[BiturboS4] RE: BiturboS4 digest, Vol 1 #68 - 1 msg

Edwards, Dave Dave_Edwards at iOra.com
Fri Aug 9 23:30:08 EDT 2002


I'd say there's something wrong there. Abt may be one of the least
'aggressive' chips about, but you still should feel the significant torque
increase. IMO it is difficult to notice the extra high-end torque which
gives the extra 40-50 hp, but the low-to-mid range torque (up 25% from 400Nm
to 500Nm) should be noticable.

You've done what the tuner should have done: A 'before and after' on a
rolling road dyno. Since your before figures are close to what Audi specify,
it suggests that your after figures are correct. If so then the chip has
clearly not done what the manufacturer intended!

A boost gauge would be useful here as primarily that is what the chip does:
Increase the boost from the typical 0.7 to 0.8 bar peak to around 1.0 bar.
Without a boost gauge you could use VAG-COM and read the car's own boost
sensor (why Audi didn't therefore give us a boost gauge is beyond me).

It is possible that the chip you have is not suitable for your ECU (there
have been several different ECU releases through the life of the Euro S4).

Unfortunately this case goes to prove how important it is to have your car
chipped at a tuner who has a rolling road. My chip cost me about 1600 Euros,
and that included a before and after dyno plot, where I could clearly see
the results (310 hp and 385
lbft torque). Even these results were disappointing to me as I also had the
Miltek cat-back fitted. Hopefully it was due to the high temp on the run (56
degrees Celsius air intake) and that my engine was still tight (13,000
miles). Another guy in the UK who has the same chip as me has measured
around 345 hp and over 400 lbft, but his car has done over 40,000 miles. I
have read that Audi engines do take a long time to loosen up!

I am having the rest of the Miltek system (cats) fitted in a couple of
weeks, and again I will have a before and after dyno plot done so that I can
see the results. I do hope I don't waste my money as it's even more than the


Message: 1
From: "David" <goodson at menta.net>
To: <biturbos4 at audifans.com>
Date: Fri, 9 Aug 2002 10:00:51 +0200
Subject: [BiturboS4] Abt modification - first impressions

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
done. 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 4=BAc 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
graph. 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 power)? 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. Adios. David.

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