| Weistec Horsepower | 535 |
| Weistec Torque | 357 |
| Manufacturer | Weistec |
| Street legal in all the US States | No |
| Stock Horsepower | 520 |
| Stock Torque | 347 |
| See more | |
| year | make | model | trim | engine |
|---|---|---|---|---|
| 2019 | Porsche | 911 Speedster | (991.2) 6MT | NA 4.0L Boxer 6 |
| 2019 | Porsche | 911 GT3 RS | (991.2) 7AT PDK | NA 4.0L Boxer 6 |
| 2018 | Porsche | 911 GT3 RS | (991.2) 7AT PDK | NA 4.0L Boxer 6 |
| 2019 | Porsche | 911 GT3 | (991.2) 7AT PDK | NA 4.0L Boxer 6 |
| 2018 | Porsche | 911 GT3 | (991.2) 7AT PDK | NA 4.0L Boxer 6 |
| 2017 | Porsche | 911 GT3 | (991.2) 7AT PDK | NA 4.0L Boxer 6 |
| See more | ||||
Product Description
The 991.2 generation didn't dial back that RSR-derived intensity. It spread it further, sharing the same high-strung, individually throttle-bodied 4.0L flat-six across three different cars: the 991.2 GT3, the 991.2 GT3 RS, and the limited-run 991 Speedster, each calibrated slightly differently but all spinning to a 9,000 rpm redline. Porsche even brought a proper manual gearbox back to the GT3 line with this engine, after the 991.1 had gone PDK-only, a clear sign of how much confidence the factory had in this unit's motorsport character.
Weistec's calibration for this engine works the same way it does everywhere else in the lineup. It's an OEM-level software recalibration layered on top of the factory's own tune, not a generic piggyback box. Knock protection, thermal limits, and every factory safety strategy remain exactly as Porsche designed them, because the gains here come entirely from refining what's already brilliant, not overriding it. On this engine that means roughly 15 additional horsepower and 10 lb-ft of torque, extracted without disturbing a single thing that makes this engine special.
How Do You Get Your Porsche 991.2 4.0L Boxer 6 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.
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