The Ford Falcon XR6 Turbo is a sensational
platform for aftermarket tuning. Twelve second quarter miles are dead easy to
achieve and, in most cases, without needing to modify engine internals. So what
mods are needed to achieve your required performance and what’s available in the
aftermarket? Well, let’s take a look...
Engine Enhancement
Mods up to around 300kW
If you’re after a relatively modest performance
improvement from a XR6 Turbo, there are several low cost approaches.
First, we suggest running the engine on the
highest possible fuel octane at all times. Ford’s officially quoted XR6 Turbo
power output is achieved on 95 RON fuel and, in the words of chief engineer
Gordon Barfield (see The XR6 Turbo According to Ford - Part One),
it’s “conceivable” that output is increased on 98 RON fuel.
For extra power there are a few Do-It-Yourself
type modifications that have become popular. Upgrading the cat converter,
removing the centre muffler, switching to an aftermarket panel filter and
installing an aftermarket intake snorkel (such as an SS Inductions snorkel) have
all been tried. The apparent effectiveness of these mods varies depending on who you ask,
but Lachlan Riddell of ChipTorque says it is possible to pick up about 10 -
15kW. You may find greater gains during initial back-to-back testing but, over
time, the engine management will compensate for some of the improvement.
Nevertheless, you should end up with a noticeable power increase along with
sharper throttle response.
But you can go only so far before the
engine management stops the fun.
The Ford management system looks at the input of
two MAP sensors and, according to Lachlan, you’ll hit a fuel-cut if measured
boost pressure exceeds the computer’s expected boost pressure. Note that this
can happen at just 1 or 2 psi as the turbocharger begins to spool up – you don’t
have to exceed the maximum factory boost pressure to hit the fuel cut. It’s for
this reason engine management mods are required in the early stage of
enhancement.
There are two common approaches to XR6T engine
management modification. The first involves re-flashing (aka remapping) the
factory system to allow greater boost pressure and alter fuel mixtures, ignition
timing, cam timing and more. The second involves an interceptor or piggy-back
computer – a device which alters incoming and outgoing ECU signals and that may
be able to drive the injectors directly. We won’t enter a debate about which is
better (that’s an article on its own!), but we will point out that re-flashing
lets you change automatic transmission behaviour and various inbuilt ECU
parameters, while an interceptor/piggy-back ECU can give smoother boost control
and is generally easier to tune.
With absolutely no other changes,
modifying the engine management of your XR6 Turbo can achieve substantial power
gains. Here’s proof...
Centrifugal Air Pumps Australia (CAPA)
offer a Stage One upgrade which comprises a Flash Tuner that arrives with
pre-programmed mapping set to different boost levels. This change alone boosts
output to between 280 and 310kW at the flywheel – a gain of 16 to 29
percent!
Nizpro also offers a Flash Tuner module which is
labelled NizEdit. We believe this unit is identical to the CAPA Flash Tuner so,
not surprisingly, it can be tuned to achieve the same power increase – typically
up to around 310kW, but slightly more if pushed.
ChipTorque has two ways of tackling the engine
management system. You can go for a Xede interceptor to adjust fuel, ignition
timing and boost or you can opt for the XFlash unit which remaps the factory
ECU. ChipTorque typically tunes each system to around 300kW at the flywheel.
Powerchip offers two different pre-programmed map
upgrades for the XR6T – the Gold map (suited to 95 - 96 RON fuel) generates
271kW while the Gold 98 map (suited to 98 RON fuel) generates a claimed
300kW.
Redcliffe Dyno and Performance (RDP) offer an
entry-level upgrade that employs a piggy-back computer to drive the injectors
directly. Using the RDP piggy-back computer along with a K&N replacement
panel filter, you can net 300kW depending on desired boost level.
Middleton Rally Team (MRT) is most popular for its
work with Subaru WRXs but that hasn’t stopped them releasing their Level One,
Two and Three upgrades for the Ford XR6 Turbo. The Level One kit provides a
Flash Tuner programmed by MRT, a 550hp in-tank fuel pump and up to 8 psi boost.
With 98 RON fuel, MRT has achieved a 35kW gain at the rear hubs – as seen in
this graph. Note that Brett Middleton is reluctant to quote flywheel power
figures – we suggest speaking to MRT for further details of the kit. A
replacement front-mount intercooler and cold air intake are also available.
