The military's High Mobility Multipurpose Wheeled Vehicle (HMMWV), or Humvee
to most of us, is a rugged four-wheel drive vehicle designed and manufactured by AM General
. In basic trim, the truck weighs about 7,500 pounds. For a beast of this stature, that number isn't overly alarming... until you realize that its stock 6.5-liter turbodiesel, running power through a four-speed automatic and portal geared hubs, only sends about 113 horsepower and 219 pound-feet of torque to the rear wheels. Acceleration is leisurely, but at least the truck can get out of its own way.
Understandably, the situation becomes much more dangerous, potentially deadly, when the Humvee is fully armored for duty in combat zones – ironic, right? Tipping the scales at 14,400 pounds, the stock engine is only able to accelerate the truck to 60 mph in 43 seconds. Equally as jaw-dropping is the lousy stock braking system, as it takes a full 307 feet to bring the truck to a rest from 60 mph.
To help our troops make quicker entries and exits, Gale Banks Engineering has crafted the Sidewinder Turbo system
with exhaust brake as an upgrade to the stock powerplant. When fitted, engine output jumps by about 50 percent. According to the dyno, 178 horsepower and 329 pound-feet of torque make it to the wheels. Acceleration to the benchmark 60 mph drops to 23.1 seconds, while braking falls to 243 feet. While those numbers still won't scare even the slowest passenger vehicle on your local highway, the improvement is dramatic - especially when under fire from an AK-47.
To demonstrate its wares, Banks recently invited us to drive both the stock and modified Humvees back-to-back at its headquarters in Southern California. (Note: The Humvee we drove was configured with some unique armor plating and a 50 caliber turret
- we've been asked to hide both in our pictures.)
- The stock armored Humvee (M1165 in military speak) borders on pathetic in terms of ergonomics, passenger comfort, and overall drivability. Not to be confused with its barely civilianized Hummer H1, the archaic military Humvee was unquestionably the most miserable vehicle I have ever piloted on public roads. Outward visibility, through brick-thick bullet-resistant glass was pulse raising. In stock form, acceleration was dangerously slow and throttle response frighteningly lethargic. Once moving, the heavy body oscillated back and forth as it floated on its squishy off-road tires (in a motion mimicking trailer sway). Hitting the brake pedal initiated a lot of grinding noise and only mild deceleration, as the inboard disc brakes howled while fighting a losing battle against inertia. I exited the M1165 covered in nervous sweat, verbally praising the troops who are forced to drive it daily under far less desirable conditions.
- Banks works its magic on the Humvee in several different ways. To improve breathing, the company fits a new intake and a wastegated turbocharger. A large air-to-air intercooler keeps the charge temperature down, while new injectors (and a new injector pump) ensure fuel flow isn't an issue. A monster exhaust finishes off the power improvements. Another important upgrade is the exhaust brake, aptly named the Banks Brake, which uses the engine to supplement the mechanical brakes and slow the vehicle.
- The modified Banks Humvee was noticeably lighter on its feet (likely strong enough to run neck-to-neck with a 1977 Mercedes-Benz 240D). Twice as quick is a huge improvement, and I was visibly more comfortable pulling into moving traffic. Running acceleration, from 40-60 mph, drops by half as well. This meant around-town throttle response was decent, and not a white-knuckle affair. The Banks Brake was set to automatically slow the Humvee each time I lifted off the accelerator (it reminded me of regenerative braking, but without any additional external noise as our soldiers prefer to arrive silently). Combined with the disc brakes, stopping distances were greatly improved.
- Like the aging B-52 long-range bomber, the multi-purpose Humvee will be in service for many more decades as the military conjures up ways to sustain the program. Age and expanded roles have burdened the original light utility. Nevertheless, my initial impressions say that the Sidewinder Turbo system from Banks appears to provide a necessary shot of adrenaline to a vehicle desperately in need of vitality.