"Measure twice, cut once" are words to live by in any kind of construction project. This is especially true when building a race car.
Random upgrades and modifications may get you a fast track car, but more often than not, the car will be illegal or uncompetitive for any kind of real circuit racing. If your goal is to one day race your car, you need to do your homework first. Andrew Horn's Honda Challenge car (seen here) is the perfect example of how to do things right. It started with a detailed plan and was finished with flawless execution. On paper the car looks almost too good to be true, so we took it to the track to see what it could really do.
The '96 Civic DX and its owner actually go back a long way. We'll pick up the story at the point where he purchased the car for the second time. There wasn't much left. There was no motor or transmission. Various components of the car that we normally take for granted were missing. It was basically just a rolling chassis with a Mugen seat and a gaudy unpainted carbon-fiber body kit. Most people looking to build a car wouldn't want anything to do with this Civic, but for Horn it was perfect.
As the warehouse manager at Password:JDM, Horn oversaw Civic Type-R clips being parted out on a weekly basis. He had access to the parts that would let him rebuild the car however he wanted. This time the car was to become a circuit car. But before getting started, he hit the books; more specifically NASA's Honda Challenge and CCR rulebooks.
The car was built to compete in the H1 hybrid class. In this class, each car is given a minimum weight based on what engine is used. A slight loophole in the rules makes no distinction between the B16A found in cars like the '99 Civic Si and the B16B from the Civic Type-R in Japan. Most serious competitors gave up on the B16A a long time ago since even at their low weight of 2,100 pounds the cars just couldn't hang with the K-swapped cars. The B16B is different though. The killer rod-to-stroke ratio gives it the ability to safely run at 10,000 rpm all day long. If the chassis could get light enough, it just might stand a chance.
The first step was to prepare the chassis. It needed to get as light as possible. The entire car was disassembled then brought to Steen Chassis for a custom rollcage. Steen designed and built a solid cage that reduced body flex and specifically satisfied the safety requirements of NASA. Next it went to Collision Works where the holes in the firewall were welded up and the entire chassis was given a fresh coat of paint. This included the front fenders and bumper that were updated to '99 spec as well as the hood, front lip and rear hatch, which were all replaced with carbon-fiber to save weight.
It just seemed wrong to leave the four lug hubs on a CTR-powered race car. The entire Type-R suspension and brake system was swapped from a donor chassis. Then to get everything to work on the racetrack, Zeal S6 coilovers were specially valved and sprung with a rear bias. Rulebook in hand, only the required wiring and other items were added back to the interior.
Aside from installing a Mugen baffled oil pan, the bottom end of the B16B remains untouched internally. The head was prepped to the limit of the H1 rules. This includes extensive headwork and some serious cams. The prototype Blox P1 cams have big primary lobes and even bigger secondaries. It took Shawn at Church Automotive Testing some time with the Hondata S300 just to get it to idle. Once everything settled down though, he brought the power numbers up quickly.
Unfortunately, the power capped off at just under 205 hp. Once it hit around 8,500 rpm the motor seemed to choke up where it was expected to pull hard all the way to redline. This was not a huge problem though. With the quality of work that had gone into the rest of the car we would expect any power issues to be straightened out before long. Besides, this car was not built to be a dyno queen. Its true test would be on the racetrack.
We brought the car to Willow Springs in Rosamond, Calif., for a thorough shakedown. There was an event being held by NASA, which included both a Honda Challenge race and open qualifying for the Super Lap Battle. While the car still needed a few more safety items to compete wheel-to-wheel, we could at least run it with the time-attack cars and compare lap times with the H1 class.
Horn's Civic was turning heads before it even made it off the trailer. It was by far the cleanest car at the event. The simple graphics inspired by the first Honda Formula 1 car, the '64 RA271, made it even more impressive. But, it wasn't until it went screaming down the front straight at 10,000 rpm that everyone really appreciated what the car was.
As the test driver, I had the best seat to witness what the car could do. The acceleration out of the pits was awesome. The sensation was amplified by the piercing note from the exhaust. Through my earplugs it sounded great. Watching everyone on pit lane cringe as I roared by provoked a cruel sense of satisfaction that only a true sadist could appreciate.
