As I prepare to leave my 06 A6 with Livernois Motorsports next week for a blower, heads, cam and headers, I decided to have the dealer flash my ECM with the latest software as a basis for the tune the car will also receive. Since having this done I've noticed that on occasion the 2-3 shift is different than in the past. While I wouldn't call it harsh, it seems to "lunge" into gear - almost as if it wasn't ready to shift, but did so anyway. It's is most likely to happen while I'm driving at relatively low speeds like 15 - 20 MPH. I did a search and found references to something called flare. Is this what I'm experiencing? The posts I've read give me the impression this is casued by a mechanical failure of seals in the trans. If that's the case, why did it seem to start following the ECM flash? I'm hoping that if it's a result of software changes it can be tuned out when the car is on the dyno.

 

In my experience "flare" is an automatic transmission specific term describing an abnormal temporary increase in engine rpm's during a shift. Kind of like a clutch pack is slipping or slow to engage allowing the increase in rpm's. Typically this would occur during normal driving, i.e. not wide open throttle. It can occur in a certain shift, say 2nd to 3rd and not happen in the others. If the rpm's are increasing faster than normal during that lunge you could have a flare but since you didn't mention that I can't make a guess. Since you are used to the car the way it shifted before you should readily notice even a slight rpm increase related to a flare. A flare can range from very slight to man I've got to get this fixed right away.

A typical flare could be caused by seals leaking, lowering pressure applied to the clutch pack or band causing slipage resulting in that increase in rpm's. The ecm flash could not cause a mechanical seal failure but could perhaps lower pressure enough to cause slippage and a flare. That would have to be a real mistake in the tune. Not something I would expect in a stock factory flash.

For your piece of mind and to prevent wondering what caused what I recommend straightening out this problem before you have any of that performance work done.

 

As someone who has personally blown up 6 transmissions with a high HP engine, I wouldn't even consider having any additional work done to the car until you can pinpoint what's causing the flare between shifts.

Best case you're looking at a situation where the transmission just needs some time to adjust to the reflash of the TCM but worse case it sounds like you've got a mechanical issue such as leaking seals (which there's a TSB out for) or possibly a clutch pack that's on it's way out.