911 TURBO 'GT2' CAYMAN CONVERSION

TO THE BEST OF OUR KNOWLEDGE A CAYMAN GT4 ROAD CAR HAS NEVER FEATURED A 'TURBO SWAP' WITH A BESPOKE 911 TURBO S ENGINE, UNTIL NOW! WHILE TURBOCHARGING OF THE MID ENGINE BOXSTER OR CAYMAN PLATFORM IS NOTHING NEW FOR THE AFTERMARKET OR THE PORSCHE FACTORY, IT HAS NEVER BEEN DONE LIKE THIS!

SHOWN ABOVE IS A ONE OF A KIND PORSCHE CAYMAN GT4 (TYPE 981) PROTOTYPE POWERED BY A 3.8L TWIN TURBOCHARGED 911 (TYPE 991.2 ) TURBO S ENGINE; TOGETHER THEY COMPLEMENT A REAR WHEEL DRIVETRAIN DEEMING IT WORTHY OF THE NAME 'CAYMAN GT2.' PRODUCING IN EXCESS OF 630 HP AND 630 LB/FT AT THE ENGINE ALL WHILE RUNNING OEM PORSCHE ENGINE AND GEARBOX CONTROLS, THE GOAL WAS TO CREATE SOMETHING THAT COMMUTED AS IF IT WERE BUILT AT THE FACTORY TO BE DRIVEN FROM YOUR HOME TO THE CANYONS AND BE THE ULTIMATE MID ENGINE PORSCHE ROAD CAR.

AFTER NEARLY 4000 STREET AND TRACK MILES CONFIRMED FULL OEM OPERATION OF ALL FUNCTIONS, WE WANTED TO GET SOMEONE ELSE'S OPINION SO WE SHIPPED THE CAR 5000 MILES ROUNDTRIP TO BE PUT ON ONE OF THE MOST WELL KNOWN, MOST DISCERNING PORSCHE PODCASTS ON THE PLANET! DURING THIS 12 MONTH PERIOD EVERY PART (INCLUDING THE CAR) WAS 3D SCANNED TO BE JIGGED AND COPIED TO GUARANTEE RECREATION ON DEMAND FOR FUTURE INTERESTED CUSTOMERS.

THE RELOCATED TURBO CHARGERS ARE HIDDEN FROM THE EXTERIOR VIEW SO AS TO MAINTAIN AN OEM LOOK. THE CUSTOM RACE EXHAUST RECEIVED HELMHOLTZ RESONATORS FOR DRONE REDUCTION AND 200 CELL SPUN METALLIC SUBSTRATE CATALYTIC CONVERTER FOR EPA CONFORMITY.

WITH ONLY SO MUCH ROOM AVAILABLE AND GIVEN THE NEED FOR THE LOWEST INTAKE AIR TEMPS POSSIBLE A WATER TO AIR INTERCOOLER SETUP WAS CHOSEN. LOCATED NEAR THE TURBOS BUT IN THE REAR HATCH AREA, THE INTAKE IS FED BY OUR DRY CARBON FIBER 'CAYMAN GT4RS STYLE' QUARTER WINDOW DUCTS.

THIS APPROACH GUARANTEES DELIVERY OF THE COLDEST AIR WITH THE GREATEST PRESSURE AVAILABLE TO THE CAYMAN GT4 PLATFORM. ONE OF THE PRIMARY GOALS WAS TO TRY AND ACHIEVE BETTER INTAKE AIR TEMPERATURES THAN A FACTORY 991.1 TURBO S ROAD CAR AND DECADES OF CAYMAN ENGINEERING AND DEVELOPMENT REITERATED THE NEED TO ABANDON THE ORIGINAL FACTORY SIDE INTAKE LOCATION AND REPURPOSE IT FOR ADDITIONAL ENGINE BAY AIR.

THE AFOREMENTIONED INTERCOOLER SETUP FEATURES A 'FRUNK' MOUNTED WATER SYSTEM THAT SENDS WATER TO AND FROM THE FRONT CENTER FACTORY GT4 RADIATOR SOLELY TO COOL THE INTERCOOLERS AND THEREFORE THE INTAKE AIR BEFORE IT ENTERS THE ENGINE. SIMILAR TO WHAT IS FOUND ON THE BMW M4 GT4, THIS SYSTEM HAS ANCILLARY TEMP DRIVEN CONTROL OF THE PUMP FOR HIGHER FLOW IN WARMER ENVIRONMENTS. THE NET RESULT IS A CAR WHOSE INTAKE AIR TEMPERATURES ARE NEARLY WITHIN 35F OF AMBIENT TEMPERATURES WHICH IS A HUGE SUCCESS WHEN COMPARING IT TO A PORSCHE 911 TURBO S RUNNING ON TRACK IN THE SAME ENVIRONMENT.

