So your thinking... ok,
ok, enough chatter... show me the numbers! Six cars and
seven hours later the results were in. For peak horsepower
and torque, APR nosed ahead of the field and put out a pack
leading 303.1 horsepower and 302.1 lb-ft of torque. Most of
the rest of the field was pretty tightly bunched right
behind APR (within 10 hp and 4.9 lb-ft torque of the best
numbers) but there has to be a winner, right?
The big surprise of the
day was AMD coming in a distant 6th place, behind the
stock car, making a whopping 31.7 hp less and
2.8 lb-ft torque less than stock--a real head
scratcher considering the upgrades to the car.
Peak Torque (lb-ft)
APR had the highest
APR had the highest
OCT had the most
consistent power curve (other than stock)
OCT had the most
APR had the most
OCT vs OCT
OCT was the only software that did not
lose torque compared to stock over the RPM range. While
the APR car had a peak torque higher than any other car,
it was under the stock torque curve between 4000-4700
rpm. GIAC had a huge deficit in torque between 3000-5000
rpm compared to stock. Even though it's peak torque was
at 3000 rpm, it could not hold the power across the
3000-5000 rpm range. AMD was way below stock torque
output during the entire rev band. Both OCT cars stayed
well above the stock torque curve, consistently.
OCT was the only software that didn't lose HP over
stock. While APR had the highest peak WHP, it had
less HP than stock between 4000-4500 rpm. GIAC had a
significant loss of HP relative to stock during the same
3000-5000 rpm range where it lost torque. AMD had lower
HP than stock across the entire rev range. OCT was the
only software to remain above the stock HP curve the
entire rpm range.
From the data, it appears GIAC and APR were tuned
specifically for HP gains with less
attention paid in terms of mid-range power. It seems
that APR and GIAC were interested in being the HP "king"
so-to-speak--APR succeeded. A loss in midrange power would
result in a slower car. Based on it's consistent high torque
output, OCT would probably yield the best "around town"
performance yet only gave up a couple of HP on the top. Nice job
The APR software looked like it was attempting to
balance itself during runs. One run would yield
high HP and low torque, then the following run would
yield the opposite, lower HP with higher torque. The
first run yielded the highest HP number but the lowest
torque number. The 2nd run yielded slightly more torque
but several HP lower than the first run. The third run
yielded the highest torque number and a slightly higher
HP over the previous run. However, the 4th run lost only
a small amount of torque and the HP was the lowest of
the run group. The software was constantly adjusting
during runs, possibly trying to compensate for a massive
exhaust leak in the front section of the APR exhaust.
The AMD car was an interesting case. The timing
looked very good, seemed pretty aggressive and well
executed. Fuel injector duty was the highest of any of
the cars suggesting it might have been running too rich
and robbing the engine of power. Take a look at the AMD
torque curve and note how flat it is. VERY flat. That
would be a great thing if it were 30 lb-ft more but not
in this case due to the very low output. Where the
losses are occurring is a mystery at this point. Exhaust
design? Software? An S4 with a fullback exhaust should
be making a lot more HP up top than a stock car.
Seven dyno pulls were made with
AMD with the later runs yielding the best power. Only two of the
seven runs are included below.
The B6 shootout was an
interesting event to participate in. All the cars were pretty
consistent. The ice cold temperatures and cooling fans helped
keep the cars from heat soaking run after run (some even
performing better after a pull or two). Even under the harsh
conditions presented by a dyno the 4.2L V8s just kept twisting
out power without fuss.