Turbo Vs Supercharged

Turbo Vs Supercharged
At a glance…
Totally standard Mk3 2-litre Sport
MX-5 with the BBR fitted Cosworth
supercharger. Basically, exactly what it
needed to add some oomph!
Spec: Cosworth inlet manifold, Eaton
MP62 supercharger, chargecooler, BBR
Interceptor 2010 ECU, high-flow air box
and filter
Power: Was: 157bhp Now: 235bhp
Torque: Was: 139 lb/ft Now: 190 lb/ft
We like: Torque at any gear from low revs,
all with a factory feel
At a glance…
The BBR Mk1 MX-5 turbo gives a modern
dose of performance to a lightweight
classic sports car.
Spec: Garrett GT25 turbo, ceramic-coated
manifold, BBR Interceptor 2010 ECU,
front-mount intercooler, longer final drive,
limited-slip diff
Power: Was: 115bhp Now: 221bhp
Torque: Was: 100 lb/ft Now: 175 lb/ft
We like: The BBR package makes a good
old car a fantastic option for the modern
day. Very few cars will match its fun factor.
BBR’s bolt-on turbo kit for the Mk1 MX-5 or their Cosworth
supercharger kit for the Mk3; two of the best reasons you’ll
ever find to get into MX-5 ownership...
Words: Andy Mills
Photos: Dave Smith
HIGH
FIVES
Some 20 years ago, BBR
unveiled their first turbo
kit for the Mk1 MX-5.
It was an official option
from Mazda dealerships, and even
now most insurers will have “BBR
MX-5” on their list of standard
cars. That kit, which limited power
to 150bhp, went on to be one of
the best-selling turbo conversion
kits ever to hit Europe, for any car,
with well over 1,200 being either
fitted at the factory or added as an
aftermarket upgrade. So, what better
way to commemorate its 20-year
anniversary than by producing a
new Mk1 turbo kit using the very
latest ball-bearing turbo and
electronic technology?
Hold on, though – back then the
Mk1 MX-5 was a new car, but now it
has virtually achieved classic status.
So what’s the rationale, aside from
commemoration? Well, there are
some very persuasive reasons, so
much so that customers are already
reaching for their credit cards.
In a nutshell, the fact that BBR
is now using modern technology in
the form of the GT25 ball-bearing
turbo and their Interceptor 2010
engine management, means they
can create an even better car than
that of 20 years ago. With over
200bhp readily achievable and
the wide availability of cheap Mk1
MX-5s, BBR believes this new kit
offers a way into an affordable
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Turbo Vs Supercharged
High Fives
performance car. And not just warm
performance, but proper, take-itto-the-track-and-give-an-Elise-apasting
performance. BBR has also
made it easy for people, offering
a DIY turbo kit for £3,995 or an
installed one for £4,995. They’ll
even supply a renovated MX-5 turbo
with leather seats and the customer’s
choice of paint colour for £7,500.
Basically, a virtually new MX-5
turbo with classic style and modern
performance for about the price of a
brand new, tiny-engine shopping car.
Neil McKay, BBR’s chief engineer,
has made an even more convincing
case with their white demo car, a
version that also sports some of the
added extras that can be specced up:
big-brake upgrade, LSD, longer final
drive and larger-diameter wheels.
The cost for something similar would
be around £12,000 all in, which
may seem a lot at first, but one drive
is all it takes to demonstrate the
value of this conversion.
Mk1 MX-5s are great fun in
standard form, but fire this BBR
turbo to life and there’s a hopeful
rumble from the performance
exhaust that only serves to increase
anticipation. Everything feels like
a normal MX-5, aside from that
beefed-up sound track… that is, until
you let the clutch out!
The turbo spools up bloody quick,
and acceleration is instant. Keep the
fun pedal planted in second or third
gear and there’s still power right to
the redline – really responsive, raw
power. There’s no two ways about it,
this is a very quick car.
What’s even better is that none
of that MX-5 agility is lost – if
anything, it’s heightened by the
engine, which now keeps up with
the inputs to the steering wheel.
On damp roads it’s easy enough to
slip the back wheels in second gear,
but it’s in no way undriveable – you
just might want to keep the missus
out of the driving seat (always a
wise move – Dav). In the dry and
on a set of sticky tyres with BBR’s
original specification springs on
SPAX shocks, you could imagine
“None of that MX-5 agility is lost...
If anything, it’s heightened.”
MK1 MX-5
TURBO ENGINE
The car in these pics was bought as
a standard vehicle in 2010, with a full
service history and 82,000 miles on the
clock. It cost BBR just £1000. Yep, clean
Mk1s are that cheap now!
