A full-interior street Civic built around F-series torque, H-series cylinder-head flow, and a GT35 turbo—with the current low-boost setup serving as the first stage of a much bigger plan.
This build combines an F23 bottom end with an H-series head to create a broad, torque-heavy turbo setup aimed at strong roll acceleration without turning the car into a stripped shell. The current stage is about proving the engine, tune, fuel system, and data before asking for more boost.
Full interior, recognizable Civic, serious hybrid powertrain. The goal is usable acceleration from a roll, a controlled boost ramp, and a build that can be upgraded in stages instead of chasing a hero number before the combination is ready.
The first working version is intentionally simple: a 2.25L G23 hybrid, GT35, cast log manifold, 340 LPH fuel pump, decapped GM injectors, 3-port boost control, and a conservative 91-octane starting target.
97 mm stroke with stock F23A7 connecting rods in the current stage.
Calculated combination lands around 10.37:1 static compression.
H22/H23A-style cylinder-head architecture over F-series displacement.
Room to grow, with boost control intended for a smoother ramp—not just a higher number.
Current in-tank pump; voltage and pressure under load remain key proof points.
Adjustable FPR setting to be verified under correct reference conditions.
Wideband, vacuum/boost gauge, and oil-pressure monitoring are installed.
A shakedown baseline before any serious increase in load or cylinder pressure.
The build has already been featured in long-form video, giving the project a real story beyond the parts list. This site keeps that media connected directly to the technical build record.
Now the build is being documented stage by stage: first-start proof, low-boost baseline, roll-focused setup work, and the durability upgrades required before the power ceiling moves higher.
See all build videos →The site is built around what matters for a fast full-interior FWD roll car: power delivery, boost ramp, heat management, fuel stability, gearing, traction at speed, and data that proves each step.
Performance content is framed for legal closed-course, drag-strip, or sanctioned competition use.
The larger power numbers belong to future hardware, not the current shakedown combination. Keeping those stages separate makes the project more credible—and makes every upgrade a new chapter.
Stock F23 rods, cast K20A3 pistons, GT35, 91 octane, and roughly 5 PSI.
Forged I-beam rods, upgraded springs, titanium retainers, and a clean conservative tune.
Forged pistons, better fuel, known injectors, sealing upgrades, and a drivetrain built to use it.