[BiturboS4] Abt modification - first impressions

David goodson at menta.net
Fri Aug 9 11:00:51 EDT 2002

This is a multi-part message in MIME format.
I had my Baby modified with the basic 310 hp/500 Nm Abt program three weeks
ago. I live in Spain, but the Abt representative here was out of order, so I
had to go to France (to Viacom Abt, only importer in France) to have the job
My impression about the French company is good : they seems to be serious
people, with a nice and clean workshop and they take time to talk with
clients. I brought my car in the morning, spent half an hour to chat with
the technician, and went back in the afternoon to pick up the car and spent
another hour chatting with him. we had a 20 minutes test drive together too
after the mod.
My first impression about the mod is :
Is that all ?
Yes, it pushes a little bit more, but for 2400 Euros (which was about 2400 $
at this time) I was expecting something more... spectacular.
I asked them to measure the power and torque before and after modification,
and they did it with an "on board" dyno system (on a freeway) since they
don't have a static dyno rolling road. They told me the figures was not
absolutely precise, but the difference between the "before" and the "after"
figures could be trusted. The results are the following :
Before mod : max power : 266.9 hp at 6090 rpm and max torque :38.19 mkgF at
3801 rpm.
After mod :  max power : 317.6 hp at 5530 rpm and max torque :47.83 mkgF at
3981 rpm.
which means a gain of 50.7 hp and 9.64 mkgF.

Since I've had a real dyno rolling road test here in Spain a few months
before, when I came back I took the car to the same place and did another
test. The results are less optimistic :
261 hp / 418 Nm before mod, and 303 hp / 432.8 Nm after mod.
Temperature was 4ºc higher on the second test.
I'm attaching to this mail the graphs of this test (before and after mod). I
have photoshoped them a little so you can see before and after on the same
Question for the specialists around : what are these little "accidents" at
the beginning of both curves (at around 1000 rpm for torque and 35 km/h for
Shouldn't torque be higher after modification ? (the gain is only 15 Nm).
Comments welcome.
Next time I will tell you about my new Stratmosphere short shifter.

[ power.jpg of type image/jpeg deleted ]
[ torque.jpg of type image/jpeg deleted ]

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