S58 G8X M2 M3 M4 X3M X4M Build Breakdown

🚘 S58 G8X M2/M3/M4/X3M/X4M Build Breakdown

Stock WHP: 498

570 WHP (+72 WHP over stock)

• RK Tunes Front Mount Intake (G8x) or (X3/4M)
• Custom Tune from RK Tunes (Link to product)
• MHD Super License (Link to product)
• MHD Wireless Flash Adapter (Link to product)
• NGK 96206 spark plugs (Link to product)
• RK Tunes High‑Output Ignition Coil Packs (Link to product)
• 2021 or newer? You need a Femto unlock! (Link to product)

600 WHP (+102 WHP)

• Hi‑Flow Catted Downpipes

700 WHP (+202 WHP)

• MHD Flex‑Fuel Kit (Link to product)
• E40 Fuel Blend

765 WHP (+267 WHP)

• MOTIV ReFlex (Link to product)
• Port Injection w/ 750 cc+ Injectors

870 WHP (+372 WHP)

• RK Tunes DVB Upgraded Twin Turbos/Single Turbo (68–70 mm)

900 WHP (+402 WHP)

• Full Low‑Pressure Fuel Pump System

1300 WHP (+802 WHP)

• Single Turbo Full‑Frame (72–75 mm)

1500 WHP (+1002 WHP)

• Single Turbo Full‑Frame (80 mm+) 

Notes (S58):

• ✅ Spark plugs every 10 k miles (NGK 96206).
• ✅ Ignition coils every 50 k miles.
• ✅ Replace injectors ~70 k miles.
• ✅ Hi‑Flow downpipes recommended.
• ✅ Charge pipes brittle at high WHP.
• ✅ Manual cars need clutch upgrade at high WHP.
• ✅ Port Injection > DI‑only at high outputs.
• ✅ RK‑Tunes parts recommended but not mandatory.
• ✅ No meth injection used.
• ✅ See DI vs DI+Port Injection breakdown.
• ✅ Spark Plug Gaps:
  – ≤ 550 WHP: .030
  – 551–700 WHP: .025
  – 701–850 WHP: .022
  – 851–1000 WHP: .018
  – 1000+ WHP: .016