Amazingly, despite having the turbo
kit fitted, the internals of the engine
haven’t been touched… they haven’t
even taken it apart to check things over!
These engines are strong – not one of
the previous BBR MX-5 turbos suffered
engine failure – as the blocks were the
same as those Mazda used in the 323
Turbo, so were built for turbocharging.
The GT25 turbo they use now is larger
than that in the original kit, but it’s a
ball-bearing turbo and actually spools up
much more quickly (the whole kit is even
mounted very differently to those first
BBR MX-5s).
As it’s a DIY kit, BBR claim the fitting
is relatively straightforward, although
a hole needs to be drilled into the sump
for the oil return pipe. The mounting of
the turbo is very different to the original
turbo kit, with the larger intercooler in
front of the radiator now, too.
With this setup on their car, running
around 10psi, BBR has seen 221bhp on
the dyno, which is around 70bhp more
than the original BBR turbos. With a
longer final drive, they’ve also made
sure that there’s plenty of frantic fun
in the first four gears, but cruising on
the motorway doesn’t become a pain
in fifth gear, helping to keep all that
power as useable as possible. The turbo
kit also fits larger 1.8-litre cars, with a
corresponding hike in power. Nice!
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Turbo Vs Supercharged
High Fives
this MX-5 would give most things
a run for their money on track and
deliver driver satisfaction on the road
that very few more expensive cars
could match. Dave Brodie (one of
the ‘B’s in BBR and a former BTCC
driver) believes their MX-5 actually
offers one of the best all-round track
solutions you could own.
“What other car could you
comfortably drive with your
girlfriend to the circuit, drop her off
at the café, then go and give it hell
for 20mins on track?” he reasons,
“then go back and tell her how
amazing you are before heading onto
the track again for another session.
At the end of the day, you can drive
home, with the roof up or down,
heating on and listening to music
in what feels like a pretty normal
car”. When it comes to lightweight,
convertible rear-wheel-drive cars
with this kind of performance and
practicality it really is hard to find
anything better. Certainly there’s
nothing else that also offers the same
affordability and availability of
spare parts, too, should you have
any mishaps.
The biggest problem with this
MX-5 turbo, though, is finding
words to explain just how right
it feels. All the superlatives in the
world don’t quite match a blast in it,
and that post-drive moment where
you pull up, open the door and
uncontrollably find yourself saying,
“I want one”. It’s a pure sports car
experience but with none of the
sacrifices in comfort – the sort of
thing that you just can’t buy from
new nowadays. Which brings us
nicely to BBR’s Mk3 2-litre Sport
MX-5, one modern car that in
standard form did try its best to
offer that pure sports car feel at an
affordable price, but didn’t quite hit
the mark.
Naturally, the Mk3 MX-5 is a
lot heavier than the original Mk1
as safety measures have had an
impact. The constraints of emissions,
insurance and taxation must surely
be the reason why even the capable
2-litre Sport only manages to push
Right Mk3 interior is a
nice place to enjoy the
extra power
Below Supercharger kit
turns the Mk3 MX-5 into
the car it should be
out 157bhp. It’s not that the Mk3 is
a bad car, it’s just like a Mk1 MX-5
that’s been smothered by health
and safety to the point where most
who drive one feel let down by the
lack of oomph. BBR were planning
to address this themselves – the
idea of a bolt-on turbo kit was
certainly discussed, but when they
realised Cosworth were building a
supercharger for this model, they
changed tack. Cosworth are one of
the most famous names in tuning so
BBR knew the build quality of this
kit would be second to none, and
having had a long history with the
company, BBR saw this as an ideal
match for them.
With BBR having fitted the
Cosworth supercharger to their
Mk3 MX-5 and utilised their own
software, Cosworth were apparently
so impressed with the result that
they made BBR the official supplier
of the kit. Using their Interceptor
2010 piggyback ECU to map the
’charger, BBR have created a Mk3
MX-5 with 77bhp more horsepower
and 55 lb/ft more torque than
standard. There’s nothing else
aside from the BBR Cosworth
supercharger kit on their 2-litre
Sport demo car – it still runs the
standard exhaust and standard
Bilstein suspension, so it’s about as
close to a factory upgrade as you
could get. On the road, it’s not as
raw as the Mk1 turbo, but the power
delivery is spot on, with smooth hits
of grunt at every gear change. The
incredible torque curve means the
car will pull out of roundabouts in
third gear with no trouble and keep
constantly piling on the speed until
the redline. Cruise along in sixth
gear and put your foot down and
it will pick up swiftly, not unlike a
torquey diesel car.
