911 GT3991.2 tuning
The 911 GT3 (991.2) uses a naturally aspirated 4.0 flat-six rated at 493 hp and 339 lb-ft from the factory. Without turbos, gains are smaller: about 15 hp at Stage 1. Most owners tune it for sharper throttle response, a stronger top end and sound.
| Stage | Power | Torque | Gain | % |
|---|---|---|---|---|
| Stock | 493 hp | 339 lb-ft | — | — |
| Stage 1 | 508 hp | 349 lb-ft | +15 hp | +3% |
| Stage 2 | 532 hp | 356 lb-ft | +39 hp | +8% |
| Stage 3 | 561 hp | 366 lb-ft | +68 hp | +14% |
- Stage 1
Software · 508 hp
ECU recalibration of ignition, cam timing and throttle mapping. No hardware changes.
- Stage 2
Software + bolt-ons · 532 hp
Stage 1 plus an emissions-legal intake and cat-back exhaust, with a calibration written for them.
- Stage 3
Intake package · 561 hp
An upgraded intake plenum and further calibration, with the factory catalytic converters kept. Offered only where an emissions-legal kit exists for your car.
Estimates for planning, not measured results. Stock figures are Porsche's factory crank ratings. Your car's numbers come from its own baseline and after-logs.
The GT 4.0
engine.
The GT 4.0 is a high-revving naturally aspirated engine built close to its limits from the factory. Power gains are small. Owners tune it for throttle response, gear-by-gear torque delivery and sound, not headline numbers. We never raise the rev limit past the valvetrain's safe range.
Every 911 GT3 tune starts with a consult and a baseline log of your car as it sits. We confirm its software version is supported before we quote, and you leave with after-logs and a signed job file. Read our step-by-step tuning guide.
Emissions-legal parts and software only. We keep the factory catalytic converters on every car. If a stage isn't available legally for your exact model and software, we tell you at the consult instead of fitting it.
How much power does a Stage 1 tune add to a 911 GT3 (991.2)?
Our Stage 1 estimate for the 911 GT3 (991.2) is about +15 hp and +10 lb-ft, taking it from 493 hp to roughly 508 hp. Stage 2 is estimated at 532 hp and Stage 3 at 561 hp. Your car's real result is confirmed with before-and-after logs.
What should be checked on a 911 GT3 (991.2) before tuning?
The GT 4.0 is a high-revving naturally aspirated engine built close to its limits from the factory. Power gains are small. Owners tune it for throttle response, gear-by-gear torque delivery and sound, not headline numbers. We never raise the rev limit past the valvetrain's safe range.
Is a 911 GT3 (991.2) tune emissions-legal?
At Redline Exotics, yes. We use emissions-legal parts and software only and keep the factory catalytic converters. If a stage is not available legally for your 911 GT3's software version, we tell you before quoting.
Request a tuning consult
Usually answered the same day.