I have a 2007 F150 Supercrew FX2 with the 5.4 3V and tow package. It has 3.55 gears. This engine is rated at 300hp at 5000 and 365lb-ft at 3800. It is supposed to make around 80% of it's peak torque starting at around 2000rpm and remain kinda flat to peak.. I use this truck to tow a roughly 5500 pound camper. It does not get hot rodded around in. It has one singular purpose. Pull my camper.

As a result it rarely sees more than 4400-4500 rpm. In fact it has only had one trip where it saw that much rpm for an extended periods. Coming back to NY from NJ though the PA mountains for 2-5 minutes at a time. Most of the time it lives in the 3500 or less range.

At that power level it has about zero power reserve to deal with grades and/or headwinds and/or almost anything. It feels like it's giving all she's got at most times. Sun shining on it almost feels like it slows it down. I curse it most of the time on most of the trips.

I can't justify the cost of a new truck to get more power or better technology, when this one is paid for and I only drive it about 2000 miles a year. A $400-500 payment for such limited use seems silly. Yet I want, no....NEED more power. Not horsepower. I don't care much about the horsepower. I need more torque to pull through wind and up grades. The added hp it brings with it is welcome, but not my focus.

When I tow, the truck really seems to like hanging out between 2000 and 3500 rpm. A modest 7-8 psi is all I'd like to have. Obviously the truck would need a tune and I'd run a large intercooler as it could see sustained load under boost at times. I would also run a secondary redundant safety system to add methanol if needed to reduce charge temps. I need it to stay in one piece and bring my family to our destination and back.

I have to pass NY emissions so I have to retain the OEM catalytic setup. When under the truck it is clear there is a crap ton of space to mount a turbo under the cab. This creates a return oil issue that can only be addressed with a scavenge pump. A solution I am open too, so long as it is a quality pump. I believe I found that pump at RB Racing.

My thought is to install a turbo just after the two exhaust banks merge into one. This is after the catalytic's and puts the turbo right under the cab on the passenger side. I would have a splash shield to deflect water away from the turbo. I would plumb the air intake and filter up under the bed into the cavity between the bed and the bedside with a splash shield to protect from water splash from the rear tires. The feed from the compressor can travel up the inside of the frame rail to find the intercooler before going up into the engine compartment and entering the engine. This layout would likely have some lag due to turbo placement and the volume of piping to get the pressure to the throttle body. However, when towing it is slow going as it is. It already feels sluggish, so it would only be noticeable if it was worse than it is and I don't know how it could be any worse.

The intercooler I would run would most likely not be a common A2A setup but more likely an A2W design. It's more complex, but I think it's worth the added effort from a reliability standpoint. This is open to being changed, especially at the relatively low boost levels. It may be unnecessarily complex at this level of boost. I am curious about this part of the idea.

Since the truck will not see high rpm and I don' t care about high rpm power and the 5.4 3V is known to have VVT issues, I would also lock the VVT and bias the stock cams to benefit low end power production. The tune would also address this change.

I am confidant the fuel system lines can support a modest ~50% increase in power, but I am not confident the fuel pump is up to the task. A larger pump is all but certainly required. And the injectors would have to be up sized to at least 42lb/hr from the research I have done so far.

The transmission in the truck is a 4R75. I believe that it is up to the task as is with optimized/increased line pressures, shift schedule tuning and an appropriately large transmission fluid cooler to keep heat in check and in the fluid in the correct temperature range.

I am open to pretty much any turbo from junkyard sourced to China to whatever, but cost is a concern. And repairability "on the road" is very important. Given the low boost level and low rpm range even a TP38 off a Powerstroke looks like it might work. When I plot 8psi on the TP38 compressor map, it's right through the efficiency zone at 7-8psi. Upgrading the wheel and running the smallest turbine housing (.84 A/R) might make sense. Can also run 1.00 A/R or the very common 1.15 A/R housing.

Items of concern are tune for safety (detonation is a major can not happen), factory rods/pistons, VVT, IAT levels, trans stuff, what turbo would be sufficient and what exhaust A/R would be proper for the turbo location and lower RPM focus. I think I've been fairly thorough in my approach, but I'd like feedback and welcome constructive criticism on the idea. If it comes to fruition remains to be seen.

Oh yeah, I think this is my first post here.