Considering the power and torque
gains, there’s nothing else aside from
the performance increases and
BBR COSWORTH
Mk3 MX-5
With 157bhp and 1132kg of weight in
standard form, the MX-5 2-litre Sport is a
little underpowered by modern standards.
It’s a shame, though, as it looks good and
offers rear-wheel-drive fun and Mazda
reliability… plus it has that useful retractable
hardtop roof, which helps refinement. So,
the Cosworth supercharger is the perfect
solution for people who like those last points
but find the asthmatic performance a little
off-putting.
The BBR Cosworth MX-5 is now the official
Cosworth offering and includes the Eaton 4th
Generation MP62 supercharger, Cosworth
inlet manifold, chargecooler, high-flow
injectors and BBR’s Auxiliary Interceptor
2010 ECU. That piggyback ECU has allowed
BBR to pull 235bhp running very low boost
(around 7psi) and increase torque to 190 lb/
ft, the curve for which on the dyno sheet is
incredibly flat.
Their demo uses the standard exhaust
system, too, but they’re pretty confident
that with additional tweaks and an upgraded
exhaust system, owners could happily
see around 250bhp. Add some uprated
suspension, brakes, lighter wheels and
bucket seats and the Mk3 MX-5 could
become a properly rapid tool on road and
track. At £4,995 fitted it’s also pretty good
value, with DIY kits will be available soon.
“It’s funny, everyone who gets out of the
Mk1 after a drive says they want one!”
Name: Neil McKay Age: 33 Occupation BBR Chief Technician Which is your favourite? I like the Mk1,
you could use that on road and track, but ideally you’d have the Mk3 for everyday use and the
Mk1 for fun Which do you drive? I’ve got about ten cars in total, the latest being a Scirocco R
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Turbo Vs Supercharged
Spec
Mazda MX-5 Mk3
• Engine
2-litre, Cosworth inlet manifold, Eaton 4th
Generation MP62 supercharger, chargecooler,
high-flow calibrated injectors, high-flow air box
with uprated air filter, competition-grade hoses
and fixings throughout, BBR Interceptor 2010
auxiliary ECU with 3D mapping and MAP sensor
• Transmission
Factory 6-speed manual
• Suspension
Factory MX-5 2-litre Sport Bilstein suspension
• Brakes
Factory
• Wheels & Tyres
6.5x17in Mazda Sport alloys, 205/45x17 tyres
• Exterior
BBR Cosworth identification badges
• Interior
Factory
• Contact
BBR 01280 700700 or www.bbrgti.com
Mk1
MX-5
221bhp
Spec
Mazda MX-5 Mk1
• Engine
1.6-litre, Garrett GT25 turbo with internal
wastegate control, water cooling and ported
turbine housing with ceramic coating, high
temp alloy cast exhaust manifold with ceramic
coating, stainless-steel heat shield, frontmounted
intercooler, competition-standard
hoses and fixings, BBR Interceptor 2010 engine
management, BBR spec larger fuel injectors,
stainless-steel separated gases exhaust
downpipe, cold air induction system, modified
sump, modified coolant and oil system piping
• Transmission
Standard 5-speed gearbox with longer final drive,
limited-slip differential
• Suspension
SPAX shocks with adjustable damping, BBR
rated springs
• Brakes
MX-5 1.8-litre front discs and calipers
• Wheels & Tyres
7x16in mesh-style alloys finished in black,
215/50x16 tyres
• Exterior
Custom white paint, black spoiler, wing mirrors
and front lip, BBR turbo decals, smoked side
repeaters, smoothed front bumper, rear fog light
removed and installed in rear light clusters
• Interior
Black leather re-trimmed seats, Momo steering
wheel
• Contact
BBR 01280 700700 or www.bbrgti.com
the tiniest occasional whine from
the supercharger that distinguishes
this from a standard MX. It feels
like a factory car, only one that
would have got rave reviews from
car journos rather than the merely
decent ones the standard Mk3 MX-5
received. In fact, don’t think of the
BBR Cosworth MX-5 as a tuned car
– think of it instead as the kit you
need to fit if you own a Mk3 MX-5.
It really is that good an upgrade.
So, two bolt-on performance
packages for two different ages of
MX-5, but both with one thing in
common; they make something good
even better. Both are highly useable
and deliver dollops of fun. Which
would we choose? We’ll take one of
each, please.
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