powertrain
How Much Power Does the Whipple Supercharger Add to a Subaru Brz?
Table of Contents
The Subaru BRZ (and its twin, the Toyota GR86) has earned a loyal following for its lightweight chassis, precise steering, and low center of gravity. Stock, it delivers around 200 horsepower from its naturally aspirated 2.4-liter FA24 engine (2022+ models) or the earlier 2.0-liter FA20. While the car is a blast on twisty roads, many owners eventually crave more punch. Forced induction is the most effective route, and the Whipple supercharger stands out as a proven option. This article provides a comprehensive look at how much power a Whipple supercharger can add to a Subaru BRZ, what supporting modifications are needed, and what the real-world driving experience is like.
The Whipple Supercharger: Technology and Design
Whipple Superchargers are known for their twin-screw, positive-displacement design. Unlike centrifugal superchargers that build boost progressively with RPM, a twin-screw unit delivers instant, low-end torque. This matches the BRZ’s character perfectly, filling in the torque dip and providing immediate throttle response from idle to redline. The heart of the Whipple system is its high-helix rotors, which compress air efficiently with minimal heat generation. Most kits include an air-to-water intercooler integrated into the intake manifold, keeping charge air temperatures low and supporting repeatable performance.
Kit Variations for the BRZ
Whipple offers several stages for the Subaru BRZ, primarily differentiated by boost level, intercooling, and fuel system requirements:
- Stage 1: Typically includes the supercharger unit, a smaller intercooler or no intercooler (depending on generation), and a calibratable tune. Power gains are moderate.
- Stage 2: Adds an upgraded intercooler and higher boost, plus necessary fuel system upgrades (larger injectors and a higher-flow fuel pump). This is the most common setup for street-driven BRZs.
- Stage 3 / Race: Uses a larger supercharger unit (e.g., Whipple W140AX) and requires a fully built engine, race fuel or E85, and aggressive tuning. This is for track-only or high-horsepower builds.
How Much Power Does It Add?
The increase depends heavily on the kit stage, supporting modifications, fuel quality, and tuning. Below are realistic wheel-horsepower (whp) numbers measured on a chassis dyno.
| Kit Stage | Stock BRZ (FA20) ~whp | Whipple Supercharged ~whp | Gain |
|---|---|---|---|
| Stage 1 (low boost, pump gas) | 165 | 235–255 | +70–90 whp |
| Stage 2 (with intercooler, pump gas) | 165 | 270–300 | +105–135 whp |
| Stage 2 (E85 fuel) | 165 | 310–330 | +145–165 whp |
| Stage 3 (built engine, race fuel) | 165 | 400+ | +235+ whp |
Data based on FT86Club forum member dyno sheets and professional tuner results. Stock BRZ figures are typical manual-transmission wheel horsepower.
Real-World Example: Stage 2 on Pump Gas
Many owners report that a Whipple Stage 2 kit with 93 octane pump gas and a professional dyno tune yields around 280–290 whp and 245 lb-ft of torque. That’s a 70% increase over stock wheel power. The torque curve is flat and broad, pulling hard from 2500 RPM all the way to redline. The car feels dramatically quicker, matching or exceeding the straight-line performance of a Mustang GT of the same era while retaining its nimble handling.
Supporting Modifications for Maximum Gains
Simply bolting on the supercharger isn’t enough. To safely achieve and sustain the power numbers above, several supporting mods are recommended:
- Fuel System: Higher-flow fuel pump and larger injectors are mandatory for Stage 2 and above. Pump gas requires about 550–700 cc injectors; E85 requires 1000 cc or more.
- Exhaust: A free-flowing cat-back exhaust reduces backpressure. A high-flow catted or catless header (equal-length preferred) helps spool and top-end power, but may affect emissions legality.
- Intake: The stock airbox can be restrictive at higher boost. A cold-air intake (e.g., from Whipple’s kit or aftermarket) is beneficial.
- Cooling: The Whipple intercooler is very effective, but an upgraded radiator and oil cooler are strongly advised for track use to prevent heat soak.
- Clutch: The stock clutch slips around 280–300 whp. A Stage 1 or Stage 2 clutch kit is needed for reliability.
- Tires: With 300+ whp, the stock Primacy tires become useless. A set of sticky summer tires (e.g., Michelin PS4S) is necessary to put the power down.
Tuning: The Key to Power and Safety
The Whipple supercharger kit often includes a base tune (e.g., via an ECUTek handheld tuner). However, custom dyno tuning by a professional is highly recommended for optimal power, drivability, and safety. A generic off-the-shelf tune leaves power on the table and may not account for local fuel quality or elevation.
