LS3 Power Upgrades - The Power Of 3

A Few Basic Modifications Greatly Enliven The Corvette's Ls3 Engine

Richard Holdener Sep 24, 2010 0 Comment(s)
View Full Gallery

GMPP LS3 vs. TSP Cam and TEA L92 Heads
As important as the huge jump in peak power (from 485 to 574 hp) is the significant improvement in torque production (from 476 to 520 lb-ft) throughout the rev range. These gains are even more impressive when you consider that the TEA heads came equipped with slightly larger combustion chambers than did the stock LS3 units (70cc vs. 68cc), dropping the static compression by nearly 0.2 points.

Vemp_1011_16 LS3_engine_power_upgrades 7/23

GMPP LS3 vs. TSP Cam and Dr. J's 81cc ProComp Heads
Despite dropping the compression ratio from 10.7:1 to 9.4:1, the ported ProComp heads and Texas Speed cam improved the output of the LS3 crate motor from 485 hp and 476 lb-ft of torque to 538 hp and 495 lb-ft. Knowing that every point of compression drops power output by 4 percent, we can calculate that with the stock chamber size, these heads would produce in the neighborhood of 565-570 hp. A full test of the standard-chamber heads will be completed soon, but for now it's clear that these large-chamber offerings combine plenty of flow with a drop in compression that makes them ideal for forced induction.

Vemp_1011_17 LS3_engine_power_upgrades 8/23

We took a set of large-chamber L92 heads from ProComp and had Dr. J's "tune them up" so we could run them on our LS3 (see graph). Thus modified, the ported ProComp heads offer impressive flow numbers, enough to support more than 700 hp in normally aspirated trim. Combine that with the drop in compression, and you have some seriously powerful blower heads. ProComp also offers LS3 heads in standard chamber sizes for the NA crowd, and Dr. J's can tune them for big-time power production.

Boosted Bolt-Ons
If you're considering a supercharger or turbo for your LS3, here's an interesting option to explore: ProComp Electronics now offers dedicated LS3 head castings in as-cast and CNC-ported form. What makes them so attractive for forced-induction applications is that they're available with combustion chambers measuring 80-81 cc's, compared with just 68-70 cc's for the production LS3/L92 heads. The larger chambers drop the compression ratio by 1.3 points, bringing it down to a more boost-friendly 9.4:1.

Sources

Comp Cams
Memphis, TN 38118
800-999-0853
http://www.compcams.com
Chevrolet Performance Parts
Detroit, MI 48232
800-577-6888
www.gmperformanceparts.com
Pro Comp Electronics
Ontario, CA 91761
909-605-1123
www.procompelectronics.com
Texas Speed & Performance
Wolfforth, TX 79382
806-866-0734
http://www.texas-speed.com
E3 Spark Plugs
Ponte Vedra, FL
www.e3sparkplugs.com

MORE PHOTOS

VIEW FULL GALLERY

COMMENTS

TO TOP