How good are the Gen 3 V-8s? Compared to the original Gen 1 (23-degree) small-blocks, the new motors offer more of everything. That list of everything includes power and torque, fuel mileage, and even reduced emissions. Also missing is engine weight, as the LS1/LS2 engines feature not only aluminum blocks and heads, but also composite intake manifolds. Imagine the response you'd get back in the 1960s or 1970s at the local drive-in after lifting the hood to reveal an all-aluminum small-block.
Now toss in a set of heads that flow more than even ported 23-degree production heads, a lightweight composite intake that offers not just impressive peak power but one hefty torque curve (thanks to the longish runners), and a sophisticated management system that allows the 5.7L LS1 (or 6.0L LS2) to both sip fuel and optimize power production at every throttle angle. And the new LS3 is better still with 6.2 liters and 430 horsepower in base trim.
Following in the footsteps of the original, the LS1/LS2 motors respond equally well to performance mods. Given that time and technology march on, it should come as no surprise that the LS1 heads flow much better than even the trick fuelie heads of yesteryear. While the stock components have improved, so too have the aftermarket versions, as flow figures from a set of ported or aftermarket CNC heads for the LS-series motors easily exceed the magical 300-cfm mark. These are flow numbers only dreamed about by stock 23-degree heads. Only a handful of aftermarket 23-degree race heads can reach 300-cfm figures, a number achieved by properly porting a set of stock LS heads.
Naturally stock LS-series motors also respond well to cam changes. Since it's unnecessary to remove the intake manifold (and distributor) to facilitate lifter removal on the LS-series motors, cam changes on the LS1 and LS2 are a snap. Simply rotating the cam will push the stock hydraulic roller lifters up and out of the way to be retained by the factory plastic guides.
Since the stock components were designed to produce a given amount of power, it's not surprising that aftermarket components can improve an LS1's or LS2's power output. Like all the previous small-blocks, there is power to be had from an intake swap. For LS1 and LS2 motors, the hot setup is actually the factory LS6 intake, though in the case of the LS2 it is necessary to step down in throttle body size. There are a number of other intakes available for the LS-series motors (with more on the way), including carbureted combinations from Edelbrock and GM Performance Parts. Headers are a solid performance upgrade, as are the old standbys like nitrous oxide and forced induction. Add an NOS nitrous kit to even a stock LS1 and you're talking about some serious power. Add it to a modified motor and you're running 10s. The same goes for blowers and turbos, as both the LS1 and LS2 respond very well to boost. Even in emissions-legal trim, a blown LS1 will pump out over 500 wheel horsepower, with 800 wheel hp available for a serious stroker effort. With turbo motors, the sky is the limit, as 1,000 hp is a common occurrence, with the ability to adjust the power output by turning a simple boost knob.
To illustrate the power available from the LS1 and LS2, we gathered together a number of combinations, ranging from 400hp stock applications to 700hp blown and turbo buildups. Since buildups most often include a power goal, we decided to provide LS1 and LS2 recipes to reach 400 hp, 500 hp, 600 hp, and even 700 hp. It's obviously possible to eclipse these numbers, but we thought these power levels best represent what can still be construed as real street motors.
In most cases, we started with a stock LS1 or LS2 crate motor from GM Performance Parts, so these buildups began with what a Camaro, Corvette, or truck owner might currently have under the hood. Since the LS-series crate motors are so popular for street rod and street machine buildups, the recipes illustrate what's possible with modifications to the basic motor. Check out the ease at which serious power is obtained from the LS series and you may rethink stuffing an original small-block in that Camaro, Nova, or Chevelle project.
Spec Sheet 400hp LS2
Take one 400hp LS2 and install it on the dyno and you have an easy 400 horsepower. For this test we equipped the LS2 with Hooker headers and an open exhaust. With optimized air/fuel and timing curves, the LS2 pumped out 462 hp and 461 lb-ft.
If you think extracting 400 horsepower from an LS1 was easy, things get downright simple with the larger LS2. Given its factory rating of 400 hp, it's not surprising that the LS2 produced 462 hp and 461 lb-ft of torque with just a set of Hooker headers. Compared to the smaller LS1, the LS2 offered not only more peak power, but also more power throughout the rev range. Down at 3,100 rpm, the LS2 produced nearly 60 more lb-ft of torque.
Spec Sheet 500hp LS1
Total Engine Airflow supplied a set of ported 5.3L truck heads. When combined with a small Comp cam and FAST LSX intake, the result was 535 hp and 478 lb-ft of torque.
As impressive as the Gen 3 motors are in stock trim, they're even more so once modified. Using the same LS1 crate motor as a starting point, eclipsing the 500hp mark required only a set of aftermarket heads, a mild cam, and an intake manifold, though the LS6 intake would also work well at this power level. The LS1 was treated to a set of ported 5.3L truck heads from Total Engine Airflow, a Comp XR265HR cam, and a FAST LSX intake. The smaller combustion chambers (61cc) on the 5.3L heads increased the compression ratio by .5 point. When combined with the mild cam and LSX intake, the result was 535 hp and 478 lb-ft of torque. Note that the power curve was still climbing at our shutoff point of 6,200 rpm.
