• Welcome to SVTPerformance!

01 4.6 DOHC swap to 02 GT. Wiring Issues

Discussion in 'New Edge Cobras' started by MarkZ, May 8, 2019.

Tags:
  1. MarkZ

    MarkZ Member Established Member

    Messages:
    59
    Joined:
    Mar 10, 2019
    Location:
    Orange
    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
     
  2. scottydsntknow

    scottydsntknow Active Member Established Member

    Messages:
    959
    Joined:
    Oct 18, 2007
    Location:
    Rota
    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.
     
    geoffmt likes this.
  3. MarkZ

    MarkZ Member Established Member

    Messages:
    59
    Joined:
    Mar 10, 2019
    Location:
    Orange
    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
     
  4. scottydsntknow

    scottydsntknow Active Member Established Member

    Messages:
    959
    Joined:
    Oct 18, 2007
    Location:
    Rota
    Depends on your alcohol tolerance lol.
     
  5. Lord2mongus

    Lord2mongus New Member

    Messages:
    5
    Joined:
    May 22, 2019
    Location:
    Chattanooga, TN
    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.
     
    shurur likes this.
  6. MarkZ

    MarkZ Member Established Member

    Messages:
    59
    Joined:
    Mar 10, 2019
    Location:
    Orange

    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.
     
  7. Lord2mongus

    Lord2mongus New Member

    Messages:
    5
    Joined:
    May 22, 2019
    Location:
    Chattanooga, TN
    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!
     
  8. MarkZ

    MarkZ Member Established Member

    Messages:
    59
    Joined:
    Mar 10, 2019
    Location:
    Orange
    Thanks again, I'll let you know how it goes.
     
    Lord2mongus likes this.
  9. scottydsntknow

    scottydsntknow Active Member Established Member

    Messages:
    959
    Joined:
    Oct 18, 2007
    Location:
    Rota
    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.
     
  10. Lord2mongus

    Lord2mongus New Member

    Messages:
    5
    Joined:
    May 22, 2019
    Location:
    Chattanooga, TN
    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.
     
  11. MarkZ

    MarkZ Member Established Member

    Messages:
    59
    Joined:
    Mar 10, 2019
    Location:
    Orange
    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?
     
  12. Lord2mongus

    Lord2mongus New Member

    Messages:
    5
    Joined:
    May 22, 2019
    Location:
    Chattanooga, TN
    They are pinned differently. But not hard to move the pins. Pcm plug is the same
     
  13. MarkZ

    MarkZ Member Established Member

    Messages:
    59
    Joined:
    Mar 10, 2019
    Location:
    Orange
    Thanks, I'll keep an eye out for that one.
     
  14. cartec

    cartec Member Established Member

    Messages:
    73
    Joined:
    Dec 12, 2015
    Location:
    Someplace, world
    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
     
  15. MarkZ

    MarkZ Member Established Member

    Messages:
    59
    Joined:
    Mar 10, 2019
    Location:
    Orange
    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
     
  16. scottydsntknow

    scottydsntknow Active Member Established Member

    Messages:
    959
    Joined:
    Oct 18, 2007
    Location:
    Rota
    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.
     
  17. scottydsntknow

    scottydsntknow Active Member Established Member

    Messages:
    959
    Joined:
    Oct 18, 2007
    Location:
    Rota
    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.
     

Share This Page