[jmciver]

Using the link above, it also looks like CG Precision now has a valve controller option for the B58 engine (40i) as well - the VSC-1. The variant they have for S63 equipped cars should work for N63 cars (50i) too based on engine similarity. I have been very pleased with this device on my F80 M3 and given the cost, simplicity of install/removal, I will strongly consider it when the time comes for me to get an X7.

For those of you considering the down pipe option, I would recommend you think hard about the "bang for your buck". Non-catted down pipes can produce nice gains, even without a tune (although a tune is required to get max gains). But due to new emissions laws, non-catted downpipes are no longer legal for sale in all 50 states. Catted down pipes don't produce the same amount of gains (due the cats of course) so a tune would be paramount. But when you take into account the added weight of an SUV (vs a car with the same upgrade), the butt dyno may be a bit disappointed..