Bonneville: “The world’s fastest salt.” What better place to take a heavily modified LSX engine, run it flat out for several miles, and see what it’s really made of? That is just what Dave Kixmiller, from Nashville, Tennessee, has been doing for several years now with his impressive LSX-powered GMC Sonoma pickup truck, and at this years’ Bonneville Speed Week, Dave and his crew pushed the Sonoma to a record setting 222 miles per hour. Dave was kind enough to take a few minutes to talk with us about his truck, its remarkable LSX power plant, and the intricacies of running a land-speed vehicle on the salt flats of Bonneville.
LSXMAG: Thanks for taking a few minutes to talk with us about Bonneville and your pickup, Dave. So, how long have you been racing the truck like this?
Dave Kixmiller: “Kris Henderson and I started building the truck about three-and-a-half years ago specifically to go to Bonneville and set a new Modified Mini-Pickup record. Kris and I make up Kix-Henderson Racing and we partnered up with Chris Coffey from Carma Performance in Nashville earlier this year. We just finished the truck in time for the Hot Rod magazine “Top Speed Challenge” in Maxton, North Carolina (part of the East Coast Timing Association series). We broke our first Maxton Mile record on a licensing pass at this event, but broke a wheel off on the next pass and smashed up the bed and rear four link and air ride. We thrashed like crazy, put on a new bed side, fixed the four link and air ride with the help of Quality Air Ride, and got the truck back together for the next event in May where we set seven more one-mile land speed records. At Maxton you can race against records in classes that have bigger engines. Our little LS is only a 358 CI and we took all the records all the way up to 500 cubic inches blown!”
LSXMAG: What special considerations did you have to take in prepping the truck to run over 200 MPH?
Kixmiller: “A lot of things come into play on a Bonneville car that actually fly in the face of the traditional Hot Rod or Drag Racing mindset. Most notably: weight. We are racing on packed down salt, so traction and stability at speed are always issues, even on good salt. We added as much weight as we could to the truck – using heavy quarter-inch plate on the floor, thick gauge roll-bar tubing, etc. The week before we left for Bonneville we spent an entire day melting lead weights and pouring them into steel tubing to bolt in various spots on the frame. I think we added over 500 pounds of lead, then stacked several hundred pounds of elevator weights over the rear axle and bolted them down. That little Sonoma weighs almost 5,000 pounds with the driver in it. We’ll add almost 2,000 more pounds when we go turbo for our next Bonneville attempt.
The other reason for adding weight is related to aerodynamics;, the front of a car acts just like an airplane wing at speed. We have seen several cars leave the line with the front air dam touching the ground, only to see pictures at mile three or four where the front end is four or five inches off the ground. Not only does this kill the aerodynamics on the car, but it also makes it hard to steer. More weight in the front helps a lot! We also had to have adjustable ride height, added caster (12 degrees) and a rock solid platform. Quality Air Ride built us a bombproof four link for the Ford 9-inch, trick front A-arms, and billet double adjustable air bagged shocks. This thing will lay frame and has the ability to rise up 5 inches without upsetting any of the steering or geometry.
The most important consideration for a Bonneville car running over 200 MPH is engine life. A lot of engines make a lot of power these days, but sustained pulls at WOT above 8800 RPM take a whole different level of planning.”
The Sonoma's de-stroked 358 CI LSX beast.
LSXMAG: Who built your engine? Can you give us some of the details of the build?
Kixmiller: “A lot of great people helped us out with the engine! We are using an ERL Superdeck 5.3L block with billet main caps, Callies billet crank, Howard’s billet rods, and Wiseco custom pistons. Bill Dailey adapted one of his Daytona Prototype billet LS dry sump setups to turn five gallons of oil exactly once during a five mile pull, so even if a return hose blows off we have enough oil to complete the pass safely. Richard at West Coast Racing Cylinder Heads CNC ported the All Pro heads and set them up with titanium valves and Trophy Truck springs. Dan Jesel built the entire valvetrain, and Billy Godbold from COMP worked with Kurt Urban to spec the cam. John Marcella fabbed up what is probably the most beautiful sheet metal intake I have ever seen, and Patrick at Pro Systems built the twin Holley Dominators to top things off. The whole thing is fired off with a custom ICE 15 volt ignition driven by a 7 amp box, and we fabbed the stepped headers in the truck with a kit from SPD. Kurt Urban expertly assembled the engine, and the attention to detail showed when we completed 21 pulls at Bonneville as high as 9400 RPM and never ran the valves once.
We’re planning to add the new Holley Dominator EFI, a massive intercooler, and two turbos for our next attempt. Going turbo will let us get it all under a factory hood and cut the aero load quite a bit. We hope to double the horsepower to 1600, and that should put us in the 250 to 260 MPH range!”
LSXMAG: What made you go with an LSX engine instead of a traditional Small Block, Big Block, or even some other type of engine?
Kixmiller: “Why an LS? Easy… head flow! Where else can you find a set of heads that can flow 429 CFM on a 358 cubic inch engine that is planning to turn close to 10,000 RPM? Plus, I worked for GM for fourteen years, so it seemed like the natural choice for the Sonoma.”
LSXMAG: Any final thoughts you can offer us on the “Bonneville Experience”?
Kixmiller: “In my humble opinion, Bonneville is the last bastion of true Hot Rodding. It’s a place where dreams really can come true!”