Engine 2007 4.6 power mods?

7991LXnSHO

wanna catch the space herp
10 Year Member
Sep 1, 2010
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Kearney, NE
I have a 2007 4.6 (in a Merc Grand Marquis) that I wonder if there are budget friendly and effective power mods for. 27 MPG on the highway is great for a something this roomy and comfortable, but I want to know if there is more power in it.
I hope the Mustang gurus of the same year here are the ones to ask what can be done since the Panther body forums are more about better handling. A DIY Maurauder or Teminator engine swap would be great, but is not in the range of my budget or workspace.
SO - what is worth doing to a Mustang 4.6 2 valve engine, and can it be done on the Merc’s engine, too?

What I have seen so far -
Going with dual exhaust and a police computer or tune is only 10 hp, and that does not seem like much for the money unless I already need exhaust work. I’ve read about a different MAF and air box, (off a Navigator?) and again, a tune.
So, is there another intake and throttle body worth changing to? Headers?
And what or who does it take to reprogram the 2007 OBD2 computer?
I would like to confirm the engine has the performance improvement heads and intake from the factory.

Thanks for helping me learn something beyond EEC IV and OBD1.
 

EmmJay

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Jun 16, 2019
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Do a tune and differential gears. I don't know what gears are stock for your car but 4.10s, or even 4.56s, is what I recommend. The tune will give you some power and recalibrate the speedometer/odometer from the gear swap. Gears work great for improving acceleration. You will lose a little mpg but it is worth it, IMO. Then throw in any other mods you want to do before getting the tune done.
 

MustangIIMatt

Easy there, this ain't a dating site.
15 Year Member
Mar 7, 2002
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I have a 2007 4.6 (in a Merc Grand Marquis) that I wonder if there are budget friendly and effective power mods for. 27 MPG on the highway is great for a something this roomy and comfortable, but I want to know if there is more power in it.
I hope the Mustang gurus of the same year here are the ones to ask what can be done since the Panther body forums are more about better handling. A DIY Maurauder or Teminator engine swap would be great, but is not in the range of my budget or workspace.
SO - what is worth doing to a Mustang 4.6 2 valve engine, and can it be done on the Merc’s engine, too?

What I have seen so far -
Going with dual exhaust and a police computer or tune is only 10 hp, and that does not seem like much for the money unless I already need exhaust work. I’ve read about a different MAF and air box, (off a Navigator?) and again, a tune.
So, is there another intake and throttle body worth changing to? Headers?
And what or who does it take to reprogram the 2007 OBD2 computer?
I would like to confirm the engine has the performance improvement heads and intake from the factory.

Thanks for helping me learn something beyond EEC IV and OBD1.
Just a heads up, your 2v 4.6 in that Grand Marquis is actually almost identical to the 99-04 Mustang 2V engine and shares very little beyond the short block with the 3V engine found in the 2005+ Mustang. I'm going to move this thread to that section.
 

7991LXnSHO

wanna catch the space herp
10 Year Member
Sep 1, 2010
7,379
3,082
194
Kearney, NE
It has been too long since I researched this, so that’s why I am asking. I left it stock under warranty and got busy afterwards. Maybe I can get some two valve ideas now in the right place.
 
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