97 cobra with a 5.4. tech thread

[svtlightning95]

hey guys. been on forums awhile now and yall have helped me out tremendously over the years with my 99 cobra. i just bought/saved a 50k 97 cobra from certain death. one of our customers at work bought a perfect car to use drivetrain in a 51 mercury. so i have a perfect car less motor and trans. i have a 32v 5.4 sitting in the garage and was wondering if anyone else on this site has attempted this conversion before, looking for any advice i can get before i dive head first into this project.:idea:

 

[mystical]

Birdman is the man for 5.4's. Check out this thread:

Turbos: out. 5.4 with Aussie intake: In. - Ford Mustang Forums : Corral.net Mustang Forum

 

[scottg]

There's a guy local here with a lightning 5.4 in his cobra. Pretty neat but it looks weird with the hood cut out for the eaton. Good luck.

 

[Ironhand]

I did the 5.4 DOHC with an 03-04 eaton conversion in my 03 Cobra.

 

[na svt]

There are quite a few 5.4 threads on Corral. The 5.4 isn't a bad option if you can handle the extra 120lbs on the nose of the car.

 

[svtlightning95]

weight is not an problem for me i wont be dragracing the car anyways, also not real converned with the hood clearance either, those are minor things at this point lol. what kind of wiring trouble am i gonna run into? thats my biggest concern, along with the upper intake delema.

 

[na svt]

The a/c lines will have to be relocated, long tube headers aren't available and there will be some clearance issues with the valve cover and hydraboost.

What upper intake dilema?

 

[svtlightning95]

what intake am i going to have to use? and how about wiring the motorup. the stock cobra computer cant be used can it?

 

[na svt]

what intake am i going to have to use? and how about wiring the motorup. the stock cobra computer cant be used can it?

The stock computer will work. You will have to use a cobra or Mach intake with adapters, an Aussie boss intake or a boss 5.0 intake. The Aussie and mach/cobra intakes have much smaller runners than those in the Navi heads. The Aussie intake's runners are much easier to make match the navi heads though.

 

[Mystic-SVT]

what intake am i going to have to use? and how about wiring the motorup. the stock cobra computer cant be used can it?

Assuming you are going with a C head 5.4L you have these intake options which will require intake adapters to fit the wider 5.4L:

-99-01 cobra intake
-03-04 mach 1 intake

You also can try to get your hands on an Aussie Boss 260 intake, they're hard to find but are made for 5.4L motors.

If you're going to stay with B-heads I believe MMR will widen your stock cobra B head intake to bolt up to the 5.4 but I doubt you want to stick with the original heads.

The stock cobra computer can run the 5.4, you will just need to have tuned of course. As for wiring you will most likely have to lengthen a couple of connectors but shouldn't be a big deal.

 

[RIO RED SNAKE]

i did the swap in my old 97....used a 5.4L dohc out of a 04 navi....used my stock computer and harness..changed the coil covers to go back to the coil and wires....bolted it up to my stock t45...used my same clutch etc...only thing i had to fab was some radiator hose...used a navigator throttle cable..and stuck it out with the navigator upper and lower intake..didnt have the funds to upgrade...sold the car thoi and the guy did the 01 upper and lower... goodluck basically a drop in and go swap..stock motor mounts etc..and it had a ton of torque...also you have to use 96-04 stock cobra manifolds..only ones that will fit..and go with a h pipe and widen it in the middle of the h..goodluck any questions just pm me