Upgrading the LS9 and LSA Engines

The LSA and LS9 engines make a lot of power. And, they can easily make more!

Upgrades are usually done in stages. Each level will provide more performance than the one before it. However, they will also be more involved and expensive.

Tuning and Bolt-on Upgrades

The first upgrade we recommend is tuning the computer. This involves changing the fuel and ignition curves to optimize performance. A good tune can gain up to 40 hp. on a stock engine. (Any significant upgrade will require re-tuning the computer.)

Upgrading a few bolt-on's makes sense at the same time. Follow the links below to see the parts we offer. (You will still need to select your specific Year, Make and Model.)

• A Cold Air Intake
• A set of Headers
• An Aftermarket Exhaust
• A Colder Thermostat

Supercharger Upgrades

With stock pulleys, the blowers spin around 16,000 rpm at redline. Changing the pulley sizes can spin it faster and increase boost. The next step on the upgrade path is a Pulley Swap. The chart below will give you some idea of what to expect.

**If you change ONLY the upper pulley, you can still run premium pump gas. If you change both pulleys, you will need an Octane Booster.**

Increasing the speed of the supercharger will create more heat. You can lower the intake air temperature in several ways.

• A Larger Heat Exchanger
• An Ice Intercooler Tank
• A Water/Methanol Injection Kit

Other Upgrades to the 1.9L LSA Supercharger

• CNC porting = about 35 hp.
• On a CTS-V, swap in a Camaro ZL1 Cover = about 15-20 hp.
• Install the 2.3L LS9 blower = up to 90 hp.
• • Requires a special blower snout and other modifications.

Other Upgrades to the 2.3L LS9 Supercharger

• CNC porting
• Install an aftermarket snout and a larger throttle body = about 30 hp.

Aftermarket Blowers are also available. Many have larger plenums, more intercooling capacity and better flow paths. They run cooler and still fit under short hood-lines.

Fuel System

Both engines have the same injectors and dual fuel pumps. However, they max out around 65 psi. The fuel pumps are controlled by a module that increases fuel pressure in relation to boost. There are aftermarket pumps and Voltage Controllers that will work with the factory ECM to increase capacity.

• The stock injectors are good to about 600 hp. at the wheels.
• The stock dual fuel pumps are good to about 650 hp. at the wheels.

Top End Upgrades

The factory heads are based on the LS3 heads. However, they have a flow vain in the intake port. This helps emissions and idle stability, but reduces flow. CNC porting the heads is common. This removes the vain and improves airflow by about 70 cfm.

Aftermarket Cylinder Heads are another option. These heads will flow even better than ported stock heads and have thicker deck surfaces to withstand more boost.

Like other LS engines, a cam swap is common. The LSA has a very small camshaft. Upgrading to a LS9 Camshaft is worth about 30 hp. However, it won’t make any more power until 4,800 rpm. It's really only worth it if you plan on running at high rpm.

Larger, Aftermarket Cams can add about 50 hp. Going as high as 0.630 in. of valve lift is also common.

The table below gives some information on what to expect from different cams. (We are assuming a standard blower, pulleys, and tune on pump gas.)

Upgrading the camshaft will require the matching

The trunnion bearings in the stock rocker arms are a known weak point. We strongly recommend a Trunnion Upgrade Kit. Swapping in a set of Full Roller Rockers is another option.

Bottom End Upgrades

Detonation can occur if inlet air temperatures get too high and/or low octane is used. This will destroy the cast pistons in the LSA Forged Pistons are a smart upgrade. (The LS9 came with forged pistons from the factory.)

Due to extremely high cylinder pressure, the heads can start to lift around 1,000 hp. At that point, you will need to basically build a whole new engine. The following upgrades will be required.

• A stronger, aftermarket engine block with 6 head bolts per cylinder
• Cylinder heads with 6 bolts per cylinder
• A center counterweighted crankshaft
• Forged steel connecting rods
• Forged pistons

Boring and Stroking

The cylinders can be honed 0.005 in. oversize. This keeps the walls thick enough to support boost. A 4.000 in. stroke crankshaft will also increase displacement. The chart below lists the specs for common bore and stroke combination.