Power Stroke Muscle

Trailer Life April 2002

by Chris Hemer

photography Chris Hemer

On-the-road testing for more power, torque and better fuel economy for Ford Power Strokes…

Dyno TestingDyno testing was conducted on Banks’ computerized chassis dyno. Testing begins at a simulated 71 mph at 3,200 rpm with the torque converter manually locked in third gear. The dyno then pulls the engine down in 200-rpm increments, each lasting 8 seconds, all the way down to 1,600 rpm at 36 mph. Banks engineers have found that this method allows the numbers to stabilize, and provides a clearer picture of power and torque at each rpm level. Large aluminum box under hood measures intake air flow velocity

 

Ottomind®Banks OttoMind control module piggybacks on the stock computer, and optimizes the air/fuel curve throughout the engine’s operating range. There is a different module calibration for each of the four Banks kits.

 

Wastegate comparisonBanks BigHead wastegate actuator (shown next to stock actuator) allows maximum boost pressure to be raised from the stock 18 psi to 25 psi.

 

Intercooler comparisonCompare the stock intercooler (above) to the Banks Techni-Cooler. Note that the Techni-Cooler’s end tanks have a smoother radius, and the cross flow tubes are larger as well. These features, in addition to an improved fin design, result in an 18-percent improvement in “density recovery,” or how efficiently the temperature is reduced without a loss of boost pressure.

 

Intake and Exhaust tubingThe intake and exhaust tubing for the Banks PowerPack® kit is enlarged, straightened, or both, to improve the flow characteristics over the stock pieces. All tubing is mandrel-bent.

 

Turbo comparisonThe Banks Quick-Turbo turbine housing (right) appears only slightly larger than the stock housing, but provides better exhaust flow.

 

Air FiltersBanks Ram-Air filter (bottom) flows more air and offers better filtration than the stock paper element filter.

 

TransCommand®Banks TransCommand module optimizes transmission shift points and torque converter lock-up to take full advantage of the engine’s newfound power.

When it comes to towing, diesel engines attract a lot of fans. Because of the great gobs of torque diesels tend to generate at relatively low engine speeds, they’re ideally suited to towing large trailers. But when the grunt of your beloved oil-burner still isn’t enough to make you king of the hills, you need some horsepower help.

Gale Banks Engineering specializes in making RVs more powerful and fuel efficient, and offers a variety of kits for gasoline and diesel powered pickups and motorhomes. We recently visited Banks’ facility to have a look at the company’s new hardware for the 7.3-liter Ford Power Stroke diesel engine.

Banks offers four kits for 1994-1997 (early) and 1999-2001 (late) Power Stroke engines, each more potent than the last. Kicking things off is the Git-Kit (starting at $795), which includes a Monster 4-inch exhaust system with Dynaflow muffler and 4-inch polished stainless-steel tailpipe, plus and OttoMind electronic module that optimizes the fuel mixture. Next up is the Stinger (starting at $1,375) which includes all of the above plus a 3.5-inch stainless steel turbine outlet pipe, Banks Ram-Air filter, DynaFact pyrometer/boost gauges, BigHead wastegate actuator, and, for automatic-transmission-equipped trucks, a TransCommand recalibration module. Stinger-Plus (starting at $1,975) adds a Quick-Turbo housing, which is slightly larger and allows better exhaust flow, according to Banks. At the top of the scale is the Banks PowerPack® (starting at $3,019), which includes everything found in the above kits, plus a Banks Techni-Cooler intercooler. Banks maintains that this kit typically produces a best gain of 91 horsepower and 200 lb-ft of torque, and a mileage improvement of up to 1.3 mpg.

