How to improve hp and torque?

[Dustin Miller]

So i just bought my first expedition. I have always drove explorers. I bought a bigger boat and my explorer was screaming pulling it so i bought a 1998 4.6l expedition. Want to know the first steps to increasing hp and torque. Do c.a.i. really work? Or are they just for sound. Never really did any kind of performance mods to any vehicle so i dont know were to start. Any info would be appreciated.

 

[1997SCEBFEX]

Welcome aboard.
How many miles on her? Last service?
CAI is a possibility. Open exhaust up too.
Sure others will chime in.

 

[Dustin Miller]

Body has 190,000. Supposedly the motor has about 100,000 on it. I just bought it so i havent serviced it yet. After reading about the 4.6 motors i wish i would of found a 5.4. But it is what it is now. I keep seeing mixed reviews about CAI. alot of people say they dont anything then a few say they do. Dont want to waste money on something that dont work.

 

[stamp11127]

CAI are a waste of time unless they are mounted in such a way that they breathe in air that isn't heated by the engine. Most of the guys around here add them on, they can hear the engine sucking in the hot air so they think they have an improvement. Keep thinking if you want, that but it isn't true. They are really letting the engine breathe in lower density air due to the air's increased temperature compared to ambient temp. This means less oxygen to aid in the combustion process & less performance.

Most of the hp gains are at the top end of the curve (close to wot), so how long are you wanting to keep your foot in it?

There is an "old school" saying, "there is no replacement for displacement". Still holds true today. There are various ways of increasing displacement - none of them are cheap though

For towing you should focus on low end torque. I would see how it tows in it's current configuration before tossing anything on it. Keep in mind the 4.6 is adequate for lighter towing but the 5.4 is the choice for heavier rigs.

If it was my rig I would make sure I haven't exceeded the towing capacity, freshen up the cooling system and brakes and just go slower.

I've towed @5000lbs with mine and you do notice a difference in performance. I just disable overdrive and accelerate easy. Works fine for me.

 

[Dustin Miller]

Towing is my main concern. I will be towing right around 5000lbs.

 

[ExplorerTom]

There are tuners available. I have no experience with them though.

 

[stamp11127]

When I worked for the county we would get a few of the older police cars that had been detuned. They let one slip by that still had the police tune on it - what a difference. And I think they had the 4.6 under the hood. The highest return on the dollar will be the exhaust and tuning.
And they didn't run a CAI.

 

[1997SCEBFEX]

++ on torque, slow, almost hypermiling acceleration.

I added the maghytec trans pan garnering an extra 8 qts of trans fluid to keep it cooler. Also put an inline B&M trans filter in too. Changed fluid and filter every 25K when towing over extended periods of time.

good luck, welcome again, and let us know what you do.

 

[Dustin Miller]

Thank u all for the info! Think i will stay away from cai. Im gonna look into exhaust and tuner. Any recommendations? I heard dual exhaust will lower torque? Is that true?

 

[ExplorerTom]

I just bought a MagnaFlow for mine. It sounds good. I never saw a dyno chart for it or heard any claims of any kind of gains or loses.

There's also Gibson. I believe they have a set for single and dual exhaust.

What gears are in it? Changing those (while expensive) can also make a big difference.

 

[Dustin Miller]

I dont know what gears are in it. I guess whatever is stock.

 

[ExplorerTom]

Look at the door sticker. There's an axle code. Look that code up.

 

[Dustin Miller]

Will do. Thanks

 

[Dustin Miller]

3.55 gears in it. Ive been looking at the jet tuners. Anyone use them before?

 

[rjdelp7]

The 4.6l is already over taxed in the EXPY. The modular V8 makes its best power near the redline and has a flat torque curve. In your case, that is like making a 70 year old man, run a marathon, with 100 pounds on his back. However, it is a truck and should be up to job, if you don't push it. I installed a K&N 0945 air filter in the stock box. I used a Dremel and cut 2-4" square openings in the box(dirty air side). I covered the holes with screen, glued to the box. You can definitely hear the difference. The power and MPG, maybe a very little gain. A co-worker had a fire chief, 2001 Expedition, with the cop tune. He said it felt, like it had extra "get up and go". A tuner will cost over $300. Probably not worth it.

 

[Dustin Miller]

The 4.6l is already over taxed in the EXPY. The modular V8 makes its best power near the redline and has a flat torque curve. In your case, that is like making a 70 year old man, run a marathon, with 100 pounds on his back. However, it is a truck and should be up to job, if you don't push it. I installed a K&N 0945 air filter in the stock box. I used a Dremel and cut 2-4" square openings in the box(dirty air side). I covered the holes with screen, glued to the box. You can definitely hear the difference. The power and MPG, maybe a very little gain. A co-worker had a fire chief, 2001 Expedition, with the cop tune. He said it felt, like it had extra "get up and go". A tuner will cost over $300. Probably not worth it.

 

[Dustin Miller]

I dont drive it hard or very often. Its mainly just for pulling my boat. It might see 3-5k miles a year. Just want a little help pulling up hills mostly.

 

[Alansd]

I've been towing with a 5.4 for a few years. About 4500 lb trailer. Just a few suggestions, to with Overdrive off. Add a trans cooler if you dont have one already. Be sure to do a complete trans fluid change at some point soon. Just get in the right lane on the hills....
I didn't buy the 4.6 as I heard it was not a tow beast. The 5.4 is very capable.
But I miss my v10 Excursion...LOL

 

[scoot0073]

++ on torque, slow, almost hypermiling acceleration.

I added the maghytec trans pan garnering an extra 8 qts of trans fluid to keep it cooler. Also put an inline B&M trans filter in too. Changed fluid and filter every 25K when towing over extended periods of time.

good luck, welcome again, and let us know what you do.

U have a link to the pan u used ?
I'm in the same boat as the OP but mine isn't from towing but from running 35's..
Everything is a crawl and gas chugger

Sent from my Nexus 6P using Tapatalk

 

[07xln]

I'm of the opposite when it comes to Intakes. They do work plain and simple. Science and many of dynos have proven they work. If they didn't k&n wouldn't be a billion dollar company. the science is simple and you can't argue with it. The more air you take in and send out the more power you can make. If you got $300 to spend then an intake is a worthy mod. Back that with a nice Borla or magnaflow catback and you'll pick up a little power. The problem though is the 4.6. It's a dog that's all there is to it. As was said earlier it's already under powered and doesn't do that great of a job just moving its own weight around. Pulling 5k lbs is gonna be a struggle. I had a 2000 model and pulled a little 6x12 utility trailer (900lbs) with my sxs on it (1500lbs) and I had to stand on the throttle just to hold it at 70mph to keep up with traffic. The 5.4 would have been better.