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)
- All above +
- Hi‑Flow Catted Downpipes
710-745 WHP (+212 / +247 WHP)
- All above +
- MHD Flex‑Fuel Kit (Link to product)
- E40 Fuel Blend
*710whp on stock exhaust 745whp with high flow down pipes
765 WHP (+267 WHP)
- All above +
- MOTIV ReFlex (Link to product)
- Port Injection w/ 750 cc+ Injectors
870 WHP (+372 WHP)
- All above +
- RK Tunes DVB Upgraded Twin Turbos/Single Turbo (68–70 mm)
900 WHP (+402 WHP)
- All above +
- Full Low‑Pressure Fuel Pump System
1300 WHP (+802 WHP)
- All above +
- Single Turbo Full‑Frame (72–75 mm)
1500 WHP (+1002 WHP)
- All above +
- 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.
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✅ Spark Plug Gaps:
– ≤ 550 WHP: .030
– 551–700 WHP: .025
– 701–850 WHP: .022
– 851–1000 WHP: .018
– 1000+ WHP: .016