[Jdub679]

I reviewed my Stage 1 a little while back (http://www.e90post.com/forums/showth...ighlight=Stage), and for those that might remember, I've delayed getting my Stage 2 for what seemed like forever because I had an older DME that BMW would not update. That all changed when I got my service this past month.

The Stage 2 install is definitely a little more involved than the Stage 1. I would say that it added approximately an hour to my install time. I took my time and followed the instructions and pictures from N54tech. My only note to add to the install is that when you're pushing the wiring pins into the existing DB25 connector, don't force the pins in by pushing. Instead, take a pair of needle nosed pliers and pull gently on the tip once you've slotted it into the DB25 connector. I do have some previous experience with modifications, including wiring and even tapping into harnesses (which is a bit nerve-wracking btw). This one couldn't be smoother or easier. No wires to cut and nothing to solder. Car started up perfectly right afterwards with no codes.

I've had over 150+ miles to drive on it since install. One of the first things I did was ~3 third gear pulls to near redline. There does seem to be a difference in the way the car reacts from the first pull to the last. The car does seem to learn, but I can't substantiate that. It's just my opinion.

Comments on performance... The most noticeable difference between Stage 1 and Stage 2 seems to be a stronger low rpm (sub 4k rpm). Where as the Stage 2 seemed to have a very strong mid-rpm performance (4-5.5k) that came on strong and fast, Stage 2 seems to have smoothed it all out so that the acceleration seems more linear. This is a GOOD thing imo. It means that pulling away from a stop is stronger with less effort. It also seems to bog less at very low rpms with minimal throttle. Top end performance on map 1 seems to be pretty similar to Stage 1 at +3.5 psi.

Shifting between gears is better as well. The car seems to hold boost better, so the bog when shifting to the next gear is reduced greatly. If I had to guess, I'd say that with the reduction in shift bog/lag + low rpm to mid rpm power alone, even if the peak hp/torque numbers are the same as Stage 1, the Stage 2 does make for a faster overall car.

Comments welcome!

The pic below is a handwritten note taped to my DME box. I sent the pic to Mike@N54tech. We both thought it was pretty funny. Nice thing about tape is, it can be removed.

[OneFastN55]

lol

[Jdub679]

I filled 3 gallons of E85 to a full tank of 91 octane. Car pulls impressively hard, even just keeping it on map 1. Seems the low to mid rpms are even stronger now.

So tempting to switch to map 2...

[Charleston335]

So probably about .1-.2 difference in 1/4 mile form stage 2 map 1 coming from stage 1 3.5+ lbs of boost?

[Jdub679]

Originally Posted by Charleston335

So probably about .1-.2 difference in 1/4 mile form stage 2 map 1 coming from stage 1 3.5+ lbs of boost?

Honestly, I wouldn't know because I don't drag anymore. Weird, I know. lol. But if I had to guess, I'd say 0.1-0.2 is reasonable. Not because it makes more peak power, necessarily, but the reduction in the bog right after a shift and more consistent power through the powerband will probably give better times (or at least more consistent).