Jeep Commander Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter #1
I have read a ton of post from the dodge guys about swapping out Cams and header to turn the 4.7 into a 4.7ho. It is a significant increase in HP and TQ. Anyone know if this 4.7 can be upgraded?
 

·
Registered
Joined
·
6 Posts
Discussion Starter #3
Well

It does not make much sense. They are both the same 4.7 block at the foundation, what changed to jump 70 HP?
 

·
Registered
Joined
·
2,473 Posts
The 2008 4.7L includes:

  • dual spark plugs per cylinder (like the Hemi)
  • increased compression
  • better cylinder-head port flow
  • and a new combustion system
  • as well as new ethanol-content calibration system to better handle E85
 

·
Premium Member
Joined
·
2,337 Posts
So how do we have the more reliable motor? I'm guessing its because it doesn't have any of these new changes but I could be wrong.

We could probably incorporate some of the Dodge upgrades for trucks, especially for power and fuel delivery. I'd love to get the supercharger for the 4.7, just don't have the cash for it right now.
 

·
Registered
Joined
·
147 Posts
What can we do to reliably increase the efficiency/power of the stock 4.7? 235hp out of 4.7L V8 is pretty low considering the 3.7L V6 makes 210hp. An intake and exhaust are good for about 10-15hp, but only at higher RPMs? What's the best chip/tuner out there? I think a sticky needs to be made about this subject.
 

·
Banned
Joined
·
3,374 Posts
there isn't much out there for the jeep GC or commander 4.7.

here are the legal things you could do.

there are headers for the 4.7L dakota. they might fit the commander. but the rest of the exhaust would not be bolt on.

there are 2 tuning chips made. a stage one you can still run cheap gas. on stage 2 you have to run premium.

the intake after the throttle body is pretty well designed. its poly and probably flows very well.

the intake piping is pretty easy to upgrade. the exhaust is also easy to upgrade.

the illegal things you could do.

remove the cats. they are usually good for 10-15 hp. i saw a dyno test on a V6 nissan 300zx where it tested how much power you can get from removing the cats.

emissions stuff. there isn't much on the newer engines. it seems like most of it is now controlled primarily through the computer with the O2 sensor. my old 300zx had about 20 different things to control the emissions. and about 30% of the crap under the hood on that car was emissions controls.

thats about all i can thing of right now.
 

·
Banned
Joined
·
3,374 Posts
another thing. the horsepower is low because in trucks there is more of a need for torque to get things moving.

i personally would have more torque from the 1000 rpm range through the 3500 rpm range.

i think the 4.7L is a pretty good motor. its designed well. i have driven jeep grand cheerokees with 150K on them and you couldn't tell the motor had that many miles on it. they are pretty reliable and powerful. they respond well to little upgrades like intake and exhaust.

i put a new foam style air filter and plugs in my jeep. it really helped it out. my mileage went up as well. i'll be doing the exhaust this year sometime, and i'm looking forward to the changes.
 

·
Registered
Joined
·
147 Posts
What kind of power would the legal ideas make. . .(chip + exhaust, chip + headers + exhaust)? I threw in a K&N filter so I could keep the stock water protection and don't have much desire to change that one.
 

·
Banned
Joined
·
3,374 Posts
i have no idea without an actual dyno test. most of the testing is seat of the pants.

i would imagine 10-20hp over stock with an intake and exhaust system.
 
1 - 11 of 11 Posts
Top