Common tuning considerations include:
- Boost control: Whipple kits use a bypass valve to control boost; the tune must manage this correctly.
- Ignition timing: Must be dialed in to prevent knock, especially on pump gas.
- Air/fuel ratio: Target around 11.5–12.0:1 on pump gas, richer for E85.
- Cold start and idle: Proper calibration for smooth operation in all conditions.
Reputable tuners like Delicious Tuning, CSG (CounterSpace Garage), and Moto-East have extensive experience with Whipple-equipped BRZs. A remote e-tune is also possible with datalogging.
Installation Overview
Installing a Whipple supercharger is an intensive but well-documented process. The Whipple kit is designed to be a “basic” install for an experienced DIY mechanic, but most owners opt for professional installation.
Steps Include:
- Removal of the intake manifold, fuel rails, and stock airbox.
- Installation of the supercharger mounting bracket and the supercharger unit.
- Running coolant lines for the intercooler system.
- Re-installing fuel rails with larger injectors.
- Connecting the intercooler pump, reservoir, and heat exchanger.
- Re-flashing the ECU with the tune.
Total labor time is typically 10–16 hours for a professional shop. DIY installation can take a weekend or more, depending on skill level.
Drivability and Reliability
One of the Whipple’s biggest advantages is how well it preserves the BRZ’s daily-driving character. The twin-screw design provides instant throttle response with no lag; the car still revs happily and feels linear. The intercooler system keeps intake temperatures in check during normal driving. On the track, frequent high-load runs will eventually heat up the charge air, but the system recovers quickly during cool-down laps.
Reliability is excellent if the tune is conservative and supporting mods are adequate. The FA20 and FA24 engines are forged internally and can handle up to about 350–400 whp on stock internals with a safe tune. Above that, forged pistons and rods become necessary. Common failure points on supercharged BRZs are fuel pump failure (upgrade to a DW300c or similar) and overheating on track (add oil cooler and larger radiator).
Maintenance Considerations
- Supercharger oil needs to be checked every 10,000 miles and replaced every 50,000 miles.
- The drive belt should be inspected regularly; a slipping belt will reduce boost.
- Spark plugs should be changed to a colder heat range (one step colder) to prevent pre-ignition.
Comparison with Other Supercharger Options
The BRZ/FR-S/86 platform has several forced induction choices. Here’s how Whipple stacks up:
| System | Type | Power Delivery | Max Power (Pump Gas) | Drivability |
|---|---|---|---|---|
| Whipple | Twin-screw | Instant torque, linear | 300+ whp | Excellent, OEM-like |
| Edelbrock | Lysholm twin-screw | Similar to Whipple | 280 whp (Stage 1) | Excellent |
| Jackson Racing | Centrifugal | Progressive, top-end surge | 280 whp (with pulley) | Good, less low-end |
| Vortech/Procharger | Centrifugal | High top-end, laggier | 350+ whp | Less civil |
Whipple offers the best low-end torque and smoothness, making it ideal for street driving and autocross. Centrifugal systems can make higher peak power but sacrifice immediate response.
Cost Considerations
A Whipple Stage 1 kit for the BRZ costs around $4,500–5,500 USD. Stage 2 kits with intercooler and fuel system upgrades are $5,500–7,000. Installation adds $1,000–2,000. Custom tuning is $500–1,000. Supporting mods (clutch, exhaust, cooling) can add another $2,000–4,000. Total investment for a reliable 300 whp build is typically $8,000–12,000.
Though significant, this cost is comparable to other supercharger kits and much less than a turbocharger conversion when factoring in labor and parts. Resale value? A supercharged BRZ is more desirable to enthusiasts but may scare off stock buyers. Keep the original parts for return to stock.
Conclusion
The Whipple supercharger can add between 70 and 165 wheel horsepower to a Subaru BRZ depending on the kit stage and supporting modifications. The result is a car that retains its lightweight, playful character but now has the torque to match its handling. With proper tuning and maintenance, a Whipple-equipped BRZ is a reliable, immensely fun daily driver that can also hold its own on track days. For anyone seeking to transform the BRZ into a serious performance machine without losing its soul, the Whipple supercharger is one of the best investments available.
Key Takeaway: A Whipple Stage 2 kit with pump gas tuning delivers ~280–300 whp, transforming the BRZ’s acceleration without sacrificing its hallmark driving experience. Custom tuning is essential for safety and peak performance.
For further reading: Visit the official Whipple site for kit listings (whipplesuperchargers.com), join the FT86Club forums for owner experiences (ft86club.com), or consult a certified tuner like Delicious Tuning (delicioustuning.com) for custom calibration.