We’ve never met a motorhome owner who felt the ol’ coach had too much
power, or that its mileage couldn’t use improvement. To this end, Gale Banks
and his staff have developed numerous performance-enhancing products
for most popular motorhomes that can improve acceleration and
hill-climbing speeds and boost fuel economy. This seemingly impossible
combination of more power and mileage is done by improving the
efficiency of the engine.
Banks has been in the hot rodding, racing and RV performance industry
for more than half a century. His background in engineering has led the
firm to develop innovative methods of gaining performance with a systems
approach — rather than piecemeal — to provide complete turnkey
products. Many vendors offer only one or a few parts and leave it up to
the consumer to try to install them, get them to work properly and
hopefully pass emissions testing if your area requires it.
We recently followed along as a retail customer from Minnesota
drove to Banks’ headquarters in Azusa, Calif., to get a “factory”
installation. These motorhome owners tow a dinghy vehicle and felt their
coach could use a little more power and mileage. Banks provided a
parking place and electrical power so the rig could be plugged in the
night before work began.
The test unit was a 2003 Itasca 32-foot Sunrise on a Workhorse W22
chassis powered by a fuel-injected GM Vortec 8.1-l V-8 gas engine and
backed by an Allison five-speed automatic transmission. This model is
rated at 340 hp and 455 lb-ft of torque, measured at the flywheel.
However, Banks chassis dynamometer testing has shown that only 241 hp
and 341 lb-ft of torque made it through the torque converter,
transmission, driveline and rear axle gears to drive the rear wheels.
We took the motorhome for a test drive before the installation and
measured acceleration and noted the sound, engine performance and
general feel of the motorhome. After the installation, we repeated the
same test drive and route.
The shop opened at 6 a.m. sharp, and an experienced technician who has
been doing installations at Banks for nine years drove the coach up on
the lift right away. Two techs began removing the stock parts,
inspecting the components and preparing
for installation of the full PowerPack System plus OttoMind
controller. It was a flurry of wrenches, but it was also obvious that
they had done this many times and knew exactly what to do.
Banks has found that there are several choke points in the stock
intake and exhaust. Think of a garden hose; flow is determined by the
most restricted point. If there is a kink anywhere, total flow is
limited by that point. Suction-loss tests show that the stock air intake
creates a high flow loss that limits air intake and maximum power
The intake solution is to install a bigger air-filter housing and
large-sized tubing, and replace the stock paper air-filter element with a
larger, cleanable, reusable K&N-designed part. Banks’ lab testing
has shown this takes care of improving airflow on the intake side.
The exhaust solution starts at the cylinder heads. Restrictive
stock cast-iron manifolds are replaced with long, smooth-flowing Banks
TorqueTube headers constructed of heavy wall 400-series stainless steel
tubing with 5?8-inch-thick flanges. Stock manifolds can exceed 1,550
degrees Fahrenheit and are known to warp, crack or shear bolts and blow
out gaskets. By reducing backpressure and providing more surface area
for cooling, the headers run cooler and the thick flanges allow them to
be run sans gaskets to eliminate any chance of failure there.
To maintain emissions compliance, the stock dual catalytic
converters are retained. This system has a California Air Resources
Board (CARB) executive order number and is smog legal in all 50 states.
Behind them, the restrictive stock mufflers are removed and a large
Monster exhaust with stainless steel tubing leads into a large stainless
Dynaflow muffler. The dual-inlet muffler has integral heat shielding
and is resonance-tuned to direct exhaust gases through a suite of
chambers, rather than using packing that can blow out or clog a muffler.
It’s capped off by a hefty chrome outlet on the driver’s side just
ahead of the rear axle.
By early afternoon the coach was finished and rolled out of the
shop. It was clean and complete — with paper floor mats in place to
protect the carpets — and ready for a road test. Before installation,
the engine ran quietly and smoothly, but felt a bit sluggish and
unresponsive. After the installation, the engine still started up and
ran smoothly, but it had a noticeable exhaust rumble from the jumbo
tailpipe tip that gave away the extra power on tap. On the road, the
engine felt more responsive and revved up more quickly. When upshifts
occurred, power didn’t seem to fade like it did before, and the engine
kept on pulling. In addition to our seat-of-the-pants impression, our
stopwatch backed it up. Zero-to-60 mph runs took an average of almost
three seconds less; that’s about a football field shorter to reach
highway speed from an onramp.
Banks’ chassis dynamometer testing on a similar 2004 Workhorse W22
chassis with PowerPack and OttoMind upgrades on the same engine and
transmission combination showed some major improvements. The best gain
showed a jump from 222.2 rear-wheel hp at 4,200 rpm to 292.4 horses at
the same speed. That’s a gain of 70 hp, 32 percent more than stock.
Torque improvement was similar, going from 302.3 lb-ft at 3,800 rpm to
394.6 at the same rpm. That pencils out to 92.3 lb-ft, a 31 percent gain
Other results included a gain from 57 mph in third gear to 67 mph
in fourth gear on a 6-percent highway grade. Being able to pull a higher
gear helps fuel economy and reduces strain on the engine. Banks’
mileage testing showed an 8-percent improvement at a steady 70 mph on
flat road. These are results you can feel in the real world.
Banks offers systems for most popular models, including the Ford
and GM P-series. Suggested retail price for the 2001-2006 Workhorse
W-series PowerPack with OttoMind is $3,049.47 and installation was
$845.50 (9.5 hours). The PowerPack without
OttoMind is $2,524.21 and installation would be $756.50 (8.5
hours). Sales tax is additional and prices may vary with individual
dealers across the country.
We found that the Banks products are well engineered, manufactured
and installed. They offer a lot of bang for the buck and improve the way
the motorhome runs and feels. We wouldn’t hesitate to recommend them.
FOR MORE INFORMATION
Gale Banks Engineering