Name: 675LT ECU Tune
Brand: Weistec
SKU: 05-838-00082-4
Price: 2999 USD
Availability: InStock

Purchase 675LT ECU Tune

SKU: 05-838-00082-4
675LT ECU Tune
Power gain Up To
+64 HP

Torque gain Up To
+137 TQ

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.
Stage: W.1 (Stock Vehicle) W.2 (Race Exhaust fitted)

Vehicle:
Please confirm:
NOT LEGAL FOR SALE OR USE ON POLLUTION CONTROLLED MOTOR VEHICLES
Learn why

Confirmation
Please confirm that you are not installing this product within the United States.

This policy only applies to installers and/or users who are in the United States, customers who reside in other countries should act in accordance with their local laws and regulations.

Some Weistec Engineering performance upgrades may solely be used on vehicles in sanctioned competition which may never be used upon a public road or highway, unless permitted by specific regulatory exemptions (such as a CARB E.O.). For state specific details please visit the following website. http://www.semasan.com/emissions

It is the responsibility of the installer and/or user of the product to ensure that it is used in compliance with all applicable laws and regulations. If a product was purchased in error, do not install and/or use it. The purchaser must arrange to return the product(s) for a full refund.

All performance modifications and installations are at the customer’s own risk. Weistec Engineering holds no responsibility either implied or otherwise for mechanical, electrical or other failure when using any aftermarket performance products.
$2,999.00 $2,999.00
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How To Tune
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.

Product details

Weistec Horsepower	730
Weistec Torque	652
Manufacturer	Weistec
Street legal in all the US States	No
Engine Family	M838T
Stock Horsepower	666
Stock Torque	515
Tuning Method	Cypher Pro Dealer
Needs Unlock?	No
Pops & Bangs Available?	Yes
Auto Start/Stop Removable?	ECU
Induction Type	Turbocharged
Module Type	ECU
See more

Vehicle application

year	make	model	trim	engine
2017	McLaren	675LT	Spider	Twin Turbo 3.8L V8 (M838TL)
2016	McLaren	675LT	Spider	Twin Turbo 3.8L V8 (M838TL)
2017	McLaren	675LT	Base	Twin Turbo 3.8L V8 (M838TL)
2016	McLaren	675LT	Base	Twin Turbo 3.8L V8 (M838TL)
2015	McLaren	675LT	Base	Twin Turbo 3.8L V8 (M838TL)

Product Description

The 675LT brought back a badge McLaren had left untouched since the F1 GTR "Longtail" race cars tore up circuits, and it earned the right to wear it. This was the lightweight, aero-obsessed Longtail philosophy translated into a modern road car for the first time, and true to McLaren's naming convention, the number in its name comes straight from what the engine actually made: 675PS, extracted from the familiar M838T V8 but paired with real weight savings, an extended tail section, and far more aggressive aerodynamics than the 650S it was built from. McLaren built it in limited numbers and pointed it squarely at the driver, not the commute.

Weistec's ECU calibration for the 675LT stays entirely within that factory M838T software architecture, recalibrating what McLaren already engineered. Every one of the factory's protections, knock control, thermal management, OEM diagnostics, remains active and untouched. Built to OEM-level standards, this calibration takes the 675LT from a factory 666 hp and 515 lb-ft to 730 hp and 652 lb-ft, giving a car built purely for the driver an even sharper edge to work with.

How Do You Get Your 675LT ECU Tune Tuned?

Follow these steps — this is what your specific vehicle needs and supports.

Choose Your Tune Stage

Core Improvements

Standard with this tune

Increased Horsepower
Increased Torque
Improved Throttle Response
Optimized Fuel and Spark
Increased Boost
Top Speed Limiter Removed

Free Add Ons

Want it louder?

Want to stop the stopping?

Pick Your Tuning Method

See the full tuning process →

1Selected

Cypher Plus

Order a Cypher Plus and tune your car yourself from your phone, entirely through the MyFlasher app. Watch how it works.

1Selected

Cypher Classic

Order a Cypher Classic handheld and tune your car yourself.

1Selected

Cypher TCU Flash Tool

We ship you the Cypher TCU Flash Tool and you tune your car yourself, connected to a laptop. No need to remove or send in your TCU.

2Selected — Pick return shipping at checkout

Mail It In

Remove your ECU or TCU and mail it to us for tuning. Required for some applications.

3Selected — Pick Will call at checkout

In Person

Bring your vehicle, or just your ECU/TCU, to our Anaheim, CA headquarters. Call 714-202-0005 or email sales@weistec.com to schedule.

4Selected — Order through your local dealer

Cypher Pro Dealer

Visit a certified Cypher Pro Dealer near you. Find one with our dealer locator.

Complete The Upgrade

An ECU tune alone won't remove all factory limits or fix how power reaches the ground. Add these to round out the upgrade with no limitations.
Read the full CPC & TCU breakdown →

What is a CPC module?

The CPC (Central Powertrain Control) is a separate control unit that manages things like the active exhaust valves, radiator fan, intercooler pumps, and speed limiter. On many newer Mercedes-Benz vehicles, it also houses torque limiters that can hold back an ECU tune from reaching its full potential.

What is a TCU tune?

A TCU (transmission control unit) tune delivers faster, firmer shifts with higher line pressure, reducing clutch slip and increasing the transmission's torque capacity. It's a worthwhile upgrade on its own, or paired with an ECU tune for a fully sorted powertrain.

Your Total

Good to Know

This is a reflash of your original module, not a stand-alone unit.
Power gains vary by vehicle, modifications, fuel, and operating conditions (ambient temperature, altitude, etc.).
New or upgraded spark plugs are always recommended when tuning.
Product may not be emissions compliant. Check local laws prior to installation.
Always use a battery charger during programming.

Select your Vehicle

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675LT ECU Tune

Power gain Up To

Torque gain Up To

Product Description