Most readers should remember our '05 RSX Type-S Challenge car that we built up for Acura in a number of tech stories throughout 2006 (Feb., March, and May). It was the one that ultimately made 310 wheel HP N/A, through a cat, on pump gas, and it still passed emissions.
Still doesn't ring a bell? It was the underdog that beat out all but one of our competitors for a shared second-place finish. The car is a piece of history, but just because the challenge was over almost a year ago doesn't mean we're done with it.
We can't say the same for the motor, however. The 2.3L K20Z that posted those unprecedented numbers is no more, by way of a spun main bearing. But instead of going through the hassle of finding a machine shop that is set up to align bore that block in order to rebuild it, we figured we'd swap the bottom end out for a fresh '04 one and give it some boost.
The rebooted DC5 starts its quest for power anew at its birthplace, After Hours Automotive in Wilmington, Calif. Brian Kono of After Hours built the first motor, so it was only fitting to bring the RSX back for a second round.
Kono installed the new bottom end using a Cometic head gasket and an ACT clutch and flywheel kit. The gasket is an MLS variety, or Multi-Layer Steel, which are comprised of three layers of stainless steel. MLS head gaskets have been said to reduce bore distortion and withstand extreme cylinder pressures, such as in forced induction apps. As for the clutch and flywheel, it appears the rigors of the Challenge destroyed our previous procurements in that department. We thank ACT for stepping up with one of its Performance Street kits.
Once the motor was back together, we were on our way to Moss Motors in Goleta, producers of Jackson Racing products, to exchange the OE intake manifold for a JR supercharger. Thanks to the Hondata K-pro engine management system already onboard, the blower install was quick and easy, as we were able to omit all of the fuel system components that came with the blower itself.
After Shawn Church had his way with the K-Pro, it all added up to a net 267 wheel hp and 175 lb-ft of torque. It's not the same gutsy 310 naturally aspirated ponies it was before, but she'll do a trip to Buttonwillow and back without flinching, and still chase down larger displacement fare on the track. We submit our photo journal of the latest tweaks.
We get some blower cams from IPS, a new intake, and bump up the boost a bit in an effort to bring the torque curve up. Yee-Haw!