1998 5.4 performance

[ultrajetboat]

hey guys. Just recently adopted a 1998 5.4 expedition from my parents. I grew up going on trips in this truck, didnt want to see it just get given away for the prices they are selling for. Pretty much everything has been replaced or rebuilt....tranny, diff, air suspension, a/c, shocks, entire front end, radiator, water pump...the list goes on, all within the last two years. It also has the more heavy duty tow package that was offered and the bigger diff with limited slip. audio system is all upgraded, and i have some subs waiting to go in. My only beef with this pig is the power! she is slow and burns gas like its going out of style. The engine has been maintained very well, already has cat-back exhaust/k&n intake and a chip. ive looked up superchargers, which are cheaper then whats available for my mustang...but still pricey. i believe i found some non-pi heads, so i was considering a head/cam swap. I dont need it to do a 14 second quarter, but i need just a little grunt out of her. looking for some experience with all the options. Im sure the 97-98 5.4 isnt popular with performance because the 99+ had better flowing heads. hopefully somebody on here has experience with this. thanks for your help in advance. -scott

 

[ultrajetboat]

also i own a 2012 mustang 5.0, now that i own another ford i may just have to take the bbc out of my boat and drop in a 460 to complete the whole ford set!

 

[catmaster25]

More power

I got the same problem, just a 97 expo 5.4, it seems like there is something holding it back, maybe the heads IDK. I read to delete the rear cats, and add true duals. Then a programmer. I'm reading the modifications of the other guys after they post to kinda go from there.

 

[jacks3am]

If your going to do a head swap you definetly do not want non pi heads you need pi heads for sure for the trouble your going to go through. cams just shift the powerband, if your going to do that make sure you have supporting mods like headers, full exhaust, beefed up air intake system and preferably a custom dyno tune for maximum power. If your dead set on the non pi heads, get them ported for sure.

 

[ultrajetboat]

If i do a head swap it will definitely get PI heads. I would delete the cats, but i cant find any bolt on test pipes that goes from the headers back, i cant have it done at a shop here in california. I dont know how long this engine will last, it has 130,000 miles on it now and seems to run like its brand new. anything i do will involve a dyno tune. I dont know what sort of "chip" it has now. im used to using a programmer on the mustang and my old silverado, i guess it has an older style chip that you just stick onto the ecu or something?

 

[ultrajetboat]

still looking for more power. now looking towards a head swap. will the aftermarket heads meant for 99+ work as long as switch to the pi intake manifold? i really dont think ill get much more power out of this thing unless i change the heads or heads/cam. even without a trailer i have to drop into 3rd to cruise up a hill at 65mph. my girlfriends 03 grand cherokee can cruise uphill in 5th gear at 1700rpm all day long. I need gobs of more down low torque! i think at 140,000 miles after being meticulously maintained its entire life the bottom end is still in very good shape with lots of life left, i should be able to change the heads and add 60+hp without change main/con rod bearings.

 

[GaryH2]

Could your cats be plugging up? At 130k maybe that has something to do with it. I hope it had a tuneup at 100k or sooner.

I had an older 2002 4.6L and it didn't have a lot, but it gave everything it had when asked. I have to floor that one sometimes. Not a whole lot of grunt there. With the 5.4L 3v in my 2007, I haven't floored it yet....

 

[FordandPolaris]

Mine downshifts on hills too. I think it has more to do with the shift map to be honest. If you are towing something up the same hill, you don't want to be waiting around in 4th (you should have O/D off anyways if it is heavy) and so it is quick to downshift. Then again I could be totally off.

That being said, doing a PI swap is not going to hurt things.
Mine is at 215k and to my knowledge, the only tune-up it has had is 3 CoP's and 3 spark plugs haha, and thats just because I put them in myself, and know my dad never did anything with it since he bought it in 2001. Cats are all original. No muffler though, so I do have less back pressure than the truck did stock. What I do know is that these came with something like 230hp and 325 lb-ft. For that day and age the torque isn't too bad.

 

[ultrajetboat]

I think I've decided to do electric fans, long tubes with custom Y pipe, dyno tune and maybe pi cams. Havnt decided on cams yet, I think they would go well with the long tubes. The electric fan is step one, now that it's hot here that fan kicks on and the truck just turns into a pig.

 

[toms89]

still looking for more power. now looking towards a head swap. will the aftermarket heads meant for 99+ work as long as switch to the pi intake manifold? i really dont think ill get much more power out of this thing unless i change the heads or heads/cam. even without a trailer i have to drop into 3rd to cruise up a hill at 65mph. my girlfriends 03 grand cherokee can cruise uphill in 5th gear at 1700rpm all day long. I need gobs of more down low torque! i think at 140,000 miles after being meticulously maintained its entire life the bottom end is still in very good shape with lots of life left, i should be able to change the heads and add 60+hp without change main/con rod bearings.

You can go one step further and install a ported PI heads with matching PI intake. If you do a cam swap I would look for a high torque cam if you wish to keep the power down low. Most performance cams trade off low end torque for high end hp. When I did my build I went with a relatively mild cam as I wanted the power right off idle for towing etc.....

Long tube "tuned" headers can help your overall powerband if you keep them 1 5/8" or smaller primaries. I think 1 1/2" primaries would be ideal for near stock expy but do not believe they are available. I would not bother with shorties as you will likely lose torque down low. They can reduce restriction up high but you lose exhaust velocity as well and since they are not tuned or equal length the pulse do not line up to aid with scavanging as long tubes would.

I still believe swapping to a higher (numerically) rear gear ratio will give you one of the best seat of the pants improvements in power put to the ground. But 4wd complicates this and makes it considerable more expensive.

 

[1997SCEBFEX]

Some pics of my setup w/ the Vortech V2-SQ.
A lot of us have done quite a bit with aftermarket and some (Tom) w/ the Lightning swap/build route.

Let me know what questions you have.

PanHandler.

http://www.expeditionforum.com/members/43969-albums199.html