Project Overview

Gale Banks has several goals he wants to achieve with his latest Duramax turbodiesel project truck, the Sidewinder D-Max Type-D. Most obviously there's speed: Gale Banks Engineering has a long history of winning races and setting records on land and in the water, and the expectations for the Type-D are no different. Banks wants to see the full-tube-chassis drag race GMC become the first diesel truck to run the quarter-mile in the 7-second range. Although diesel-powered dragsters are already that quick, reaching into the 7s in a lightweight, dedicated drag car with the aerodynamic signature of a dart is much easier than clocking that time in a vehicle that still bears the upright and blocky silhouette of GMC's compact street truck.

Banks wants his drag-race truck not just fast, but clean, too. The Type-D's Duramax 6.6L LBZ V-8, with its unique twin-turbocharger system and highly modified Bosch common-rail fuel-injection, will produce in excess of 1,000 horsepower - far more than even the land-speed-record holding, Cummins-turbodiesel-powered Banks Sidewinder Dakota.

In the current state of diesel drag race technology, high-powered engines typically produce huge amounts of black smoke pouring out of the exhaust pipes as the trucks power up in the staging lanes. Banks, however, sees the future of diesel drag racing differently. He's currently working with the NHRA to change its rulebook to allow diesel trucks to use nitrous oxide in conjunction with turbochargers. The "throttle in a bottle" power adder has a side benefit in diesels: It clears the smoke during starting-line power-ups, eliminating the choking exhaust clouds that would otherwise turn off many of the NHRA's loyal drag race fans. The late Wally Parks, the NHRA's founder, had personally assisted Banks in his quest; and currently, three national classes and six Western Division classes have agreed to the rules change. Read Gale Banks' letter to the NHRA.

There's another, longer-term reason for building and campaigning the D-Max Type-D. For years, Banks has advocated the use of diesel as a powerful, yet efficient alternative to gasoline, and not just in the trucks and motorhomes that have been Banks' specialty since the 1980s. Banks wants to see diesel spread to the mass automotive market, both as a choice for those seeking its frugal efficiency, as well as for those willing to pay for a premium, powerful vehicle. He's even trademarked the slogan, "Guilt-Free Performance," to describe the powerful-yet-economical benefits of using diesel in a light-duty automotive application.

To Banks, there's no better way to promote the viability of diesel performance than to showcase his technology in front of the NHRA's rabid fan base via the D-Max Type-D. Drag-race fans are gearheads who understand diesel's inherent power and efficiency characteristics. They also tend to be the automotive opinion leaders in their communities - the "car guy" down the street who's often asked, "What kind of car should I buy?" Win these opinion leaders over, and they'll drive market demand for light-duty diesel through their own purchases and recommendations to others. When that happens, Banks will have made significant progress in his long-time quest for diesel's acceptance as a viable alternative fuel.

Watch a short video highlighting the engine work on the Type-D, including a dyno run...

Why Did We Start the Project with an S10 Pro Stock Truck Body Chassis?

When Gale Banks decided to showcase one of his twin turbo Duramax diesel engines in a drag race vehicle, he wanted to start with a chassis combination that was well built, light, and proven. Naturally it had to represent a GM truck model. After a little searching, he found that Panella Trucking in Stockton, California had a rolling chassis 2001 Chevy S10 Pro Stock Truck for sale.

Click on the thumbnails below to see larger images
	The Panella team had been strong competitors and ultimately Pro Stock Truck World Champions. They had taken delivery of this chassis to replace their very successful S-10 when the NHRA closed the Pro Stock Truck category. The truck was virtually brand-new when Gale bought it, having made only eight passes down the track. But even in that short time, the truck was running within .03 seconds of the rest of the field, demonstrating that this was a proven chassis with enormous potential.
	But this was not just any Pro Stock Truck, but an unusual Don Ness Racecraft built body/chassis with a swing arm rear suspension, instead of the conventional four link. Even the swing arm construction was different in that it offered six pivot point locations for suspension tuning rather than a single point as in a ladder bar style setup. It was also one of the lighter Pro Stock Trucks, and it was already painted RED, the only acceptable color for Gale’s race vehicles. Gale had to have it.
	This view under the truck shows the swing arm rear suspension and a close look at the adjustable forward mount points. The advantage to using a swing arm-type suspension over the more traditional four-link is that it distributes power to both rear tires equally without transmitting any sort of torsional or twisting motion to the axle. This eliminates torque steer - a very real concern given the power levels expected from the race-tuned Duramax - and helps the truck launch in a straight line. While many swing arm designs offer no means of adjustability, this particular swing arm has six different forward mount points: three different pivot points on two levels. This design allows the suspension to be tuned for different track conditions.
	Chassis builder Don Ness paired the swing arm suspension with a custom-built axle housing and Lamb rear disc brakes. The brackets visible on top of the axle gusset and at the trailing edge of the swing arms are used to mount the truck's wheelie bars, which also can be adjusted and tuned to help the truck's launch.
	Inside the custom axle housing are Mark Williams Hi-Torque forged steel drag-race axle shafts. Lamb disc brakes front and rear are used to stop the truck.
	This overhead view of the Chevy's bed area shows off the intricate chromoly tubing that makes up the truck's rear half, the two Koni coilover shocks used to suspend the swing arm, and the truck's batteries, mounted to the rear for optimal weight distribution.
	The Chevy's front suspension is more conventional than the swing arm, utilizing Lamb Pro Stock struts. In this photo the coil springs have been taken off to test the suspension's travel and measure how much clearance there is between the front tires and the twin turbochargers when the struts are at full compression.
	While the front coils were off, members of the engineering team were fabricating shock travel sensors that will mount to the struts to measure front-end lift at launch. Similar sensors will also be fabricated for the Koni coilovers at the rear to measure squat. All these data points will be evaluated and factored into the truck's setup to optimize its launch characteristics.
	A close-up shot of the attention to detail this chassis received from the Don Ness fabricators. The blue tape on the cage is there to protect it as the turbo components are mounted, removed and remounted during their initial configuration.

