As I'm possibly the last VAG diesel owner in the UK to try a 'resistor mod' tuning box 
I thought I'd report on my initial findings over the last 600 miles or so.
Car is a 2002 model Passat PD130 sport, bog standard apart from an £18 tuning box on the fuel temperature sender, bought from a German supplier. I don't know what value resistance is in the box. Car has 42,000 miles up, owned from brand new.
On fitting, extra torque was immediately noticeable from 1500rpm upward.
Tickover is a tiny bit lumpier when engine is hot but certainly not a problem, and most of the time not really noticeable. Cold tickover and starting is no different to standard.
Throttle response is more abrupt than normal, a little finesse is required to stop lurching when going on and off the throttle but you soon get used to it.
There is no more smoke / soot than normal (as observed by my dad, following me for 20-odd miles ... although mine has never been sooty anyway).
No check engine light or fault codes after 600+ miles of mixed driving, including sustained high speeds and long periods in traffic jams (the pre-2003 PDs are supposed to be better than post-2003 for not giving fault codes with this mod, apparently).
Figures:
On my private test track, 40-60mph acceleration in 4th gear is a repeatable 7% quicker (now 4.6 seconds average, compared with just under 5.0 seconds average without the box). Other in-gear times show a similar 6-7% improvement.
Actual brim-to-brim fuel consumption has increased by about 3-4% (down from my usual 46-47mpg to 44.5) over the same type of driving.
The fuel computer is waaaaaayyyyyy off -- it's now about 25% optimistic overall, where before it was just 5% optimistic. However, it's more optimistic at light throttle / low load than it is at motorway speeds.
Overall -- a good bit of fun for pocket money costs
I thought I'd report on my initial findings over the last 600 miles or so.Car is a 2002 model Passat PD130 sport, bog standard apart from an £18 tuning box on the fuel temperature sender, bought from a German supplier. I don't know what value resistance is in the box. Car has 42,000 miles up, owned from brand new.
On fitting, extra torque was immediately noticeable from 1500rpm upward.
Tickover is a tiny bit lumpier when engine is hot but certainly not a problem, and most of the time not really noticeable. Cold tickover and starting is no different to standard.
Throttle response is more abrupt than normal, a little finesse is required to stop lurching when going on and off the throttle but you soon get used to it.
There is no more smoke / soot than normal (as observed by my dad, following me for 20-odd miles ... although mine has never been sooty anyway).
No check engine light or fault codes after 600+ miles of mixed driving, including sustained high speeds and long periods in traffic jams (the pre-2003 PDs are supposed to be better than post-2003 for not giving fault codes with this mod, apparently).
Figures:
On my private test track, 40-60mph acceleration in 4th gear is a repeatable 7% quicker (now 4.6 seconds average, compared with just under 5.0 seconds average without the box). Other in-gear times show a similar 6-7% improvement.
Actual brim-to-brim fuel consumption has increased by about 3-4% (down from my usual 46-47mpg to 44.5) over the same type of driving.
The fuel computer is waaaaaayyyyyy off -- it's now about 25% optimistic overall, where before it was just 5% optimistic. However, it's more optimistic at light throttle / low load than it is at motorway speeds.
Overall -- a good bit of fun for pocket money costs
