o0aits0o

<center><img src="http://pictureposter.audiworld.com/103700/p1010071.jpg"></center><p>
2000 s4 w/94,000 miles APR chipped.(Warmed up engine,Then sat for 3 hours,like 35 deg outside,cold inside shop when put on the dyno)My fist pull ran 281.30 HP n 338.02 TQ (on 93 setting,With AC on).Second run pulled 252.25 HP n 303.52 TQ (91 setting, With AC on). And my last run was 263.18 HP n 302.85 TQ (Back to 93 setting, With AC on). My question is, Why did it drop down 18HP And 35TQ after The car warmed up on the 93 Octane? Does the AC have an effect on the motor when it is still Cold?, does it even engauge? This was bugging me allday. Any Help Would Be Appreciated. Thank You.

zeus1

heatsoak.why did you have the a/c on too?

o0aits0o

I had it on auto and forgot about it.

quickaudi:STFA

GIAC and APR both strongly insist that you don't change your program on a dyno. See, when you change, your car loses all settings and goes into learn mode, which can really suck when trying for max power. In other words, don't do that.

o0aits0o

When I did my first run I changed The program to the first setting from the second setting. That showed the highest number and stayed lean the longest with a smoother run. (compared to my second and third run.)Why was that the highest? Any Help appreciated Thx.

quickaudi:STFA

Dunno. Probably be better to ask a chip expert.

Mike@StartupRacing

There are usually code in the ECU that richens up the car with the AC on, it will usually raise the idle a little also. Depending on engine temp &amp; outside temp.