 

Your idea isn't new, but I don't believe i've seen one come to completion yet, so there's very little comparable info out there. The biggest issue with this is that boost at low rpm is extremely tough on parts, especially since the intent is long loaded pulls. Anything you can do to run above peak torque, and use rpm in your favor will help in making the lower end live. That being said, you'll need a very good tuner with some experience in control of torque production/ cyl pressure to make it safe. It will be much tougher to tune/make it live/get the most out of it than the average build.

 

I agree, unless you plan on building the motor I think you'll be risking the reliability of the engine. The meth is a great idea but I think you will be spraying a lot of it on long grades. Those trucks have pretty good transmissions stock, if its got some miles there are performance rebuilds available. An engine swap might be a more cost effective plan for what you are trying to accomplish. What gearing does this truck have in it? A good running 5.4 should tow 5k alright.

 

The truck runs like a fine clock. The transmission shifts crisply with no hit of flair. When I check fluids, they are always text book clean. It has 3.55 gears. 3.73's were an option but it didn't get them. On flat grades in favorable weather conditions it tows like a dream. Some times I forget till I check my mirrors that the camper is even behind me.

But the moment there is a hill of any grade or a head wind, it feels like it loses half it's power and there is nothing to give to counter that.

I've driven all over NYS to Buffalo/Niagara Falls, to the 1000 Islands, to Watkins Glen, through the hills into VT and up to Burlington, across Massachusetts to Cape Cod, through Eastern, Central and Western PA, to Ocean City NJ, and to the Cleveland OH area in the last 3 summers. The truck has taken us to every destination and back without a single issue or hiccup. It is no doubt a tank. It gets the job done. I just curse how it does the job about 50-60% of the time.

The worst it ever was, we were coming back from the NJ trip coming up the Northeast Extension of the PA turnpike. If anyone has driven it, it's more or less all up hill from Philly to NY. Coming out of Philly I was able to gain and hold 65-70 mph with the rest of traffic. I look way ahead and way behind to plan my driving and I used every hole and lane availability to walk that truck around other vehicles and up the turnpike at 65-70 the whole way. I passed a lot of everything. I'd be surprised if I was getting 3 or 4 mpg's. I knew that if I gave up the momentum, it'd take forever to get it back. But to do it, I was in second gear at 4000-4200rpm for 3, 4, 5 minutes at a time sometimes. At first I cringed. It was screaming. I could literally hear the transmission internals spinning. I don't know what kind of rpm's they were spinning, but it was A LOT. It sounded like mechanical armegeddon was nearly upon me at times. 5.4's make a lot of mechanical noise at those rpm's. When I was able to I did gave it a break. Turned O/D on for downhill and flat sections to give the transmission a chance to cool down as much as possible before the next pull. Piled on some extra speed before hitting the next climb. The peak torque happens up at 3800ish so I figured then truck is designed to tow and that's the peak power point. It has to be up to pulling at that rpm for bursts.

With my current gearing I was sending about 2000 ft-lb to the wheels after gear multiplication to maintain those speeds. If I had 500lb-ft and re-geared to 4.10's, I would be in the same ball bark but doing it in 3rd gear instead of 2nd.

When we got home and I checked the fluids, they were all normal. That run was at just over 120,000 miles on the clock. I am not opposed to building an appropriate long block swapping the long block in. And from what Mnlx said that would probably be wise. Low rpm load would be pretty high on the rotating assembly.

I need to think more about this. I would be looking at $30-40K to get a newer (not new) F250 gas truck. And it still might not be quite what I want. I don't want a diesel however. Cost of operation is way too high for my usage and if it were to break, repair costs are astronomical. So spending several thousand over a couple years to upgrade what I have is palatable.

Thanks guys. Anyone else with any other input continues to be welcome.

 

An f250 is overkill for a 5k trailer, a Used EcoBoost would be a good fit, I pull a 9k arctic fox all over, I live in CO and since I did a tuner, radiator and intercooler upgrade I can pull most passes at 65. On the flats I'm running 1850 rpm. I Average 10.5mpg with the trailer. Pulling 5k in a stock 3.5 would be modification free and easy going. I think by the time you do the turbo, forged bottom end and work out the kinks the trade to the EcoBoost would be worth it.

