I have been searching online for a baseline HP on my 2005 5.4L FX4 and just about all the websites I look at say my engine is a 330CI 3V 5.4L with stock 300hp, but I look on here and see people with a 5.4L with mods and they claim only between 240-280HP after running a Dyno. Am I missing something?

 

Yes. The stock HP ratings from Ford are at the flywheel. The dyno tests are at the rear wheel. The drive train causes a loss of HP.

 

that engine is rated at 300 HP at the crank but after you factor in parasitic loss through the drivetrain measured on a chassis dyno you get the real rear wheel horsepower. 15-20% of HP is lost through the drivetrain

 

ive already done exhaust, intake, and gettin a programmer any other suggestions to get the power up there with out spending thousands

 

There have been a few guys that had their stock trucks dynoed and most have seen 200-205 rwhp stock.

Besides the mods that you have already done, the best for hp would be: E-fans, underdrive pulleys, and custom tunes.

 

I've heard of underdrive pulley's, but what are E-fans exactly?

 

you currently have a mechanical fan with a clutch

this sucks up a few HP from the belt having to turn the fan. e-fans = electric fans


most cars come with them from the factory. but trucks almost never do.



you can unbolt the stock fan, and then install an e-fan onto the radiator. besides freeing up some HP, the e-fans will cause less drag on the motor...which means it will rev up quicker



just throwing this out there, but you can still get the Roush Supercharger for $2,300. That will put you at 412 crank HP, 477 crank TQ...which equates to about 300 RWHP

 

Just before you think of supercharging, realize these transmissions aren't made of platinum either, beef the engine up, beef the trans up, because its a good possibility of failure. Not the general modifications, but supercharging and using the supercharger to its full potential can kill these weak transmissions.

 

yeah the nonintercooled charger can come pretty cheap now days but i wouldn't say he would loose 112hp in the drive train

 

I would

4x4 trucks lose more HP than a 4x2 truck via the t-case (roughly 15 HP)...and the drivetrain on a 04-08 F-150 sucks up HP without good tuning

custom tuning will place a N/I Roushcharger @ about 330 RWHP. the Roush tuning sucks...it leaves HP all over the table that any 1/2 decent tuner can recoup safely



FYI, there are many 400+ RWHP trucks on this site with the stock tranny and zero issues. I drove my FX4 like an idiot up to the day I sold her and the tranny was solid...not bad for a 6,000 lb truck that could powerslide pretty much on command. and mine only had the 412 crank HP roushcharger



edit:
sorry, but I have to disagree on this. these are hardly weak trannies. prior to buying my RoushCharger, the tranny was scaring the crap out of me. I finally called up Roush with a list of questions.

1 of the questions was specifically aimed at how strong the tranny is. The guys at Roush apparently did some drivetrain testing back in 2004/2005 and they rate the 04-08 F-150 drivetrain as capable of handling 500 WHEEL HP. That is anywhere from 550-600 crank HP. this is why Roush offers to replace the 3yr/36k warranty when you install their blowers on a new truck

Couple that with the # of guys who've been running blowers since 2004 with zero issues...and the way I drove the truck....I would say these trannies are pretty damn stout.


I know there has been a plethora of "broke tranny" stories recently, but then again, these trucks have been on the road for 5 years now. Also, Ford made millions of them. It's all about percentages. Sh*t happens guys. I'm sorry for those it happens to though

 

Great info on getting HP, forgot to add exhuast. This will help lots of people who are new to this site.

 

Compared to Mopar trannies, these are bullet proof.

 

Someone help me out. What exactly are underdrive pullies and how would they help increase power?

 

Take a look at this and see if it helps out.

https://www.f150online.com/forums/ot...e-pulleys.html

Also just search for "Underdrive Pulleys" and you get a bunch of threads on this topic as well as the e-fans.

Good Luck!!!

 

a stock non i/c roush setup should yield about 310-320 rwhp. i dyno'd at 308 when i only had the s/c, but my truck seems to be a bit slower than most.

I can attest to the weak transmission issue. I will admit that I am hard on the truck, but I'm currently at 85K miles and already had the tranny rebuilt once and then replaced after that... I seem to get around 35000 supercharged miles between transmission issues....