Reading through these boards...there is a lot of criticism, and dis-liking for the 3V 5.4L. I feel that with the current package Ford has put together with the 5.4L doesn't allow it to perform up to it's 300 horse name.

First off, the throttle by wire. It seems to respond fine in everyday driving, but it could be a lot better then it currently is. You can especially see it's weakness when mashing the throttle. It takes almost a full second for the engine to react.

The 4 speed OD automatic tranny simply shouldn't be. Not only does Ford not offer a manual tranny in the new F-150, but there is no 5 speed auto. A 5 speed auto tranny would greatly improve upon this engines performance in the F-150. If there was a manual option...all who don't see what the benefit of 80% peak torque at 1000 RPM would find out real quick. I just plain do NOT understand why Ford would not offer a manual transmission for this truck. I'm sure there is still a large enough market for it, and you don't see Dodge or GM giving it up. (although, I understand how rare the GM manual 1/2 ton is)

The truck itself gained quite a fair amount of weight when Ford redesigned the truck as well. Weight is one of the biggest factors here, these trucks are getting heavier, and heavier each year. This is mostly due to the electronics, but the new boxed frame had a fair bit of contribution to the weight factor. I'm not complaining about the frame, it is a very sturdy frame.

All this, coupled with the claimed 300hp engine, seems to disapoint most people when there is finally a chance to drive one. 300hp is obviously a generous number, but I hate it when people assume the engine is weak, and inferior, when driving one of these trucks. The F-150 is still a truck, and with the massive weight, sluggish throttle, and poor 4 speed tranny, the 3V 5.4L still does just fine. The engine is very reliable, gets great hwy mileage, and decent in town fuel mileage, all while having tons of low end grunt, and enough power to move this heavy vehicle out of it's own way if needed. If we changed the variables slightly, such as offering a 5 speed tranny(auto/manual) and reprogramed the throttle by wire to react faster, I believe this engine, and truck would be more of a competitor with the 5.7L 'hemi', and 5.6L Endurance.

What are your thoughts?

 

the throttle by wire is more for emissons control. there is a good write up on it. the tranny is not poor it is a good towing tranny. i have driven the manual version of the 5.4 in a f-250 it is a lot faster.

 

I should re-state that. I'm not saying that the tranny isn't capable, infact, it takes a good beating, and keeps going, but I feel a nice 5 speed would be MUCH better. Can you give me the link that explains just how a throttle by wire system delivers better emmissions?

 

yes let me dig up the link.

 

engines have an advanced computer control for precise injection timing and fuel quantity. The computer control unit gets its input from the accelerator pedal and several other sensors to adjust the fuel quantity and timing of the injection in a fraction of a second for most efficient combustion. This provides superior responsiveness and enhances the drive experience. The efficient combustion ensures better fuel efficiency and reduced emissions, thereby making it extremely environment friendly

this is from fords website.

 

Makes sense. I feel that it could be faster though, I don't even notice with the Powerstroke.

 

on the web they show you how to get it to be faster. they did it to a mustang. do you know if all of them have the new pre cat in the air intake?

 

I agree with the original post in this thread. I'm driving a Nissan Armada after selling my older Expedition and test driving new full sized SUV's. The three valve 5.4 is severely handicapped by the four speed auto tranny and by the serious weight gain.

Put these trucks on a diet and get them back to the same weight as the competition and give them a good closely spaced properly geared 5 speed auto and the 5.4 will perform much better.

With the four speed, just when things get into the power band, the auto shifts and the revs fall too far - out of the power and the truck has to climb back into the power before it gets going again. This is especially noticable when pulling a load.

But, Ford should not have embraced the three valve design when it already had a far better cylinder head on the shelf and in production, the DOHC heads on the Navagator.

I just don't understand why Ford handicapped us with the four speed tranny and then didn't use the excellent Navagator heads. And then it piled on extra weight compared to its previous mode, sapping performance even more.

Because I tow an 8,000 lb. load with my SUV from time to time, the DOHC Nissan paired to its very well matched 5 speed tranny and gearing equivalent to 4.10 gearing in the first three gears was just much better for my application.

I keep hoping that Ford will step up and fix this with a true DOHC 4 valve head, the 5 speed auto and more peppy gearing for those who tow. 3.73 was the max when I was looking and I think it still is with this engine and tranny combo.

 

I knew that you could adjust the throttle computer with an aftermarket chip...but don't you think that it should be performing like that from the factory? Pre cat in the intake? Not as far as I know, maybe someone who does will chime in. There sure is a LOT of restrictive tubing used for sound dampening.

Armada, I've also wondered about this, but I can't really draw any conclusions...is VVT too complicated for DOHC engines?

 

No. Honda has been doing VVT for years. Nissan has had VVT on the DOHC V-8 in the Infiniti Q-45 for years. That engine is the design basis for the 5.6L Titan/Armada truck engine.

For the trucks they left out the VVT -- at least for now. I suspect they will add it in the future and then we'll see the horsepower jump up again.

 

Nick I agree with you on the throttle by wire problem. Even though I don't own a F150 the Mustang uses the same system. I bought a tuner for it and just using the basic tune the problem is gone. I'm also getting a vette soon and the same problem exist there.

 

I honestly don't know why they have an issue with the electronic throttle.
None of my mod motors had (but they ran a different calibration).

The electronic throttle doesn't HAVE to give poor throttle response - it is calibrated that way to prevent jerkiness, especially with cruise control on a 10% lag is created.

 

Which raises more questions. Why wouldn't Ford design a VVT 4V 5.4L? I'm not complaining, I mean, the 3V isn't a bad design...but it seems to me that just taking the already in house parts, and developing on them would be easier. I guess we can't know everything.

Same on your Mustang, and Corvette? Like Fred already said, it doesn't have to be like that, and I don't quite understand it. I can understand (although i do not agree) from an offroad standpoint, as they made a big deal about the throttle by wire not being jerky. In a Mustang though...that doesn't make any sense. A simply re-calibration will do the trick.

 

nick the 4v heads would be a no go. the navigator requires premium 91 octane with those heads. for ford to appeal to the normal buyer regular 87 octane was needed to do the job.

 

O really? I didn't know that...but at the risk of sounding ignorant, couldn't the engine be developed to run 87?