Parts graph
B18C
The B18C is the high-water mark of Honda's NA screamer era — 8,400 rpm from the factory in the DC2/EK9 Type R, with a bolt-on ladder (header, cams, tune) topping out near 215 whp before forced induction takes over. The speed-density OBD1 ECU makes Hondata S300 the hub of nearly every build, and the stock rods draw a hard line around 350-400 whp that forged internals must erase before the big-turbo tier opens.
Compatibility intel 17 edges
The rules that make combinations work — or not. This is the knowledge that used to live in dead forum threads.
- Injector Dynamics ID1050-XDS (set of 4)requiresWalbro GSS342 255lph Fuel PumpID1050s can outflow the stock 190lph pump above ~300whp; a 255lph GSS342 holds base pressure to redline.
- B18CconflictsInjector Dynamics ID1050-XDS (set of 4)The stock OBD1 P72 has no injector scaling — 1050cc saturated injectors flood it at idle; S300 or a standalone is mandatory to resize.
- Acura RDX 410cc Injectors (OEM Denso, set of 4)recommendsHondata S300 V4RDX 410s bolt in cheap but run pig-rich on a stock chip; rescaled on S300 they idle and cruise like OEM.
- Garrett G25-550 TurbochargerrequiresInjector Dynamics ID1050-XDS (set of 4)550whp on 93 octane needs ~1000cc of injector per cylinder; even RDX 410s are maxed out by 300whp.
- Garrett G25-550 TurbochargerrecommendsMishimoto Universal 24x12x3 Front-Mount Intercooler + PipingA mid-frame turbo at 20psi heat-soaks anything smaller on back-to-back pulls; a 3in-core front mount keeps IATs where the tune expects them.
- Wiseco 81.5mm Forged Pistons + Eagle H-Beam RodsunlocksGarrett G25-550 TurbochargerStock B18C rods bend around 350-400whp; forged rods and pistons are what open the door to the G25's 550whp tier.
- Garrett G25-550 TurbochargerrequiresCompetition Clutch Stage 4 6-Puck (B-series hydro)The stock ITR clutch slips past ~220wtq; a Stage 4 six-puck is the minimum that holds mid-frame turbo torque.
- Garrett G25-550 TurbochargerrecommendsHaltech Elite 1500 + B-series Adapter HarnessPast ~450whp with flex fuel and closed-loop boost control, a modern standalone beats tuning through a 30-year-old chipped OBD1 board.
- Garrett G25-550 TurbochargerrecommendsMFactory Helical LSD (B-series hydro)GSR and EG boxes are open-diff; past 250whp an open front end one-wheel-peels out of every corner — ITR boxes already have a factory helical.
- Kraftwerks C30-94 Supercharger KitrequiresHondata S300 V4Kraftwerks ships its startup basemap for S300; boosting the stock ECU with no fuel control leans out and detonates.
- Kraftwerks C30-94 Supercharger KitrecommendsWalbro GSS342 255lph Fuel PumpAt the C30's ~9psi the stock pump is at its limit; the 255 adds the headroom a smaller pulley will need later.
- Kraftwerks C30-94 Supercharger KitrecommendsKoyorad HH-Series 36mm All-Aluminum Radiator (DC2/EK)A centrifugal blower dumps constant heat into the bay; the 36mm dual-pass core stops the coolant creep the stock DC2 radiator can't shed.
- Skunk2 Pro 1+ Camshafts (B-series VTEC)recommendsHondata S300 V4Pro 1+ cams only pay off after lowering the VTEC point and dialing cam timing on a dyno — a locked stock map leaves 10whp on the table.
- Skunk2 Pro 1+ Camshafts (B-series VTEC)recommendsSkunk2 Alpha Series 4-2-1 HeaderCam gains stack on top of breathing mods; without the header and exhaust underneath, the Pro 1+ mostly shifts the powerband instead of raising it.
- Skunk2 Alpha Series 4-2-1 HeaderrecommendsSpoon Sports N1 Muffler (60.5mm)The 4-2-1's midrange gains die into a restrictive stock cat-back; the 60.5mm straight-through N1 keeps the path free.
- Haltech Elite 1500 + B-series Adapter HarnessconflictsHondata S300 V4Pick one brain: the Elite replaces the OBD1 ECU entirely while the S300 lives inside it — running both is redundant money.
- Wilwood Forged Dynapro 6 Big Brake Kit 12.19in (DC2)recommendsEnkei RPF1 15x8 +28 (set of 4)Dynapro 6 calipers need spoke clearance most stock-style 15s don't have; the RPF1's flat spoke face clears without resorting to spacers.
Manufacturer application charts 8 records
Fitment straight from the manufacturers’ current application pages — chart-level ground truth for this platform.
- EF9EK9DB8
The current product manual explicitly identifies these chassis and engines.
- DC2
Application page lists DC2/B18C.
- EK9
Application page lists Honda Civic EK9.
