Motor Magazine takes the Autotech's APS
Twin Turbo LS1 for a spin...
Starting at the beginning,
the kit involves new, cast exhaust manifolds
which position each ball-bearing Garrett snail
way down low near the front cross member and
well and truly in the undercar slipstream. A
steel plate that bolts to the cross-member and
spans the width of the vehicle protects the
turbos from roadkill.
From
there, the dead gasses head south via a twin
three-inch exhaust system and out :ria big,
polished dump-pipes. On the intake side, there's
an air-to-air intercooler living behind the
grille.
Interestingly, too, each hose
from each turbo to the' cooler and back to the
throttle-body are the same length so you don't
get one half of the engine huffing-up faster,
or one turbo trying to blow boost backwards
up the other one.
The stock injectors are flung
and replaced by units that will flow enough
to keep up with the airflow, and the on-board
computer is fiddled slightly as well as being
augmented by a piggy-back unit.
The standard fuel pump is retained
but now feeds into an accumulator can (about
the size of a Milo tin, but much shinier) which
contains two high-pressure pumps to supply the
new fuel rails via their new regulators.
Sounds simple, but of course it
devoured many thousands of hours to get right
and no doubt owes APS a lazy squillion or so.
And based on local volumes, it'll never make
money But throw in the potential demand from
Stateside owners of Pontiac GTOs and it all
starts to make sense. Especially since the kit
is entirely compatible with the LS2 (as fitted
to '05 model GTOs and our own current-model
HSV stuff).
Now, as regular readers of this
fine family magazine will know, I'm no great
fan of the original recipe LS1. But ain't it
great what a couple of hairdryers can do, because
this thing rates as one of the most exciting
road cars I've driven.
Boost comes on from less than
2000rpm and all of a sudden, those l-o-n-g gears
in the sixspeed 'box are viable. Indeed, it'll
pull sixth gear from 90km/h and actually accelerate
when you ask the question.
Hit 3000rpm and the twin-turbo
Munro is hurtling, accompanied by a demonic
kind of rushing sound from under the lid and
near enough to 500 pre-metric neddies tearing
at the road.
First gear is academic with the
traction off (and you will turn it off because
it pulls the pin way too early) and it'll even
spin up on dry bitumen in second regardless
of whether you have some lock on or not. Third
gear is the first of the ratios you can use
with any sort of abandon, but even then, if
you have any lock dialed in, the rear treads'll
go up in smoke.
I reckon third and fourth gear
are the highlights of this twinturbo monster.
There's enough traction for it to hook up cleanly
(usually) but both gears can still be legitimately
referred to as sprint ratios. Especially so,
given the way the engine blows the tacho into
the rev limiter faster than you can think about
what to do next.
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2004-2005 AutoTech Engineering