Truely making use of the Honda parts bin
by Dan Frio
photography by Henry Z. DeKuyper
We've seen some innovative swaps and conversions in the USCC-a twin-engine Hyundai Tiburon comes immediately to mind-so a mid-engine Integra, rare though it may be in the Honda world, fits right into the USCC ranks. Still, David Dunn's H22-powered 1994 Integra/1997 Prelude blend kicks ass and earns our attention and respect.
"My idea for a mid-engine conversion started in the early 90s while autocrossing my '84 Civic Si," says Dunn. "I was raised on rear-wheel-drive cars and it was always frustrating trying to put power down with front-wheel drive. After having an NSX, I was addicted to the mid-engine feel."
When Dunn finally set about this project in earnest, he approached it from an intellectual angle, not just as a guy in a garage who always wanted his own taste of the mid-engine CRX aesthetic. He started reading Race Car Vehicle Dynamics by William F. Milliken and Douglas L. Milliken, asked his friends on Team-Integra.net for advice, and spent hours on the internet searching for similar projects.
"I found an NSX-powered CRX and an H22 del Sol, so I was relieved to find that I wasn't the only lunatic with this idea," says Dunn. He established a budget, started measuring every Honda and Acura he could get his hands on, and finally decided on a '94 DC2 Integra chassis and a Prelude H22 powerplant. The 'Teg he chose because of its long hatch-allowing the engine to be lifted in and out from above-as well as its generous overhang, providing room for the exhaust system.
After giving a K-series engine much thought, it was the low cost, availability and torque output of the H22 that sealed the deal for Dunn. He found a totaled '97 Prelude on eBay and picked it up as a donor car. Most of the vehicle was useless, but the engine and interior were intact, which Dunn describes as having been excellent for a 90,000-mile machine.
With parts in hand, many stacked floor to ceiling in his dining room, Dunn broke ground on his project, first locating his suspension mounting points, then completing the chassis structure. Next in was the engine and subsystems, then all the fabrication necessary to make a Prelude interior fit into an older Integra.Dunn elected to keep his mods as close to factory as possible. That's why we don't see any notable block or valvetrain changes, or any major powertrain enhancements. With the exception of a two-inch custom exhaust (attached to a factory cat) and a Toyota MR2 fuel tank, Dunn's power mods match pretty closely what Honda intended. This was a fairly conscious decision.
"Another goal was to use as many OEM parts as possible to minimize custom fabrication," Dunn explains. "That said, I still had to design and make a number of custom parts."
On the transmission side, a fabricated shift linkage uses stock cables with a reverse motion mechanism to select gears. Dunn has added a few other tricks to the trans, namely a limited-slip differential from an Accord Euro-R and an Exedy clutch and flywheel combo.
Rather than open up the H22, Dunn looked to his suspension to unlock speed. The Teglude perches on Koni shocks and Eibach springs. Factory Integra and Prelude anti-roll bars keep things tight in the turns, and custom fabricated caster, camber, toe, and bump steer adjusters, along with stock Prelude knuckles and custom outer tie-rod ends, allow Dunn to dial in his steering performance precisely.
With a wide range of adjustable suspension geometry and an Explicit Speed Performance traction bar, Dunn has all he needs to maximize his chances on the road course. Further adding to his road-course edge, Dunn is an accredited NASA driving instructor, with loads of track day and club racing experience.
With a stock H22A4 rated at only 195hp, it may seem that Dunn is outgunned by the Supras and Skylines making perennial appearances in the USCC. But even if he is undermatched in many events, we're sure he's checked every angle and clocked every advantage. Plus, with engineering panel, ride quality, base price, and other real-world concerns factored into the USCC, you never know where Dunn may finish.
This is a guy who admits that splicing the wiring harnesses between cars was "one of the more enjoyable jobs" of the build; a guy who studied up on DMV statutes and met with DMV inspectors to ensure he could title and sell the car if he wished; a guy who grafted a Prelude interior-HVAC, center console, wiper and turn signal stalks, and all-into an Integra body, even down to adapting Prelude window and mirror control to the Integra door panels. If any competitor can find a hidden advantage in the USCC format, we're confident it's Dunn.