Odd A4 dyno graph - any guesses as to the problem?
04-28-2009, 06:56 PM
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Odd A4 dyno graph - any guesses as to the problem? Had my car dynoed at a dyno day over the weekend and ended up with a really strange graph.
The shop seemed to think the transmission was slipping. However, I had it dynoed and tuned by a different shop last week on a hub-type dyno and got a normal looking graph. I also haven't noticed any signs of slipping. The fluid still looks and smells new (changed a few months ago) and I haven't noticed any RPM freakouts.
Mods include a Vigilante 3200, TR224, JBA shorties, cat back, underdrive pulley.
Anyone make anything of this dyno graph? Was the pull done incorrectly? I don't know what gear he did it in and wasn't paying close enough attention to notice any abnormalities.
Weird graph (dynoed unlocked on a DynoJet):
Normal graph (dynoed locked a week prior on a Dynapack):
The shop seemed to think the transmission was slipping. However, I had it dynoed and tuned by a different shop last week on a hub-type dyno and got a normal looking graph. I also haven't noticed any signs of slipping. The fluid still looks and smells new (changed a few months ago) and I haven't noticed any RPM freakouts.
Mods include a Vigilante 3200, TR224, JBA shorties, cat back, underdrive pulley.
Anyone make anything of this dyno graph? Was the pull done incorrectly? I don't know what gear he did it in and wasn't paying close enough attention to notice any abnormalities.
Weird graph (dynoed unlocked on a DynoJet):
Normal graph (dynoed locked a week prior on a Dynapack):
04-28-2009, 11:46 PM
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Also, correct me if I'm wrong, but the HP numbers are in the ballpark for locked (347hp) vs unlocked (336hp).I suppose it could have been tires slipping on the rollers, but my car isn't exactly a powerhouse and they did pulls with cars in the 500+ hp range that day. They primarily dynoed M6s, and did three A4s. Mine was the only one with a stall so it's looking like the dyno graph view might be the issue.