That said, the forged and boosted 5.4 would blow the EcoBoost out of the water. It would sound better, have more power, and be a truck your intimately comfortable with.

 

10.5 mpg would be about 25% better than what I get. For this application, I do not care even one little bit about sound beyond it being so loud that my wife or kids complain about it. Literally my only concerns are reliability and doing the job much, much better. Turning 1800ish on flats would be amazing. I have to run in drive most of the time and that's 2800 revs. Sometimes I can drop into O/D and turn 2000ish.

 

With an CAI a tune and catback the 365hp ecoboost 3.5 is making around 425hp which would make for a great tow vehicle for a f150. The f250 with the 6.2
Makes 411 hp which would tow your trailer with no problem. If it were me though I’d pick the f250 just for the fact that it’s less strain on the truck. Stronger frame ,stronger axles,stronger brakes.stronger suspension.If you want to pull more weight it will. The 5.4 3v was never that good of an engine and I’m a ford guy the 6.8 was a better engine but only made 10 hp over the 3v but was not available in a f150. The 5.4 3v in the f250
Is underpowered too.It all depends on your budget too

 

toting hp numbers is pretty useless for towing its the tq you need

I say keep your truck, toss a small 67mm turbo on it or the like and enjoy. At 8lbs or so you'd gain about 120rwtq or there abouts. That should be more than sufficient to get her moving significantly easier on them steeper grades.

I would recommend getting a tune on it now to help it for the time being. Not to mention it would help iron out any issues you may have before hand as well and make it easier with already having a known base for when you start it up with the turbo. Any reputable tuner will not charge you again for a re-tune when you do toss the turbo on as long as its the same vehicle being modified. If you'd like give me a shout and we can discuss it more.

 

Both the 3.5 and 6.2 have at least 420 lb ft of torque and the newer ones a bit more. That 3v has pretty long rods and when you add boost where the torque curve is is quite a bit more stress.

 

My opinion, the 6.2s are slugs. Maybe they got better since 2010. My 88 351w pulled better.

 

Anytime you add boost (and load) to an engine that wasn't engineered for it you are risking parts failure. If you were pulling your boat an hour to the lake or camper to a local campground, i'd be more inclined to say go for it, you'll only need to tow it a short distance when something goes wrong.... Pulling long grades hours from home with my family would make me nervous. The Eco boost, or more cubic inch is the easy more reliable answer if wanting to keep your brand of truck.

 

I say do it.
I have done 2 v10 trucks with undercab turbo's and a 4.6 truck the same way.
It will be fine if you do it right. Keep peak torque below 450 at the tire and you'll be fine. those short blocks are not anvils but they will handle 10 pounds. While I agree with alot of the current sentiment that lots of boost at peak torque breaks things, I think it may be getting blown out of proportion a bit.
The 2 valve lightnings had the same short block as the 2v trucks and were fine. The saleen 3v cars running SC's with factory shortblocks were fine too. The 3v roush trucks with a blower were fine as well.
So far I have found the stock 3v rods to start getting short at at around 525 RWTQ.
I have used 3 different turbo's on the three I remote mounted. They all worked fine. A cheapy ebay gt45, a real t70 p trim, and what I think and was told a 78mm cast wheel.
Run oil feed from the side of the block for the oil pressure sending unit. Drill a hole in the oil fill cap and plumb your return to it. Lightning injectors or 03-04 cobra injectors will flow plenty, an in tank 340 will work and is affordable. I would run the slot style maf in blow through and size the pipe you put it in accordingly. A MAFia will get you more range if for some reason you need it. I would tune it with sct if it was me. There are plenty of good guys back east.
Buy a turbo timer and wire it to your scavenge pump so it runs for a few minutes on shut down. This will help ALOT in keeping the oil out of the exhaust and intake. Other then that, keep the thing on the rich side in boost, around 11:1 a bit of meth is added insurance and your timing artound 14* at 10PSI. You will need to run good gas and your economy will suffer. But if your driving this thing 2k a year who cares?
Hell I'll bet you 3-4 PSI would tranform the thing for you.

 

Linear boost from a sc is a little different animal imo. I really don't think anyone said not to do it, we're just pointing out the possible issues that many don't consider, and could easily leave them stranded, and needing major repairs. The oem spends countless hours tuning something like the Ecoboost or lightning, much more than he'll get from a few hours at his local wot tuner.

