2003 P71 Performance Questions

I am seriously thinking about adding some more grunt to my P71. I am a little confused about some items and am looking for some input. I only want to spend the money once to get a good combo.
What I really wanna do is buy a 2003-04 Mercury Marauder motor, but finding one is really hard since they are so rare, and plus I live in a rural part of Canada making them even rarer...lol. Anyway...here goes.

1. I am fairly sure that the 2003 P71 came factory with PI(performance improved) heads and plenum/intake. I have been looking to replace my heads for a while due to spark-plug blowout problems. I have heli-coiled the plugs that have popped out(3), but I wanna replace the heads outright and get some added power. I have been looking at getting some factory 2003 Mustang GT(SOCH) heads that are fully assembeled with the valvetrain and cam. Will the Mustang heads be any better than what I already have?

2. I want to put on a 70mm throttle body. Heck I have no idea what's on the motor right now so I am wondering if this is an upgrade, or just replacing the same thing that I already have?

3. Porting the upper intake plenum.

4. Removing the 3.27 gears and replacing with 3.55 gears in the rear.

5. 2004 P71 zip tube - Have considered the MArauder Map and airbox swap, but I have not found anyone locally to reprogram the computer for the upgrade.

6. Kinda expensive, but installing shorty headers and hi-po cats with 2 1/4 exhaust front to back with hi-po mufflers.

Maybe I'm crazy, but I want to try to make my car run like stink without putting the motor on the gas/nitro. I find it hard to find info and parts for the Crown vic to satisf my desire. I have been to the Angry Duck Tofu Racing site. I e-mailed to asked if they sell and deliver to Canada, but no answer so far. Anyone dealt with them before?

Thanks for taking the time to read this long and crazy list of ideas.:screwy:

Paul

I am seriously thinking about adding some more grunt to my P71. I am a little confused about some items and am looking for some input. I only want to spend the money once to get a good combo.
What I really wanna do is buy a 2003-04 Mercury Marauder motor, but finding one is really hard since they are so rare, and plus I live in a rural part of Canada making them even rarer...lol. Anyway...here goes.

1. I am fairly sure that the 2003 P71 came factory with PI(performance improved) heads and plenum/intake. I have been looking to replace my heads for a while due to spark-plug blowout problems. I have heli-coiled the plugs that have popped out(3), but I wanna replace the heads outright and get some added power. I have been looking at getting some factory 2003 Mustang GT(SOCH) heads that are fully assembeled with the valvetrain and cam. Will the Mustang heads be any better than what I already have?

The GT heads are exactly the same as what you have. Try "Time Serts" next time, they work WELL.

2. I want to put on a 70mm throttle body. Heck I have no idea what's on the motor right now so I am wondering if this is an upgrade, or just replacing the same thing that I already have?

Replacing the TB with a larger one will gain you nothing at all. Works on some vehicle models, but not these.

3. Porting the upper intake plenum.

Pointless, lots of people do it, none can PROVE it adds any power at all, and can reduce Tq. My advice, DON'T.

4. Removing the 3.27 gears and replacing with 3.55 gears in the rear.

I had 3.55s in my '99 CVPI, and took them out in favor of the 3.08s. There is virtually ZERO measureable difference between the 3.55 and 3.27 RAR. I would NEVER suggest anyone swap one for the other. You will not really notice any change - except your pockets will be lighter.

5. 2004 P71 zip tube - Have considered the MArauder Map and airbox swap, but I have not found anyone locally to reprogram the computer for the upgrade.

The MM MAF/Airbox IS the mod to make. Contact Lonnie at www.blueovalchips.com, he can get you the programming you need.

6. Kinda expensive, but installing shorty headers and hi-po cats with 2 1/4 exhaust front to back with hi-po mufflers.

Save your $$$$. Unless you REALLY increase the engine's RPMs (which WILL hurt the trans), you will gain little to nothing with this. The mufflers are NOT a restriction on a Panther with factory duals.

Maybe I'm crazy, but I want to try to make my car run like stink without putting the motor on the gas/nitro. I find it hard to find info and parts for the Crown vic to satisf my desire. I have been to the Angry Duck Tofu Racing site. I e-mailed to asked if they sell and deliver to Canada, but no answer so far. Anyone dealt with them before?

Thanks for taking the time to read this long and crazy list of ideas.:screwy:

Paul

Chris at ADTR is a really good fellow, but Lonnie at BlueOval Chips is THE guy to help your car the most with the tuning parts. Chris at ADTR offers the MM parts, and combined with Lonnie's tune, you can expect to gain some noticeable power.

I had 3.55s in my '99 CVPI, and took them out in favor of the 3.08s. There is virtually ZERO measureable difference between the 3.55 and 3.27 RAR. I would NEVER suggest anyone swap one for the other. You will not really notice any change - except your pockets will be lighter.

