| Weistec Horsepower | 730 |
| Weistec Torque | 652 |
| Manufacturer | Weistec |
| Street legal in all the US States | No |
| Engine Family | M838T |
| Stock Horsepower | 592 |
| See more | |
| year | make | model | trim | engine |
|---|---|---|---|---|
| 2021 | McLaren | 600LT | Spider | Twin Turbo 3.8L V8 (M838TE) |
| 2020 | McLaren | 600LT | Spider | Twin Turbo 3.8L V8 (M838TE) |
| 2019 | McLaren | 600LT | Spider | Twin Turbo 3.8L V8 (M838TE) |
| 2021 | McLaren | 600LT | Base | Twin Turbo 3.8L V8 (M838TE) |
| 2020 | McLaren | 600LT | Base | Twin Turbo 3.8L V8 (M838TE) |
| 2019 | McLaren | 600LT | Base | Twin Turbo 3.8L V8 (M838TE) |
Product Description
The 600LT is the fourth car to earn McLaren's Longtail badge, and it's the one that proved that philosophy wasn't reserved for the Super Series. McLaren brought the lightweight, track-honed thinking first shown on the 675LT down into the Sports Series, and once again the name says it all: 600PS, straight from the same 3.8-liter M838T V8 that powers the rest of the Sports Series, now paired with extended bodywork, a lighter exhaust, and a sharper aero package than the 570S it's built from.
Weistec's calibration for the 600LT is a software recalibration of that factory M838T, built to work with McLaren's own engineering rather than override it. Every factory safeguard, knock protection, thermal management, OEM diagnostic behavior, is preserved exactly as designed. Delivered with OEM-level validation, it takes this 600LT from a factory 592 hp and 457 lb-ft to 730 hp and 652 lb-ft, adding another gear to a car that was already built to be McLaren's sharpest Sports Series statement.
How Do You Get Your 600LT ECU Tune Tuned?
Follow these steps — this is what your specific vehicle needs and supports.
Choose Your Tune Stage
Core Improvements
Standard with this tuneFree Add Ons
Pick Your Tuning Method

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

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

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.

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.
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.
Fitment not confirmed
This part is not confirmed to fit your selected vehicle.


