Most racers stick to a tried-and-proven formula when building a 9 second
You buy a thoroughly R&D’d car (such as a Holden VL Turbo), add 'X'
turbocharger, 'Y' valvetrain and 'Z' transmission. With a set-up like this, you’re
onto a sure thing.
But Anthony Briggs’ 1981 Cortina breaks new ground - no one has been here before!
Anthony got stuck into modifying his Cortina back in the late ‘80s. At a time
when bent-eight 308s, 350s and 454s were all the rage, Anthony went in his own
direction and built fire-breathing carby turbo set-ups for the contemporary Ford
“I built turbocharged 3.3 and 4.1 litre sixes for the car and, although the
4.1 doesn’t rev like the 3.3, it has a big torque advantage,” says Anthony.
“I ended up using a Holley 750 double pumper in a draw-through turbo set-up
and the quickest time I ran was a 11.5 – using a 4-speed manual and slicks,” he
Not hanging around!
But that carby turbo set-up was extremely difficult to tune and, inevitably,
there were a few engine casualties. This was the motivation for Anthony to
switch to programmable fuel injection – and a whole new engine while he was at
Anthony currently uses a Falcon XF pushrod 4.1 litre (250ci) six with an
alloy head. The engine – developed in conjunction with Toowoomba’s Paramount
Performance - was built with cast (yes, cast) ACL 9.0:1 pistons, shot-peened EA
Falcon rods (which are manufactured by TRW) and ARP bolts. The crankshaft and
block remain standard aside from being O-ringed to improve the sealing performance of
a copper head gasket.
The valvetrain was spiced up with aftermarket pushrods, aftermarket roller
rockers, screw-in studs and bigger valves. The 2-valve cylinder head was also
subjected to a major port and polishing job which included careful shaping of
the combustion chambers. The camshaft delivers 240 degrees of intake and exhaust
duration at 50-thou lift.
We’re told that the 4.1 engine – although immensely torquey – cannot handle
high rpm operation. Despite the aftermarket valvetrain parts, it’s likely the
pushrods and rocker gear would explode beyond 6000 rpm. As a result, Anthony
up-shifts at just 5500 rpm – incredibly low for a drag car.
Anthony is a pretty handy sort of guy and was able to fabricate the intake
and exhaust manifolds. The current intake manifold uses internal ram-tubes, a
large volume plenum and a Mazda RX-7 throttle body - which was chosen because
it’s big and cheap. Anthony says he’s tested a few different intake manifold
configurations and this is as good as any.
The exhaust manifold is the third different design intended
to improve turbo spool-up. There have also been more than ten different
turbochargers tried on the dyno. The current ball-bearing turbo is described
simply as a “bitsa” and comes on at about 3200 rpm. This works side-by-side with
a Garrett 45mm external wastegate. A single 3 inch exhaust is bolted on for
occasional street use while a twin 3½ inch system is used on the strip.
A big PWR air-to-air intercooler consumes the area behind the grille and
reaches down as near as practical to the bitumen. This photo also shows the
transmission fluid cooler. A TurboSmart atmospherically-venting blow-off valve
is installed near the turbo compressor outlet. No need for an air filter.
Despite efforts to improve spool-up, Anthony finds it necessary to run a 40hp
nitrous boost to help sprint off the start line. The car is held on the trans
brake, the lights turn green and Anthony hits the nitrous. The gas injected into
the intercooler plumbing prior to the throttle body and is deactivated when
boost pressure reaches 12 psi.
Fuelling the beast is a MicroTech LT8S management system working with
Rochester 96lb injectors (fitted to a modified Ford XF rail), a Malpassi
pressure regulator, twin 500hp pumps and an in-boot fuel cell. Ignition is taken
care of by a Crane Hi-6 booster, high-energy coil, Magnecore 8mm leads and NGK
plugs with a 7 heat range.
One of the biggest challenges with the car has been finding a suitable torque
converter to work with the tricked 2-speed Powerglide trans. We’re told that the
engine makes so much torque they can’t find a torque converter that is capable
of locking. The current 3000 rpm stall converter slips even when it’s supposed
to be fully engaged.
From the back of the transmission you’ll find a heavy-duty tailshaft that’s
similar to those used in Pro Stock cars. This connects to a Mark Williams 9 inch rear
running a 3.0:1 mini-spool centre and billet axles. Amazingly, the rear-end
hasn’t been tubbed but the rear guards have been massaged to fit a set of 26 x 9
Hoosier drag slicks.
And how much power is there at those big, soft treads you ask?
Well, in the existing configuration, the car has spat out a humungous 560hp
(418kW) at the wheels on Paramount Performance’s Dyno Dynamics chassis dyno.
This is with 26 psi boost and avgas flowing through the injectors.
The flywheel output is probably around 870hp (650kW)...
The Cortina’s suspension is the focus of on-going development. Spring and
damper rates are continuously being tweaked and the diff assembly is locked to
the chassis. This helps the car launch evenly without a corkscrew action.
Anthony says the front wheels pick w-a-y off the ground, but not quite enough to
require wheelie bars. Brakes are Ford XB Falcon.
The body is standard 1981 TF Ford Cortina coated in Chev Z28 Camaro blue. The
only mods are a parachute, bonnet pins, nosecone cut-out for the intercooler and
Cragar alloys. The kerb weight is almost 1500kg – there’s no avoiding the extra
weight of the 9 inch diff, cage, turbo system and beefy rear wheels.
Inside, the Cortina is essentially a drag car with some road car luxuries.
There’s a full roll cage, harnesses, RPM race seats, SAAS wheel, AutoMeter
gauges (for transmission and water temperature, boost and rpm), EGT display and
custom switchgear. And we can assure you the radio/cassette and equaliser have
helped shave a couple of tenths off the ET...
At the time of writing, Anthony and the team at Paramount Performance were
still fighting problems relating to the torque converter – but you wouldn’t know
it given the car’s quarter mile prowess. The best time is currently a 9.63
second ET with a trap speed of 140 mph.
Amazingly, the engine had remained completely intact (cast pistons and all!)
for around 4 years. Unfortunately, the engine made its last roar shortly after
our photo shoot – and in spectacular fashion! We are told that one of the
pistons broke, punching a hole through the side of the block and causing oil to
spew out from under the car – all while travelling at well over 100 mph!
The mishap happened in the second half of a quarter mile run and when the oil
got under the tyres Anthony was demoted from driver to passenger – there was
nothing he could do to keep the Cortina straight. The car hit the wall causing
damage down the entire right side of the body.
On the upside, it’s all repairable and the car will re-emerge with a little
extra something... Anthony has purchased a BA XR6 Turbo engine which will receive many of
the bolt-ons currently fitted to the ol’ pushrod 4.1. According to Anthony, the
BA DOHC engine should be able to rev about 1500 rpm harder than the existing engine
– this will give the scope for more power and make it easier to sort the
A XR6T-powered 1981 Cortina?
Now that’s a new formula!
Paramount Performance +61 7 4659 9711
Anthony would also like to thank MTQ Engine Services, Performance Cylinder Head Dynamics, Keas Automotive, R&L Mullers and Paramount Performance.