This article was first published in 2004.
See bottom of article for video download of this dyno run!
If there’s one thing we’ve learnt about Simon Gichus of Nizpro it’s that he’s
more than willing to spend the time and money developing the most super-duper
tuned engines. Every time we have a peek inside his fully equipped dyno cell
there’s something wild bolted to the engine stand.
The last time we poked our heads into the dyno cell we happened to see this –
most powerful Ford XR6 Turbo engine!
With a last run of 1035hp – running a mild 23 psi boost and with Mobil 98 RON
fuel – Simon has been the first to crack the magic tonne. Interestingly, Simon
says there will be quite a few people making big power with XR6Ts in the next
few years. “We wanted to get in early and develop something that will make that
1000hp figure while still holding together and being nice an’ driveable,” he
Simon was drawing on his wealth of experience tuning Nissan RB-series engines when he tackled the new Ford six. “At 4.0 litre it’s a big engine
and, in that context, it can rev alright with the right gear – we plan on taking
it to around 8000 rpm.” And that takes us to one very important point. Simon
says that achieving 1000hp+ reliably
calls for a fine balance of torque and revs.
“We’ve held to an 800ft-lb torque limit, which we aim to get up to and
maintain as far through the rev range as possible. This should protect the rods
and various other parts of the engine, compared to sticking in more and more
boost and watching torque go up,” he says.
With this in mind, the engine has been built to withstand high rpm as well as
The standard crankshaft has been replaced by a fully counterweighted steel
billet crankshaft, which Simon had manufactured locally. Rods are H-beam forged
items working with local forged pistons. These provide an 8.3:1 static
compression ratio (0.4 lower than standard) and slide in 0.05mm oversize bores.
Rings are described as “special”.
The Ford DOHC has been slightly modified. “compared to a Nissan GT-R head, in standard form the XR6 head
flows about 12 percent better on the inlet and 15 percent better on the exhaust.” Cam specs are a closely
guarded secret but we can tell you upgrade valve springs are necessary.
Simon was concerned by possible oil starvation of the big-end bearings and
has modified the oil system. An oil cooler is fitted for dyno use and will
be retained once the engine is fitted to a car (Simon will be dropping the
engine into his everyday XR6T ute for on-road trials!).
The whole purpose of an engine dyno is to allow extensive engine development.
Simon has used his dyno to good effect, having tried three other turbochargers
before settling on the current jigger. And, no, Simon isn’t going to give that
info away... Likewise, the exhaust manifold design is a secret but Simon tells
us fabrication of a compact, 6 cylinder turbo manifold is a very difficult
Simon went with his preferred approach to boost control – the combination of
a wastegate and pressure relief valves on the intercooler plumbing. A 44mm Teal
external wastegate and a pair of ex blow-off valves serve to maintain the
desired turbine speed. Maximum boost pressure is about 23 psi, but Simon
generally tips in a couple of psi more boost through the top-end to maintain his
desired torque figure.
Intercooling in the dyno cell is left to a water-to-air arrangement. This
provides a thermostatically-controlled 40 degrees C intake temp charge that
we’re told is representative of what you’d find in a car with a front-mount
Pre-compressor intake flow is almost restriction-free thanks to a huge
K&N pod filter, while a 4 inch dump pipe lets the turbine breathe.
According to Simon, this flows similarly to the twin 3 inch set-up currently
used in his car.
The intake manifold is the same set-up used in the off-the-shelf Cobra 3
kit. Nizpro has developed a replacement intake upper section of manifold that
mates to the factory lower section. This replacement part features a revised
internal volume and the factory
Ford throttle is relocated to one end of the manifold.
The complete replacement engine management system is the only one on the market
that’s up to the task of controlling the Ford’s electronic throttle and variable
cam timing: a MoTeC M800.
Mapping of throttle strategies will probably be finalised when the engine
hits the road, but – for now – Simon says the ability to alter cam overlap (by
altering the relationship between inlet and exhaust cams) makes a huge
difference. In the bottom-end, at about 2000 rpm, Simon has picked up around
teamed with the factory rail, lines and regulator, a massive set of ‘drop in’ injectors provide the necessary fuel flow. Twin Bosch 984 fuel pumps
maintain flow and pressure.
The ignition remains completely stock, except the plug gap is dropped from
1.0mm to 0.9mm.
Running straight Mobil 98 RON fuel, the mega XR6T engine has recently turned
Nizpro’s DynoLog engine dyno to the tune of more than 1000hp – 1035hp to be
exact. That, readers, is more than three times the factory output... Simon
casually makes the point that he engine makes about 250 percent more torque than
standard and revs 25 percent harder than standard.
Peak power is achieved at around 6800 rpm with the rev limit currently set at
7500. This, believe it or not, is a relatively conservative tune and Simon says
the engine has now reliably racked up more than 24 hours of full-throttle dyno
Despite already owing about AUD$45,000, Simon plans to reset the rev limit to
around 8000 rpm and install a larger turbocharger to satisfy his new goal. A
goal of 1000 kilowatts...
And what kinda driveline is gonna cop with this, you ask?
“We’re planning a C9 auto trans and a stall converter of around 2500 rpm,”
says Simon. Interestingly, Simon says there’s a good chance the factory diff
should be able to cope with the strain – rear wheelspin will take some of the
load off the diff gears.
We’ll be keeping a close eye on further development!