BoostLine Connecting Rods are your best option for any high horsepower Subaru EJ engine build. Track proven in Mark Jager's 900hp+ Time Attack record holding Subaru. Our engineering team created this new, patented 3-pocket design specifically for demanding turbocharged applications. BoostLine Connecting Rods provide 60% more bending strength compared to common H-beam rods! Each rod is designed, finished and inspected in the USA and includes a detailed inspection report generated on our Zeiss Coordinate Measuring Machine (CMM). Machined from premium 4340 forged steel.
Part Number: SB5137-905+
For the most extreme applications, BoostLine Subaru EJ rods can be ordered with ARP 625+ bolts. These space-age bolts provide even more clamping force making this rod as tough as possible! 625 Plus upgrade provides 27% more tensile strength.
Because of the high cylinder pressures associated with big boost, BoostLine engineers focused on making the rod more resistant to bending under massive power loads.
BoostLine connecting rods for highly boosted Subaru EJ20 and EJ25 engines were launched a little over three years ago. These unique, lightweight rods can handle upwards of 1,000-horsepower in 4-cylinder applications and are a substantially more durable alternative to aluminum drag racing rods.
Note that while the 625 Plus bolt’s absolute tensile strength does increase slightly, the yield strength is significantly greater. This allows a greater clamping load to be applied to the bolt in order to maintain big-end concentricity.
But it gets better. The common misconception is that higher tensile strength automatically means the bolt is now more brittle. While that is true of some materials and heat treatments, certain materials, like Custom Age 625 Plus actually offer improvements in both tensile strength and ductility. This is important because there are bending moments that occur at the parting line of the connecting rod that make the rod bolt’s ductility an important safety factor. That’s the advantage Custom Age 625 Plus bolt offers.
Choosing this bolt also means a significant change to the validation process for the connecting rod. With a greater clamp load applied with the better bolt, this means that the stretch factor is also different, something that must be strictly adhered to both when checking bearing clearances and during final assembly.
All the above reasons are why it is critical that these rods be assembled with a rod bolt stretch gauge.
The combination of an incredibly strong rod with an equally high yield strength offers that safety margin that is necessary when pushing the performance limits of any engine. The combination of the BoostLine rod and ARP Custom Age 625 Plus bolt delivers exactly that kind of reciprocating peace of mind!