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I’m Pete Gildenhuys from Pretoria, South Africa. I
bought a new Honda Jazz/Fit 1.4iDSI CVT in August 2005, and at April
2007 it has done 59000Km trouble-free. I originally bought the car
for my son who’s attending University, but have since bought him a
Honda CBX 250, for obvious reasons. Some of the modifications I’ve
done may have impeded the car’s warrantee, but what the heck. I’ve
been driving Mercedes Benz cars for the past 30 years, and I wanted
to see if I can make the Jazz as comfortable and as quiet. My latest
Merc is an E320CDI (2007 model) with air suspension and all…
Modifications done to the Jazz so far: Leather upholstery and
sheepskin seat covers (softer ride), anti-smash film on glazing and
loose full-size pile carpeting (adds to sound-insulation), hand-operated
throttle for long journeys, Unichip piggy-back programmable ECU, air
intake duct widened (the headlight unit causes some restriction on
the standard setup), Xenon headlights fitted, wheel tracks widened
by 10mm (toe-in and camber set at zero degrees), Michelin EA3 195/55
R15 tyres on standard mag. road wheels (originals were Bridgestone
185/55R15). 50x5mm neoprene O-rings were added between damper bump-stops
and car body (rear shock header bushes lengthened accordingly). All
stowage compartments lined with felt-cloth, body cavities in
vicinity of suspension sub-frames filled with liquid poly-urethane
foam (taking care not to block water drainage holes), and further
insulated with high-density foam rubber inside and out (most road
noise enters the cabin via suspension mountings and wheel arches),
rubber dampers fitted to torsion-bars and coil-springs to reduce
metal harmonics. Rear swing arm filled with poly-urethane foam. All
body panels (doors, quarter-panels, rear gate, under-bonnet) lined
with 10mm high-density foam rubber (works better than commercial
sound-deadening pads, and is much cheaper). I Also lined the inside
door U-channels for reduced wind noise. Roof pillars, tail-gate and
gate-cover, doorstep channels, part of rear roof, under-dash
cavities all filled with 50mm low-density foam rubber or poly-urethane
foam. The complete boot tub (a beeg sound box) lined with seamstress-type
batting, moulded in place with white Castrol motor cycle chain wax.
So, some parts have up to four layers of insulation. Tailgate-wing
fitted (a la vtec). All panels, mounting pins, etc. was treated with
wax before re-fitting, to prevent rattles and squeaks. Complete
under-side of car, including rear wheel-arches, covered with 1mm
PVC-sheeting and/or 4mm PVC foam-sheeting, lined with 5mm high-density
foam rubber. (I made templates from card-board first.) Under-engine
cover sculpted to aid air flow through the engine compartment.
Standard engine splash guard tends to sag in the middle, so I
stiffened it with aluminium channeling tied to the cross-member.
Total added weight about 9Kg.
No holes were drilled in the car, all modifications can be undone
and the car returned to standard. All mounting screws were glued to
the car with epoxy putty or thermal glue. All body-mounted foam (except
under front wheel arches which is glued in place) is fixed with
removable double-sided tape. The only modifications readily visible
from the outside are the slightly wider tyres and the tailgate wing.
The net result of it all? Dyna-tuning the engine with Unichip added
almost 5kW and 9Nm @3000 rpm at the wheels, at 1700m above sea level
(no noticeable improvement on fuel consumption, though). The
Michelins (run slightly under-inflated for a smoother ride) are
nothing short of superb (maybe I should have fitted 185/60 R15 for
lower rolling resistance, but the increase in circumference bothered
me). The low noise levels inside the car is almost eerie-like (I can
almost hear my passengers breathe at 120Km/h, and I drive around
without the tonneau-cover, which makes a whooping sound on bumpy
roads. Still needs fixing). The sound of the doors, bonnet and tail-gate
opening and closing, is Limousine-like. The under-body covers which
started as an experiment have now become a permanent fixture: the
cover between the rear bumper and rear swing arm had had a major
impact on the car’s aerodynamics. The widened tracks added to a
smoother ride and exceptional directional stability, even while
doing 212Km/h (Garmin Nuvi 300 GPS-measured) along a long, steep
down-hill. The lower front-end cover disintegrated during that run,
so I had to rethink its fitment. The modified engine air intake
system allows for some hot engine compartment air to be sucked in,
which slightly leans out the fuel mixture on hot days. Normal open-road
cruising around 115km/h with two adult passengers plus luggage
returns fuel consumption figures of 5,2l/100km (best achieved
4,7l/100km over 1500km round trip). Hand-throttle in tandem with CVT
works like a charm. In-cabin noise stays virtually the same for wet
and dry roads. Oh yes, I fitted a modified air filter element as a
cabin air filter, as my wife is sensitive to odours and dust. (GUD
AG868, side grooves removed, 2mm sealing strip added, plus 20mm foam
strip at the back. It needs replacement every two months.)
I once fitted a 20Kg lead weight in the spare wheel well, between
the wheel and jack: it smoothed out the ride even further, but adds
a bit to the fuel consumption. And I still want to reduce the engine
noise further by wrapping the front part of the exhaust system in
suitable insulation material: couldn’t find any to date. The hand
throttle may be augmented by an electronic cruise control, but
modified to keep the engine revs/load constant rather than the
cruising speed. I still occasionally drive around in the Merc, just
to keep its batteries charged. And when I have to show-off, of
course... |
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