In the early days of XR6 Turbo modification, Air
Power Systems (APS) released a Phase I upgrade that comprised just a UniChip
interceptor tuned to deliver 280kW at the flywheel. Interestingly, APS claim
that 280kW is a safe limit when using the standard fuel system - however, it
should be noted that the mentioned companies have seen 300+ kilowatts with no
reports of directly related engine damage. As always, the tune – rather than the
method of tuning – plays a major role in terms of reliability.
Today, you can purchase the UniChip from APS as a
stand-alone component while the ‘second generation’ Phase I kit adds an upgrade
set of multi-hole injectors. These bigger injectors provide the fuelling
capacity APS feels necessary to support the claimed 300kW output.
Melbourne based tuning company Advanced Vehicle
Operations (AVO) offers a Stage One upgrade for the XR6 Turbo that, like the
current APS Phase I upgrade, includes upgrade fuel injectors to ensure safe
mixtures. You also receive a Xede interceptor (instead of the previously
employed Perfect Power SMT6) and a cat-back 3 inch stainless exhaust. AVO is
very conservative with its quoted power output – they claim around 290kW at the
flywheel but, realistically, the kit would be a close match for some of the
other kits with slightly higher quoted output. See XR6T Power Play for
our road test.
Mods up to around 400kW
Interestingly, Australia’s most popular XR6 Turbo
tuners take some distinctly different approaches to achieve outputs in the mid
300kW range.
The APS Phase II kit incorporates the same UniChip
and injectors as in Phase I but adds a cold air intake to the airbox and a
high-flow exhaust to enhance breathing efficiency. The exhaust is constructed
from high quality 304 stainless steel, employs a 3 1/2 inch cat converter and
meets regulation noise tests. With boost pressure typically set between 10 – 12
psi, the Phase II kit produces a claimed 330kW (depending on the vehicle). It’s
a package that is proven to deliver high 12 second quarter mile performance
while also meeting ADR 79/00 emission standards. See Fanatical Phase
for
our test of the Phase II package.
Although also employing a high-flow exhaust, CAPA
takes a different approach to achieve a claimed 310 – 330kW. In the Stage Two
kit, the CAPA Flash Tuner is carried over and a twin 2 ½ inch mandrel exhaust
makes it possible to reach a maximum of 330kW. But in contrast to the APS Phase
II kit (and even the Phase I), this output is achieved with absolutely no change
to the fuel system. An optional over-the-radiator intake snorkel and aftermarket
filter element can also be added to further bolster power.
MRT’s Level Two and Three upgrades employ the same
Flash Tuner and upgrade fuel pump included in the entry-level kit. Level Two
adds 440cc injectors which enable up to around 10 psi boost while Level Three
comes with a larger turbine housing with an enlarged wastegate and a full-length
high-flow exhaust. Boost pressure is further elevated and the optional
intercooler upgrade is highly recommended. Note that in Level Three guise, the
intercooler upgrade comes with high-flow plumbing that involves relocating the
throttle body to the opposite side of the valve cover. According to MRT, this
eliminates the most restrictive part of the factory plumbing arrangement. Again,
contact MRT to discuss power output numbers.
ChipTorque and Nizpro take yet another approach in
achieving mid three hundreds. The ChipTorque 340kW kit gives you the choice of a Xede
interceptor or XFlash remap in addition to heavy-duty valve springs, bigger
multi-hole injectors, an upgrade fuel pump, high-flow cat converter, SS
Inductions snorkel and a panel filter. As its name suggests, the ChipTorque
340kW kit produces three-forty kilowatts at the flywheel.
Like the ChipTorque kit, the Nizpro Stage One and
Stage Two Cobra packages incorporate upgrade valve springs to produce 315kW and
395kW respectively. Simon Gischus from Nizpro says the standard Ford valve
springs don’t have enough tension to maintain valve control in many boosted and
tweaked XR6 Turbos – Nizpro’s upgrade springs are firm enough to perform in
high-power applications and can handle a set of aftermarket camshafts if
desired. The Stage One Cobra kit achieves its quoted 315kW using a NizEdit Flash
Tuner, upgrade injectors and heavy-duty valve springs.
The Stage Two Cobra kit goes further adding an
upgrade intercooler, a cast alloy intake plenum (which relocates the throttle
body), rocker cover garnish, a K&N filter with a fibreglass airbox, Odyssey
battery (which is mounted on the opposite side of the engine bay) and all
associated hardware. To achieve its 395kW output, the Stage Two Cobra kit is set
to around 14 psi boost. Note that the exhaust remains entirely standard –
amazing given the power output.
