Chipping
10 June 2006, 60,312
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he 9-3 TiD
lasted for a week as standard, then I dropped into DieselTune to have a
performance module fitted. Really, I was
wanting to have the TiD remapped, but I was impatient for results. The DieselTune module is reputed to take the
2·2 TiD from 115 brake horsepower and 192 foot pounds up to 140 brake
horsepower and 233 foot pounds.
The difference on the road is...
“as expected,” since you’re increasing maximum power by around a quarter. The disadvantage of the performance module is
turbocharger lag, which seriously
blunts acceleration when changing gear.
But once over the lag and the tachometer needle is between 2,000 rpm and
3,500 rpm, you are good to go.
This turbocharger lag is indicative of a faulty air
mass meter.
The difference is obvious in all
gears, but in the lower two, whereas before it never felt “point and squirt,”
even if you nailed the throttle. Now the
nose rises, the tail squats and it squirts forward. From 40 in fourth gear (just under 2,000 rpm) the pickup is significantly better; there is
more turbo lag but if you start accelerating from 1,900 rpm there’s very little
difference.
The difference to in-gear acceleration
is material, but the difference when accelerating through the gears is less
impressive. When overtaking it is now absolutely critical to use the correct
gear unless you want the embarrassment (and
potential danger) of having to change up and waiting for the
acceleration. I can't stress how
important it is to be in the right gear.
If you want to overtake a heavy goods vehicle at 40, it is tempting to
use third. Here, well as soon as you
nail the throttle, the turbocharger is blowing as it should but all too soon
you need fourth gear because you’re running out of revs. Then when you snatch fourth gear you have
somewhere between half and one second before you are back on boost once more. Instead, overtake in fourth gear… the pick up
will be initially slower but you won’t have to change gear until the
speedometer needle is above the speed limit.
Comparing this with the Honda, try
the same overtake in third and you won’t need fourth until the speedometer is
well over the legal limit. The Accord’s
acceleration from 40 in third isn’t the same as the 9-3. You’d need second in the Honda to match the
9-3... And then you’d also be changing up as the speedo approaches 60.
Is there such a disadvantage? Not really...
In essence, then, the chipped 9-3 TiD (like many other turbodiesels that are at or over the 120 brake
horsepower level) is unable to exploit its full performance because the rev
range is too short. Hmm. Its fault is that from 2,000 rpm it’s pulling
nicely, by 3,000 rpm it’s seemingly on a charge, but by 4,000 rpm you’re
rapidly running our of revs. The 9-3
hits peak power at 4,300 rpm, the governor is at 4,600 rpm but, really, there’s
so little point in exceeding 3,500 rpm...
Otherwise I’m settling down with
the 9-3. I am still not used to the
climate control, I want to manually control certain elements myself or I need
to learn to trust it. It’s also sipping
its diesel, if you believe the trip computer it’s averaging fifty four so far. Knock a few percent off but it’s probably the
right side of fifty.