G8 Catastrophe = Jaguar Opportunity……|
Part 1- (below)
Go on to Part 2- Engine Prep
Go on to Part 3- Engine Package Installation
Go on to Part 4- Wiring Details
Go on to Part 5- Exhaust System
Go on to Part 6- Driveline and Shifter
(These are a series of articles on installing Gen4 LS engines in our Jaguar
cars. New links to follow-on articles will be posted from time to
Part 1- The Donor...
So first of all, please don't worry- this 2009 Pontiac
G8 GT came to us in this condition- the accident happened before we got the car.
For those not familiar with the G8, this was a model built by GM of Australia
(Holden) from 2008-2009 as a high powered sport sedan. In its best year (2009),
it came with 3 models: a base car with a 3.6L V6/automatic (boring), and 2 V8
LS choices- the L76 6.0L engine (361 hp) and 6L80E (6 speed automatic
transmission) and the LS3 6.2L engine (415 hp) and 6 speed manual transmission.
The LS V8 cars were the ones to have and now, almost 10 years later, they
are still very popular among LS performance enthusiasts. Overall production was low-
remember, these cars came out right at the time of the great recession, which
quickly led to the shuttering of Pontiac as part of GM’s bankruptcy. Even with
aggressive discounting only some 30,000+ G8 cars (of all types) were sold here
in the US.
Getting back to the car at hand here, this one is a GT model
that has the L76 LS engine. This is the newer variety of the LS engine family,
called the Gen 4 (small block Chevy’s are Gen 1, and the 92-97 Chevy LT1 is the
Gen2, the original LS is referred to as Gen 3). Besides great power, the L76 makes
plenty of torque (385 ft-lbs) and also has some interesting other features such as
“Active Fuel Management/Displacement on Demand” technology that, under low load
conditions, disables as many as 4 cylinders to increase fuel economy. This
feature was only offered on the automatic transmission cars, and was also
included in the 6.2L L99 (also Gen4 LS) engines for the (then) new 2010 Camaro (again only with
Enough on the tech and on to the donor itself. So this
was a creampuff 2009 G8 GT with only 52k original miles. Unfortunately it had a
heavy encounter with something in front on a rainy night and was totaled.
Once all of the bent sheet metal was removed in front of the engine it still ran
fine. The drivetrain was pulled out as a whole unit along with the complete wiring harness
and controllers. Once the engine was out, some of the major similarities/differences between it and
the earlier LS/4L60E packages we have mostly used were apparent:
Engine Mount Positions- all of the key bosses on the block are the same
as earlier LS engines, but…
Drive- the later model accessory drive pulls the alternator, power
steering pump and AC compressor (though all still in the same relative
positions on the engine as other LS engines) back further on the block which
may impact our Jaguar-LS engine mounts. The different accessory drive, being
further back, does increase the space in front of the engine (helpful when
running cold air intake systems, etc.,.)
while this is a 6 speed automatic, GM did a good job of packing it all inside
the same general space. What I mean here is that the 6L80E is actually nearly
identical in length to the 4L60E (4 speed) automatics we have used before. The
new transmission has more girth around the middle and is much bulkier than the
4L60E. Interestingly, the 97-02 XK8 and 98-03 XJ8 cars all originally used a
ZF 5-speed automatic transmission that has a very similar shape to the 6L80E
which may alleviate concerns about adequate space in the transmission tunnel.
And the rear transmission mount location is just an inch or so rearward of the
4L60E position, so we’re in the ballpark. Check out the fixed output shaft- we'll have
to do something special there for the driveshaft.
ECM and TCM-
what a difference 10+ years makes. The L76 ECM
(engine control module) is about half the size of similar units for the earlier
LS1 engines. And the TCM (transmission control module), formerly part of the
LS1 ECM is now located completely inside the 6L80E transmission itself. Only
the basic commands, power, and GM LAN/network wiring go in and out of the
case. It greatly tidies up the wiring.
As of this writing, I am working carefully on the engine
control harness, removing all of the non-essential wires and components (and
there are many of them). It may sound difficult, but using the factory shop
manual set (which includes detailed descriptions of every connector in the car
and the wires it holds) makes it pretty straightforward. Once the wiring is
prepped, the mechanically prepping of the drivetrain can begin- installing the
correct oil pan and exhaust manifolds to fit an XK8 chassis (oops, that was
supposed to be a secret...). Stay tuned for
The pics above are of the G8 as it arrived and later with
the damaged front end removed. Below you can see some detailed shots of the
engine all around as we get ready to move forward.
Want an LS-powered Jaguar for yourself??
Click the links below to Jaguar-LS conversion information on our website and
a also photos of many
different completed cars, most by our customers:
Our Jaguar LS kits and parts:
Gallery of completed LS-power Jags: