23/08/2026
Built B18C Turbo | Dyno Tuning & Diagnostics
Sometimes, it’s more than just a “tune.”
Returning customer Manar recently brought in his newly acquired B18C turbo Honda Civic for the BYP Racing team to go over, diagnose and tune.
With a stack of receipts from multiple workshops that had worked on the car over the years, taking on someone else’s build can often mean stepping into uncharted territory.
After servicing the car and resolving an initial starting issue, we strapped it onto the dyno to assess the existing setup. On the very first pull, we noticed the AFR leaning out as fuel pressure began dropping around 5,000rpm.
Basic diagnostics quickly led us to the fuel pump setup. The existing Radium dual-pump hanger wasn’t providing adequate fuel pickup at around 1/4 tank due to the previous installation.
Based on the current turbo combination, there was no need for a dual-pump setup. A single Walbro 525LPH pump provides more than enough fuel capacity for this package. We removed the dual hanger and installed a modified OEM hanger with a single 525LPH pump and the correct-angle fuel strainer.
The result was immediate — stable fuel pressure throughout the rev range and we could finally get on with the tuning.
At 18psi, we also encountered a misfire, which was resolved with a fresh set of correctly gapped NGK spark plugs.
With the mechanical issues sorted, we finished the calibration at 360kW on 21psi, reaching the practical limit of our chassis dyno — and more than enough power for a street-driven package.
We also dialled in boost-by-gear, RPM-based boost control and a switchable dual boost-map setup.
Plenty of tuners could have stopped the session and sent the car away to have the mechanical issues sorted elsewhere. With our experience in these Honda platforms, we make every effort to diagnose and resolve the gremlins in-house so the customer gets the car back sorted, tuned and ready to enjoy.
