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ENGINEERING THE FUTURE OF PERFORMANCE ™
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W.3 Turbo Upgrade, M838T
Purchase W.3 Turbo Upgrade, M838T
  • SKU: 01-838-01836-8

    W.3 Turbo Upgrade, M838T

  • Advertised gains are estimates of HP and Torque “at the engine” calculated from gains as measured on a Dynojet Dynamometer in ideal conditions and typically show the largest possible change.  Actual gains are dependent on the following: Learn More about Crank HP Vs Wheel HP

    Model – Manufacturers use the same engine in multiple model vehicles and often times they are in a different state of tune, for example: 2008 C63 and a 2008 CLK Black Series.  Both have the same engine, but the C63 has 451hp while the CLK63 has 500hp.  Naturally the C63 will show more gains as it starts at a lower level.

    Model Year – Similar to above, as time progresses, Manufacturers tend to slightly increase power output via software from one year to the next or offer “Performance Packages” with increased power.  The engines remain largely unaltered and as a result, final tuned output remains the same, while the gains are lower as the starting point is now higher.

    Fuel – Fuel quality is HIGHLY important with performance vehicles.  Low quality and/or low octane fuel will greatly impact engine output and potentially even engine health.  Top tier brand premium fuels should always be used to achieve the best results possible.

    Drivetrain – All wheel drive has higher drivetrain losses than rear wheel drive.  This results in lower numbers when testing on a chassis dyno.  Wheel/tire size and weight will also impact chassis dyno results

    Weather/Conditions – Temperature, humidity, altitude, and air density all impact engine performance.  Heat, high humidity, and thin air will all work towards reducing engine output

    Engine Health – Higher miles tends to result in increased build up and lower compression which can and will impact engine output.  Properly maintained engines will have better performance than abused or neglected engines.

    Supporting modifications – The highest power levels require supporting modifications.  Depending on the engine, this could mean forged internals, built transmission, upgraded fuel system, 110+ octane race fuel, etc.

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  • Prop 65 warning
    Warning

    This product can expose you to chemicals including carbon black, silica - crystalline, formaldehyde, and lead which are known to the State of California to cause cancer, and lead, which is known to the State of California to cause birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Weistec Horsepower 786
Weistec Torque 663
Turbo Type W.3 (Factory Upgrade)
Manufacturer Weistec
Street legal in all the US States No
Engine Family M838T
See more
year make model trim engine
2021 McLaren 620R Base Twin Turbo 3.8L V8 (M838TE)
2020 McLaren 620R Base Twin Turbo 3.8L V8 (M838TE)
2017 McLaren MSO 688 HS Base Twin Turbo 3.8L V8 (M838TL)
2016 McLaren MSO 688 HS Base Twin Turbo 3.8L V8 (M838TL)
2021 McLaren 600LT Spider Twin Turbo 3.8L V8 (M838TE)
2020 McLaren 600LT Spider Twin Turbo 3.8L V8 (M838TE)
See more

Product Description



How Does The Weistec W.3 Turbo Upgrade Work?

The factory turbochargers are disassembled and fully inspected. The compressor cover and center cartridge are then machined to accept our 5-axis CNC-machined impeller wheel. Externally, no changes are made, preserving a completely stock appearance. The new impeller wheel supports greater power levels than the factory unit with little to no sacrifice in spool or response. The turbochargers are then reassembled with new seals and fully balanced for smooth operation and OEM service life. All original oil and coolant lines bolt right up, making for a simple install.

side by side comparison between the Weistec W.3 Turbo Upgrade for the McLaren M838T engine and the factory turbo unit


Improved Top End Performance

The Weistec W.3 Turbo Upgrade for the McLaren 3.8L Twin turbo vehicles provides vastly improved top-end performance of the M838T Engine. Where the factory turbos peak out shortly after 6000 rpm, causing power to drop as revs increase towards 8000 rpm, the Weistec W.3 Turbos hold power until the rev limiter.

For maximum results, the combination of our Weistec Downpipes and Weistec High Flow Air Filters is recommended. A Weistec W.3 Turbo Specific ECU Upgrade is recommended.



Key Features

  • Significant horsepower and torque gains depending on fuel and supporting modifications
  • 5 Axis CNC Machined
  • High RPM Balanced for perfect operation
  • Substantial power throughout the RPM range
  • Stock Appearance when installed
  • 100% Bolt on installation
Turbine Comparison

Good to Know

  • This is a rebuild of your original factory turbochargers, not a set of brand-new units.
  • Your turbochargers must be sent to us to complete this upgrade.
  • Please include your wastegate actuators along with your turbos, this allows us to test and set the gate preload during the process.
  • Once your turbos are received, they're fully inspected for damage on any of the reused components. If a built core is in stock, it will be sent back to you immediately. If a core is not in stock, your exact unit will be rebuilt, which can take up to 2 weeks depending on timing.
  • Power gains vary by vehicle, modifications, fuel, and operating conditions (ambient temperature, altitude, etc.).
  • Custom tuning is required for best results.

See the full core exchange process →