OEM B58TU Pump vs Dorch Stage 1 & 2
Fuel volume is the ultimate gatekeeper of power on the BMW B58 engine. While the factory rotating assembly and cylinder head can easily produce 500+ WHP, the stock high-pressure fuel pump (HPFP) on B58 Gen1 engines crashes past ~430 WHP on pump gas and starves instantly if you attempt to run ethanol blends.
Upgrading the HPFP is the single most critical modification to unlock Stage 2+ and Stage 3 performance. Below is the direct comparison between the OEM B58TU pump and the motorsport-grade Dorch Engineering Stage 1 and Stage 2 pumps.
| Parameter | OEM B58TU Pump | Dorch Stage 1 | Dorch Stage 2 |
|---|---|---|---|
| Displacement / Flow Rate | 0.83 cc / rev | 0.91 cc / rev (+10% vs TU) | 1.17 cc / rev (+41% vs TU) |
| Stock Turbo E30 Support | 100% Supported (~490 WHP) | 100% Supported (~500 WHP) | 100% Supported |
| Stock Turbo E50 Support | Maxed out / Limiting (~510 WHP) | Comfortable (~520–540 WHP) | Effortless (~540+ WHP) |
| Stock Turbo Full E85 | ❌ Rail crash under 100 bar | ❌ Marginal (Lean safety risk) | ✅ 100% Full E85 Capable |
| Hybrid Turbo (Pure800) Support | Up to ~550 WHP (Pump 93 / E30 only) | Up to ~620 WHP (E40 blend) | Up to ~730+ WHP (E60 / E85) |
| Plug & Play Installation | Requires wiring harness pin swap or adapter | 100% Plug-and-play wiring kit included | 100% Plug-and-play wiring kit included |
| Average Price | ~$350–$450 USD (Bosch OEM) | ~$1,050 USD | ~$1,550 USD |
1. The Budget King: OEM B58TU Retrofit
For B58 Gen1 owners (F30 340i, F32 440i, G30 540i pre-LCI), the OEM B58TU fuel pump (Part #13518631642) is the ultimate dollar-for-horsepower modification in the entire BMW aftermarket. Developed by BMW for the second-generation Supra and M340i, it bolts directly onto the Gen1 vacuum pump housing with minor wiring harness adaptation.
At under $450 USD, it delivers enough high-pressure fuel to max out the stock factory turbocharger on E30-E40 fuel, taking you directly into the 480–500 WHP club without breaking the bank.
2. When Do You Need a Dorch Stage 2?
If your ambitions include upgrading to a Pure800, DAW Ultra Flow, or Pure900, the TU pump quickly becomes the bottleneck. At 25+ PSI of boost on high-ethanol fuels, the engine requires enormous fuel mass. The TU pump will trigger DME rail pressure drop fault codes (11A002).
With its massive 1.17 cc/rev plunger displacement, the Dorch Engineering Stage 2 outflows the factory pump by over 40%, delivering unwavering 200+ bar fuel rail pressure all the way to 7,000 RPM.
🏆 The Final Verdict
Choose the OEM TU Pump if: You are on the stock turbocharger, want to run Stage 2+ with E30–E40 ethanol, and want the absolute best performance value on the market.
Choose the Dorch Stage 2 if: You plan to install an upgraded hybrid turbo, want to run Full E85 from the pump with zero blending headaches, or plan to target 600 to 730+ WHP on direct injection.
Frequently Asked Questions
Can an OEM B58TU pump run Full E85?
No. The OEM TU pump maxes out around E40 to E50 on stock turbo, and around E30 on hybrid turbos. Attempting to run Full E85 (85% ethanol) will cause the high-pressure fuel rail to crash below 100 bar, triggering limp mode code 11A002.
Does a Gen2 B58 (M340i / Supra MK5) need an HPFP upgrade?
The Gen2 engine comes factory equipped with the TU pump! You do not need to upgrade your HPFP unless you are going with a hybrid turbo (Pure800/Pure900) or want to run high ethanol mixtures (E50-E85), in which case you need a Dorch Stage 2 or Port Injection.
Do I need to change software settings when installing an upgraded HPFP?
Yes. When flashing MHD or bootmod3, you must check the HPFP configuration box in flash options (select 'B58TU Pump', 'Dorch Stage 1', or 'Dorch Stage 2'). This recalibrates the fuel pressure regulator valve scaling in the DME.