This fortwo started out, many moons ago, as a standard 2002
599cc mk6 Passion City Coupé (as they were called back then).
We're going to skip taking you through the
early days as the bar has been considerably raised, due to the fact
a lot of knowledge is now in the public domain from web sites exactly like this one. The
early modifications are now everyday items and totally uninteresting by today's standards.
Within the Smart world, modification has always been a very big thing.
Back in 2003 when the car was purchased, there was very little in the way of off the shelf
product available. Anything more than a set of wheels, remap or air filter had
to be developed; this where we really started here at FQ101, working on our own.
This Ferrari red fortwo was our project car, if a
modification was being tested, generally it was on this car during a set
period to ensure correct operation.
This fortwo's big power jump was produced in
2005 when a Brabus engine was fitted from a 699cc G2 car. We
stripped and cleaned the whole unit, finishing it in the same
Ferrari red paint for that special touch.
The engine itself is a direct fit if just
swapping the block and head, the standard 45kw gearbox was left behind
and blue Brabus injectors were fitted to compliment the existing Smart Tune
remap.
Fitting a bigger turbo the car
required a new exhaust as the 45kw unit has a
smaller inlet and different stud pattern on the exhaust site of the
charger..
Below are two pictures of
the turbo chargers inlets, starting with the new bigger turbo.
The EGR valve was blocked off and removed at the pipe. As the
pre-2003 cars never had this feature, this was quite simply dumped.
The car was tested and GPS verified at 117mph
in the middle of summer which is quite a result in a fortwo. Most
owners we've spoke to inflate their figures, guessing their top speed at the pub
rather than real world testing.
Come the end of 2006, we were becoming itchy
when it come to modding, people were coming too close with modded
Roadsters (with very little done) so it was time to raise the bar
again.
After sitting down and looking at dyno plots,
it become clear that we just couldn't get the power down off the
line in the older G1 fortwo even with the Brabus power plant; a G2
conversion was now on the cards.
The car was absolutely stripped to the core
including all cables and wiring looms. Everything was removed from
both the interior and exterior to leave this poor smart carcas open
to the next stage of the plan.
The car was then fitted with a Roadster engine
wiring harness, a 2004 G2 cabin and a front ESP loom. Later we were
hit with a spell of realisation that the rest of the car's
electronics system and hydraulics are totally different as
nothing mated up under the car.
This is precisely the problem with a project
like this, we were in uncharted territory as no one had attempted
this type of conversion before, we were left to work it out
alone with no literature to look at for reference.
We were budgeting a month of
our time on this project which had now just tripled, we were feeling disheartened
to say the very least and at the point of no return.
We pushed on and continued to fit the car's new
wiring loom and as we started to replace sensors one-by-one, things started
to come together.
The ECU, SAM unit and gearbox fitted were
from a G2 Passion so these should produce 61bhp standard (without mods).
This would give us more ground to play with regards to mapping
(already having 10bhp from the old 51bhp unit).
One of the main objectives for this conversion
was the quicker gear changes and the addition of 'sports start' so
the G2 two-stage pedal was added.
A cheap wrecked roadster came up through
someone we knew. Without delay we were there trying to salvage any
parts for the conversion that could be used.
We left there with a 80bhp Roadster
gearbox, SAM unit, ECU, keys, speedo head and pods. As we had a G2 block
installed, these parts could give us the Roadster's 80bhp base rather than the
61bhp from a G2 Passion.
Off come the 45kW G2 box (that we'd only fitted
days before) and on with the 60kW unit combined with a Brabus clutch and flywheel.
After connecting the sensors and control units, we turned the key
just one 'click' and we had signs of life. Our enthusiasm was restored.
Our next hurdle was the ESP and ABS system.
With the exception of front flexy hoses and calipers, the G2 has a
completely new brake system with regards to hydraulics. It become
apparent that major work was required to get everything working,
including:
New ESP / ABS unit.
Master cylinder.
G2 pedal box.