APS combats the Nizpro 395kW package with its
Phase III upgrade which is good for 390kW. The Phase III (which is APS’s wildest
off-the-shelf package) employs the same bits found in Phase II (a UniChip,
upgrade injectors, cold air intake and replacement exhaust) but adds a high
performance fuel pump, DR-series air-to-air intercooler, an upgrade wastegate
actuator, replacement wastegate swing valve, high volume blow-off valve and a
completely new air induction system comprising a cylindrical filter and new
airbox assembly. Upgrade valve springs are not included in the kit. The Phase
III kit cranks out 390kW (depending on the particular car) and, again, meets ADR
79/00 emissions testing. This kit can give high 11 second quarter mile
performance – and we’ve seen it pushed considerably quicker on ultra high boost.
See APS Phase 3 Teaser for
our early sample of a Phase III equipped XR6 Turbo.
The CAPA Stage 3 kit offers performance at a
similar level. By adding a Vortech-based water-to-air intercooler system, a
replacement intake manifold plenum (which relocates the throttle body), K&N
pod filter and shroud, bigger injectors and a high-flow fuel pump to the
existing CAPA components, you’re looking at a claimed 350 – 420kW (depending
largely on boost level). CAPA claims this kit can be pushed to more than 600kW
given suitable engine internals and fuel system mods.
Redcliffe Dyno and Performance (RDP) also offer an
upgrade in the upper 300kW range. The RDP 360kW kit comprises a RDP piggy-back
computer, K&N panel filter, a replacement exhaust, new boost control
solenoid, Split-fire spark plugs and bigger injectors. The exhaust is a mandrel
bent 3 incher constructed in either stainless or mild steel and, interestingly,
using a pair of GM LS1 cats. RDP is very flexible in supplying what you want in
a kit – for example, a popular addition is the fitment of a SS Inductions
snorkel. With boost set to around 12 psi, the RDP upgrade achieves a
conservatively quoted 360kW through the standard intercooler. At higher power
levels it is suggested you upgrade the intercooler and fuel delivery system. See
Redcliffe XR Turbo Test
for
our road test of the 360kW RDP kit.
AVO also offers customers around 370 - 380kW at
the flywheel using their Stage Two upgrade. Stage Two includes the components in
Stage One (a Xede interceptor, upgrade injectors and a cat-back 3 inch exhaust)
plus you get a new dump pipe, cat converter, upgrade intercooler and high-flow
plumbing. Output is around 370 - 380kW at the flywheel depending primarily on
boost level. See AVO XR6T - The Next Stage for
our on-road test which employed the now-replaced Perfect Power SMT6
interceptor.
Durability
Issues?
With
outputs up to around 400kW you may be wondering how well the standard engine and
driveline cope with the increased stress.
Well,
the XR6 Turbo is a very strong car but there are a few hurdles that must be
overcome. First is valve springs. Each company has a different opinion at what
stage the standard valve springs should be upgraded but, as a guide, Simon from
Nizpro says they’re typically needed at about 350kW (depending on the revs that
peak power is achieved). However, he also points out that they can be a problem
at ‘just’ 300kW and that the later-model cars seem to be slightly improved in
this area.
The
next engine components on the agenda are the conrods. The standard XR6T rods can
bend under increased combustion pressure and, depending on the severity, this can
easily go overlooked. It’s impossible to suggest at which stage the conrods will
bend because it depends largely on tuning. It’s quite possible for a well tuned
350kW XR6T engine to out-live a 300kW engine that’s running on the edge of
detonation.
And
what about the driveline?
Well,
the early XR6T drivelines aren’t as strong as later models. The early T5
five-speed can survive at outputs typically up to around 350kW but this depends
largely on driving style and intelligent tuning – a big mid-range torque hump
will likely kill the ‘box if an upgrade clutch is fitted. When you get to this
stage, a T56 six-speed is a popular upgrade. Likewise, the early four-speed auto
cannot cope with huge dollops of mid-range torque. A high-performance trans
rebuild (with heavy-duty clutches, a modified valve body, custom servo and
perhaps an oil cooler) is the way to go if you drive hard. Note that we’ve heard
of troubles with the four-speed auto before engine modification...
The
late-model T56 six-speed is a very strong gearbox that’s unlikely to fail in any
street application – the back tyres will slip before any damage is done to the
gearbox. The latest ZF six-speed auto is also much stronger than the four-speed
but, at present, its limits have yet to be explored.
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Stick around for the fourth and final
part of the series – we’ll check out extreme engine mods as well as suspension
and brake enhancements.
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