HP decrease with tune - WTF
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Pro
Joined: Jan 2009
Posts: 605
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From: Havelock North Carolina
HP decrease with tune - WTF
In March I had my A4, C6 tuned at a not so local performance shop. At that time the only mods I had were a Corsa Cat-back exhaust and a CAI. At that time it pulled 353hp and 353tq. Not much of a gain but all I was really looking for was a quicker throttle response time, which I got. Last week, after installing long tube headers with hi-flow cats I took it back to the same shop for an update. To my surprise the hp dropped to 350 but the tq went up slightly to 354. That didn't seem right so I asked the guy about it and he blamed it on the humidity. I was under the impression that they were supposed to adjust the dyno to compensate for the weather conditions. After reading post on this forum about gains after adding headers I'm thinking I should have gotten more. The shop is about 3 hours away so I just can't keep running back and forth. I chose that shop based upon a forum members recommendation and the many positive reviews I found when I did a search. Bottom line - am I right to be concerned that something was amiss or should I just let it die and accept those numbers?
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March is cold and August is hot. You lost 3 HP but picked up 1 in torque. Sounds like you are a victim of the summer heat for your numbers. 
The A/F and KR are the controlling factors in tuning. You can only do so much when those numbers are at the limits.
Elmer
The A/F and KR are the controlling factors in tuning. You can only do so much when those numbers are at the limits.
Elmer
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Joined: Mar 2005
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From: Austin Texas
The Dyno can't compensate for your ECM pulling timing and adjusting fuel for intake air temperature changes and coolant temp changes.
Wait until temps go down in the fall and dyno it again, you'll see differences then.
Wait until temps go down in the fall and dyno it again, you'll see differences then.
Thread Starter
Pro
Joined: Jan 2009
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From: Havelock North Carolina
Sounds much louder but the jury is still out on the faster part. I haven't had a chance to try it out due to poor road conditions.For example? Of course, that possibility always exist but installing headers isn't that hard of a thing to do although I did have to have new O2 bungs put in since the ones on the header were the wrong size.
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