Forced induction is one of the quickest ways to add extra horsepower to your engine, but you need to ensure the engine’s internals are up to the challenge. Using a set of connecting rods designed to handle boost is one way to defend against problems while making a boosted engine more reliable. If you’re thinking about cranking up the boost you’ll want to read on and see what you need to keep in mind when selecting a set of connecting rods.
It doesn’t matter if you’re bolting a blower up on top of your engine or creating a jungle-gym of exhaust tubing for a turbo system, the boost that comes from your power adder is going to put stress on the engine. Every part of the rotating assembly has to work harder or deal with more force as a result of the air and power being added.
Evan Perkins from BoostLine knows what it takes to put parts in an engine that can deal with boost and harness its potential power. He explains what goes into the design theory of a connecting rod that’s capable of making large amounts of boost work in any engine.
“Designing a connecting rod for high-boost situations requires careful analysis of the application the rod is being designed for. The majority of aftermarket rods are made to fit in the same physical envelope of a stock rod. Better material, better fasteners, and a slight increase in material thickness add strength over stock. With BoostLine, we actually scanned the factory blocks and figured out what space we had to work within the crankcase. That allowed us to add more material to the connecting rod without the concern of interference. Material in the right places, ARP 2000 fasters, and premium steel make for an extremely strong rod.”
The material you select for a connecting rod will need to be based around the application of the engine and vehicle. When a car is going to see street duty a 4340 chromoly steel connecting rod is going to be the best choice. Aluminum connecting rods aren’t a great choice for street use since they have a shorter fatigue life.
When it comes to the important attributes a connecting rod should have in a boosted application you need to look beyond just the material makeup, according to Perkins.
“A boosted application is going to create higher cylinder pressures at much lower RPM than a comparable naturally-aspirated engine. This puts the rod under considerably more stress. One of the key areas we focused on with BoostLine is making the rod strong enough to deal with this added strain. This strength stems from the design, and allocating material to the most heavily stressed areas of the rod.”
When it came time to start making some connecting rods, BoostLine took their knowledge and created a unit that was boost ready right out of the box. By understanding just how dynamic an environment a boosted engine is allowed them to make a connecting rod that was more than capable of dealing with high levels of boost.
“The BoostLine three-pocket design dramatically improves the rod’s big end stability under tensile loads. This arrangement drastically increases the rod’s bending strength, giving it a 60-percent improvement in bending stress than a similar H-beam design, making it ideal for forced induction and high cylinder pressure engine combination. Simultaneously, a 20-percent stress reduction in tension was observed with the BoostLine design,” Perkins explains.
You can learn more about BoostLine connecting rods right here.