There are plenty of mods for them. The same as any other motor. People, including myself are just afraid to open these things up.

 

wierd fact: 5.4 is the same motor as the 4.6 in longblock form

only difference is the displacement. same heads and other incidentals.

strangely...you will find tons of mods for the 4.6 motor. I think many of you guys are seeing "no gains" due to the 4R100 transmission. I've tuned quite a few 4.6 and 5.4 motors and they all responded excellently...2v and 3v variants. Especially on manual trans rigs. Automatics suck most of those gains out.

if you really want to bump your HP, look into Camshafts, intake swaps, and full exhaust systems.


I do agree though that GEARS are the best money spent to "gain" HP


btw: nice dead thread bump. 12yrs is up there for longest idle time

 

In the diesel world of high tq and high hp the 4r tranny is kind of a big deal. They can be built and get swapped into everything because when properly built they tick thru the gears like a rolex ticks time. They also handle more power than most of your high hp mod motors are making and double the tq.

 

4R100 is a decent trans...that is about the only word for it. For a 4R100 to hold up to real power, you need to spend a pretty penny on it. High HP/TQ 7.3 trucks and the Lightnings kill the stock 4R100 pretty quickly.

now take a 5R110 (2003+) trans...that trans is amazing out the gate. She'll hold 500 RWHP and 800 RWTQ on stock components. just tuning and occasionally a 2nd gear solenoid to stop the flare.


My comment in the previous post was that the 4R100 is the last of a dying breed of trans. It bridged the gap between mechanical and electrically controlled transmissions. With modern Fords, the tuning from the factory is pretty decent. Most times the "gains" people see are actually trans tuning. A 4R100 can only be adjusted so much electronically. IMO, that is the true reason so many people are negative about tuning the 5.4 2v Superduty. The trans isn't helping out much, and a stock 5.4 motor only has so much tweaking before you need to break into the internals

 

like said above, the 4R is being used in 1000hp+ 6.4s...because its faster than a 5R. The biggest problem i had with my 5.4 is yes, there may have been some things to increase power...but do i want to spend $600 on cams? $2000 on gears? ???? on a supercharger? For what, 100hp?

No...that's why i bought a diesel. $75 tune and i have more power than i could ever want

Carry on...

 

lets not make this into another Gasser Vs. PSD thread

yes the 4R100 can be made into a killer. yes you are going to spend at minimum $3-5,000 in doing so to get a reliable transmission that can hold killer power. No, a OEM 4R100 is not going to hold high HP/TQ levels. The 4R100HD trans is better at least and slightly cheaper...but we keep digressing.

that isn't the point of this thread. it's about 5.4 guys looking for gains. I've been down that route. I ended up getting a Supercharger. The CAI and tuning were okay...the blower really woke that bad puppy up. I still think best bang for the buck though is gearing. You get an instant "gain" of lets say +30 RWHP. It's an immediate boost in the butt dyno-meter. As a bonus side effect, it actually often helps raise around town MPG's as well due to the increased mechanical advantage since the engine is working less



I have to say though that the whine of a supercharge is addictive. I found myself looking for reasons to bury the pedal so I could hear the motor

 

Blower whine is addictive. I loved it. If I had the money is have a roushcharger(or something similar) on my 350

 

agreed as i am one myself looking for JUST a little extra. i already bought the SPD y pipe havnt had it installed yet. probably gonna wait till i have the funds to get exhaust and have them done at the same time. thats probably all i will do as she already does what i ask her to do

 

Wow. I never even looked at the thread date... How do I go about figuring out what gears to get? Thanks for the info guys.

 

what year and body type and what size tires do you plan on running?

 

Use a gear calculator. Randys ring and pinion used to have one. Make sure you know the final drive gear of the tranny. You want to be at or silightly lower geared than stock for near stock performance. Alot of people recommend 4.30 gears for towing with the 5.4

 

4.30 should have been a stock option on the 5.4

If you want a bigger tire I would recommend 4.56 or 4.88

 

v-10 can come with 4.30's stock. I have 35's and 4.30 gears and my X feels almost normal. I shudder to think what a 5.4 and 35's would feel like using a 3.73 gearset


I'd look at 4.56 minimum for a 5.4

 

It feels like 1700 RPM at 55 MPH.

 

I had 3.73's in my 02 5.4l With 38's It was a dog. Do not advise highway driving and you will never see 4th locked in, always hunting gears. I did a switch up to 5.38's and it did wonders she humms right along now and will burn the 38's off in a second. Doing a 7.3L swap right now and I am a little concerned about the 5.38's and the new found power.