	Read more about the Type-D and see more photos in the project overview...
	Bonus article from SEMA! Read Ty Michaels' "Diesel—The Performance Option Embraced By Enthusiasts"

Dyno Tuning the Type-D

Enthusiasts understand that a dynamometer measures an engine’s output by gauging its torque, taking measurements from the flywheel (in the case of an engine dynamometer) or a vehicle’s drive wheels (with a chassis dynamometer). A dyno, though, is a far more versatile diagnostic tool than a mere power reader. When the dyno is properly set up, there’s a world of data available to those savvy enough to interpret the information and use it for a wide variety of tuning purposes.

Case in point: the 6.6L LBZ Duramax engine under development for Banks’ Sidewinder Type-D drag race truck. As the second of two Duramax-powered race trucks under construction in Banks’ Advanced Product Engineering shop, the engine slated for the Type-D initially received many of the same upgrades as did the Duramax built for the Sidewinder Type-R road-race truck (Insert link here to Type-R engine pages). Those upgrades not only increased the power output far beyond factory levels – to 650 horsepower and 800 lb-ft of torque – but also insured the engines’ durability while producing that much power under racing conditions. (story continued after photo gallery)

Click on the thumbnails below to see larger images

	The Duramax turbodiesel slated for use in the Sidewinder Type-D drag race truck was hooked up to Banks’ Superflow engine dyno in the Number One dyno cell, the cell used for testing all of Banks’ diesel engine products. Cell Number Two, on the other side of the back wall, is set up for gasoline-powered engines. Note that in the time that elapsed between when this photo was taken and the others in this article, the intake air stacks at the left were replaced by tubes vented up through the roof.
	The Superflow dynamometer is a water-break dyno, which uses water pressure (in the blue absorber at the rear of the engine) to put a load on the engine during tests. That load simulates the resistance the engine will feel in the real world when it tries to accelerate the vehicle. The dyno measures the engine’s torque output by gauging the crankshaft’s twisting action against that load.
	During each dyno run, dozens of temperature and pressure sensors send data points to the dyno’s computers to monitor the performance of various engine components. This box collects the input from 16 pressure sensors; another box elsewhere in the cell collects readings from 32 different temperature sensors.
	Here’s just one example of a data collection point: Sensors at the end of the intake manifold record the temperature (the hard line) and the pressure (the braided line) of the air inside the manifold.
	The engine is even set up with a device that measures the travel of the turbo’s wastegate.
	One data logger that’s exclusive to the diesel engine dyno cell is this opacity meter, which measures how dark the exhaust is leaving the engine. The meter works by shining a light through the exhaust and then measuring the percentage of visible light. Opacity, or the lack thereof, is an important measure of any diesel engine’s performance. Excessive smoke is an indicator of unburned fuel, which is power lost.
	A clean burn is especially important for the Type-D, as Banks wants this truck to be a clear departure from the “Smoke Boys,” who have erroneously equated the belching smoke produced by their drag race trucks with diesel performance.
	Here’s the view of the dyno from the operator’s control room. The engine can be started and “driven” from here, while computers record all of the engine data. Depending on the sophistication of the dyno program, an engine can be put through simulated driving conditions – mirroring how the engine’s speed will rise and fall as it laps around a road-race course, for example. Drag race conditions are harder to simulate on the dyno, because the operational time is so short during a quarter-mile pass. Instead, the testing will encompass measuring data at the various rpm points the engine will go through during a typical run.
	The Type-D’s current test program is to determine whether nitrous oxide injection will cool the engine’s intake charge enough to be able to eliminate the heavy air-to-air intercoolers currently used on the truck. To simulate the chilling effect of an air-to-air intercooler mounted on a moving vehicle, the Banks’ dyno uses these air-to-water intercoolers, which are charge-air coolers used with Cummins diesels in marine applications. Once the cooling effect of the nitrous has been calibrated, the dyno operators will introduce increasing amounts of nitrous while throttling back the water flowing through these coolers, to see if the nitrous can actually replace the intercoolers.
	When the intake air leaves the turbocharger, the act of compressing it has heated it – to upwards of 400 degrees F. It’s the intercooler’s job – and eventually the nitrous oxide’s – to bring those intake air temps back down to around 110 or 120 degrees F.
	One critical part of the test is to determine the most effective way to deliver the nitrous. The Duramax on the dyno has been fitted with two nitrous injection solenoids, one on each intake tube. Four different nozzle sizes were tested to see which would deliver optimal nitrous flow.
	Banks’ engineers are also experimenting with a single, central nitrous solenoid split to two nozzles. This would be a simpler system, but would require longer lines between the solenoid and the nozzles than the setup shown above. The single solenoid system was mounted to the demonstration engine seen when the truck was displayed at the SEMA Show.
	Banks plans to run two nitrous bottles when the truck races. This wasn’t done for total nitrous capacity, but to maintain consistent nitrous pressure through the run. The pressure in a single tank drops too much by the end of the pass to deliver the nitrous consistently. This update was written while the nitrous tests were still ongoing; we’ll report their results in a later update.

