Product Overview
BoostLine Forged Conrod Set β Mitsubishi Lancer Evolution X 4B11T β ARP 625+ β MI5657-905-PLUS
Upgrade the bottom end of your Mitsubishi Lancer Evolution X 4B11T with the BoostLine Forged Connecting Rod Set MI5657-905-PLUS, engineered specifically for extreme-performance turbocharged and motorsport engine builds.
Manufactured from premium forged 4340 steel, BoostLine connecting rods feature the company’s patented three-pocket design, combining excellent strength with reduced rotating mass. This innovative construction provides significantly increased resistance to bending compared with a conventional H-beam connecting rod, making these rods particularly suited to high boost, competition and high-horsepower 4B11T applications.
The MI5657-905-PLUS version is supplied with premium ARP Custom Age 625+ rod bolts, offering an important upgrade for serious performance engines where exceptional fastener strength and reliability are required.
BoostLine states that these rods have been proven in 1000+ horsepower four-cylinder applications, making them an excellent choice for Mitsubishi Evo X owners building anything from a fast road car to a dedicated drag, track or motorsport engine.
Key Features
- Designed specifically for the Mitsubishi Lancer Evolution X 4B11T
- Complete set of 4 forged connecting rods
- Manufactured from premium 4340 forged steel
- Patented BoostLine three-pocket rod design
- ARP Custom Age 625+ connecting rod bolts
- Designed for extreme turbocharged and high-boost applications
- Suitable for 1000+ HP engine builds
- Approximately 60% greater bending strength compared with conventional H-beam designs
- Reduced tensile stress compared with traditional H-beam designs
- High-quality AMPCO bronze wrist-pin bushings
- Individually subjected to a detailed 26-point CMM inspection
- Inspection report supplied with each set
- Ideal for high-performance road, drag, track and motorsport builds
Technical Specifications
| Specification | Details |
|---|---|
| Brand | BoostLine |
| Product | Forged Connecting Rod Set |
| SKU | MI5657-905-PLUS |
| Manufacturer Part Number | MI5657-905+ |
| Engine | Mitsubishi 4B11T |
| Rod Type | I-Beam / Patented Three-Pocket Design |
| Material | Forged 4340 Steel |
| Quantity | Set of 4 |
| Centre-to-Centre Length | 144.00 mm |
| Nominal Application Length | 143.7 / 144 mm |
| Wrist Pin Diameter | 23.00 mm |
| Journal Size | 52.00 mm |
| Big End Bore | 2.1655 in |
| Big End Width | 21.87 mm |
| Small End Width | 0.782 in |
| Rod Weight | Approx. 622 g |
| Rod Bolt Size | 3/8 x 1.600 in |
| Rod Bolts | ARP Custom Age 625+ |
| Bolt Part Number | BT61601-625 |
| Pin Bushing | AMPCO Bronze |
| Application | Mitsubishi Lancer Evolution X 4B11T |
| Power Capability | 1000+ HP applications |
Why Choose BoostLine Conrods for the Evo X?
Increasing boost and cylinder pressure places enormous loads on the connecting rods in the 4B11T engine. Standard connecting rods can become a limiting factor as power levels rise, particularly on engines running upgraded turbochargers, increased boost pressure, race fuel or aggressive ECU calibration.
BoostLine’s three-pocket forged rod design has been developed to provide exceptional big-end stability and bending resistance without unnecessarily increasing rotating mass. This makes the MI5657-905-PLUS an excellent foundation for a serious Mitsubishi Evo X forged engine build.
The inclusion of ARP 625+ fasteners makes this PLUS specification particularly suitable for high-output builds where maximum connecting-rod bolt strength is required.
Ideal For
- Mitsubishi Evo X forged engine builds
- Big turbo conversions
- High-boost 4B11T engines
- Fast road applications
- Drag racing
- Track cars
- Time attack builds
- Motorsport applications
- Engine rebuilds targeting substantially increased power
Vehicle Application
Designed for:
Mitsubishi Lancer Evolution X / Evo 10 equipped with the 2.0-litre turbocharged 4B11T engine.
This includes relevant UK-market GSR and FQ-series Evo X models, providing they retain the compatible Mitsubishi 4B11T engine configuration.
What’s Included?
- 4 Γ BoostLine forged 4340 steel connecting rods
- ARP Custom Age 625+ rod bolts
- AMPCO bronze pin bushings
- BoostLine dimensional inspection documentation
Important Fitment Information
These are specialist internal engine components. Engine specification, crankshaft dimensions, pistons, wrist-pin diameter and intended engine build should always be checked before installation.
Professional engine assembly, measurement of bearing clearances and correct ARP fastener installation procedures are strongly recommended.
SKU: MI5657-905-PLUS
The technical dimensions, 4340 material, 622 g rod weight, 23 mm pin, 52 mm journal, ARP 625+ hardware and other specifications above come directly from BoostLine.





