From the grandstand, watching the truck run is like watching a missile launch. It's loud, but not so loud you need earplugs to be nearby, and then the truck disappears down the track, straight as an arrow, with perfectly progressive, continuous acceleration through the traps. Driver Wes Anderson describes the ride as "seven seconds of freaking pure rush." He adds, "Compared with a gas car, the feeling is of smooth, constant acceleration. With a gas car, there's more noise, it's more violent, and there's more rpm--it slams you around more."
"It's kind of busy in there," he tells us. "You hit second gear in less than a second."
Spectators have a hard time believing the truck is actually a diesel. The burnout results in billowing tire smoke, but when the truck runs down the track, there is literally zero smoke. In the pits, when the truck is started, there's just a whiff of diesel scent, but even at low rpm with essentially no boost and no nitrous running, the exhaust is clean. To eliminate confusion and reinforce the message, Banks painted "Diesel Powered" on the hood, and on the back, "tire smoke only."
The clean-burning engine uses the same tricks GM Duramax engineers used to make their newest diesel emissions-compliant, plus a few more. Like the newest Duramax, the computer-controlled fuel-injection system uses multiple squirts of fuel instead of one big slug, to make sure all the fuel is burned, and the ceramic injectors have multiple holes in each tip so the fuel spray is widely dispersed.
Just as on a stock truck,...
Just as on a stock truck, computer processors are everywhere on the Banks Sidewinder, managing the air/fuel mix and recording data. The difference here is that, with nitrous in the mix, the air/fuel control becomes a critical part of the engine-management challenge. Nitrous delivery has to happen at exactly the right instant, in exact proportion to fuel and air, for the truck to launch correctly. The 6.6-liter Duramax expends somewhere between six and 10 pounds of nitrous oxide in every run, which also functions to cool combustion.
Between runs, the Banks crew...
Between runs, the Banks crew meticulously analyzes the data, re-tightens critical fittings, and reviews its "pre-flight checklist." Here the crew iced down the transmission cooler, which keeps torque-converter temperatures under 250 degrees F. As they stage the truck, the torque converter gets so hot the ice in the cooler will have turned to hot water by the time the S-10 returns to the pit.