LS3 Bolt-On Intake Manifold Comparison
It’s important to note that this is not a shootout between these intakes – it’s a fact finding mission. In comparing the results between these four options, we get a better idea of the strengths and weaknesses of different designs when applied to a control, and in this particular scenario, that control is a fuel injected, 550 horsepower engine built for street use.
That means that while this LS3 might be able to take advantage of the design of LSXr, that particularly well-matched pairing is to some degree happenstance – if we were using a pair of four barrel carbs or a supercharger, the Mid-Rise might’ve yielded more gains than the FAST intake. And if this engine were built with high-RPM competition in mind, the Hi-Ram likely would have widened its gap on the top end in relation to the other three even further.
As a quick summary, here’s a look at the results of all the intakes we tested:
- Stock LS3 – Peak: 556.3 hp at 6,500 rpm /497.2 lb-ft of torque at 5,500 rpm, Average: 311.82 hp /430.66 lb-ft (3000-4500 rpm), 513.64 hp / 479.83 lb-ft (4500-6800 rpm)
- FAST LSXr – Peak: 566.3 hp @ 6,600 rpm / 515.3 lb-ft @ 5200 rpm (10hp / 18.1 lb-ft gain), Average: 316.45 hp /437.8 lb-ft (3000-4500 rpm), 524.35 hp /489.84 lb-ft (4500-6800 rpm)
- Holley Hi-Ram – Peak: 605.4 hp @ 7,000 / 496.7 lb-ft @ 6,100 rpm (49.1 hp gain, 0.5 lb-ft loss), Average: 301.32 hp / 419.12 lb-ft (3000-4500 rpm), 529.08 hp / 479.62 lb-ft (4500-7100 rpm)
- Holley Mid-Rise – Peak: 555 hp @ 6,900 rpm / 483.3 lb-ft @ 5,700 rpm, (1.3 hp / 13.9 lb-ft loss), Average: 308.99 hp /429.06 lb-ft (3000-4500 rpm), 507.03 hp / 465.32 lb-ft (4500-7000 rpm)
The takeaway here is that it’s important to consider not only how your engine is built, but how it will spend the majority of its time as well, as an intake that sacrifices low-end grunt for gains on the top might be ideal for a racing application but could easily be perceived as a net loss on the butt dyno if the engine is being used on the street the majority of the time. Putting together a clear strategy for your modifications will ensure that you get the most bang for your performance buck.