Integra-swapped 1992 Civic is emissions-legal and back on the street
I've owned a very battered 1992 Honda Civic DX hatchback for 12 years now, making it the car I've owned for longer than any in my life (including my notorious 1965 Chevrolet Impala sedan). It's by far the most reliable motor vehicle of the dozens I've owned in the 38 years since I bought a '69 Toyota Corona for 50 bucks, and I've used it for everything from V8 engine hauling to serving as a mobile platform for animatronic skull brake lights to running some of the slowest quarter-mile passes in the history of Bandimere Raceway. Nearly two years ago, I had a party that forced me to move forward on my long-stalled engine/suspension-swap project for this car, and it has taken me this long to get around to wrapping up all the hundreds of loose ends involved. Now it's a real car again, in full legal compliance with Denver County's vehicle-emissions laws and back on the street. I'll be telling the full story of this project during the coming weeks, and here's the introduction.
The fifth-generation (1992-1995) Honda Civic has become one of the most popular engine-swap recipients in North America, much as the Model A Ford was during the 1940s and 1950s and the '55 Chevy was during the 1960s and 1970s. The main reason for this is the same as it was for those older Detroit cars: the ready availability of lots of bolt-in or near-bolt-in performance upgrades. The third-generation (1994-2001) Acura Integra was based on the fifth-gen Civic, which means that Integra stuff and many members of the Integra-powering Honda B engine family come very close to being easy bolt-ins for the Integra's Civic sibling. Thousands, maybe tens of thousands, of 1992-95 Civic owners have dropped Integra running gear into their cars, but I chose to do my swap the hard way.
The D15B7 engine that came in my car was rated at 103 horsepower— when it was new, and when it was at sea level. With 200,000 miles at Denver's 5,280-foot elevation, I think it was delivering maybe 70 horses to the front tires. The 1996 Integra GS-R engine under its hood is good for 170 horsepower, and getting bolted in was just a matter of playing mix-and-match with a bunch of junkyard engine mounts (online resources on the subject of Honda engine swaps are, to put it mildly, a miasma of confusion, flame wars, and outright hallucinatory gibberish, and we'll explore that topic in greater detail later on). The really hard part about this swap was that I wanted the GS-R's original factory computer to believe that it still lived in its original home, with all emission-control features working correctly and no Check Engine Light nightmares. To do this, I had to make an adapter harness to connect the car's OBD1 ECU connector plugs to the B18B1's OBD2 ECU. Most people doing this swap either use an aftermarket ECU or get a Japanese-market OBD1 ECU, both of which disable most or all of the emissions-related features, not to mention the cool intake-air bypass feature in the B18C1 that delivers better low-end torque. Making this harness took many junkyard trips, weeks of maddening research, and endless soldering and insulating of tiny connector pins.
Along with the Integra GS-R engine, transmission, and wiring came a bunch of aftermarket Integra suspension stuff of unknown origin. That all went into the car, along with a complete junkyard-derived Integra brake system. There isn't much of the original Civic left. The car sits lower than I'd like for what's supposed to be a beat-up-looking sleeper and the ride is hilariously harsh, so I think I'll swap in some softer/taller springs soon.
I brought the car to AA Performance Muffler, just south of Denver, and had a stock-looking exhaust system installed, complete with a catalytic converter that would pass even California's brutal emissions standards. It's on the loud side, but only under load and when VTEC kicks in, and the tailpipe is just barely bigger than the one Honda of Canada installed in Ontario, back in 1992.
Once I had the new ECU adapter harness in place, it took me a while to chase down the handful of ECU trouble codes. All were traceable to either vacuum leaks or my bad wiring. Once the car could go through the gears and not pop a Check Engine light (I'm even using the old Civic instrument cluster), I took it down for a Denver County emissions check. Would it pass?
In fact, the tailpipe-gas numbers are far cleaner than the ones I got with the original D15B7 engine; this is partly due to the brand-new, high-quality catalytic converter and partly due to the more modern engine controls on the OBD2 engine versus the old OBD1 setup. So now I've got 70% more horsepower and I'm making less HC/CO/NOx smog per mile driven.
When a 24 Hours of Lemons team blew up the B18A1 engine in their Integra at the Get Yer Phil 500 race (named after me), I convinced them to drive to Denver and pick up my old engine and related hardware. They couldn't get it swapped in before the checkered flag, unfortunately. So, new engine in the car, which drives very well. Old engine gone. It's a win-win!
I'll go into more detail on this project in future Civic Engine Swap Hell posts, including track-day results from High Plains Raceway, so check back regularly.