This fortwo started its life as a 2000 registered imported mk4
Passion. The car was bought looking very sorry for itself and in the real world
the car would have been broken for spares. However the decision was
made to buy it and give this classic shaped City-Coupé a new lease of life.
The engine was at the end of its life with nearly 90,000
miles on the clock and with a massive list of problems. this list grew under closer
inspection:
Turbo's manifold was severally cracked in several places.
A dump valve had thrown oil all over the engine's ECU and wiring.
Piston rings were needing replacement.
Input shaft seal was leaking.
Both driveshaft seals were gone.
The clutch plate was contaminated with gearbox fluid.
Rocker cover had a severe leak.
Dip stick guide was leaking from the bottom of the block.
Both breather pipes had perished.
One breather valve had failed totally.
Amongst the major things wrong with the car, the
exterior had this pretty heavy list of issues needing addressing:
Smashed N/S rear quarter.
Numeric Blue N/S front quarter.
Headlight mounts were snapped both sides.
Exhaust pipe was broken along the lower weld.
Fog lights didn't work.
Wiper arm capping was missing.
N/S rear brake cylinder was leaking.
The original plan was to rebuild the engine that was
already in the car but as you can see it just wasn't viable, especially with the
turbo in such a state.
A 2003 Roadster engine was bought as a replacement using
the experience gained from building the old project car (599cc to 698cc). We knew this setup worked
very well on the older management system and gearbox.
The old engine was pulled from the car on the
rear subframe and the swap began. It's worth noting that anyone
planning on doing this conversion should bare in mind a few differences that could cost you alot of
time if you are not aware of them.
Upto mk4:
Water housing - There is a coolant flange on
the back on the head that needs to be transferred off the older
engine as the newer models have three outlets rather than the older
two.
Cycle valve and wastegate need to be transferred to the new engine.
When mounting the turbo ensure you have the new 'bigger' 7mm studs and nuts along with the newer
manifold gasket.
If changing the exhaust for a later one like us ensure you have something to block the second
lambda sensor hole.
The EGR (exhaust gas recirculation) valve needs
to be blocked off at source as its not fitted on the older engines.
Alternator - Use the old unit as it is
earthed back through itself rather than having a dedicated lead on
the loom like the later models. (see the picture below to compare the two
units).
Mk5/6:
When mounting the turbo ensure you have the new
'bigger' 7mm studs and nuts along with the newer manifold gasket.
The EGR (exhaust gas recirculation) valve needs
to be blocked off at source as its not fitted on the older engines.
The engine itself is a direct swap if just
fitting the block and head, following the changes listed above.
The standard 45kW gearbox needed to
re-fitted to ensure correct operation with the car's standard
management system. This is true even with the addition of a Roadster clutch and flywheel
assembly to aid the spoil up and gear changes.
If you are doing this conversion you will need
a newer style turbo, ensure you make the right choice for your
own personal needs as its an expensive bit of kit to be spending out on.
45kW - A standard fortwo exhaust fits
with no modification along with the Brabus SB1 version and many
aftermarket suppliers.
60/74kW - Brabus G2 or an aftermarket exhaust
needs to be fitted to match the bigger outlet and stud pattern.
We fitted a standard G2 45kW unit in place of the 60kW Roadster
charger to allow us to fit a standard 45kW fortwo exhaust.
Below you will see the differences in charger
inlet sizes. Again you will be faced with a choice of TIK (turbo to
airbox pipe).
They are available in the aftermarket in
several different makes and sizes, however they are also available
direct from smart in three sizes to match their three turbo sizes.
Below are two pictures of
the turbo chargers inlets, starting with the bigger 60kW turbo.
This is the EGR system we talked about earlier, it quite simply
needs to be discarded as it doesn't fit the older pre-2003
models.
The car was reassembled with its new engine, filled with oil, the
cooling system bled, along with the brakes and wheel cylinder
replacement.
It fired up without problems.
We have driven the car for over 1,000 miles now on a daily basis and
it is a pleasure to drive compared with the older 599cc engine. This
fortwo now has bottom end grunt that the 599cc always lacked.
The body work was replaced and sprayed to match the yellow colour
scheme and fitted with countless new trim clips that had got lost
over the years. The headlights fitted with new beam benders and
cleaned thoroughly to produce a very good example of the older 'classic'
shaped City-Coupé.