01 4.6 DOHC swap to 02 GT. Wiring Issues

MarkZ

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I'm about to start installing a DOHC 4.6 from an 01 Cobra into my 02 GT. The motor is rebuilt and ready to drop in, but I'm not sure what I'm going to run into as far as the wiring. This coming from someone who HATES wiring. I bought the Cobra as a parts car, it was complete and running when it was taken apart, so anything I need from the 01 is available.

Any feedback on what I'm going to run into and what I need to move over from the 01, is much appreciated.

After I'm done with the swap if anyone needs parts for an 01 Vert let me know.

Thanks
 

scottydsntknow

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There are literally dozens of guides online on the 4V swap wiring. Its extremely simple.

Cliff's notes:

-Extend and REVERSE all COP wires and use 4V COPs. 4V COPs are different polarity than 2V COPs and you will fry your ECM if you don't do this. Also they won't reach around the back of the heads...
-Extend the wires for the IAT and I think the TPS sensors... its 2 or 3 sensors, not hard. No polarity reverse there.
-Buy the 4V alternator repair harness from any Ford dealer and that is your pigtail for the 4V alternator. Reverse polarity here too, the middle wire on the pigtail is not used, just the outer two. If you **** up you'll get a light on the dash so you'll know you reversed the wrong wires and need to switch them.

That's literally all the wiring. Why I don't get why more ppl who do all the bolt on 2V shit don't just go by a JY Mark VIII engine and drop it in, its a 95% direct drop in and takes a weekend. Re-use your 2V accessories except you need the 4V alternator. Computer can run the 4V without a tune initially but that should just be for a drive to the tuner unless you do a remote datalogging tune like I did. If you don't get a tune you'll be leaving a ton of power and about 1000RPM of peak powerband on the table.

So get a $15 soldering iron/solder kit from Amazon, a 100ft roll of wire, some shrinktube, electrical tape and a 6 pack and a few hours one evening and there you go.
 

MarkZ

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Thanks, that's just what I was looking for!

I was looking at a Lincoln motor, but I got luck when an 01 Cobra parts car fell into my lap at just the right time, so that's what I'm starting with. Got the motor back from being rebuilt and waiting for a couple of weekends in a row to get it going.

Then I got lucky again. A guy who was keeping an eye out for a motor for me, called and hooked me up with a guy who crashed his 99 Cobra Convertible with only 53k miles on it and I got that one too. The guy had all the receipts from when he bought it new. Wish I had picked that one up first, I would have just dropped it in and not rebuilt it. The nice thing is the car starts, runs and drives, just a little out of square and a little sideways.

Thanks again for the information. Just one more question, does the 6pack come before or after I finish the wiring? LOL
 

Lord2mongus

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It is pretty simple to swap out all the wiring. Yes. All the wiring! The dash is the hardest part. But even the dash is pretty simple. Do it the right way. No splicing, or hacking up wires. If you have the full parts car, it is super simple. Good luck to you! You are welcome to message with any questions if you run into problems. I have tackled this one many times.
 

MarkZ

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It is pretty simple to swap out all the wiring. Yes. All the wiring! The dash is the hardest part. But even the dash is pretty simple. Do it the right way. No splicing, or hacking up wires. If you have the full parts car, it is super simple. Good luck to you! You are welcome to message with any questions if you run into problems. I have tackled this one many times.


Thanks for the encouragement! Doing it right is the only way to do it. I use this Mustang for the Silver State Classic Challenge and 165 MPH +, is a very bad time to find out I did something wrong!

But like I said, "I hate wiring", but I'm willing to do what I can up to a point..

When you say dash wiring, what are the differences under the dash? I was hoping I could take the complete engine harness from the 01 Cobra and connect it to the interior harness of the 02 GT.
 

Lord2mongus

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Some of the connector pig tails are different from the 2v/v6 cars and the 4v cars. Also, the harnesses also changed through 99 to 04. If you have all the correct harnesses, use them! Door harnesses and deck harness are the same. Everything else has to be swapped. These are the easiest of all mustangs to tear apart, and reassemble. Yes, even easier than a fox!
 

scottydsntknow

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2V to 4V swap shouldn't be screwing with the dash or any harnesses at all minus what I already described. Just the COP wires, a few sensors and that's it. Get a good tuner to load a 4V tune to the 2V computer and roll.
 

Lord2mongus

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Sorry. Wasn't saying your way doesn't work. It does. But for future power, the 4v cobra pcm has a faster processor as well. And I like all stock, non hacked wiring when possible. Maybe Im picky. But whatever turn your motor.
 

MarkZ

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I'm going to put on a Novi 2000 and was planning on a reprogram, but didn't know the pcm was faster. Is the plug different?
 

cartec

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Who did the rebuild and did you upgrade the internals for a supercharger? And what did it cost if you don’t mind sharing that too.

Thanks
 

MarkZ

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The internals were mostly stock. I'm only looking for 425 - 475 hp and from what I've seen the stock internals are good for 600 hp safely. I use my car for road racing so the higher hp is not as important. I did upgrade the oil system and added a separate cooler. I also had them put in a set of ARP bolts.
When I went to check out the shop they were in the middle of rebuilding another Cobra motor and I was impressed with what I saw. I haven't used them before, they were recommended by my mechanic. I'll find out how good they are after I get it started.
As far as the cost the best I can do is give you a range, because it all depends on what the condition of the motor they start with. So I'd say $3800-$4500. The biggest variance is in the condition of your heads.

Same Day Cylinder Head Service
1223 E Ash Ave
Fullerton, CA 92831-5019Map
(714) 680-3006
 

scottydsntknow

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You heard wrong. 425-475 is right on the edge. 600 would spit a rod out of the block in 2 seconds. You might have heard that about the Coyote engines or a 03/04 Cobra engine but for damn sure not an 01.
 

scottydsntknow

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Sorry. Wasn't saying your way doesn't work. It does. But for future power, the 4v cobra pcm has a faster processor as well. And I like all stock, non hacked wiring when possible. Maybe Im picky. But whatever turn your motor.

Ah, talking about using the 4V computer... yeah then you'd need to just do all the harnesses. Not sure at what power level you'd require a 4V computer speed... maybe for shifting like the SYM2 Mach computers but if you are in a car that shifts so fast that the stock ECU is having issues you might as well go to an Optishift.

I like using the 2V computer because the wiring is simple, takes a few hours, is reversible easily and no removing any dashes or any other craziness.
 

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