All new metal brake lines front to rear.
ESP loom from SAM to control unit.
Fabricating a control unit mount as they mount differently to the old units.
Additional lines needed to be added to the back wheels for the addition of the ESP's independent four wheel braking.
What we did find interesting is the fact Smart increased the size of the brake lines from the master cylinder
to the ABS pump from 3/16 to 5/8.
Once the brakes were bleed and the speedo head
connected, the car was carefully taken out for a little drive, this
was to ensure that everything functioned as it should and after a few teething problems
sure enough it did.
We were happy with the results so moved on to
the fit and finish of the car, a totally custom mount was made to
house the roadster speedo head. This, of course, was a necessity of
the conversion to obtain the correct speed reading as we were using full 60kW Roadster gearbox.
The first prototype was developed (pictured
below in white). After a few revisions to seating angle, the unit
was re-made and shown below finished in black.
In addition to the speedo conversion we looked
at adding the Roadster pod gauges. These just didn't look right
anywhere in the cabin due to their small size, so we fabricated mounts for them to
fit flush into the roof lining (just above the rear view mirror)
where they could be seen with just a glance.
While we had the car stripped out we took the
opportunity to fit a Brabus Roadster paddle
steering wheel and the sound upgrade bass bins.
Just when we think it's done and it's running
well we discover that the fuel gauge is actually reading wrong.
After investigating the problem, we traced it to the sender
unit that is combined with the fuel pump into one unit.
There was no alternative, we ordered the item from smart and
swapped the arm and float assembly from the old fortwo unit so it
would read correctly.
After lots of testing we were faster than every
80bhp Roadster just on weight so we decided to up the game yet
again. Several hundreds of pounds were spent on the following mods
to bring the power right up to make the car a complete handful:
4 Bar fuel pressure regulator.
Mocal silicone intercooler pipes.
Modified Pipercross Viper induction kit from a
Ford Focus (this was alot bigger than the smart designed kit).
Big Performance camshaft.
Mocal front mount oil cooler (for extra oil capacity).
mk1 fuel rail and IAT sensor.
74kw Brabus roadster TIK.
Throttle body butterfly modification.
De-catted stainless steel exhaust.
60kw yellow injectors (had a better spray
pattern than the Brabus blues).
Brabus charge cooler unit with a custom front
mounted radiator unit, combined with large high flow pump for extra,
more stable water holding capacity.
The picture below showing the installation of
the oil cooler and charge cooler radiators, the second picture is
displaying our charge cooler's high flow pump with our custom mounts
and rubber supports.
This combination of performance parts in
addition to the existing selection and new management system
obviously boosted the car's performance way up to what we were
looking for. However, there is always room for improvement and seeing
as the car was only running as the standard 80bhp with mods there
was definitely alot of room for improvement.
Ian at Big Performance talked about mapping the car when we were
building it so I took him up on his offer. To get the map right
that suited the car's extensive modifications it took most of the
day, by about 3pm he cracked it and we had a car that was boosting
to 1.4 bar (1.5 on overboost) that pulled hard in every single gear
without any flat spots. This also allowed the car to accelerate off
the new 120mph speedo with ease.
Now with the car on Schmidt Space alloy wheels and Eibech suspension, it
handled pretty well but not quite good enough. We removed and
replaced the whole setup for a complete Brabus Widestar kit
(including the huge arches), with 17's on the rear and 16's on the
front. The car sat perfectly on its new 40mm lower springs. These
Brabus Monoblock alloys wheels were custom finished in BMW M5 black
chrome to darken them right down.
We dyno'd the car in January 2007 at Red Dot Racing in Watford
with a result, we were all happy with, of 119bhp but more importantly a huge 117ft lbs
of torque.
The smart was run twice as they thought there was an error as the
graph showed such a powerful line so quickly and torque to match the
power. Its quite possible to get over 100bhp
in a smart now with the right combination of modifications but
getting the torque figure to match is
almost impossible. As of today the car is still unrivalled.