More performance and better fuel economy at the same time? It may seem improbable, but by improving the flow of air into and out of the engine, and modifying the fuel curve, the engine will make more power. More power means less throttle opening is required to maintain a given speed, which, theoretically, should yield a fuel economy gain. To put the theory into action, we tested a Banks PowerPack on a 2001 Ford F-350 dually. As is standard with our Trailer Life performance testing, the first step was to determine the baseline power and fuel economy numbers for the stock truck. On Banks’ computerized Mustang chassis dyno, the stock truck made 227 hp at 2,800 rpm, and 486 lb-ft of torque at 1,800 rpm. Next, on the road, we recorded solo 0-to-60 mph times of 12.7 seconds with 460 pounds of ballast on board to prevent rear-wheel spin. With a 10,000 pound weight trailer attached, the stock F-350 managed 24.98 seconds 0-to-60, while the 40-to-60 mph time came in at 13.79 seconds.

Next, it was off to the fuel station to top off before weighing the truck and trailer combination at the local truck scales. Diesel fuel foams, and this characteristic necessitates having a visual confirmation of the fuel level, at the top of the filler neck, before departing on an economy loop. At the truck scales, the test rig weighed in at 18,010 pounds.

We checked real-world fuel economy on a highway course that includes some challenging grades as well as flat stretches, while carefully recording the results. Our trip took us from Azusa to Barstow, California, via Interstate 15 and the infamous Cajon Pass. The idea was to maintain an average speed of 60 mph for the entire 187-mile round trip, both before and after the Banks PowerPack was installed. This would be the fairest, most accurate method of determining average fuel economy (and keep us close enough to California’s trailering speed limit of 55 mph without attracting the highway patrol’s attention).

The Cajon Pass is a stepped grade that is mostly 6 percent, and it tends to take the wind out of a tow rig about half-way to its 4,190-foot summit. Approaching the base of the grade at 60 mph at 1,800 rpm in overdrive, the test truck managed to top the first section of the grade in third gear unlocked, at 60 mph and 2,700 rpm. By the top of the grade, the transmission had downshited into second gear, and we had slowed to 55 mph at 2,900 rpm. On our return to Banks headquarters, the truck had traveled 186.8 miles and consumed 14.49 gallons of fuel, for an average of 12.89 mpg.

With the stock test results in hand, installation of the Banks parts commenced, and we planned to perform the “modified” test the next day.

DAY TWO

We observed Banks engineers Matt Wilson and David Vermilion as they ran the final dyno pulls on the truck before we started on the acceleration test and the mileage loop. The kit seemed to be working as promised, delivering an even 300 hp at 2,800 rpm and a whopping 635 lb-ft of torque at 2,200 rpm.

Our acceleration tests were the proof in the pudding; solo, the truck went from 0- to-60 mph in just 9.9 seconds, for a 2.8-second improvement over stock. Towing, the numbers were even more impressive; 0- to-60 mph took just 19.13 seconds, for a 5.85-second improvement, and 40- to-60 mph only required 11.29 seconds, for a 2.5-second improvement.

After once again topping off the rig at the filling station, we departed on our mileage loop to see if any sacrifices in fuel economy were required for such impressive performance. As soon as we merged onto the freeway, it was easy to feel the increased power; the engine seemed to respond more willingly to part-throttle input. In addition, the Banks low-restriction intake and exhaust systems give the truck a satisfying, throaty growl when the throttle is nudged—but it was not intrusive by any means.

Back on the highway, we again approached the base of the Cajon pass at 60 mph at 1,900 rpm. As before, the engine downshifted to third gear to maintain 60 mph—but this time it stayed in third for the remainder of the grade, and even shifted back into overdrive near the top. Moreover, the climb required less throttle input to maintain the same speed as before, and it seemed like the rig had plenty of power to spare. The Banks DynaFact instruments confirmed this; we were running only 19 psi boost (out of a possible 25 psi) and the exhaust temperature was a cool 800 degrees.

At the conclusion of the mileage loop, we once again topped off the fuel tank and got a surprise: the engine had used 14.21 gallons of fuel for an average of 13.14 mpg—a .25 mpg improvement over stock. Granted, this may not be a huge gain—and your own results may vary depending on your driving style—but we think any fuel economy improvement is impressive when it comes with an increase in horsepower and torque.

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