5.4 Navi Ecu Questions

Discussion in '1996 - 2004 SN95 Mustang -General/Talk-' started by 5.4beast, Apr 10, 2014.


  1. 5.4beast

    5.4beast New Member

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    I'm working on project to put a 2001 navi engine into a 98 Mustang GT. In the process of building the engine at the moment. Here's a few questions I've yet to figure out:
    1. Can I use the stock computer to run the navi engine? Knowing I'd have to convert it to COP ignition, how is this done? How hard is it?
    3. Should I just use the Navi computer? If so, can I modify the rev limiter? It tops the engine out at 5500 RPM from what I understand.
    Can anyone explain what I use to modify stock perimeters? And what perimeters are adjustable. I don't have an unlimited budget so I'm not shipping my car to be tuned professionally. Plus, I'm looking forward to learning to do it myself.
    Bare in mind, this will be a street car. Probably wont see the track. And will never be a daily driver!

    Hopefully I've asked the right questions, feel free to help with any info you can provide.
    (I have already picked my project, please keep your opinions about whether or not this is a good idea to yourself)

    Thanks all!
     
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  2. 5.4beast

    5.4beast New Member

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    Thanks for the help yall;)
     
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  3. Three50won

    Three50won Member

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    You need to get an ECU that is compatible with or made for the engine you are installing. So get the 5.4 DOHC Navi ECU for COP ignition. If you GT is auto then I'd recommend also getting the Navi trans to make things easier. Once all is swapped in, then you just get a tuner (DS, SCT, Sniper, etc) and flash a tune in. Some tuners give you the ability to fine tune the canned tune they give you. You can add or remove timing and fuel. I'd say run the base high performance tune first and enjoy the car. Then get yourself a wideband O2 sensor and play with the AFRs.

    Side note, make sure you have extra money for small things. Last time I did a 5.4 conversion there were lots of little things that need to be fabbed...and that was with a 2V 5.4 engine. Off the top of my head I will tell you that you'll need an X/H-pipe made specifically for a 5.4 swap. And you may need headers/exhaust manifolds specifically for this also. Because the 5.4 exhaust ports sit higher and wider than the 4.6. So 4.6 headers/exhaust manifolds might not reach. And do yourself a favor and look into getting a tubular K-Member for the swap. It'll save some weight and make the entire process a bit easier. Make sure you are getting a complete 5.4 engine from intake manifold to oil pan. Another thing you may have to modify will be your EGR valve (you can delete that if you want). And believe it or not, the 5.4 DOHC Navi engine is a lot heavier than your 4.6 SOHC engine. You will notice the weight difference once the car gets moving. You may wanna upgrade your brakes in the future.

    A 5.4 conversion is fun and cool especially a 4V engine. But take your time, do everything correctly, and plan it out. Don't try to make it a one night or a weekend gig. Plan it out and ask questions if you get stumped.
     
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  4. Decipha

    Decipha Member

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    If you have a 5spd use the navi ecu

    If you have an auto you should swap the ecu to a 99-04 stang v8 ecu

    the 5.4 auto in the navi has an e4 trans IIRC, which means the trans shifts differently than the 4r

    its worth a shot though if you want to try that ecu with your auto, 50/50 chance it can work when tuned properly
     
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  5. Mr. Rustypwnz

    Mr. Rustypwnz Advanced Member

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    just keep the stock ecu in it, and tune afterwards. You will have to lengthen the cop wires, and maybe some more, but thats it. Its very easy.
     
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  6. Three50won

    Three50won Member

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    98 GT ECU will not work with COP ignition. I know this from experience. He would have to convert the engine to coil packs. Also, the Navi engine has those intake manifold restriction plates. So he would have to delete them if he kept the 98 GT ECU. The knock sensors would have to go as well.

    If he swapped to a 99-04 GT ECU, then he would still have to eliminate the restrictor plates and the knock sensors. And he would need to tune it for the extra cubic inches, higher compression, and larger injectors. Otherwise the engine will not run correctly if at all.