Funny that you say that, I have a 92 Marquis with 3:55 gears and 265,000Km, 94 Vic with 3:08 gears and 130,000km, a 97 Vic with 3:27 gears and 145,000 km. The gas mileage is worse on the 94 then the other two in the city, not sure on the highway as I don't do much highway driving with the 94, but the 97 and 92 are about the same. The 92 and 97 also have better pickup then the 94.

just buy a mustang if you want more power

A '92 CV with 3.55s? They are not stock.

They are stock, 92 Grand Marquis with HP, axle code 2. 3:55 gears were offered until 2003 when only 2:73 or 3:27 where offered. In 1998 to 2002 2:73, 3:27 3:55 were an option. From 1983 to 1997 2:47, 2:73, 3:08, 3:27, 3:55 were an option.



A '92 CV with 3.55s? They are not stock.

They are stock, 92 Grand Marquis with HP, axle code 2.

Axle code 2 is for 3.55s, your car must have Trailer Tow or HPP during one of the two years 3.55s were avaialble prior to '99.

3:55 gears were offered until 2003 when only 2:73 or 3:27 where offered.

The 3.55 RAR was available only in Town Cars with Limo Prep package (some years), or the CVPI/HPP/Town Car "Touring" edition for 18 months from '99 to mid '00. The 3.55 RAR was made available again in '04 as I recall, in the CVPI only for Urban use (city cars).

In 1998 to 2002 2:73, 3:27 3:55 were an option.

That is incorrect, the 3.55 RAR was unobtanium from mid '00 thru '03 EXCEPT for the '03/'04 Marauder.

From 1983 to 1997 2:47, 2:73, 3:08, 3:27, 3:55 were an option.

The 2.47 RAR has not been available since AT LEAST 1991 in any commercially avaialable Panther. The 3.08 was common on the Town Car, and Aero CV/GM cars thru the '94 MY, after which is was Town Car only due to NVH. No axle ratio was NEVER an optional RAR until '04? with the CVPI where you could choose either the 3.27 or the 3.55 depending on it's intended use. You get whatever ratio Ford puts in it, this has been true since the 1992 MY. Different "packages" do include alternate RARs, but you cannot choose which one.

You are right, my 92 grand marquis has both HPP and Trailer Tow, The only thing it did not get ordered with was a heated windshild and leather seats.


[QUOTE=ModMech]Axle code 2 is for 3.55s, your car must have Trailer Tow or HPP during one of the two years 3.55s were avaialble prior to '99.

just buy a mustang if you want more power

Sorry, not interested in pony cars. I lover of full size muscle. :grinyes:

Replacing the TB with a larger one will gain you nothing at all. Works on some vehicle models, but not these.

What models does it work on? What does the model have to do with the engine performance at the throttle body?

Is there a speed limiter on the 1999 P71?
Also, i hear a clunk when i turn the fan on after the car has been running for a minute or so after starting. Any ideas?

The 3.55 RAR was available in 2003 in the CVPI. I have one. Only available as a traction lock/limited slip. Not available as open type with electronic traction control according to the fleet ordering options sheet for 2003. I would not bother with a rear diff swap either. The Marauder air box/maf/zip tube/chip tune is about the cheapest and best performace mod you can make without going hog wild. If money is no object, how about an AED blower with +4 boost, any more and you will need to build the bottom end of the motor. As for the clunk when you turn the fan on, I assume you are talking about the ventilation system. I would bet a sticky air door and the fan pops it open with airflow or a slow vacuum controlled air door switch.

Personal tip. I know it might sound weird, and yes, you might be losing comfort (ac, etc). If you really want performance, and yes, you can laugh at this, but have you thought about swapping motor to built crate carbuerated engine? It's simple. cheap, and what the hell. No sensors to deal with! A 351 cleveland sounds great. I don't quite know about engine mounts, and i'll have to look into that.

I have gone on to modify my Crown Vic since I started this thread. I have had a lot of success. I really feel a difference in the accelleration of my car,..especially off of idle from a standing start. I estimate 270 hp at the flywheel.
List of Mods
-Steeda underdrive pullys 2003 mustang gt
-Airaid throttle body spacer 2003 mustang gt
-Steeda intake manifold spacer
-2.5" dual exhaust from the cats back with h-pipe
-Vortex mufflers
-2.5" tailpipes into 3" tips
-NGK TR5 sparkplugs
-MSD coils 2003 mustang gt
-polish inside of upper intake tube
-polish inside throttle body before the throttle-plate

I own 2 crown vics, a 2003 p71 n a 2008 p71. I have tinkered with my 03 alil n im almost running with newer mustangs. I had Superchips build me the 1st Cortex Superchip 4 a crown vic http://www.automotiveforums.com/vbulletin/images/icons/icon14.gif which works great, lovin it. I also built a custom 4" intake tube which leads 2 a 4" by 10" Spectre filter that really helped it breathe. I have a Helix throttle body spacer and looking add n Accufab plenum n throttle body with a plenum spacer. Im saving up right now 2 install 4:10 gears n a posi rear 2 turn 245/55/16. Id like add undrdrive pulleys n some sort of quiet performance exhaust. Does anybody have any ideas on what would work?