2004 +F-150 ROUSHCharger Supercharger 101
By Sam Haymart
The ROUSHCharger supercharger system offered for the Ford F-150 5.4 V8 is another successful package from Roush Performance that offers an OEM level of engineering, quality, design, and drivability. While it does not add the kind of horsepower that other known aftermarket kits from Procharger, Kenne Bell, Paxton and others it offers things in the way of warranty and livability that the others do not. As Roush does most of Ford Motor Company’s R&D for high performance vehicles, it is no surprise that the Roush system looks and acts like factory component while delivering a significant power increase.
The information is gathered from Roush Performance documentation, reports from Roush supercharged F-150 owners, and bit of wisdom we have gleaned from sources within the engineering brain trust that created these cars. Because of this, the following information should be considered to be somewhere between opinion and fact, but closer to the latter. We suggest that your results may vary and we invite you to keep us up to date on what has worked for you and to what degree it has not.
The 2005 Roush F-150 supercharger system is offered both in aftermarket kit form to the public and is offered as a dealer installed option at Certified Roush Ford Dealers. The system differs from the packages that Roush has offered for Mustangs in a number of ways, but shares many of the same characteristics.
The heart of the supercharger system is a custom specification M112 blower that was been optimized by Roush. The M112 used has some proprietary differences that Roush specified for their units that gives it superior efficiency and flow compared to the “off the shelf” blower from Magnussen/Eaton. The unit used for the F-150 package is different visually from the Mustang supercharger systems in that it has a different casing with the air inlet on the top. This is a necessity due to engine bay characteristics of the truck. Also, unlike the Mustang packages the F-150 ROUSHCharger is not inter-cooled. Because of this the intake manifold is a simpler one-piece unit. The bypass valve in the Roush supercharger becomes controlled by the same circuitry that controlled the charge motion control valves that are tossed aside with this installation. Roush points out emphatically that disabling or modifying the action of the by-pass valve has no benefit to performance as it only allows bypass when boost is not being created or needed.
The F-150 ROUSHCharger system has a secondary sheave front engine accessory drive (FEAD). This provides bracketry and additional idler pulleys supporting a second serpentine belt to drive the supercharger. This design allows the existing accessory drive system to remain largely unmodified and therefore keeps belt life longer for them. The FEAD that Roush designed for this application is far less complex than the system of the 2001-2004 Mustang supercharger. It forgoes the floating crankshaft pulley, allowing for less castings, bushings, and additional weight. This makes installation a bit easier and takes some of the cost out of the package.
There are still some advanced electrical wiring, modification of steel and plastic parts, and plumbing tasks that require an experienced and able installer with the appropriate tools. See the 2004+ F-150 ROUSHCharger Parts List and Installation Manual PDF (4mb) for more details.
The package includes an ECU reprogramming that utilizes proprietary software. The supercharged 3V 5.4 wont work without it. This software is all new as variables such as the drive-by-wire throttle body, variable valve timing and the CMCV system have to be counted into the programming. While at the time of this writing we do not yet have all the background information on the software, previous experience with Roush products tells us that the OEM programming taps the maximum safe performance from the stock 5.4 3V engine. The Roush software adjusts various data tables based on readings from the standard hardware such as the O2 sensor, MAF sensor, and adjusts the tables and where in them to read the data. Thus MIL eliminators and other sensor replacements with a Roush supercharged car cripples the Roush ECU software’s ability to read and adjust to important data. (see Exhaust section)
The Roush Supercharger package uses a completely new air intake tube that carries the factory MAF sensor, albeit in a new location nearer to the throttle body. The stock factory Ford throttle body is retained. An all new sheet-metal “cold air” style air-box is provided that uses a high flow cone style air filter. Because the 2004 and up F-150’s have and integral MAF sensor, replacement MAF has been a difficult proposition. The Roush air tube provided with the supercharger is a pretty good sized tube with little restriction in the design.
The ROUSHCharger package does not provide any fuel system modifications above and beyond a modified software program. There is obviously enough fuel system capacity in the factory hardware as the system is currently configured. The future will tell as to what fuel system mods are necessary as our owners test the waters.
Most aftermarket cat-back exhaust systems can add anywhere from 5-15 rwhp and an additional 5-8rwhp with catted X-pipes. Note again, that using MIL eliminators and/or and off road X pipe severely cripples the Roush ECU's ability to adjust and compensate, setting the table for less performance and unsafe AF ratios.
There have been smaller supercharger pulleys marketed for the earlier generation Roush supercharger systems that up the boost by about 1-2 lbs. The presumption is that this pulley would attach to the F-150 unit. Owners of the similar 2001-2004 Mustang superchargers have reported a stronger pull and rwhp gains of 9-15 hp on average have been reported. Of course, adding a pulley increases boost and theoretically leans out the AF ratio. The ECU can mitigate this to a degree but if you live in areas with high altitude like Colorado or hot temperatures like Arizona, you probably want to make sure your AF ratios are safe once installing the pulley. Again, we are awaiting data on both available pulleys and what results owners will have.
Under-drive Accessory Pulleys:
On the F-150, under drive accessory pulleys may be an option on the accessories ONLY. However, the supercharger uses its own crankshaft pulley that utilizes a special adapter that may not work with aftermarket under drive pulley kits.
Heads, increased displacement, and cams:
At this point we don’t have any data from real world owners or cars who have utilized larger displacement versions of the 4.6 engine or have had custom head or camshaft installations. There have been a few owners reported to be working on such modifications and we will revise this archive when we get data from them.
If you do it, don’t do it upstream of the supercharger. The jury is still out on the viability of the new 3V 5.4 at the time of this writing, as to the amount of power the engine can make before coming apart. Surely in time we will be revising this.
So how much power can I get?
Roush quotes 412 hp depending on the press release. Our experience is that Roush historically undervalues its performance numbers, meaning that in the real world, performance usually exceeds their claims. We will revise this archive with real world results as they come.
Are you a pioneer? Let us know about your ROUSHCharger experience, what mods and what power you have.