Hey,

I just got a 2000 Expedition with the 4.6L. I had a 2000 Mustang for a short time with the same motor. I noticed that the HP was down by 45 ponies. Obviously some differences are there that aren't advertised. Can anyone tell me what?

Also, the Expedition has 73k on it right now. What should I be zeroing in on right now in regards to maintenance?

Thanks for the help. Kinda new on these new fangeled motors. Got an FE that I am very familiar with but not so on the modular V8's.

 

Not familiar with 4.6L's after '97, but true dual exhaust on the Mustang, better intake/exhaust manifolds possibly, etc. It also might be the "PI" (Performance Improved) heads vs. regular Romeo heads which would explain the difference. I think it was 225 HP for the '97 Mustang, when they went to the new heads it went up to 260 or 270 HP, which would be right on with the 45 HP decrease.

As for maintenance, read the owner's manual... some things are better off done quicker than what the manual says (oil being a big one), but it's usually about right.

 

Yea, the previous owner took off with it. The dealer is supposed to be getting me one.

Thanks!

 

the mustang had the pi heads whereas the truck does not.

Simple as that.

 

Any reason why they wouldn't work on the this motor? Same motor right?

 

Any Mod motor 99up has the PI (Performance Improved) heads on them.
I believe that like said, the true duals on the Stang helps along with different PCM tuning for different powerbands. The stang is made to run at higher rpms where the heavy Exby is set up to have more low end torque. The camshafts are identical in the car and truck.
The Stang also had a different intake manifold.
Jimmy

 

Well, I drove it Virginia over the weekend. It did really good except at highway speeds and keeping 65-70 on the cruise. It had to downshift alot of some not so tall hills. I am hoping I can do some simple bolt ons to increase HP. Larger Mass Air Sensor, K&N filter, etc. Not looking for tire blistering power, just 20 or 30 more horse.

 

Think "torque" not "horsepower" - you can raise the horsepower pretty easy, but to get to that power, you'll still have to downshift going up those hills! Keep torque constant, but rev higher means higher horsepower. Doesn't do much, it's just higher horsepower.

You need to increase the mid-range torque, say around 2000RPM, your Expy should be doing around 2000-2200RPM at 70MPH, right?

The other thing to think about is the computer may just be tuned to downshift a lot instead of lugging the motor. You might need a chip/tuner to change the shiftpoints. The 4.6L might have enough power to pull those hills in overdrive without slowing down, but the computer is seeing the gas pedal go down, and it downshifts too quickly.

 

On second thought, a chip/tuner might do enough to get you more "torque" that it won't be downshifting so much...

A Superchips on my '96 4.6L t-bird got something like an extra 30 ft/lbs of torque (gross) down below 4000RPM, and certainly a good 10-15 down around 2200RPM (70MPH). A chip/tuner might do more for you with the PI heads... but you also might have to buy 93 octane gas...

 

Thanks Krewat.

Yep, you are right. Your estimate on the rpms and speed is dead on. I don't want to tear into the motor if I don't have too, so heads were just a thought. I'll check into the Superchip.

Thanks again for the tip.

Tim

 

Scamardo, keep me posted on the chip...I am thinking doing the same thing. I'd like to see how you fare after the chip mod. I may do a bigger MAFS and am thinking a possible cat-back sometime down the road, too.

 

The Panther platform did not get PI heads until 2001.

 

Sorry, I was talking F150's. The Mustang's did too. The SuperDuty's didn't get them until 2000.

Jimmy

 

I installed a cold air intake, flowmaster exhaust and a Superchip microtuner to my 4.6 F150. I haven't got it dyno'd but I can feel a big difference in torque and HP, especially down low in the rpm range (2000 to 3000 rpm). It can maintain highway speeds going up hills easier without downshifting as much as before.

Superchips claims 25 HP increase using the performance tune. The exhaust maybe got me 5 HP and the intake another 10 HP. So with these simple mods, 40 additional HP and 50 lb. ft. torque isn't bad.

 

While it may be comparing apples to oranges, I have a '96 t-bird 4.6L with a Superchips.

They claimed only 20ft/lbs or so more peak torque, but looking at their published curves, I got another 35 ft/lbs of torque later in the range, which was a big gain.
Sometimes their "peak" gains are not as good as you'd think, but overall, the added torque in that one area was a big bonus...