Understanding the 4G63's Turbocharged Potential

The Mitsubishi Lancer Evolution VIII remains a benchmark in the world of all-wheel-drive performance sedans, largely due to its legendary 4G63 engine. This iron-block, aluminum-head four-cylinder features a robust bottom end, forged connecting rods, and oil squirters that cool the pistons—making it an ideal foundation for substantial power increases. The stock TD05HR-16G6 turbocharger, while responsive, hits a ceiling around 350–380 wheel horsepower on pump gas. For enthusiasts seeking a meaningful jump into the 400–500 whp range (corresponding to roughly 50–80 crank horsepower gains, though actual gains depend on supporting mods and fuel), upgrading the turbo is the single most effective path. This article examines top-tier turbocharger options from Garrett Motion and Precision Turbo & Engine, two manufacturers with decades of proven results on the 4G63 platform.

Turbo Upgrade Basics: Matching Goals to Hardware

Before selecting a turbo, it is critical to define your driving intent. An Evo 8 used primarily for daily street driving benefits from a turbo that spools early (around 3,500–4,000 rpm) and provides a wide torque curve, while a track-focused car may prioritize top-end flow at the expense of low-rpm response. Both Garrett and Precision offer turbo families that span these objectives, but the key differentiators are compressor wheel design, turbine housing A/R ratio, and bearing system. Journal-bearing turbos are more affordable but suffer from slower spool and less durability under high heat, whereas ball-bearing turbos reduce lag and improve transient response. All upgrades recommended here assume the use of proper engine management, larger fuel injectors (at least 1,000 cc/min), a high-flow fuel pump (Walbro 450 or equivalent), and a custom tune.

External resources for understanding turbo selection on the 4G63 include the in-depth guides at EvolutionM.net and MAPerformance’s Evo turbo guide.

Garrett Turbo Upgrades for the Evo VIII

Garrett GTX2867R Gen II – The Fast-Spooling Daily Driver

The Garrett GTX2867R Gen II is a 53-mm inducer / 71-mm exducer compressor wheel turbo with a 60-mm billet wheel and a low-inertia turbine (48.5 mm inducer). It uses a dual ball-bearing center housing and a cast turbine housing available in .64 or .86 A/R. For the Evo 8, the .64 A/R T25 turbine housing is the most common fitment, allowing the turbo to reach full boost by 3,600 rpm. On pump gas (91–93 octane) and with proper tuning, the GTX2867R produces 420–450 whp, which corresponds to a gain of approximately 50–70 whp over a stock Evo 8 making 300–320 whp. This turbo is ideal for street-driven cars that retain a stock-block long-block and want immediate throttle response. The Gen II version features a new compressor wheel design that improves efficiency at higher pressure ratios, reducing heat soak during sustained pulls.

Garrett GTX3071R Gen II – The Balanced Mid-Range Powerhouse

Stepping up, the GTX3071R Gen II features a 54.9-mm inducer compressor wheel and a 61.4-mm turbine wheel. It is available with T3 or T4 turbine housings in A/R ratios of .63, .82, or 1.06. For the Evo 8, the T3 .82 A/R housing is a popular choice, offering a compromise between spool (full boost around 4,000 rpm) and top-end flow. On pump gas, this turbo supports 470–500 whp, and with E85 or race fuel, it can push beyond 550 whp—representing a gain of 80–120 hp depending on fuel and supporting mods. The GTX3071R uses Garrett’s Advanced Girodynamic System (AGS) ball bearings, which reduce frictional losses by 46% compared to journal bearings. This turbo is a staple in the 450–550 whp street/track hybrid builds. For those seeking a true 50-80 hp gain on pump gas, the GTX3071R will deliver that while leaving headroom for future upgrades.

For official specs and fitment guides, refer to Garrett Motion’s GTX Gen II product page.

Precision Turbo Upgrades for the Evo VIII

Precision 5862 Gen2 – Quick Spool with a Flat Power Curve

Precision Turbo & Engine’s 5862 Gen2 turbo uses a 58-mm inducer compressor wheel (62-mm exducer) and a 62-mm turbine wheel, housed in a T4 .84 A/R turbine housing. It employs a billet compressor wheel and a dual ball-bearing CHRA. This turbo is designed for early spool—reaching 25 psi by 3,800 rpm on a 2.0L 4G63—while still flowing enough to support 450–480 whp on pump gas. The power curve is notably flat, delivering strong mid-range torque and holding boost to redline. For the Evo 8 owner looking for a 50-70 hp gain with excellent drivability, the 5862 Gen2 is a direct competitor to the GTX2867R, though with slightly more top-end potential. It pairs well with a ported exhaust manifold and a 3-inch turbo-back exhaust system.

Precision 6266 CEA – The High-Horsepower Benchmark

The Precision 6266 CEA (Competition Engineered Aerodynamics) is one of the most popular turbos for the 4G63, often used in 600+ whp builds. It features a 62-mm inducer compressor wheel (66-mm exducer) and a 66-mm turbine wheel. The CEA billet wheel design improves flow efficiency by 15–18% over previous cast wheels. In its standard T4 .84 A/R housing, full boost arrives around 4,200–4,500 rpm, making it a bit lazier than the 5862 but capable of massive top-end power. On pump gas, a properly tuned 6266 can produce 480–520 whp; on E85, 600–640 whp is achievable. For the 50-80 whp gain target, the 6266 is overkill at low boost—it will easily add 80+ hp even on a relatively conservative tune with stock camshafts. However, it requires a high-flow fuel system, upgraded intake manifold (or ported stock), and a 3.5-inch downpipe and exhaust to realize its full potential. It is the go-to choice for enthusiasts planning to run ethanol or add a nitrous shot later.

