pi motors

[fast97gt]

ok im extremely pissed right know, my buddy has a 2001 gt 4.6 with almost the same mods as mine. i rode to the parts house with him in his car, starts in first rolls into 2nd gets to round 2grand and nails it, the car gets stupid crazy. at this point im jealous my car with the pi motor pulls and runs like hell but dont do nothing like his just did. he has the same gear, motor, tranny, ud puleys, 75mm tb and accufab upper plenum. all 2.5in exhaust, the rear tires are 275/60/15, mine 285/40/18s both are street radials. i can barely get mine to bark 2nd, let alone smolder the rear tires. the only thing mine doesnt have that his does is the tb, and tune. what gives anyone know. will the tb and tune make that big of difference.

 

[ninjastang125]

Tunes make a big difference. I picked up a whole mph with my tuner just sending me a canned tune for my cams.

 

[Deleted member 38176]

Im confused about something here....

You mentioned that you have a 4.6L 2V out of a 2005 Crown Vic right? Is the motor exactly as it was in the Vic or did you swap the heads, cams, etc? I ask because the 2005 4.6 2V's in the Crown Vics are rated @ 224HP and 275TQ. Thats basically equal to an NPI 4.6 2V.

....and the tunes on those Crown Vics make the motors even worse.

 

[wmburns]

Im confused about something here....

You mentioned that you have a 4.6L 2V out of a 2005 Crown Vic right? Is the motor exactly as it was in the Vic or did you swap the heads, cams, etc? I ask because the 2005 4.6 2V's in the Crown Vics are rated @ 224HP and 275TQ. Thats basically equal to an NPI 4.6 2V.

....and the tunes on those Crown Vics make the motors even worse.

The 2005 CV has the same motor as the Romeo Mustangs. Internally the motor is the same as the 2001-2004 Mustang GT. Same heads, cam, pistons, rods, crank, and block.

Note, that the CV/GM's do have different fuel injectors, exhaust, EGR, throttle body, upper intake, and most importantly a very different PCM calibration. Hence the reason for the different HP/TQ rating.

My vote on why the 97 with a PI motor doesn't perform as well as the factory 2001 is the PCM calibration. The 97 PCM is still calibrated for the Non-PI motor. Where as the 2001 has a calibration that works better with the PI motor. Get your car tuned and I think it will surprise you.

 

[Dark04GT]

You need a tune. Don't know why after all the work you have done that you didn't get one.

 

[bhuff30]

Tires can make a big difference. You may think he has good tires, but they could just as easily be hard all seasons, hard from age, junky korean tires, or just nearly worn out. Plus, another factor is the surface of the street. My NPI will go into major tire spin on some surfaces, even with good tires.

In short, just because he is spinning the tires doesn't mean he's going anywhere, or making that much power. Hit the track together and see what the truth is.

 

[ChillPhatCat]

Tires can make a big difference. You may think he has good tires, but they could just as easily be hard all seasons, hard from age, junky korean tires, or just nearly worn out. Plus, another factor is the surface of the street. My NPI will go into major tire spin on some surfaces, even with good tires.

In short, just because he is spinning the tires doesn't mean he's going anywhere, or making that much power. Hit the track together and see what the truth is.

Yeah... not sure why you're assuming he has good tires, just because they're wide. Get it tuned on a dyno... that ought to cheer you up.

 

[98COBRA281]

Tires can make a big difference. You may think he has good tires, but they could just as easily be hard all seasons, hard from age, junky korean tires, or just nearly worn out. Plus, another factor is the surface of the street. My NPI will go into major tire spin on some surfaces, even with good tires.

In short, just because he is spinning the tires doesn't mean he's going anywhere, or making that much power. Hit the track together and see what the truth is.

+1 well said!

 

[Deleted member 38176]

The 2005 CV has the same motor as the Romeo Mustangs. Internally the motor is the same as the 2001-2004 Mustang GT. Same heads, cam, pistons, rods, crank, and block.

Note, that the CV/GM's do have different fuel injectors, exhaust, EGR, throttle body, upper intake, and most importantly a very different PCM calibration. Hence the reason for the different HP/TQ rating.

My vote on why the 97 with a PI motor doesn't perform as well as the factory 2001 is the PCM calibration. The 97 PCM is still calibrated for the Non-PI motor. Where as the 2001 has a calibration that works better with the PI motor. Get your car tuned and I think it will surprise you.

Ok gotcha. Its amazing how a simple tune affects an engine.

It'd be pretty funny if this guy went through the trouble of swapping in a PI motor that performs like an NPI.

 

[fast97gt]

to nightfire, yes its a full pi engine, all the research i had done pointed to the engine being identicle to those of the mustang engines. dont know if it made a difference since the engine is out of an interceptor CV. also i found that 5.0 magazine had an article pointing out fords best stock parts, they stated that 03 and newer pi heads were the best then recent years. however they didnt state why, im assuming because the thread count in the spark plug hole, maybe nothing to do with the performance aspect. i reused all the 97s fuel management stuff, the CVs fuel management is drive by wire, and has a returnless fuel system. i basicly stripped it down to the intake, valve covers, and oil pan. then i bolted all my existing stuff to it, as far as injectors, rails, wire harness, tb, and upper plenum. the new does have all the pi stuff still, i swapped nothing npi wise to this new engine, (like heads, cams, intake, etc).

 

[fast97gt]

does anyone know of a tuner near charlotte nc, thats reasonible.

 

[Mike97gt]

The 2005 CV has the same motor as the Romeo Mustangs. Internally the motor is the same as the 2001-2004 Mustang GT. Same heads, cam, pistons, rods, crank, and block.

Note, that the CV/GM's do have different fuel injectors, exhaust, EGR, throttle body, upper intake, and most importantly a very different PCM calibration. Hence the reason for the different HP/TQ rating.

My vote on why the 97 with a PI motor doesn't perform as well as the factory 2001 is the PCM calibration. The 97 PCM is still calibrated for the Non-PI motor. Where as the 2001 has a calibration that works better with the PI motor. Get your car tuned and I think it will surprise you.

Very true on the tune.. day and night difference with the mail order tune on my pi swapped car

I never ran it on the track pre tune but it would not chirp the tires into third pre tune... post tune it chirps 4th with 3.73's and 275's 1-2 on a powershift it just smolders the tires for a good second or so..

 

[COramprat]

Mine gets squirrelly in second. Tune it up and you'll get the full advantage.

 

[Maxpowers]

Butt dyno can be deceiving. Second the thought of lining them up.

A good set of tires can also make a huge difference.

Yes, a tune will make a big difference with decent mods.