At low speeds the performance was phenomenal. The extreme lightweight allowed the nimble car to dart through the tight corners with amazing precision. The stock shifter with hard bushings made for a really positive action. There was no need to feel if it was feeding into gear properly like you need to do with a cable shifter. All I had to do was think "shift" and it was right there. Combined with the lightweight flywheel, blipping up and down through the gears was just cherry.
In the high-speed stuff, things got a little hairy. According to the telemetry the car was running through Turn 8 right at 120 mph. At that speed it was recording lateral G spikes of around 1.4. The back end would wobble a bit as it took a set. What may have been happening was that as the suspension loaded up, the rubber bushings were distorting. The rear trailing arm bushings were already replaced with bearings, but that normally only stabilizes the car under braking. These "wobbles" were happening under lateral loads. I think a car as built as that one would definitely benefit from spherical bearings in the control arms as well.
A few times the car really stepped out and required close to full opposite lock to catch. This was particularly challenging since the motor was running out of breath at those speeds. Another 20 or so horsepower up on the top would have made throttle steering out of those situations much more effective.
These perceptions of questionable handling aren't always accurate though. Sometimes it's just a result of a car that is going really fast. Only the data could tell us what was happening.
Our official best lap time was a 1:35.269. The fastest H1 time of the weekend was a 1:34.603, set by Michael Lee in a K20 powered DC2 Integra. This was really encouraging but before we could come to any conclusions we needed to get the car weighed. The minimum weight for a B16 powered H1 car is 2,100 pounds including the driver. With Horn in the car it tipped the scales right at 2,210. With me it was slightly more than that.
Being that the car is as fast as it is even though it's still slightly overweight is great news. When Horn is finished with his licensing, he can pull the passenger seat and get even closer to that minimum weight. Then, with a little more refinement it could go even faster. Normally it takes years for street cars to get dialed into competitive race cars. This H1 Civic just goes to show what can be built with the right plan and the dedication to finish it.
Bolts & Washers Andrew Horn's '96 CivicPropulsion
A B16B CTR motor is built to H1 specs keeping a stock bottom end with a Mugen oil pan to feed the pump while pulling Gs. A Mugen head gasket raises compression for the Industrial Flow ported head. Peak cam gears secure Blox P1 cams that regulate Supertech springs and retainers. A Hondata S300 sends fuel through RC 440 injectors and spark through Ultra wires to NGK plugs. Samco hoses connect a Fluidyne radiator to the motor that's bolted in with Innovative motor mounts. Air comes in through a Password:JDM Carbon Kevlar Intake and out through a HyTech header and race exhaust. A Password:JDM oil plug, cap and cam seal keep the motor tight while its Kevlar wire cover keeps it looking tight. Power is transferred through an ACT Prolite Flywheel and clutch to a stock '97 spec ITR box with Password:JDM shift linkage bushings.
Password:JDM bars tie together Zeal S6 coilovers sprung 8kg/mm front and 12kg/mm rear. Blox UCA's control front camber while Vision units handle the rear. A CTR sway bar sits up front balanced by a 32mm hollow ASR rear bar and subframe brace. Password:JDM spherical trailing arm bearings control the front, back and side-to-side.
Hawk Blue pads squeeze Civic Type-R brakes, fed by Baker Precision lines that are pumped by a CTR master cylinder.
Rims & Rubber
R compound 235/40/17 Toyo RA-1s cling to 17x8+37 Advan RGIIs torqued onto APR extended wheel studs.
Password:JDM fenders, hood shocks and front lip mount to a front end updated with '99 spec CTR headlights. A VIS carbon-fiber vented hood, hatch and hatch spoiler reduce weight along with FAL windows. OEM JDM, keyless Rear Sedan door handles, '99 tail lights, thin side moldings, smoked amber side markers and window visors are complemented by Vision carbon-fiber mirrors. The body's finish comes courtesy of Collision Works.
The driver is strapped into a Mugen seat by a Takata harness within perfect reach of Mugen pedals, Password:JDM titanium shift knob and a Sparco wheel that's mounted to a detachable NRG hub. The driving coach sits in a Bride Kevlar seat, while both are protected by a NASA certified Steen rollcage with high-density padding. A Password:JDM Floor Plate, and carbon-fiber air bag tray and fuel pump covers make the final touches to this all business interior.