Weistec W.4 Direct-Fit Twin Turbocharger Conversion for BMW M5 and M6 S63 and S63TU
Unlock serious performance with the Weistec W.4 big turbo conversion for the BMW 4.4 V8 twin‑turbo platform. This is a complete plug‑and‑play twin turbocharger package that replaces the factory units without cutting or welding, delivers OE‑level fit and finish, and is designed to support four‑figure power targets when paired with the correct calibration and supporting mods. No core return, no exchange and no downtime on your original chargers.
Whether you drive an F10 or F90 M5, or an F06 F12 F13 M6, this direct replacement twin set is engineered around Garrett GTX Gen 2 ball‑bearing technology for rapid response and massive top‑end flow. All the essentials are included, from TIG‑welded 304 stainless downpipes to revised inlets and charge pipes with built‑in water‑methanol bungs. Factory heat shields and wastegate actuators are retained, and the stock engine cover refits for a clean OE look.
Why enthusiasts choose this conversion
- Drop‑in twin turbocharger set that mounts like stock for hassle‑free installation
- No core return or exchange required
- Garrett GTX Gen 2 dual ball‑bearing cartridge choices for fast spool and huge airflow
- Supplied 304 stainless downpipes built specifically for these housings
- New inlet pipes that mate to the OE airboxes or popular bolt‑on intakes
- New charge pipes with integrated WMI ports to the factory intercoolers
- Braided stainless oil and coolant lines with CNC‑machined, anodised fittings
- Retains OE wastegate actuators and uses the original heat shielding
- Direct fitment with no cutting or welding required
- Factory engine cover retained for a stealth finish
Compressor and turbine choices to suit your goals
Choose the Garrett Gen 2 option that best matches your build and driving style:
- GTX3071R Gen 2
- GTX3076R Gen 2
- GTX3576R Gen 2
- GTX3582R Gen 2
Housings are optimised with a 0.75 A/R turbine and 0.70 A/R compressor cover for an ideal balance of transient response and headroom. From quick‑spooling road cars to high‑output track builds, there is a W.4 combination for every S63 owner.
Output potential
- Power capability: up to 1000 hp
- Torque capability: up to 900 lb ft
Results depend on fuel quality, calibration and supporting hardware. Custom ECU tuning is required to realise the full potential.
What is included in the kit
- Pair of Garrett Gen 2 GTX turbos - choose GTX3071R, GTX3076R, GTX3576R or GTX3582R
- High‑flow Weistec stainless turbine housings
- Weistec 304 stainless downpipes designed specifically for the W.4 housings
- Weistec turbo inlet pipes and charge pipes with methanol injection ports
- Braided stainless oil feeds and coolant lines
- CNC‑machined, anodised oil and coolant fittings
- All required gaskets, fasteners and hardware for a bolt‑in install
Note: Standard pattern downpipes are not compatible with these turbo housings. The supplied Weistec downpipes ensure correct alignment to the remainder of the exhaust system.
Vehicle compatibility
- BMW M5 Saloon F10 S63 2010‑2016
- BMW M5 Saloon F90 S63 2016+
- BMW M6 Gran Coupe F06 S63 2011+
- BMW M6 Convertible F12 S63 2011+
- BMW M6 Coupe F13 S63 2011+
Installation and support in the UK
Professional fitting is recommended. MJ Modifications in Warwickshire can supply and install this package. Request a tailored quote at info@mjmodifications.co.uk. We have fitted this system for UK customers and feedback on drivability, build quality and performance has been outstanding.
Ordering and lead time
This assembly is a special order item. Lead times may apply. Custom ECU calibration is required after installation.
Part number
01-563-01810-5
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