Introduction
The BMW S55 (found in the M3, M4, and M2 Competition) is a high-performance twin-turbo engine that responds extremely well to upgrades. With the right hardware, the S55 delivers massive gains while maintaining excellent reliability. At RDM Performance, we supply proven parts designed for fast road and track use.
Stage 1 Upgrades (400–500+ bhp)
Stage 1 focuses on simple bolt-on upgrades that improve airflow, cooling, and reliability.
Typical Stage 1 mods:
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High-flow air intake system
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Charge pipes & J-pipes upgrade
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Upgraded diverter valves
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Performance panel filters
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Catback exhaust (optional)
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Spark plugs (colder grade recommended)
Benefits:
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Sharper throttle response
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Reduced heat soak
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More consistent performance
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Improved turbo efficiency
Not sure which parts you need?
Message us with your registration number, power goal and budget and we’ll spec the right setup for you.
Stage 2 Upgrades (500–600+ bhp)
Stage 2 unlocks the full potential of the stock turbos.
Typical Stage 2 mods:
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Sports cat or decat downpipes
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High-flow heat exchangers
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Front-mount charge cooler upgrade
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Upgraded J-pipes
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Performance intakes
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Professional ECU tune (Bootmod3 / MHD)
Benefits:
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Much stronger mid-range
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Improved cooling
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Faster spool
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Excellent on road or track
Not sure if Stage 2 is right for your setup?
Message us with your registration number, current mods and power goal and we’ll advise the best next step.
Hybrid Turbo / Stage 3 (650–750+ bhp)
For customers chasing big numbers, hybrid turbos are the best option.
Typical Stage 3 mods:
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Hybrid turbo upgrade
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PI (Port Injection) or upgraded HPFP
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Larger heat exchanger
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Meth injection (optional but effective)
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Full supporting mods
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Custom tuning
Expected power: 650–750bhp depending on setup.
Hybrid and big-power setups vary from car to car.
Message us with your registration number, turbo choice and power goal for a tailored recommendation.
Recommended Brands
We stock trusted brands for the S55 platform:
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VRSF
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RDM Performance Turbos
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MST
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Torefi Sports
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Forge Motorsport
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Tial
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Torefi Coils
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Genuine BMW parts
Expected Gains
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Stage 1: +40–60bhp
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Stage 2: +80–120bhp
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Hybrids: +200–300bhp (depending on spec)
Why Choose RDM Performance?
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Specialists in BMW tuning platforms including N54, N55, B58, S55, S58, B48 and more
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Fast UK delivery with reliable shipping and real-time order updates
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Carefully selected brands that we trust and use on our own vehicles
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Clear, honest advice — no upselling, no pressure
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Proven power upgrade paths with safe, reliable recommendations
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Excellent customer support through Instagram, WhatsApp and email
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UK-based business focused on quality, value and customer satisfaction
Disclaimer:
All performance figures are estimates and will vary depending on vehicle condition, supporting modifications, fuel quality, tuning software and installation quality. Some upgrades, such as decat downpipes, are not road legal in the UK and are intended for off-road or track use only.RDM Performance uk ltd is not responsible for any mechanical issues that arise from improper installation, aggressive tuning or pre-existing vehicle faults.For best results, always use a reputable tuner and ensure your vehicle is well-maintained.
