The AMS Alpha 9 Turbo upgrade has become a go-to choice for Nissan GT-R owners aiming to push their cars well beyond factory output. While the stock VR38DETT is a stout engine, the Alpha 9 kit unlocks a level of performance that transforms the driving experience. This article dives deep into the real-world power gains from a 750hp setup, covering dyno results, supporting modifications, drivability, and what you need to know before pulling the trigger.

What Is the AMS Alpha 9 Turbo Upgrade?

AMS Performance, a legendary name in Nissan GT-R tuning, designed the Alpha 9 kit as an entry-level big turbo solution for the R35. Unlike a full built-engine swap, the Alpha 9 uses upgraded turbochargers that bolt directly onto the factory exhaust manifolds. These turbos feature larger compressor and turbine wheels, improved bearing systems, and optimized housings that flow significantly more air than the stock units. The package typically includes modified fuel injectors, a high-flow fuel pump, and a custom intercooler, all tuned via a Cobb Accessport or EcuTek calibration.

The “9” in Alpha 9 refers to the power level AMS targets: roughly 900 crank horsepower (approximately 750-800 wheel horsepower on a Dynojet). This positions the kit as a step below the Alpha 10 and Alpha 12 packages, which require more extensive engine work. According to AMS, the Alpha 9 is designed for cars with stock engines and driveline, making it a popular choice for enthusiasts who want reliable high power without rebuilding the bottom end.

Real Power Gains: Dyno Numbers and Track Results

The central question is: how much power does the Alpha 9 actually add? On a stock GT-R (MY 2009-2019), factory output ranges from 480 to 600 hp depending on the year. The Alpha 9 kit, when combined with proper supporting mods and a conservative tune, consistently delivers between 730 and 780 wheel horsepower on 93-octane pump gas. On race gas or ethanol (E85), those numbers can climb above 850 wheel horsepower.

Dyno Examples

  • Pump gas (93 octane): 740-780 whp, 720-760 lb-ft torque
  • E85 blend (up to E60): 800-850 whp, 780-820 lb-ft torque
  • Race gas (100+ octane): 850-900 whp, 800+ lb-ft torque

One independent test from AMS Performance’s technical blog shows a 2012 GT-R on 93 octane laying down 762 whp and 737 lb-ft on a Mustang dyno (which usually reads lower than a Dynojet). On a Dynojet, the same car would likely read closer to 800 whp. Track results back up the dyno numbers: many Alpha 9 cars run consistent 9.8-10.2 second quarter-mile passes with trap speeds in the 145-150 mph range.

Essential Supporting Modifications for a 750hp Setup

A turbo upgrade alone will not unlock the Alpha 9’s full potential – the engine management, fuel system, and intake/exhaust must keep pace. Below are the modifications typically found on a fully optimized Alpha 9 car.

  • Fuel Delivery: Upgraded high-pressure fuel pump (e.g., Walbro 450 or AMS brushless pump) and larger injectors (1,200-1,700 cc). Without enough fuel, the tune will run lean and risk knock.
  • Intercooling: The stock GT-R intercooler chokes airflow above ~650 whp. A front-mount or upgraded core (AMS, GReddy, PRP) reduces intake air temperatures, allowing safe boost levels.
  • Exhaust System: A full 3-inch or 3.5-inch downpipe and cat-back exhaust reduces backpressure. Many opt for high-flow cats or test pipes to help spool and peak power.
  • Intake: Larger intakes or a cold-air box feed the turbos. AMS recommends their own carbon-fiber intake kit.
  • ECU Tuning: The VR38’s stock ECU can be re-programmed via Cobb V3 or EcuTek. Professional tuning is mandatory to set boost, timing, and fuelling for the specific fuel used.
  • Drivetrain Upgrades: At 750+ whp, the factory GR6 transmission and ATTESA system can slip or overheat. Many owners add a billet clutch basket (e.g., SSR, SSP) and a transmission oil cooler.

AMS’s official package includes many of these parts – the Alpha 9 kit itself (turbochargers, wastegates, boost controller), fuel system upgrade, and a custom tune. For the full 750hp experience, you should budget for these ancillaries. A common discussion on GTRLife highlights that many owners add a flex fuel kit and a built transmission shortly after the turbo install.

Comparison with Alpha 10 and Alpha 12

AMS offers three Alpha levels: 9, 10, and 12. Understanding the differences helps you decide if the 750hp target is enough.

