2003 F-150 Heritage.

[Saber123316]

So i have a 03 Heritage, 5.4 4r70w 4x4. AFE stage 2 intake and magnaflow cat back exhaust.

I have been contemplating upgrading to a larger throttle body and a lightning MAF with the custom tunes will this lead to more usable HP from these 3 combined mods?

also will I need custom tuning for longtube headers?

AND

If I go longtubes into a single 3 inch Y will I belimiting horsepower production in the future?

goal is to have a 14.5 second truck in the 1/4 mile.

thanks for your inputs

[cleatus12r]

14.5 in the 1/4?

Time for a blower.

In all honesty, you will probably see very little gain (if any) from those bolt-on parts listed.

You MAY need custom tunes for the headers, but as I tell most people: Try it and see what happens. If you can save money by not having to spend the money on custom tunes, by all means, go for it.

[Saber123316]

Ugh I knew you were gonna say blower..... Problem with supercharging the truck is trying to find a kit that's decently priced.

[cleatus12r]

Another problem....
If you want to maintain a decent amount of fuel economy, you're out of luck.

[Saber123316]

Originally Posted by cleatus12r

Another problem....
If you want to maintain a decent amount of fuel economy, you're out of luck.

what about nitrous? seems like a good way to make power with a decent fuel economy,

I just head to the track and see these guys in Thundra's Hemi rams and 1500 gmc / chevs and nissan titans (notice nothing ford) all running decent times with minor bolt ons they all seem capable to break into the 14's or in the thundra's case do it stock.

and my truck is running 18.3 consistently. the only decent ford trucks are the diesels with tuning but that is comparing apples to oranges.

I understand the 5.7 iforce is a dohc 32 valve motor, as well as the 5.6 triton engine. the 5.3 is based off the LS series and responds to bolt on's and the HEMI motor is a beast in stock form.

2003 f-150 5.4 260hp and 350 ft lbs (got torque?)

2004 dodge ram hemi 345 hp 375 ft lbs of torque

2003 5.3 vortec 295hp and 335 ft lbs

5.7 iforce 381 hp and 401 ft lbs

5.6 triton 317 hp and 385 ft lbs


I understand the last 2 engines are technology superior being DOHC and newer engine designs.

but the 2 pushrod engines seem to have decent HP and torque ratings yet fords sohc 5.4 leaves much to be desired. I have read about some mustangs that made decent rwhp with N/A power with cam's head work and a intake. with the increased displacement it should be easier to make more power with a 5.4 right?