- DC2DB8EK9AP1AP2FD3SSE3P
Requested-engine chassis extracted from the current July 2026 LSD application chart; the chart is chassis/drivetrain based and does not assert engine fitment.
- EK9DC2DB8
Application list covers EK9 early/late and DC2/DB8 1996/1998 specifications.
- EK9DC2DB8
Application page lists EK9, DC2 and DB8.
- EK4EK9
Application page lists EK4 and EK9.
- DC2DB8
Application page lists Integra Type R DC2 and DB8.
Turbo & power
Kraftwerks C30-94 Supercharger Kit
Kraftwerks
Rotrex centrifugal blower at ~9psi on the stock bottom end; linear boost curve keeps stock-like driveability, the safe forced-induction tier.
Garrett G25-550 Turbocharger
Garrett
Modern dual ball-bearing mid-frame; needs a ramhorn manifold, downpipe, and full fuel system — no bolt-on kit exists, budget for fabrication.
Engine internals
Skunk2 Pro 1+ Camshafts (B-series VTEC)
Skunk2
Drop-in grind that runs on stock ITR springs and retainers; worth 12-15whp with a proper cam-timing dyno session, the top rung of the NA ladder.
Wiseco 81.5mm Forged Pistons + Eagle H-Beam Rods
Wiseco/Eagle
The standard forged bottom end for boosted B-series; stock sleeves are safe to ~600whp — past that, budget Darton sleeves and ARP head studs.
Injectors
Injector Dynamics ID1050-XDS (set of 4)
Injector Dynamics
Good for 600+whp on pump gas, ~450 on E85; published dead-time data makes them trivial to characterize in S300 or a standalone.
Acura RDX 410cc Injectors (OEM Denso, set of 4)
Acura/Denso
The classic budget Honda injector — OEM-reliable saturated units that need clip adapters on an OBD1 B-series harness.
Fuel system
Walbro GSS342 255lph Fuel Pump
Walbro
Drop-in for the stock hanger; spec the high-pressure 342 variant, which holds rail pressure under boost where the 341 sags.
Engine management
Hondata S300 V4
Hondata
Board installs inside a chipped OBD1 P28/P72; full speed-density tuning, injector scaling, launch control, flex fuel, datalogging — the default B-series brain.
Haltech Elite 1500 + B-series Adapter Harness
Haltech
Full standalone with closed-loop boost, flex fuel, and CAN; overkill under 400whp but the cleaner platform for serious turbo builds.
Intercooler
Mishimoto Universal 24x12x3 Front-Mount Intercooler + Piping
Mishimoto
Bar-and-plate core rated past 550whp; budget time for bumper trimming and crash-beam clearance on an EK/DC front end.
Cooling
Koyorad HH-Series 36mm All-Aluminum Radiator (DC2/EK)
Koyorad
Dual-pass 36mm core that sheds the track-day heat soak the thin stock radiator can't; keeps stock fan and hose locations.
Exhaust
Skunk2 Alpha Series 4-2-1 Header
Skunk2
Tri-Y design with collectors tuned around the VTEC crossover; the standard first rung of the NA bolt-on ladder.
Spoon Sports N1 Muffler (60.5mm)
Spoon Sports
The iconic kanjo-style straight-through can — loud, light, and worth ~5whp over the crushed-bent stock cat-back on an ITR.
Clutch
Competition Clutch Stage 4 6-Puck (B-series hydro)
Competition Clutch
Sprung six-puck that holds ~400whp; daily-able but grabby — pair with a lightweight flywheel and re-bleed the hydraulic slave on install.
Drivetrain
MFactory Helical LSD (B-series hydro)
MFactory
Maintenance-free torque-biasing helical; the trans must come out and apart, so do the clutch while you're in there.
Suspension
BC Racing BR Series Coilovers
BC Racing
30-way adjustable with optional Swift springs; the value pick for street duty with occasional track days.
Ohlins Road & Track DFV Coilovers (DC2/EK)
Ohlins
Dual Flow Valve damping that stays composed over curbs and street lumps alike; the benchmark damper for time-attack EK/DC builds.
Brakes
Wilwood Forged Dynapro 6 Big Brake Kit 12.19in (DC2)
Wilwood
Six-piston bite and real pad volume in a kit light enough for a 2,600lb chassis; verify wheel spoke clearance before ordering.
Wheels
Volk Racing TE37 15x8 +35 (set of 4)
RAYS/Volk Racing
The forged icon at ~10.4lb in 15x8; Type R chassis run 4x114.3 or 5x114.3 hubs, not the GSR's 4x100 — verify PCD before ordering.
Enkei RPF1 15x8 +28 (set of 4)
Enkei
The budget grid staple at ~10.5lb per wheel; the flat spoke face clears most big brake kits without spacers.
Prices are typical 2026 USD street prices. Fitment data is community-sourced tuning knowledge, not a guarantee — verify with your tuner before ordering. Marketplace links (Yahoo Japan, UpGarage, Nengun, RHDJapan, eBay) land here next.