  • Alpha 9: Stock engine long block, stock cams, stock transmission (with clutch upgrade typically). Power ceiling: ~850 whp on race gas. Ideal for street-driven cars looking for strong acceleration without major engine surgery.
  • Alpha 10: Requires built bottom end (pistons, rods, bearings) and billet main caps. The turbos are larger, supporting 1,000+ whp. The transmission must be fully built. More intensive, much higher cost.
  • Alpha 12: Full race-oriented setup with massive turbos, sheet-metal intake, and extreme engine work. Over 1,200 whp possible. Not suitable for daily driving.

The Alpha 9 hits the sweet spot for enthusiasts who want a fast GT-R that still retains reasonable drivability and reliability. Many owners report that the car remains a pleasant daily driver with the Alpha 9, provided the tune is conservative.

Drivability: How the Alpha 9 Alters the GT-R Experience

A 750hp GT-R is a different machine from stock. The upgraded turbos spool later than factory units – expect full boost around 3,800-4,200 rpm rather than 3,000-3,500. Below that, the car feels mildly laggy compared to stock, but once on boost, the surge is dramatic. The mid-range torque pulls hard all the way past 7,000 rpm. With an E85 tune, the powerband is flatter and more responsive.

On the street, the Alpha 9 demands respect. The GT-R’s all-wheel drive system helps put the power down, but the acceleration is brutal – zero to 60 mph times hover around 2.5 seconds with a professional launch, and highway roll-ons are staggering. The car will feel significantly faster than anything short of a supercar. However, the increased power also means more heat and drivetrain stress. Keeping an eye on oil and transmission temperatures is crucial during spirited drives.

Reliability and Longevity: What to Expect

The stock VR38 can handle 750-800 whp reliably if properly tuned and maintained. However, the Alpha 9 upgrade does push the engine closer to its limits. Key considerations:

  • Fuel Quality: Use only premium fuel (93+ octane) or a calibrated ethanol blend. Detonation can quickly break ring lands.
  • Oil System: The VR38’s oil sump can starve under high-G turns. Many upgrade to a baffled oil pan or a dry sump for track use.
  • Spark Plugs: Step colder plugs (e.g., Denso IK27) are mandatory to avoid pre-ignition.
  • Intercooling: Heat soak on a hot day can cause the ECU to pull timing. A proper cooling system (intercooler, cylinder head cooling mod) is highly recommended.

With proper care, an Alpha 9 car can last many tens of thousands of miles. But aggressive driving on a poorly tuned car or with low fuel quality will drastically shorten engine life. A TorqueNews article on GT-R tuner reliability notes that conservative tuning and regular maintenance are the keys to enjoying the Alpha 9 long term.

Potential Drawbacks and Cost Considerations

Before jumping into an Alpha 9 build, weigh these downsides:

  • Cost: The complete kit plus installation and tuning can exceed $10,000. When you add required transmission upgrades, a full build can reach $20,000 or more.
  • Fuel Economy: Expect a significant drop in MPG – you’ll see around 10-12 mpg in normal driving, and worse under boost.
  • Emissions: In many regions, the test pipes and modified ECU tune make the vehicle illegal for road use. Check local laws.
  • Maintenance Interval: Oil changes become more frequent (every 2,000-3,000 miles), and spark plugs need replacement every 10,000 miles or less.
  • Transmission Weakness: The GR6 is the Achilles’ heel. Even with a clutch upgrade, the stock transmission can fail with repeated hard launches. A built transmission adds $4,000-$6,000.

That said, for the enthusiast who can afford the total package and accepts the trade-offs, the Alpha 9 transforms a GT-R into a genuine supercar slayer. The feeling of a 750hp all-wheel drive sedan is unmatched in the price range.

Conclusion: Is the Alpha 9 Right for You?

The AMS Alpha 9 turbo upgrade adds real, dyno-verified power – easily lifting a bone-stock GT-R from 500-600 hp to 750-850 whp depending on fuel and tuning. That’s roughly a 200-300 whp gain, enough to lower quarter-mile times by over a full second. For drivers who want a dominant street car that can also run 9-second passes at the drag strip, the Alpha 9 is the most proven and reliable package on the market. It’s not cheap, and it demands careful supporting modifications, but the result is a vehicle that will deliver thrills and performance that rival European exotics costing five times as much.

If you’re ready to take your GT-R to 750hp, start with a solid plan for the fuel system, transmission, and engine cooling, and always trust an experienced tuner. The Alpha 9 upgrade is a proven path – one that has earned its reputation in the GT-R community for more than a decade.