[zcspec]

It’s been a couple of weeks since I installed BMS’s JB stage 1 for the N20. Having experience with installing the JB4 on my 335, the process was virtually identical. You’ll tap into 2 sets of sensors, then neatly tuck away the BMS control module. The install process took me no longer than 30mins, most of which was consumed by my OCD to zip tie and secure all the wiring in place.

Initial driving impressions…in comfort mode, Stage 1 is very civilized. Unless you go WOT in comfort, the difference is slight and very linear. In Sport Mode, the little N20 drives completely different. Throttle response and power increase is very noticeable, so much to the point that my wife’s neck snaps back and forth upon depressing the throttle. The default boost increase makes the N20’s power closer to my N55’s in stock trim. It definitely put a smile on my face. What I don’t care for though, is the jerkiness of the shifts and unforgiving throttle response. From what I read prior to the install, I was not surprised by the jerkiness.

Would I recommend this upgrade, without a doubt. The power increase is well worth the price of admission. What I enjoy most is, the ease of install and removal.

[thecrewuno]

I've been thinking about doing this to wife's '17 x3 28i. Have you had any issues with the JB4 stage 1 tune since installation?

[MichiganMike]

Originally Posted by thecrewuno

I've been thinking about doing this to wife's '17 x3 28i. Have you had any issues with the JB4 stage 1 tune since installation?

Increased power and "jerkiness" due to the tune might put additional stress on the timing chain and guide. Should the timing chain fail, a known potential problem with some N20 engines, please consider whether BMW may deny a warranty claim if it deems the modification to have contributed to the failure.

[FSociety]

I had X3 28i for 2yrs and had a Racechip on it, raced for fun 328i w/ BMS stg1 and X3 BMS Stg1 and even Dinan Stag1 .. My piggyback was reliable and faster i was happy

Racingpowersports.com offers Racechip for BMW, and I remember (hopefully still works) the discount code "bmwchip"

[zcspec]

Originally Posted by thecrewuno

I've been thinking about doing this to wife's '17 x3 28i. Have you had any issues with the JB4 stage 1 tune since installation?

No issues thus far, but the only time we really "tap" into the JB tune is when I drive it. My wife is kind of clueless when it comes to the D and DS modes and I can tell because her MPGs will always be higher than when I drive her car.