991.2 TURBO S POWERED CAYMAN RUNNING A STOCK ENGINE CALIBRATION AND 91 OCTANE FUEL VS 718 GT4RS CLUBSPORT RUNNING A STOCK ENGINE CALIBRATION AND 98 OCTANE RACE FUEL

ALL PRICING INCLUDES INSTALLATION
WE DO NOT OFFER REMOTE SUPPORT OF THIS CONVERSION

REQUIRED MINIMUM LABOR OF 250 HOURS @ $279.00 PER HOUR
REQUIRED MINIMUM PARTS COSTS OF $46,000.00 (NEW FACTORY PORSCHE TURBO CHARGERS, CUSTOM REAR INTERCOOLER, CUSTOM REAR AIRBOX, DRY CARBON FIBER INTAKE DUCTS, 'FRUNK' MOUNTED PUMP AND INTERCOOLER WATER SYSTEM, CUSTOM PORSCHE MOTORSPORT 718 GT4 CLUBSPORT EXHAUST, ALL REQUIRED TUNING AND MORE - SEE BELOW)
EXCLUDES COST FOR 'DONOR' 991.1 OR 991.2 TURBO S ENGINE READILY AVAILABLE ON THE OPEN MARKET FOR LESS THAN $25K
PORSCHE 'CRATE' REMAN ENGINE COST FOR FACTORY 991.2 GT2RS ENGINE IS $80,000.00 USD AS OF AUG. 2025 AND REPRESENTS AN INCREMENTAL COST OF AN ADDITIONAL $55,000.00.
LABOR TO:
- REMOVE EXISTING 3.8L ENGINE
- CONVERT SOURCED 991 TURBO S ENGINE TO CAYMAN / BOXSTER FITMENT
- INSTALL 'FRUNK' MOUNTED ANCILLARY WATER COOLING SYSTEM
- INSTALL 911 TURBO S ENGINE IN VEHICLE
- INSTALL CUSTOM INTERCOOLER
- INSTALL CUSTOM AIR BOX
- RELOCATE 911 TURBO CHARGERS
- REMAP ENGINE AND TRANSMISSION CONTROL UNITS
- DYNO & ROAD TEST VEHICLE
- ADDITIONAL DAY OF DRIVER COACHING AND VEHICLE ORIENTATION AVAILABLE UPON REQUEST
PARTS:
- INCLUDES NEW PORSCHE CARS AG OEM TURBO CHARGERS @ $6,122/EA. OR $12,224.00
- 718/981 GT4 'TURBO KIT'
  - 718 / 981 ‘FRUNK’ MOUNTED WATER SYSTEM (SHOWN BELOW)
  - 718 GT4 CLUBSPORT EXAUST MANIFOLDS & TURBO INLETS
  - TRUNK MOUNTED INTERCOOLER
  - TRUNK MOUNTED AIRBOX
  - ALL REQUIRED TURBO COMPONENTS IN THE FORM OF INTAKE PLUMBING, OIL LINES, COOLANT LINES, BLOW OFF VALVES, EXHAUST PLUMBING, ETC.
  - CUSTOM EXHAUST (FEATURES 200 CELL SPUN METALLIC SUBSTRATE CATALYTIC CONVERTERS REQUIRED FOR FEDERAL DOT HIGHWAY USAGE)
  - ALTERNATE ENGINE COOLER FROM PORSCHE FOR 2WD TURBO APPLICATIONS
  - ALL REQUIRED SENSORS, WIRING, CONTROL UNITS TO COMPLETE 991 TURBO INTEGRATION
  - SUBSTITUTION OF NEW PURE 850 991.1 TURBO S TURBO CHARGER HOUSINGS AND TURBOS IS AN AVAILABLE OPTION AND REDUCES SPARTS COSTS BY $8,724.00.
ADDITIONAL INFORMATION:
- NEARLY ALL AFOREMENTIONED PARTS ARE MADE TO ORDER AND THEREFORE REQUIRE A NON-REFUNDABLE 50% DEPOSIT DUE AT SIGNING
- ESTIMATED TIME OF COMPLETION IS 6 MONTHS AND REMAINING MONTHLY PAYMENTS WILL BE MADE DURING THAT PROCESS UNTIL TIME OF COMPLETION

PRICING VARIES PER REQUEST AND IS THEREFORE LABELED AS 'STARTING' SO WE ASK THAT YOU PLEASE CONTACT US FOR A CUSTOMIZED QUOTE E.G. IF CUSTOMER DESIRES USED ENGINE, PORSCHE CARS AG REMAN OR NEW CRATE ENGINE, HAS MANUAL 6-SPD CAYMAN GT4 AND DESIRES ALTERNATE CLUTCH OR IF CUSTOMER WOULD RATHER KEEP EXISTING TURBO CHARGERS FROM DONOR ENGINE, ORDER NEW FACTORY TURBO CHARGERS OR OPT OUT FOR PURE 850 991.1 TURBO S TURBO CHARGERS.

SOCIAL MEDIA LINKS:

@CAYMANGT2 INSTAGRAM ACCOUNT
PORSCHE CLUB OF AMERICA AMELIA ISLAND WERKS REUNION REVIEW
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RENNLIST ARTICLE - APRIL 2025
THE SMOKING TIRE - TWIN TURBO CAYMAN REVIEW - JULY 2025