 

I know you guys were. I think its great you all took time out of your day to offer some help/direction. And I agree with alot of those points. But I've done it 3 times. And its worked well with no issues to speak of. I was simply relaying my experience and from it, offering an opinion the OP asked for.
From my point of view, the boost from a turbo is a ton nicer to the short block then the insta boost roots blowers that can make 15-20PSI at 1500 that roush, saleen, whipple, Kenne Bell, magnuson, VMP ect use. Not to mention the lightnings, cobra's, GT's, and gt500's. At full song the lightning blower takes over 75 HP to turn and offer no "cushion" on the exhaust stroke from the drive pressure. My point was that while limiting boost presure at peak torque is recomended and even needed to make a SBE live while making lots of power, its just not a needed strategy at this power/boost level in my experience. Fords factory calibrations are pretty "torque-centric"
As far as tuning goes, open a factory lightning file and a factory f250 5.4 file and compare. Other then the obvious tuning for boost, the "bones" of the file are almost identical. My point is because of that, you are still useing 95% of the factory calibration, so your not re-inventing much. The majority of the difference between the two is emissions related.

 

Part of my point was that the tuning in boost will absolutely make or break this, especially under varying loads, rpm, and boost for miles vs a quarter mile at a time. It really sucks to start up a grade, get halfway up, and realize you can't stay in the throttle because of heating, or mechanical issues. Not a good position to be in.

 

Lot's of good replies. Really appreciate them. Much to consider. In many ways and for several reasons I'd prefer a newer truck, but man are they expensive. I priced the closest spec F150 to what I currently have (Supercrew 4x2 2.7 Ecoboost which has the closest power rating) and it was like $42K. For my needs, that's just not an option. Even if I went out and bought an 80,000 mile 3.5 Ecoboost (I'd get many years from it towing only a little bit each season) I'd still be looking at well over $15 grand.

If I move forward, it's pretty clear (from a reliability standpoint) that decent rods and forged pistons are pretty much a requirement. I'd also consider VCT lockout a given as well as a set of TSS oil pump gears. I think a basic stock type rebuild with just a couple mods for reliability and power handling could survive at a low 7-8 psi boost level, with a proper tune of course. That would put me in the 450hp and 540lb-ft ball park. And if 80% of the stock 365lb-ft is in fact available at 2500 rpm I'd have nearly 460lb-ft to pull me over hills and through the wind.

When I tow, I am not really concerned about fuel economy per say. I mean I don't want to flush fuel away, but if I am getting what I want performance wise, the fuel usage is the fuel usage. The earlier story about my climb back from NJ through PA was an extreme. Most of time I find I am rolling along at 65-70mph on the highway. Turning 2800ish rpm. Loafing along really. I come upon a small grade and before I crest it, I lose 10 sometimes 15 mph. I hate that. The very common occurrence is I get into a situation where I can't get around someone and end slogging my way along at 50, maybe 55mph with no power reserve to recover. I have to wait for a downhill to get back my speed. Like the time I was coming down I81 on my way back from the 1000 Islands. I got stuck behind this stupid dirty hippee in her Subaru Impreza wagon. I'd run up on her on the down grade, pull out to go around, she'd speed up a little bit, then we'd hit an up grade and I'd lose speed and have to pull back in behind her where she woudl proceed to slow down a little bit. You would think that someone would notice what's going on. But she was either oblivious or was being a big C. After the third time, I got up to almost 80 before the next up grade and got around her. I was fuming. I so wanted to let my near 12,000lbs plow into here 3000lb pile of crap at 70 mph. I knew people did dumb things around bigger heavier vehicles, but never realized how dumb they are until I started towing.

Anyway, I'll have to sit back and create a build plan and evaluate the costs.

 

Stupidity is the New Jersey way especially when it comes to driving. I lost two trucks because of dumbass people . My pristine Jeep TJ was totaled to a moron not paying attention and rear ended me while I was at a stop light with a f350. A Jeep TJ with perfect paint and no rust not even the frame is like a unicorn in no The second one was when a JO
t boned and rolled my 09 Trailblazer on its roof going the wrong way up a one way.

 

Sounds like you have a solid plan. Fresh 5.4 with a little boost ought to be a happy tow pig. Start a build thread when you get it going, i'd like to see how it turns out.