It takes a high-capacity cooling system to handle over 700 horsepower during a sustained Land Speed Record run at Bonneville, so Project Sidewinder has two unique systems.
Two unique cooling systems are required for Project Sidewinder. For street use a conventional radiator system is utilized, while the Bonneville configuration includes a supplemental water tank that is housed in the bed of the truck. This added tank also serves double duty as part of the ballast system.
To cool the turbocharged Cummins® diesel on the street, a relatively conventional, if somewhat enlarged, cooling system is used. The heart of the cooling system is a large, high-capacity C&R® aluminum radiator. Multiple thermostats assure unrestricted coolant flow. Dual Spal® electric fans help move air through the radiator when the truck is stopped or moving slowly in traffic. These fans are mounted behind the radiator.
For the sustained full power runs at Bonneville, extra cooling capacity assures that the Cummins diesel doesn't overheat. An additional coolant tank is installed in the bed of the truck. This supplemental coolant tank has the added benefit off providing extra ballast to improve traction on the salt. A pair of shut-off valves will allow the supplemental reservoir to be isolated from the system during engine warm-up.
Cummins Base Engine
Already a surprisingly strong performer as delivered, the Cummins 5.9L diesel is the foundation of Project Sidewinder. Banks modifications have only made it stronger.
The engineering team at Cummins® built the base engine code named "Salt Quake" for the Sidewinder Project on their own time. This is the same basic engine that Banks® has further modified for Bonneville. This compression ignition (diesel) engine was used in baseline testing in preparation for the performance modifications by Banks. The Cummins baseline engine is a 5.9 liter, 24 valve inline six-cylinder design utilizing a Holset® HX40 turbo. Displacement is 359.0 cu. in. with a compression ratio of 15.1:1. Power output is 393 brake horsepower at 3800 RPM and 600 lbs.-ft. of torque over a broad RPM range. The electronics are Cummins and the fuel injection is state-of-the-art common rail. This stout engine has provided a durable, powerful base on which to build, impressing the dynamometer test engineers at every step. Most notable has been the apparent ease with which this engine makes power. It is deceptively quiet and doesn't sound like it's laboring even when subjected to a full load on the dyno.
Cylinder Head Development
Additional power comes from making the engine a more efficient air pump. This begins by improving airflow through the cylinder head.
Extensive cylinder head modifications have been tested at Banks® for the Project Sidewinder Cummins® compression ignition (diesel) engine. Cylinder head expert Victor Bangle handled the porting and polishing on the four-valve-per-cylinder head in preparation for dyno testing. Optimum intake and exhaust valve sizes continue to be evaluated in an effort to extract maximum flow from the head. The goal is maximum power output, but also drivability, low emissions and fuel economy for the ultimate street/competition combination.
The hand reshaping, contouring, and polishing of the ports is time consuming, but porting also produces the best airflow gains. When the final configurations have been determined through flow bench and dyno testing, as well as actual vehicle testing, a CNC milling program will be created to accurately reproduce the high-performance ports on Banks Big Hoss™ replacement cylinder heads.
Cylinder Head Modifications
Comprehensive cylinder head modifications and flow testing have been conducted on numerous Cummins heads at Banks. This cylinder head work allows the Banks engineering team to explore what can and cannot be done to the port configurations and valves, as well as possible ways to create efficient manifolding for the turbo system. More porting and flow work will be undertaken as refinement of the Big Hoss head continues.
The compression ignition engine dyno at Gale Banks Engineering is one of two recently completed. A one-of-a-kind installation, it is able to handle up to 1000 horsepower, 3000 lbs.-ft. of torque, and engine speeds of 4500 RPM. It is based on a Superflow dyno model SF3100, a Superflow Pro-console with Wyndyn software, and a Superflow cooling tower #CT1002, which is fed by a 1750-gallon water storage tank, both of which are located outside, behind the dyno cell. The diesel dyno's first job was to "baseline" the ISB 24-valve as received from Cummins in a slightly hopped-up form. It produced 393 horsepower and 600 lb.-ft. of torque at 3600 rpm. But after installation of a Banks Big Hoss fully ported cylinder head, aluminum intake manifold, tubular stainless exhaust manifold, and Holset HY 55 variable geometry turbocharger, as used in the Sidewinder at Bonneville, this engine produced 700-plus horsepower and 1100 lb.-ft. of torque, just in its first week of testing.
For high performance, getting the exhaust gases out of an engine is just as important as getting air into it. For our modified Cummins turbo-diesel, that required a custom stainless steel exhaust manifold.
To compliment the increased airflow of the ported cylinder head, the Big Hoss® aluminum intake manifold, and the Holset® HY55 turbocharger, Gale Banks Engineering designed a new high-flow exhaust manifold to channel the exhaust from the cylinder head to the turbine inlet of the turbocharger. This exhaust manifold design includes stainless steel tubing and a 3/4-inch thick steel flange. To allow for the different expansion rates of the flange and the tubing, four stainless steel expansion bellows are welded into the manifold. The turbocharger bolts directly to the exhaust manifold for maximum heat energy transfer to the turbine.