Spec Sheet 500hp LS2
The CNC-ported AFR 205 heads were a big part of why this LS2 produced such big power. Combining the free-flowing heads with a custom AFR-spec cam resulted in 571 hp and 500 lb-ft of torque.
Like the smaller LS1, the 6.0L LS2 responded just as well to modifications. By equipping the LS2 crate motor with a set of AFR 205 heads, a custom AFR cam profile, and an LSX (90mm) intake, the power numbers reached 571 hp and 500 lb-ft of torque. Remember that the LS2 motors sport the better LS6 heads (243 castings), so additional power from aftermarket heads is more difficult to come by than with the smaller LS1. With 571 hp, this is one serious normally aspirated street motor.
Spec Sheet 600hp LS1
It's obviously possible to exceed 600 flywheel horsepower with a normally aspirated LS1, but life is so much easier with forced induction. Rather than go the wild cam, high-compression, or even large-displacement route, simply adding a supercharger to an otherwise mild LS1 will result in some serious power. Exceeding 600 flywheel horsepower is no problem; in fact, this modified LS1 managed to exceed 600 wheel horsepower (closer to 700 at the flywheel) running just 10 psi of boost. Credit the efficiency and power potential of the Kenne Bell twin-screw supercharger for the impressive power. The test motor featured a 5.7L LS1 short-block equipped with LS6 heads and cam. The motor exhaled through the stock LS6 titanium exhaust. Run on the Dynojet chassis dyno, the Kenne Bell supercharged Vette produced 600 wheel horsepower and 658 lb-ft of torque. How does 500 lb-ft of torque at just 2,000 rpm sound? If you put your foot in this bad boy's throttle, you'd better be sure the wheels are pointed in the right direction.
Adding a Kenne Bell supercharger kit to your C5 or C5 Corvette is a surefire recipe for performance. Running the kit on an LS6-enhanced LS1 resulted in 600 wheel horsepower. Adding the same kit (with more boost) to a 408 stroker version resulted in 800 wheel horsepower.
Spec Sheet 600hp LS2
Given the impressive starting point, exceeding 600 flywheel horsepower from a 6.0L LS2 is every bit as easy, especially when you introduce a little nitrous oxide to the mix. Running a set of Trick Flow Specialties CNC-ported LS1 heads, a small Crane Z-series cam (212/224 duration), and a set of Hooker headers, the mild LS2 produced 524 hp. After adding the NOS plate system to the mix, the peak power numbers jumped to 632 hp and 649 lb-ft of torque. The transition from a mild (albeit powerful) 525hp daily driver to serious street machine comes at the push of a button. The instantaneous thrust of torque offered by the NOS kit is seriously addictive.
Whether stock or modified, nitrous oxide can add power to any combination. We installed an NOS plate system on an LS2 equipped with Trick Flow CNC-ported LS1 heads, a small Crane cam, and Hooker headers. Adding the NOS kit to the modified LS2 motor resulted in 632 hp and 649 lb-ft of torque.
Spec Sheet 700hp LS1
The twin turbo kit from HP Performance was installed on the engine and then into a C5 Vette with excellent results. Running 13 psi, the turbocharged LS1 stroker produced 706 wheel hp and 713 lb-ft of torque. The same HP kit has been used with 67mm turbos to exceed 1,100 wheel hp on a purpose-built 408 stroker.
What power recipe story would be complete without a turbo system? Extracting 700 horsepower from a 6.0L LS1 is not particularly difficult, but having that power come in a driveable combination makes life somewhat more difficult. The challenge is overcome with boost, in this case from a twin turbo kit from HP Performance. HP combined its intercooled twin (57mm) turbo system with a low-compression short-block (using a 6.0L truck block), a set of AFR 205 heads, and a FAST LSX intake to produce 706 rear wheel horsepower and 713 lb-ft of torque. These power numbers came at a peak boost pressure of 13 psi. Note that 706 wheel horsepower translates into something near 800 flywheel horsepower-a stout LS1 indeed.
Spec Sheet 700hp LS2
Running a mild Lunati Voodoo cam, a set of Trick Flow CNC-ported LS1 heads, and a FAST LSX intake, the Vortech supercharged LS2 produced 710 hp and 610 lb-ft of torque. The impressive thing about this supercharged combination was the fact that all this power came at just 7.7 psi of boost.
Running the LS2 crate motor from GMPP, we added Trick Flow Specialties CNC-ported LS1 heads, a small Lunati VooDoo cam (212/218 duration), and Hooker headers. Though the Vortech supercharger kit was equipped with an air-to-water intercooler, we also ran a Snow Boost Cooler water/methanol injection system to further keep detonation in check. This also allowed us to get more aggressive on the timing and air/fuel ratio to maximize power production. Running a peak boost pressure of just 7.7 psi, the supercharged LS2 produced 710 hp and 610 lb-ft of torque. Note from the curve's shape that the power was still climbing at 6,500 rpm.