681 HP and 617 LB-FT Supercharged LS3 Crate Engine - Twisted LS3

Chevrolet Performance Crate On Boost

Jake Amatisto Jul 11, 2014 0 Comment(s)
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If you’re looking for a crate engine for under ten grand, Chevrolet Performance’s LS3 is a solid foundation. At $8,567 (Summit Racing), you get a ton of parts that aren’t typically included with other crate engines, such as coil-on-plug ignition, fuel injectors, flexplate, water pump, and other items that make it ready to drop into your hot rod. Introduce a power-adder like a supercharger to it and you can have one wicked-fast, highly efficient modern engine that can pump out loads of horsepower. Case in point: our Chevrolet Performance LS3 engine we’ve been playing with over the past year. Basically, we combined three part numbers (PN 19301360 for the LS3, PN TS9008-2.8LC for the blower, and PN 554-114 for the EFI) and turned our stock LS into a 680-plus-hp pump gas fueled monster, and that’s without even touching the insides of the engine.

This month we trekked our LS3 down to Westech Performance Group in Mira Loma, California, to put Kenne Bell’s 2.8L supercharger and Holley’s Dominator fuel injection to the test. This engine will be the base for a 416ci stroker engine in the future, but for now we wanted to see what we could get out of Kenne Bell’s smallest supercharger. The 2.8L twin-screw blower is the base model for a stock fifth-gen Camaro, so if you’re in the market for one, this is a good example of the kind of horsepower you can expect (at the crank) and still drive your Camaro every day if you want to.

Kenne Bell offers three blowers for GM’s LS line of engines: the 2.8L, the 3.6L, and the 4.2L – an even larger blower is in the works for serious race applications. Each supercharger can be ordered with a liquid-cooled front bearing case option that’s separate from the intercooler system. This $300 option essentially cools down the front bearing in the case, which increases power and rpm potential.

The third component in this combination is Holley’s Dominator EFI system. This setup has near limitless capabilities and its simplified interface makes tuning a breeze. When it comes to tuning or data logging, the Dominator does it all, and what’s cool is we’ll be able to use this setup in all the stages of the engine as it progresses. With Westech’s Eric Rhee at the keys, we coaxed our powerplant to make impressive steam on California’s winter blend of 91-octane fuel.

Kenne Bell’s 2.8LC Twin-Screw Supercharger

Kenne Bell Supercharger 2/20

  • Silent operation
  • Rear inlet manifold accepts large throttle bodies
  • Large 4x6-inch rotors for more hp potential
  • Integral intercooler

Chevy’s 6.2L LS3 Crate Engine

Chevy Ls3 Crate Engine 3/20

Chevrolet Performance’s LS3 is a 6.2L (376ci) V-8 that features 10.7:1 compression from hypereutectic pistons, a nodular iron crankshaft, a cast aluminum engine block, and powdered metal connecting rods. It’s also equipped with a hydraulic roller camshaft that has 0.525-inch valve lift and 226/236 degrees of duration at 0.050.

Parts include:

  • Ignition coil packs
  • Spark plug wires
  • Spark plugs
  • Intake manifold
  • Fuel injectors
  • Throttle body
  • Exhaust manifolds
  • 14-inch flexplate
  • Front timing cover
  • Aluminum water pump
  • Harmonic balancer
  • Passenger side, right-hand dipstick and tube

Holley’s Dominator Vehicle Management System

Holley Dominator Efi 4/20
Holley Dominator Wires 5/20

There were many reasons why we went with Holley’s top-of-the-line EFI system on our LS3 engine. The main reason was that as the engine progresses, it will allow us to easily change and data log the various tune-ups the engine will see. The Dominator’s comprehensive interface makes adjusting engine parameters a breeze and we’ll definitely need to adjust the tune once we go with E85 fuel. We’re running some pretty large injectors on this engine, 220-pounders, because at one point we’ll be putting a larger Kenne Bell supercharger atop of this engine (once it’s stroked) and seeing what kind of power can be had from GM’s latest small-block with even more boost from a twin-screw. The Dominator is much more than a standalone EFI system; Holley calls it a “Vehicle Management System,” which is accurate because it can do so much more than just control fuel. The Dominator can control coil-on-plug ignition, multiple progressive nitrous systems, and it even allows for control over transmission features. If you want to be really trick, the Dominator can be ordered with a full-color LCD touch screen (PN 553-103) that eliminates the need for a laptop computer.

Features include:

  • Plugs into factory GM 24x and 58x LS engines
  • Integrated electronic transmission control (4L60E and 4L80E)
  • Integrated dual-channel wideband oxygen sensor controls
  • Integrated drive-by-wire throttle body control
  • Four-stage progressive nitrous oxide controller
  • Turbo boost control
  • Internal data logging standard with 2 GB of memory
  • Store and change between four calibrations
  • Individual cylinder fuel and spark control
  • Plus much more


Ls3 Crate Engine Turn Key Brackets 6/20

1. We have to give major props to Turn Key Engine Supply in Oceanside, California, for providing all the brackets and accessories for this project engine. We will be using them on this and the next incarnation of this powerplant, when we bolt up the larger 3.6L Mammoth supercharger to our stroker LS3.

