I am posting this for 3 reasons:

1. My dip is still prelevant at approximately 4k rpm.

2. I just got off the phone with Jim Conforti.

3. I wanted to share the info....with the Family.

He spoke with me for roughly an hour. It was an interesting discussion...that entailed training on DISA valve operations, adiabatic ignition, the 4k power dip, software tuning, Ferrari's, gasoline quality, NORAD and what his future holds.

With regard to the 4k power dip.....his impression is - As told by me (I need to remind you guys....that he only comes on the boards and says something....if he has run the numbers himself and has verified it to be true): I will never say it like he does, as he was feeding me knowledge from a fire hose. Basically there are two phenomina that contribute to the 4k Power dip:

1. Mechanical sticking / Operation of the DISA. This is normal operation.....as rpm's increase to a point (3750 rpm's) the DISA valve slams open. There is no slow progession through that "dipped" power range.

2. Knock sensor adaptations, regarding DISA. He has disabled the DISA in cars that he has supercharged. This did result in a bit of torque loss in that power range, but the car operated overall, smoother and more efficient with zero power dip. As far as he knows, tuning will not remove the dip. Tuning may reset the adaptaion values, so initially, the dip will not be there (or be less prevalent), but after fuel management system adapts to new limits, the dip will be back. I think this is the case for me. He additionally said altering the knock sensor adaptations on a street driven car was suicide.

As an aside.....we had an interesting gasoline discussion. He said that 91 octane from Sinclair (or any other gas station for that matter) and 91 octane from Shell, with equal RM values, will not be the same gas. Mind blown.

So.....if you couple a tune (that alters the knocks sensors), with a tank of gas.....other than Shell....melting a hole in your piston, could occur. Interesting statement here. For this sole reason, when he was performing dyno's, he instructed customers to only fill up at a Shell, near the dyno shop (Then followed and interesting story about a kid not following these orders, which resulted in Jim chasing his tail for 5 hours on the dyno, and resulted in a full drain and purge of the cars fuel delivery system)

So....in a nutshell.....there is no, known fix.....in his opinion, for the dip. Remember...there's 2 issues here. One is mechanical. One is electrical.

As a favor to me (and the community), he will be asking his contacts at BMW, if they have addressed this issue with a fix yet.

When he replies to my email....I will post here, or he'll come on and update the thread with his thoughts and findings.

Jim...I apologize in advance for butchering what you told me on the phone. You were shifting gears pretty fast......between a myriad of topics, and I could not fully wrap my head around some of the concepts. At this point....I hope all is well with you, and I appreciate you taking my phone call.

~DW