RECIPE FOR POWER
Anybody with knowledge about Honda engines knows that aiming for greater power levels will only lead to expensive holes if the appropriate measures aren’t taken. Increasing the power output of the GS-R’s native B18C1 engine began on the inside. Somers Auto Machine fitted the block with ductile-iron cylinder liners from Golden Eagle before increasing the bores by 3mm over stock. Then, the 84mm bores were filled with 10.5:1 compression Wiseco pistons that make the connection to the stock crankshaft by way of Manley Turbo Tuff rods. To improve the volumetric efficiency of the engine, English Racing ported the cylinder head and upgraded the valvetrain with Ferrea Comp Plus Valves and shimmed Supertech valve springs. Once the longblock was assembled with ARP head studs, it displaced 1,933cc and could spin to 10,000 rpm. To remedy his oil starvation issue, Kerr added a Moroso aluminum oil pan that increased the oil capacity by an extra quart and features baffles to trap oil around the pickup.
ROD-TO-STROKE RATIO MATTERS
Since the engine’s inception in 1989, Honda has offered more than a dozen iterations of its DOHC B-series powertrain. Displacement ranged from 1.6L to 2.0L. Some featured variable valve timing, some did not. The GS-R’s B18C1 has proven to be one of the most popular, even two decades after its introduction. Part of what makes it special is its unique geometry. Its 1.58:1 rod-to-stroke ratio means spinning the rotating assembly to as high as 10,000 rpm was possible. An engine’s rod-to-stroke ratio represents the length of its connecting rods compared to how far up and down the bore they travel. The smaller the ratio, the greater the rod angle, which can lead to premature piston, cylinder wall and bearing wear, among other things. The GS-R’s relatively higher ratio allows its rods to remain closer to vertical while traveling through the bores, exhibiting less side load against the cylinder walls, resulting in longer engine life and better durability.
Kerr elected to retain the Extreme Turbo Systems turbo kit, which centers on an ETS manifold and a Precision Turbo 6262 turbocharger. At the time this set up had not yet been tested to its fullest capacity, and he felt more could be had from the system. When English Racing was tuning the Hondata V3 S300 ECU, they noticed the higher boost levels were blowing out the spark and causing incomplete combustion. He sourced a viable solution from T1 Race Development. The T1/M&W Pro 10 ignition system improved the spark energy being delivered and permitted tuning at higher boost levels. With the tables adjusted accordingly, the Integra generated 742 horsepower and 467 lb-ft of torque to the wheels.
STREET CAR, LOOSELY DEFINED
Kerr wasn’t just aiming for 190 mph. He wanted to do it in something that still resembled a street car. Inside, most of the GS-R’s interior had been retained, including its original seats, albeit ones now enshrouded inside of a five-point roll cage and with GForce harnesses strapped about them. It’s insured. It’s registered. And as far as the state of Washington’s emissions testing standards are concerned, it passes muster. Kerr will tell you it’s a streetcar but without the wink and the nod that you’d expect. He drives it every weekend, accumulating at least 500 miles of abuse every month. Hondata’s S300 engine management system and traction control allow Kerr to tailor boost pressure to all five gears. The results are decreased boost and torque distribution in lower gears where traction’s harder to come by and the full 31psi at higher vehicle speeds.