Ls3 Crate Engine Coil Pack 7/20

2. We actually upgraded a few things on the crate engine before we started the dyno tune, the ignition system being one of them. First, the coil pack brackets must be removed.

Ls3 Crate Engine Spark Coils 8/20

3. Performance Distributor’s Sultans of Spark were chosen for the coils on our blown LS3. The hotter spark from these coils will more effectively burn the mixture that’s forced in from the supercharger.

Ls3 Crate Engine 90mm Throttle 9/20

4. We used a 90mm throttle body from Kenne Bell on this project. However, the manifold itself can house nearly any throttle body combination you can think of.

Ls3 Crate Engine 09 10/20

5. The high-flow intake manifold features a liquid-cooled intercooler that keeps the incoming boost cool. “For every one psi of boost, it’s 10 degrees of temperature,” Mike DeCourcey from Kenne Bell said. “The cooler the boost, the more power it makes.” What this tells us is, the cooler you can make this supercharger, the more power you’ll make. In this case however, we were at the limit of what’s attainable with pump gas and the stock engine. While the LS3 design as a whole is a stout piece, it has hypereutectic pistons, which are strong yet their brittle construction doesn’t handle detonation very well. Westech’s Steve Brulé made sure to take the necessary precautions to ensure the engine lives under wide-open pulls.

Ls3 Crate Engine Intake Elbow 11/20

6. The intake elbow we tested was Kenne Bell’s cast version of their Mammoth intake manifold. You can also order the intake in a polished version, like the one we have for the 3.6L supercharger we’ll be testing in the future.

Ls3 Crate Engine Damper 12/20

7. Innovators West supplied the lightweight damper, which is a staple part in Turn Key Engine Supply’s bracket and pulley system, and is another upgrade from the stock crate engine. This will also be used in the higher horsepower version of this engine.

Ls3 Crate Engine 13 13/20

8. We upgraded to Performance Distributor’s Live Wires as well. They have low-resistance and work in conjunction with their coils.

Ls3 Crate Engine 14 14/20

9. The first screen you see when delving into the Holley Dominator software looks like this. To start from scratch you would select Create New Global Folder, however, since Westech had a similar tune from a previous dyno session, we were able to get one that was close, then modify it to our engine’s needs.

Ls3 Crate Engine Tunes 15/20

10. For those with common combos, Holley also includes an array of tunes preloaded into the Dominator ECU.

Ls3 Crate Engine Fuel Pump 16/20

11. Aeromotive’s Pro-Series fuel pump (PN 11102) provided the fuel flow like a champ. It’s designed for power levels up to 1,700 horsepower and was more than enough for our application.

Ls3 Crate Engine Ratios Graph 17/20

12. Once we fired the engine, Eric Rhee was able to tune the air/fuel ratios live, while the engine was running, increasing and decreasing fuel in the areas where it needed it until the boosted LS3 ran smooth enough to make a full pull.

Ls3 Crate Engine Power Graph 18/20

13. After a couple of low-rpm pulls in the 500hp range, the motor screamed to 641.7 hp at 6,700 rpm. Not bad for a stock engine with a blower.

Ls3 Crate Engine Pulley 19/20

14. We were only making about 8.4 psi of boost with the large 4-inch pulley, so we mixed in a bit of 100-octane and swapped to the smaller 3.75-inch pulley to try for 10 psi.

Ls3 Crate Engine Superflow Dyno 20/20

15. A hard pull to 6,800 rpm on Westech’s SuperFlow and the engine nailed 681 horsepower and 617 lb-ft of torque. The next time you see the numbers of this modern small-block they will be considerably higher. CHP

Sources

Westech Performance
Mira Loma, CA 91752
951-685-4767
www.westechperformance.com
Performance Distributors
Memphis, TN 38132
901-396-5782
www.performancedistributors.com
Aeromotive
Lenexa, KS 66214
913-647-7300
http://www.aeromotiveinc.com
Holley Performance Products
Bowling Green, KY 42101
270-781-9741
http://www.holley.com
Chevrolet Performance
800-450-4150
http://www.chevroletperformance.com
Turnkey Engine Supply
www.turnkeyenginesupply.com
Kenne Bell Enterprises
Rancho Cucamonga, CA 91730
(909) 941-6646
www.kennebell.net

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If you’re looking for a crate engine for under ten grand, Chevrolet Performance’s LS3 is a solid foundation.
Jake Amatisto Jul 11, 2014

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