Fuel Delivery System
The fuel system for the Project Sidewinder combines proven racing technology with the stock Cummins system to assure an adequate supply of No. 2 diesel to the engine.
As with most systems on the Project Sidewinder, the fuel system is a combination of performance and safety. The stock fuel tank has been replaced with a 22-gallon Fuel Safe® fuel cell. The fuel cell features an internal fuel trap with one-way valves to assure a continuous supply of fuel during the high G-forces expected during the road race and handling dynamics expected from this sport truck. The actual cell is contained in a standard Fuel Safe metal enclosure, which is then secured within a framework, constructed of 1x1 x .090-inch square steel tubing. The framework is attached to the floor of the truck bed.
The No. 2 diesel fuel flows from the fuel cell through -10AN (5/8-inch i.d.) lines to an adjacent Holley® 110 GPM pump, which supplements the stock Cummins® diesel lift pump in the engine compartment. The fuel then flows through a stock Cummins fuel filter/water separator assembly and then to the mechanical high-pressure fuel pump.
The common rail fuel injection, which operates under extremely high fuel pressure, requires electronic control of solenoids that inject fuel directly into each cylinder. Exact timing and a duration of one millisecond require state of the art electronic controls designed by the Banks® team. The common rail fuel injection system uses an inlet metered high-pressure fuel pump with eccentric cam pump, and three pumping elements. The fuel flow requirements for 700 hp will approach 270 cubic mm/stroke. Common rail fuel injection is a key element in the ability of the Project Sidewinder Dakota to reach the performance, economy, noise and emissions goals established by Gale Banks Engineering™. Cummins advises their fuel system is capable of supplying fuel for up to 800 horsepower, which will hopefully be adequate for our needs. Dyno testing has pulled 700+ horsepower from our modified 5.9L beast!
Replacing the original Cummins intake manifold with the Banks Big Hoss intake greatly improves airflow to the modified cylinder head.
A complete intake manifold system has been fabricated for the turbocharger on the Sidewinder Cummins compression ignition engine. The system is completely custom to accommodate the large turbo in the tight confines of the Dakota engine bay while achieving optimum flow characteristics. After the stock cast iron air box is cut from the cylinder head and the intake port surface is machined flat, the new, high-flowing Big Hoss intake manifold replaces it. Cast from aluminum, the manifold is designed to withstand high pressures and the hostile environment under the hood.
Charge air cooling, or intercooling the intake air on a turbocharged vehicle is essential to achieving maximum performance. Project Sidewinder uses two intercooling systems to meet the demands of both street and racing operation. On the Bonneville Salt Flats, an air-to-water system was used, but on the street a more conventional air-to-air system does the job.
When it comes to turbocharging, or supercharging for that matter, compressing the intake air to high boost levels raises the temperature of the intake air. On the Land Speed Record attempts at Bonneville, our Project Sidewinder utilized a unique air-to-water charge air cooling system laid out by Bob Robe and Sheldon Tackett. The high-performance Holset® HY55 variable geometry turbocharger used on the Sidewinder for this endeavor heats the intake air to approximately 480-500° F. while compressing it to over 50 PSI boost. Such high intake temperatures greatly reduce the charge density and maximum power potential of the engine unless intercooling is used to bring the temperature back to manageable levels of 100-120° F. Cooling the intake air that much is a challenge. It takes serious heat exchangers and an adequate cooling medium to get the job done. The only practical way to do it is with air-to-water intercoolers using very cold water. And even then, the water flow rate through the intercoolers must be substantial.
With all of the above taken into consideration, Banks® engineered a recirculating water system to intercool the compressed intake air for the Sidewinder's Bonneville runs. The system uses twin Cummins® marine air-to-water intercoolers fed by dual Stewart-E.M.P.® high-capacity electric water pumps. The combined water flow rate is an incredible 120 gallons per minute. The ice water, taken from a custom 40-gallon tank designed by Gale Banks EngineeringTM and assembled by Glenn Lirhus, is located at the rear of the pickup bed. Internal vertical baffles divide the tank into four compartments with alternating bottom and top crossovers to the next compartment. Dual pickups, drawing from the bottom of the fourth compartment, route ice water to the pumps, which are mounted directly to the side of the tank. A horizontal, expanded metal baffle inside the tank prevents any ice chunks from being sucked into the pumps. The water starts out at 33-35° F. and is fed through dual 1-3/4-inch supply lines to the intercoolers. The water, which exits the intercoolers an average of 6° F. warmer than it entered, is returned through 2-inch lines to the tank where it is then forced to flow through the four chambers in the tank to mix with cooler tank water before being picked up and pumped to the intercoolers again. Of course, during a run the average temperature of the tank water rises. The tank water was recooled to 33-35° before the start of each run. The 300 pounds of water weight at the rear of the Sidewinder also helped rear wheel traction on the salt.
