved?"



I am a realist, you are speaking my language.....
 
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