The competition conditions each truck will face are considerably different, however. The Type-R needs to sustain its power delivery over the long haul of endurance racing. The Type-D, on the other hand, will produce even higher levels of power – in excess of 1,000 horsepower – in short, wide-open-throttle bursts, enough to meet Gale Banks’ goal of making this the first 7-second diesel drag-race truck. Not only will the truck be quick, it will be clean, too, making those ultra-fast passes without emitting the clouds of choking black smoke that characterize other diesel drag-race vehicles.

Meeting those power and emissions goals meant taking the Type-D’s Duramax in a different engineering direction from the Type-R engine. One of the first tasks on the development agenda was to design, install and dyno test a nitrous oxide injection system.

Nitrous oxide has a long history as a power adder for gasoline engines, but its job in the Type-D goes beyond power-making. Introducing nitrous oxide into the diesel’s intake system, which adds oxygen to the intake air, leans the air/fuel mix. While this could be disastrous in a spark-ignited, gasoline-fueled engine, it actually helps the diesel by making it run cooler and more efficiently. The smoke you see pouring out of drag-race diesels while they power up at the starting line is unburned fuel – and wasted power. The addition of nitrous and its oxygen molecules will help that fuel burn, eliminating the starting-line smoke improving the engine’s efficiency.

Nitrous oxide has another benefit Banks plans to tap. When nitrous is introduced into the intake tract, the change in its structure from liquid to gas has a refrigeration effect, cooling the air around it. Banks wants to use this phenomenon, called latent heat evaporization, to cool the air charge coming from the turbos so much that the nitrous oxide can replace the heavy air-to-air intercoolers currently used to chill the intake air.

This is where the dyno testing comes into play. When the Type-D’s Duramax was initially hooked to the dyno, the air coming from the turbocharger’s compressor was plumbed through two air-to-water intercoolers to simulate the effects of the air-to-air intercoolers on the truck. The engine was then baseline tested to ensure it was producing its target 800 lb-ft of torque while fuel-injection rates, exhaust gas temperatures and other critical factors were optimized. Among the dozens of data points recorded during the baseline runs, temperature sensors in the intake system before and after the intercoolers tracked the cooler’s effectiveness.

When the baseline tests were completed, it was time to start testing the nitrous. At first, small amounts were introduced into the intake flow, while data acquisition measured temperatures in the intake manifold to determine how many BTUs of heat the nitrous could absorb. Early testing revealed a positive side-effect to the nitrous: The engine’s combustion process became so efficient, the team saw a 150 lb-ft gain in torque. On the other hand, the extra oxygen caused the fuel burn to start sooner, which expended some of the burn’s energy while the piston was still moving up to top dead center. This diluted the effectiveness of the power stroke, so the Banks team had to remap the fuel delivery to better match the fuel injection and burn timing with piston travel.

Once those issues were sorted out, it was time to put the nitrous to the true cooling test. As of this writing, the dyno operators are beginning to throttle back the amount of water flowing through the intercoolers while dialing up the nitrous, to see if, indeed, the nitrous injection can replace the intercoolers as the intake air’s cooling source. Early indications show intake temps where they want them, so the results look promising. We’ll bring you updates on this process as the testing proceeds.