Intercooling for the street is less challenging. Because the boost pressures are more conservative, the intake air is not heated as much as in the full race setup. And full throttle operation of the vehicle will be for shorter periods of time. Consequently, a Banks Techni-CoolerTM air-to-air intercooler, positioned in front of the radiator, is used. The Techni-Cooler features a 4-inch inlet and outlet. This is adequate to keep the intake air temperatures to less than 150° F. Besides, on the street, utilizing a recirculating water system, such as used at Bonneville, would be both impractical and unnecessary. Using an air-to-air intercooler also allows removal of 300+ pounds from the rear of the truck to improve both handling and acceleration/braking performance. It also allows the removal of the air-to-water intercoolers, electric water pumps, and associated plumbing.
It is, after all is said and done, a sport truck for the street.
The Cummins 5.9L oiling system remains stock except for modifications to the oil pan for extra ground clearance and oil capacity.
The oiling system of the Cummins 5.9L turbo diesel was given careful scrutiny and deemed adequate for the power levels anticipated by the modifications that would double the engine's torque and horsepower output. However, the oil pan required modification for two reasons. First, the depth of the oil pan sump had to be reduced to provide necessary ground clearance once the engine was installed in the Project Sidewinder Dakota. Second, internal baffling and trap doors would be required to keep the oil around the oil pump pickup during the dynamic movements of the Sidewinder on the road race courses.
Consequently, the oil pan was modified with a wider, but shallower, sump. The new sump actually holds more oil than the stock sump, and it contains all the necessary baffling and trap doors to prevent uncovering the modified oil pickup during high-G turns, braking, and acceleration.
A remote-mounted high-capacity Moroso oil filter handles the filtering chores.
Ram Air Ducting
A new front air dam not only reduces aerodynamic drag, it also provides an ideal location for ram air ducting to feed the turbocharger.
The custom front air dam made at Banks Engineering for Project Sidewinder serves a dual purpose. The first, of course, is to improve the aerodynamics of the pickup by limiting the amount of air that can get under it. The underside of any vehicle, with no bellypans, is a very "dirty" area. The air dam improves aerodynamics significantly by pushing air to the sides instead of underneath the truck.
But, since the engine needs to ingest air-the more the better-why push all this air out of the way, when we can "swallow" some of it and feed it to the engine? That's the second thing our custom air dam does. Two carefully contoured inlet openings scoop up air and direct it to the turbocharger inlet. Not only is the cooler, outside air denser than hot air under the hood, but also the air pressure at the front of the truck provides a free supercharging effect at high speeds. At Bonneville, the primary hindrance to speed is wind drag. The vehicle is literally pushing air. This wind drag increases with the square of speed (that is, exponentially). The air pressure at the front of the truck is equal to the wind drag, and it gets significant at high speed. This pressure then "rams" the air into these scoops, creating pressure in the ducting even before it gets to the turbocharger. Air drag is bad. But ram air ducting is good.
On the street, the ram air ducting will not be used since it provides no filtering of the incoming air. Instead, the ram air ducts will be removed and an air intake with a conical K&N filter will be positioned immediately behind the right ram air opening in the front air dam. A sheetmetal rain shield prevents rain from soaking the filter through the ram air opening.
Turbocharger Control Electronics
Electronic control coupled with variable geometry within the turbocharger provides the means to optimize boost and turbo shaft speed for maximum turbo diesel performance.
Optimum boost and turbocharger shaft speed are crucial for peak performance and throttle response. The variable geometry technology of the Holset® Hy55 turbocharger now allows these parameters to be controlled. Since the turbocharger is capable of such sudden changes in shaft speed, only electronic control offers the quick response time necessary to vary the turbine inlet geometry to maintain peak boost without encountering a dangerous turbocharger overspeed condition, which could result in a failure. The Banks® VGT controller automatically controls the variable geometry of the turbocharger for optimum boost pressure and turbo shaft speed according to varying input from the driver, engine and road conditions. The Holset VGT technology, along with this controller, allows torque curve shaping not even imagined in the past.
Holset Variable Geometry Turbocharger (VGT) technology has been applied to the Project Sidewinder Cummins for maximum diesel performance potential for both racing and street applications.
Project Sidewinder uses Holset® turbocharger technology. A modified HY55 variable geometry turbocharger (VGT) was used for maximum power during Bonneville speed record runs. The variable geometry of the Holset turbo allows rapid changes in boost pressure. In simple terms, the variable geometry technology helps the turbocharger to maximize and totally control the boost pressure over the widest range of engine operating speed as possible. By using an axially sliding ring nozzle that varies the velocity of the exhaust gasses entering the turbine housing, the constant alteration in the geometry of the turbo allows for the creation of a wide range of boost while controlling turbocharger shaft speed. This virtually eliminates turbo lag and improves power, fuel economy and noise levels.
A Holset HY40 turbocharger that does not have VGT is also being evaluated for possible street use on the Sidewinder, although the VGT HY55 may provide all the flexibility that is needed for both competition and street use.