FAS850
850 Wheel Horsepower. Built for Reliability at Speed.
The FAS850 adds the critical reliability layer to the FAS800 foundation — fuel injectors sized for the demand, a pinned crank to secure the drive hub under sustained boost, and a performance thermostat to keep temps in check. 850 WHP. Street-legal. Fully dyno-verified.
What's Included
The FAS850 build sheet adds essential reliability components to the baseline platform work. Everything installed, calibrated, and verified in-house.
- Pulley Upgrade Package
Smaller lower pulley for higher boost pressure and increased supercharger speed across the RPM range.
- Upgraded Fuel Injectors
Higher-flow injectors matched to the increased fueling demand of an 850 WHP calibration.
- Pinned Crank Assembly
Crankshaft pin upgrade to secure the supercharger drive hub under sustained high-boost conditions — a critical reliability item at this power level.
- Performance Thermostat
Lower-temperature thermostat allows the engine to maintain optimal coolant temperature during extended high-output pulls.
- Full Custom Dyno Tune
Complete calibration developed for your specific vehicle on FAS in-house AWD dynamometer. Not a mail-order tune — done by FAS technicians.
- Installation Labor
Full installation at our Punta Gorda, FL facility. Every build follows the FAS validated build sheet for your platform.
Platform Variants & Pricing
The FAS850 is platform-specific in pricing and tune but follows the same build process and quality standard across all three Hellcat variants.
| Platform | Price | Power Target | Fuel | Action |
|---|---|---|---|---|
| Charger & Challenger Hellcat Platform | $6,699.00 | 850 WHP | 91–93 Oct | Order → |
| Trackhawk / Durango SRT Hellcat Platform | $7,099.00 | 850 WHP | 91–93 Oct | Order → |
| RAM 1500 TRX Supercharged HEMI | $7,499.99 | 850 WHP | 91–93 Oct | Order → |
Note: Vehicle not included with purchase. Prices shown are for installation service at our Punta Gorda, FL facility. Modifying your vehicle may affect factory warranty. ← FAS800 · FAS900 →
Why the Pinned Crank Matters
At 850 WHP, the forces on the supercharger drive hub exceed the factory design intent. The pinned crank eliminates the failure mode before it becomes a problem.
The Problem
The factory Hellcat supercharger hub relies on friction and a pressed fit to drive the blower. Under sustained high-boost loads, the hub can spin on the crank nose — causing immediate and expensive damage to both the engine and supercharger.
The FAS Fix
The pinned crank installs a positive mechanical lock between the crank nose and the supercharger drive hub. The pin physically prevents rotation under any load condition. It is a standard FAS procedure at the 850 WHP tier and above.
The Result
A mechanically sound foundation that supports the FAS850 calibration reliably — on the street, on the strip, and on the dyno — without the risk of supercharger hub slip that comes with lesser builds at this power level.
The FAS Performance Ladder
Every FAS tier builds on the last. Start here. Move up when you're ready.
Common Questions
- What separates the FAS850 from the FAS800?
- The FAS850 adds fuel injectors, a pinned crank, and a performance thermostat to the baseline FAS800 pulley and tune combination. These additions support both the higher power target and long-term reliability at 850 WHP.
- Does the pinned crank affect drivability?
- No. The crank pin is a reliability upgrade — it reinforces the supercharger hub attachment without changing engine feel, response, or day-to-day streetability.
- Can the FAS850 run on pump gas?
- Yes. The FAS850 is calibrated for 91–93 octane pump gas. E85 is not required at this tier, though it is available as an upgrade at the FAS900 and FAS1000 level.
- How long does the FAS850 build take?
- Typical build time is 1–2 days depending on shop schedule and vehicle condition. Contact FAS to get a current timeline and schedule your slot.
850 WHP. Proven. Reliable.
The FAS850 is the smart step up from the FAS800 — more power, more reliability, same in-house dyno standard.
F.A.S. Motorsports · 6161 Riverside Dr, Punta Gorda, FL 33982 · Mon–Fri 9AM–5PM