Next are the connecting rods, and JE works closely with K1 Technologies. K1's off-the-shelf H-beam rods are billet 4340 Steel, and feature tolerances of .0001-in and 1 gram per end, which is among the tightest in the industry. They're also shot-peened for extra strength and use ARP 2000 fasteners, ensuring the caps don't loosen up at high RPM.
|Handling our compression and tensile loads are K1 Technologies' H-beam forged steel rods. While the Supra's stock forged I-beam units are very strong, K1's H-beam design is better suited for higher horsepower applications. Plus, they're forged from 4340 steel, which has a tensile load rating of 145,000 PSI, which is much higher than the 5140 or 4130 steel (They're rated at 115,000 and 125,000 PSI, respectively). They're strong, but also super light–in this case a 26% weight savings over stock!|
|The strength of the K1 rods will do no good to cope with high rpm tensile loads if the caps are going to come apart. To prevent this, K1 rods come standard with ARP 2000 bolts rated at 220,000 psi tensile strength. This combo makes the setup safe to over 1000 WHP and 9,000 RPM on a Supra.|
At only 561 grams (vs 761 grams a the stock 2JZ unit), K1 rods are not only stronger, they're significantly lighter too.
While it may be pushing the limits, the stock internals have been proven to hold over 800 WHP and 7500+ RPM repeatedly. Even this car's previous setup dyno'd 760 WHP at 29 PSI and drove for years at the 650 WHP level.
Our new JE/K1 setup should safely handle over 1000 WHP and 9500 RPM, which is plenty for our 800 WHP/8000 RPM goal. Plus a 20% weight reduction means faster revving and less strain on the crank!
Further consideration for reliability was given to the main bolts, which were replaced with ARP's main stud conversion for greater clamping force. Manufactured from 8740 chromoly steel with a 200,000 PSI tensile strength, ARP studs feature precision J-form threads that reportedly provide ten times greater thread strength. While the factory stretch bolts have fared fine, ARP studs add that extra insurance for peace of mind. It's also imperative to use their supplied thread lube to gain a more uniform torque across the threads.
With great parts in hand, none of them do us any good if we're not working with a competent shop. Throughout this series we're working with three local shops, and all of which are well acquainted with each other. Four Ring Performance (FRP) Engineering is prepping and building our bottom end while the cylinder head is visiting both FRP and Noland Cylinder Heads for clean-up and assembly. Motor installation, tuning and dyno testing will take place at Modified by KC. All three boast unprecedented reputations for engine building and tuning, and are thankfully local to the car's home in the Kansas City area.