Official product details for the CEA series can be found at Precision Turbo’s Gen2 CEA Ball Bearing page.

Comparing Garrett GTX vs. Precision CEA: Real-World Results

Independent dyno testing on the 4G63 shows that the Garrett GTX2867R Gen II and the Precision 5862 Gen2 are very close in performance, with both achieving 440–460 whp on 93 octane at 25 psi. Spool is nearly identical, with full boost occurring near 3,700 rpm. The GTX3071R Gen II edges ahead of the 5862 by about 10–20 whp on pump gas but spools 200–300 rpm later. The Precision 6266 CEA, when paired with a .84 A/R T4 housing, will spool 500 rpm later than the 5862 but pour on power past 6,000 rpm, making it the best choice for road courses or drag racing where top-end speed is critical.

For a street car where 50-80 hp gain is the goal, either the GTX2867R or the Precision 5862 delivers the quickest spool and easiest installation. Both are bolt-on units that fit the stock manifold with minor modifications (such as requiring a custom divorce-style downpipe for the GTX2867R). If you plan to upgrade to cams and an intake manifold later, the GTX3071R or 6266 will provide better headroom without needing to swap turbos again.

Essential Supporting Modifications for 50-80 HP Gains

Fuel System Upgrades

Any turbo upgrade that increases airflow by 25–35% requires a corresponding increase in fuel delivery. At a minimum, install a Walbro 450-lph fuel pump (or DW400) and 1,000 cc/min injectors. For the 6266 turbo, 1,300 cc/min injectors are recommended on E85. Use a fuel pressure regulator (Aeromotive or FIC) to maintain 43 psi base pressure.

Engine Management and Tuning

The stock Evo 8 ECU can be reflashed via OpenECU (Tephra mod) or replaced with a standalone like AEM Infinity or Haltech Elite 2500. A professional tuner experienced with the 4G63 is mandatory; each turbo has unique wastegate spring rates and boost control requirements. Expect to pay $500–800 for a custom dyno tune.

Intercooler and Induction

An upgraded front-mount intercooler (e.g., ETS, AMS, or Garrett) reduces intake air temperatures by 30–50°F, directly increasing power. Pair it with an aluminum cold-side hard pipe kit and a high-flow intake filter (like a K&N or AEM DryFlow).

Exhaust System

A cat-back or turbo-back exhaust with a 3-inch diameter and a metal-core catalytic converter (if emissions testing is a concern) is essential. A larger downpipe (3-inch outlet from the turbo) reduces backpressure and improves spool. Downpipe-back systems from HKS, GReddy, or MAPerformance are proven.

Engine Mechanicals

While the stock 4G63 block and head can handle 450–500 whp, a fresh set of head studs (ARP 2000 or L19) and a new OEM or MLS head gasket are recommended for any turbo upgrade targeting 50+ hp gains. If your mileage is above 100,000, replace the valve springs with OEM or Supertech dual springs to prevent valve float as boost levels rise.

Installation Considerations: Clearance and Oiling

Most Garrett and Precision ball-bearing turbos require a restrictor in the oil feed line to limit oil pressure to 30–40 psi. The 4G63’s oil pressure at the head can exceed 80 psi, which can damage bearings. Use a -4AN feed line with a 0.040–0.065-inch restrictor. The stock oil drain line can be reused if it is a -10 or -12 AN line, but upgrading to a braided stainless hose is wise. Water cooling lines should be looped or capped if not using the factory coolant lines; both Garrett and Precision offer water-cooled centers that help prolong bearing life.

For fitment with the Evo 8’s cramped engine bay, aftermarket turbo manifolds like the Full Race or Racer X equal-length short-runner manifolds provide clearance for larger turbine housings and improve spool. Alternatively, porting the OEM manifold to match the turbo inlet opens up flow without changing geometry.

To ensure a safe and powerful tune after installing your new turbo, work with a tuner who specializes in the Evo 8. Some of the most respected names include Tom Dorsey (Automotive Tech), Eric Basile at MoTec, and the team at AMS Performance. For do-it-yourself tuners, the EcuFlash forum on EvolutionM.net offers abundant base maps and tuning advice. Also consult AMS Performance’s Evo VIII Turbo Upgrade Guide for additional real-world build data.

Final Thoughts: Choosing the Right Turbo for Your Evo 8

Both Garrett and Precision offer turbochargers that can deliver the advertised 50–80 hp increase on a Mitsubishi Evolution VIII, provided they are matched with sufficient fuel delivery and expert tuning. For the enthusiast who values immediate response and a broad power band, the Garrett GTX2867R Gen II or Precision 5862 Gen2 are excellent choices that will transform the driving experience without overwhelming the stock drivetrain. If you are building a car for track days or drag racing and plan to push past 500 whp, the GTX3071R or 6266 offer the flow capacity needed to exceed the original power gain target. No matter which path you choose, investing in quality components from these two manufacturers ensures reliability, repeatable performance, and long-term satisfaction with your Evo VIII.