The standard BA – BF Ford Falcon is a deceptively quick machine – but it’s
nowhere near as quick as
this! When the tacho needle passes 5500 rpm in
the stock Falcon, the engine starts to run out of puff. But with the latest
mods from Jim Mock Motorsport (JMM) you have plenty more rpm and kilowatts up
your sleeve. The big DOHC six can roar to around 7000 rpm and hurtle you down
the road with the speed approaching an XR6 Turbo.
The team at JMM (Jim and Brendan Mock) has been playing around
with big camshafts and a replacement intake manifold and the results are
spectacular. Dyno testing has shown the modified atmo engine to deliver more
power than the factory turbo engine! That’s more than 240kW at the flywheel.
So let’s look at how it’s done.
Stage One – Bolt-ons
JMM are specialist Ford six-cylinder tuners and offer a range
of bolt-on go-fast parts to suit the BA to BF atmo engine. Their DEV 3 kit comprises ‘Scavenger’ headers, a custom exhaust
(comprising a 3 inch front section with a metallic cat converter and a 2½ inch
mandrel bent system), modified air intake, different spark plugs and a flash-tuned ECU. (The retuned ECU replaces the previously employed interceptor.) These
mods increase output from around 140 to 180kW at the wheels (in the case of a
manual gearbox vehicle).
See BA-LLISTIC
for our full review of this popular upgrade.
But extracting further power isn’t easy.
Next Level Modification
So what do you do to unlock even more performance from the
Falcon six?
Well, JMM has flow bench tested the standard Falcon DOHC head
and come away very impressed. According to Brendan Mock, the BA head offers
airflow potential for around 400 horsepower (298kW). So in a street application it’s hardly restrictive.
On the other hand, the standard camshafts are relatively tame
to ensure an acceptable combination of emissions, idle quality, smooth torque
delivery and fuel consumption. JMM has fitted a pair of secret-spec development
camshafts which are described as ‘mild’. The new camshafts operate with the
factory dual VCT system and Brendan says its likely BF models (with independent
dual VCT) will offer even greater power thanks to the ability to alter valve
overlap.
But the big camshafts are a compromise – they detract slightly from
idle quality and bottom-end performance but deliver improved top-end power.
At this point, Brendan highlights a limitation of the standard
Ford engine.
“When you rev a BA six to around 7000 rpm there’s a pretty good
chance you’ll have an oil pump failure. The pump in our car blew and took out
the timing cover.
“We replaced it with a balanced and blueprinted pump using
heavy-duty steel gears. We also fitted a Ross harmonic balancer - and we’ve had
no worries since.”
JMM has also elected to rebuild the engine using Ford E-Gas
conrods and pistons for a 10:1 compression ratio. Brendan says this is about as
high as you can go while running pump fuel.
Next, Brendan decided to test an off-the-shelf aftermarket
intake manifold. The factory dual-stage intake manifold is a proven performer –
but can it be bettered?
This particular aftermarket manifold is developed and sold by
Croydon Racing Developments in Sydney. The product of around 12 months'
development (which includes tests with different size plenum volumes), the
manifold is primarily intended for big horsepower XR6 Turbo applications. The
manifold employs CNC machined billet runners and a precision welded aluminium
plenum chamber. Runner length is quite short (to aid high rpm operation) and
each runner features a bell-mouth entry which is concealed in the plenum. The
throttle body is also forward mounted.
Brendan says the new manifold is dead easy to install – it’s a
direct bolt-on using the standard Ford gasket. An extension loom is required to
relocate the electronic throttle and Brendan has fitted a generic pod filter
directly to the throttle body. A cold air induction system is yet to be
fabricated.
The new manifold is supplied with a replacement fuel rail which
Brendan configured with standard BA injectors and a Malpassi pressure regulator
to increase rail pressure to around 4 Bar (the same as used in the XR6 Turbo).
The only other change is a custom mounting arrangement for the dipstick
tube.
Results
Brendan is quick to point out that the camshafts fitted to
their demo car are development jobs; they aren’t currently on the JMM product
list.
“We’re still doing some more work with camshafts but, on
average, the cams we’re using will pick up about 10kW at the wheels
[assuming
the car already has suitable bolt-ons]
. The idle is a bit ugly at the moment but
we might change the cam profile and spend more time developing the tune,” he
says. Price of the camshafts will be around AUD$490 each.
And that sexy Croydon Racing Developments intake manifold?
Well, once the big cams are fitted and the engine can breathe
at high rpm, the manifold can deliver a further 30kW ATW gain. This brings total
output up to around 220kW at the wheels – according to Brendan, about 10kW more than a standard XR6
Turbo manual.
However, at the other end of the rev range, the engine loses a
substantial amount of grunt and you need to wait until 4000-4500 rpm to overtake
the performance of the standard manifold. Output then holds strong to about 6500
rpm and the rev limit is set just over 7000 rpm.
The Croydon Racing Developments manifold retails for AUD$2850
and you’ll need to allow about AUD$900 for an aftermarket fuel pressure
regulator, air filter and installation. JMM’s tuning costs are yet to be
determined.
In normal driving, the cam and manifold equipped BA Falcon
sacrifices much of the effortlessness found in the standard car. The 4-litre
capacity of the engine means it’s not slow, but it lacks the off-idle slog of
the standard car. But from about 3500 rpm onwards the story changes. The engine starts
to roar and can torque hard to near 7000 rpm. However, we
reckon a shorter diff ratio would improve the overall package -
the improved top-end power would be that much much more accessible in normal driving.
Interestingly, the aluminium intake manifold also causes a
raspy noise on cold start-ups – this appears to be an in-plenum resonance. The
noise disappears when you hold your hand on the plenum chamber. Odd...
And the verdict?
The cam and manifold combo certainly delivers plenty of top-end
performance. But we have reservations recommending it to anyone who drives the
car in traffic every day; the trade-off in low rpm torque is very
noticeable.
Brendan answers this by revealing JMM is currently assessing
the results of honing the standard dual-stage intake manifold. If a similar
top-end gain can be achieved without sacrificing bottom-end, we reckon this
would be an absolute ripper combo.
Contact:
Jim Mock Motorsport +61 3 9399 4401
www.jimmockmotorsport.com
Croydon Racing Developments +61 2 9648 4264
www.croydonracingdevelopments.com
Did you enjoy this article?
Please consider supporting AutoSpeed with a small contribution. More Info...
|
More of our most popular articles.
|
|
|
Email a friend
Print article
|