[austintexasathlete]

I just wanted to thank the author for the pictures as this REALLY helped a lot. I'm not a mechanic and had never done a modification on any of my cars before. The pics were a lifesaver. I'll pass along my experience so far:

I actually purchased the Turbo Tuner as well as the Cold Air intake from Jeff at Eurobahn Performance a few weeks back. The products were backordered so it took a bit to get them in stock and shipped out. After they arrived, I started the install process. It took me just under 2 hours to install both products since I went very slow and methodical as this was my first time to even peek under the hood of my 535xi, let alone install anything. I opted to disconnect the battery before doing the install to make sure I didn't goof anything up.

My first impression on driving is that there is quite a noticeable difference in horsepower and acceleration. The car can pull at all speeds. No turbo lags or downshifting here. Quite nice.

I did however start getting an error code "Engine Malfunction - Reduced Power". This came on twice when I was putting the car thru some hard accelerations. When I turned the car off/on, the error code went away each time.

I emailed Jeff at Eurobahn and he had this response:

"Most likely this is being caused by the vehicle not having adapted yet to the new unit. I recommend disconnecting the negative battery terminal on the car and letting it sit for an hour. Then reconnect it and drive the car around normally for a few miles. Then progressively get more aggressive with your driving. This will cause the vehicle to adapt at an appropriate level of performance. WE have not much in the way of trouble with the units at all. However yours is the first I can remember of a xi vehicle with both the intake kit and the Turbo Tuner. But I doubt that either product is going to be a problem. I am sure we will get it sorted. Make sure you are running the best gas available in your area."

I took Jeff's advice and disconnected the battery. I'm guessing (hoping) that this will fix the problem. I also think that the last tank of gas I put in the car was lower octane, so I'll opt for high octane next time.

The upgrades have been really fun so far and have breathed new life into the engine. I'm guessing that the combination of the cold air intake and the Twin Turbo together probably added about 70hp all together.