Author: Ken Payne
"Roush" -- the name means performance. "Supercharger" means power. Combine them and you have the Roushcharger. Roush's intercooled supercharger kit turns a mild mannered 2004-2007 Ford F-150 into a fire breathing torque monster. Two questions come to mind: How much power and can it be improved upon?
The answers? Lots and yes.
During the installation and tuning of Roush's intercooler supercharger on our Roush F-150 project truck we conducted dyno pulls on a Dynojet dynometer in order to get accurate numbers of the gains available over stock and how much more power is still available from the 5.4L 3V modular V8.
Here you see the dyno plot for the stock 5.4L. The graph shows power all the up to 5800 rpm. In real driving the vehicle will shift at 4900 rpm so keep that in mind. This Roush F-150 is equiped with Roush's 20-inch wheels so this number is slightly lower than it would be on F-150's with OEM tires and wheels. Stock power is 207.54 RWHP and 254.64 ft/lbs RW torque.
This is the same engine with the intercooled Roushcharger installed. Power is 329.23 RWHP and 371.51 ft/lbs RW torque. Very impressive. Notice the sudden drop-off at around 5300 rpm? The tune which Roush supplies dumps boost at exactly 5312 rpm. In normal driving conditions this isn't an issue because the truck shifts at 4900 rpm, well before the boost is dumped.
Next, Mike Troyer of Troyer Performance put his considerable F-150 tuning experience to work on this truck and the results were stunning. A slightly larger boost pulley was installed (only about 1/2lb extra boost). The primary reason for installing this pulley is rotational mass. The pulley supplied by Roush weighs in at over 10lbs while the after market pulley is just under 2.5 lbs.
Royal Purple 5w/20 synthetic oil was used to give this truck the added benefits of a good synthetic oil. When you're dealing with the power levels it will put out it pays in the long run not to put in cheap oil. We've since run oil analysis on the oil and the results are really good. These will be presented in a follow-up article.
Next, Mike worked on the PCM's tune. Torque management during shifts was vastly improved. This won't show up on the dyno but my experience shows that it makes a huge difference in both driveability on the street and ETs. Mike then worked on other aspects of the tune (I can't give specifics because it's proprietary) and we did another dyno run.
Here you see the results of Troyer Performance tuning. The truck gained a huge 44.33 RWHP and 45.31 ft/lbs RW torque for a total of 373.56 RWHP and 416.82 ft/lbs RW torque. Numbers like this, with a good set of tires, puts the truck in Ford Lightning performance range. Not bad for a 4 door Supercrew. Again you'll notice the boost dumping at 5312 rpm. Unfortunately, with these power levels the 4900 rpm shift point isn't optimal. A 5400 rpm wide-open-throttle shift point provides the quickest ETs and max power. Move the shift point to this rpm and you bump up against the boost dump and ultimately end up with lower ETs as a result....
Here is the final dyno run. Mike has worked some tuning magic to circumvent the 5312 rpm boost dump. The truck now makes power all the way up to the 5800 rpm rev limiter. Peak power is 376.48 RWHP and 415.55 ft/lbs RW torque. Even more important that these numbers is the WOT shift point can now be moved up from 4900 rpm to 5400 rpm.
The most incredible thing about the custom tuning is we gained roughly 155 RWHP and 200 ft/lbs RW torque over the what the Roush tune provided at the rpm ranges beyond the boost dump! This shows you what can be accomplished with proper custom tuning.
Here are all three graphs overlayed, with RWHP on the top and RWTQ on the bottom. It illustrates the gains achieved better. The top/right of this article page has a text file attachment you can download to see the raw data dumps. Note the date/times are from when the file was exported by the software (January), not from the days of the pulls (November).
Unfortunately we ran out of time (I had to be back in Atlanta for a business trip the following day) and could not go further but this gives a very good idea of how much can be gained with a competent tuner like Mike Troyer. Mike's tuned more F-150s than probably anyone else in the USA and knows a lot about squeezing out every ounce of safe performance from them (and not so safe if you're willing to do that). Mike is confident that with a little more time on my truck he can get it to the 400 RWHP mark without additional hardware. I hope to take him up on that offer soon.
On the street the Troyer Performance tuning is a sheer pleasure to drive. 1-2 shifting is much better, power comes on with less throttle and it'll light the tires across an entire intersection if you're so inclined to burn up your hard earned cash on tires. How fast will the truck go? I buried the needle around 130 mpg and my courage ran out long before the truck ran out of power. I'm planning some track time this spring to see what it will do. If you have an F-150 without a Roushcharger look up Troyer Performance and get one installed. You won't regret it. If you already have a Roushcharger... get a tune from Mike and you won't be able to wipe the grin off.
Roush F-150 Project Truck Source:
(Copyright 2007 Ken Payne, All Rights Reserved. This article is used by Internet Brands, Inc. with permission - no license is given beyond this permission and may be revoked by Ken Payne.)
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