When Powerchip offered us the opportunity to test
their newly introduced PowerFlash for the Ford XR5 Turbo, we were bursting with
enthusiasm. The XR5 Turbo is one of our favourite performance hatches, so surely
a performance tuned example would be mind-blowing.
Well, that’s not the case.
First, the power gain achieved with the PowerFlash
is relatively minor. The biggest performance gain comes from a fatter torque
curve and a maximum power ‘plateau’ that is created.
The second problem is a misfire or stutter when
you nail the throttle from low rpm. More on this later.
The Powerchip PowerFlash
At the time of writing, Powerchip is the only
company in Australia able to direct-tune the Ford XR5 Turbo. The Powerflash
retails for AUD$1290 but premium members of www.fordxr5turbo.com can
buy it for just AUD$890.
According to Bill Ingram, Powerchip’s
Technical Manager, the XR5 uses a Bosch ME9 management system which is very
similar to that used in the Volvo S40 T5 introduced a couple of years ago.
Powerchip uses in-house programming software which
connects to the vehicle’s ECU via the OBDII port. Programs are generally sold
‘off the shelf’ but custom changes are available on request.
“We can’t change as much in the program as we can
in our Alloytec system [see Alloytec Awakening] but we can control
fuel, ignition timing, boost pressure and the throttle,” Mr Ingram says.
Functions such as rev limit and
closed-loop switch-over cannot at present be altered.
The standard PowerFlash reprogram involves
increasing boost pressure from 0.65 Bar to a maximum of around 1 Bar. This peak
pressure is achieved at mid-range rpm and tapers to around 0.8 Bar at high rpm.
According to Wayne Besanko, head of Powerchip, the
XR5 doesn’t generate much extra power with further increased boost pressure. The
standard turbocharger and intercooler are thought to be the restrictions.
On-Road Results
Powerchip customer, Justin X, handed us
the keys to his XR5 Turbo for back-to-back testing with and without the
PowerFlash.
In standard form, this particular car offered
typical XR5 low rpm flexibility, strong mid-range but a slightly breathless
top-end. There were no noticeable driveability problems.
With the PowerFlash upgrade, the car felt slightly
more aggressive – as evident by increased torque reaction through the steering
wheel. But top-end power was not dramatically increased. The overall performance
improvement was relatively minor.
Unfortunately, the PowerFlash’d car also brought a
misfire or stutter under full load. This was evident accelerating from low rpm in
second or third gear and occured when boost pressure neared its maximum.
We reported this problem to Powerchip who twice
took the opportunity to retune the car and make it available for further
testing. In both instances the problem remained, although it was less noticeable
on the final attempt where boost pressure (and therefore performance) had been
reduced.
So what’s the cause of the XR5’s full load missing
problem - is it simply a case of bad aftermarket tuning?
Mr Ingram says the XR5 Turbo uses
closed-loop boost control and is very sensitive to the relationship of the
wastegate duty cycle map and the desired boost map.
“If the values in these maps are too far apart it
can cause wastegate control problems. This is quite pronounced in the XR5 as it
is capable of making a lot of boost at low rpm.”
In addition, Mr Besanko suggests there appears to
be a problem in the standard engine management which may be exacerbated by the
PowerFlash. As discussed in various threads at www.focusstoc.com,
there is a misfire in some XR5s which is believed to be caused by one of the
knock sensors. A Ford software update and/or replacement knock sensor is
said to solve the problem.
Interestingly, we have since driven another XR5
which was equipped with a UK-sourced Bluefin engine management upgrade – and it
had the same type of misfire...
At this point we are unsure on the cause of the
problem. But the fact remains that our demo car had no obvious driveability
problems until the aftermarket tune was installed.
Dyno Results
Powerchip literature has recently been revised to claim 177kW at the
flywheel - a gain of 11kW over the 166kW standard output. This is closely
supported by the company's chassis dyno figures.
This Dyno Dynamics chassis dyno graph compares the standard XR5 to the
PowerFlash'd version. Standard output (plotted in red) peaks at 172hp while
the PowerFlash tune (plotted in blue) makes 178hp at the wheels. That's a
peak gain of around four percent. More important is the strong mid-range
gain and peak power is achieved earlier in the rev range.
Verdict
The Powerchip PowerFlash doesn’t achieve the
mind-blowing peak power gains we were hoping for. Instead, the most noticeable
improvement is at the mid-range rpm.
But more importantly, the high load stutter which
is introduced is a problem we wouldn’t be happy with - no matter what’s causing
it...
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