    Best bet is to get the Navi ECU and use that along with modifying the X/H-pipe and exhaust.
     
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  7. 5.4beast

    5.4beast New Member

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    thanks for this info guys! I'm using a 5 speed so the tranny wont be a problem. But using a 5-speed, and the computer limiting my revs to 5500, seems like this will be bothersome.. can the 5500 rpm max that's built into the navi ecu be changed?
     
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  8. 5.4beast

    5.4beast New Member

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    Thanks for your positive response! I've had a lot of nay-sayers.. I have been working on my navi engine for a month, complete tear down and rebuild. I have unlimited time and I'm working on this as a project that I hope wont end too quickly. (I love to project, the end of the journey isn't as great as the journey itself). I will for sure be getting a tubular k-frame. I can do the exhaust work myself. (I may do it from scratch) Haven't made up my mind about exhaust manifolds yet, but i know thats something I'll need to figure out.. I'm planning a lighter hood to save weight. (may need a cowl anyways depending on how short i can make the intake while keeping the runners fairly long). Believe me, for every hour I've spent on my project, I've spent 3 hours reading. This project will be done well! I'll create a new post with pics and updates soon;)
     
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  9. Three50won

    Three50won Member

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    You can change or eliminate the rev and speed limiters. And you can adjust the shift points and shift firmness. Talk to a tuner first tho. Because I'm not sure how simple or difficult it is to change the parameters from an auto trans to a manual trans.
     
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  10. Three50won

    Three50won Member

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    No problem. To be honest tho, it will be a difficult swap. But it will be unique. Not many 5.4 DOHC 98 GTs out there. SO if you're gonna do it, then just do it for the bragging rights. If you were just going for performance, then this probably wouldn't be an ideal swap.
     
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  11. Mr. Rustypwnz

    Mr. Rustypwnz Advanced Member

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    yes it will! my 98 gt has cop's on it. A navi does NOT have imrc plates either. Who cares about knock sensors, throw em away.

    A navi ecu will not run in a mustang without some serious modification/pats delete and lots of re-pinning on the harness. Installing a navi engine in a sn95-newedge is not hard at all. The stock ecu will run the engine fine for the time being, obviously he will need a tune but thats it.
     
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  12. Mr. Rustypwnz

    Mr. Rustypwnz Advanced Member

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    If you dont want to convert to COP's, get some valve covers off a mk8 or 96-98 cobra and use your old coils.
     
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  13. Three50won

    Three50won Member

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    An ECU from an engine with coil packs will not work on an engine with COP ignition as a plug and play. Some modifications will have to be done. If your 98 GT has COP ignition, then you modified the wires to the plugs, the coil packs, or the ECU. But you're not gonna install it and just start it up.
     
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  14. 5.4beast

    5.4beast New Member

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    For sure your right. I did consider leaving the 4.6 and adding boost. (like everyone else) but I want this to be relatively unique. And as much fun as 1000 hp would be, I'm not that big on racing. Even street racing. But I'll drive this beast with pride that its something that not everyone does, and i guarantee it will be fun;)
     
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  15. 5.4beast

    5.4beast New Member

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    For sure you are correct. What I was asking is, can I use my gt ecu? if so, how is it modded to run COP? i.e. there are 4 wires in each coil pack, you need to pull them, identify which wire is for each cylinder, then attach them to the corresponding COP. (I hope its that easy anyways)
     
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  16. Mr. Rustypwnz

    Mr. Rustypwnz Advanced Member

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    The coil packs have 3 wires each, 2 signal wires to trigger the coils (wasted spark). The middle wire is 12v. There is a write up on the TCCOA website. Its very easy. Plus it cleans up the whole engine.
     
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  17. 5.4beast

    5.4beast New Member

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    Perfect! Thank you!
     
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