Car Craft – November 2019

➔HANDS ON

28 CAR CRAFT NOVEMBER 2019

W

hy were we excited about

having just installed an LS9

cam in our 5.3L? Well, partly

because upgrading the cam and

springs only cost $100, but there was

actually a second reason. As most of

you know, the LS9 cam was designed

for the factory supercharged LS9

motor, meaning the LS9 was techni-

cally a blower cam. If it was a blower

cam, then why on earth did we install it

in our naturally aspirated 5.3L?

The first reason was obviously the

cost, but the real reason was because

we intended to add boost to the 5.3L

all along. Even before the cam upgrade,

we knew we had the Vortech super-

charger waiting in the wings. If you are

going to all the trouble to add a blower

cam, why not combine it with some

boost? For those just joining the party,

replacing the stock LM7 cam with the

LS9 cam and matching LS3 springs

increased the power output of the 5.3L

from 342 hp and 373 lb-ft of torque to

402 hp and 379 lb-ft of torque. Every

bit as important was the fact that

the LS9 cam pushed the peak

power higher in the rev range, and

nothing likes extra rpm more than a

centrifugal supercharger!

While turbo 5.3L motors seem to

take center stage, the reality is not

everyone wants to deal with the com-

plexity and heat issues associated with

a turbo kit. Though DIY turbo kits are

popular, it’s harder to find kits designed

for a specific chassis/engine applica-

tion. There is no denying the power

potential of a good turbo system, but

that doesn’t mean there isn’t room for

other forms of boneyard boost. We

liked that Vortech went to the trouble

to build a kit designed specifically for

the junkyard 5.3L crowd. After all, it is

the most common and popular LS

swap engine out there, but we see no

reason why this system won’t fit on a

similar 4.8L or even the larger 6.0L.

Right off the bat, it should be pointed

out that this Vortech supercharger kit

was not designed to make massive

By Richard Holdener / Photos: Richard Holdener

CHEAP TRICK,

PART 2

Our Junkyard 5.3L LS Gets a

Vortech Blower for an Easy 180 hp

In Part 1, we upgraded our junkyard LM7

with an LS9 cam, LS3 springs, and a set of

80-pound ACCEL injectors. The $100 cam

swap improved the power from 342 hp

and 373 lb-ft to 402 hp and 379 lb-ft, and

pushed the power peak all the way up from

5,300 to 6,200 rpm.

power. The V3 SCI supercharger

included in the kit was capable of sup-

porting 725-plus horsepower, but for

most guys, even that number is above

and beyond the level of a typical bolt-

on, non-intercooled kit. This kit was tar-

geted at the LS enthusiast looking to

quickly and easily bolt on an extra 150

hp (or more) to their stock or mildly

modified 5.3L before swapping it into a

muscle car or truck (or any of the end-

less other LS-swap applications).

Having already run our 5.3L with the

LS9 cam, we tore into the junkyard