Thread: JB4 on the M2
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      01-13-2018, 02:14 AM   #9
SeanWRT's Avatar

Drives: E90 M3 & F87 M2
Join Date: Sep 2015
Location: Shanghai

iTrader: (1)

GregoryK To all of your questions:
JB4 was on my wife's 328i years back, car sold already. With M2, I'm on flash only.
The higher boost you push, the more sensitive DME is to octane and thus IAT. Most agree that stock IC is incapable of managing IAT when you crack up boost. My mechanic did all the install of my hardwares. As for the difference in experience, it's been incremental power improvement every step of the way, but I wouldn't say "day and night" difference like some others would tell. To those unfamiliar with stock M2, my car feel just like a powerful stock car that sounds not bad either

DME is load based and adjust boost mainly to intake air density (elevation and IAT). Normally you will see boost peaks at 15psi at 4500~5500 range, given 90F of IAT at sea level and tapers to 12ish psi at redline.

All the standard, or OTS as most like to call it, flashes will get you 18psi or so from 3k5~5k range and taper all the way to around 14psi at top end. JB4 will can do that too.

Originally Posted by GregoryK View Post
Hey Sean. This is really great info. So you are running a JB4 with a custom map. You did however upgrade your IC? Why is that so important? What did you use and did you change it yourself?
Love to know the difference in your experience with the car before and after your tune. Greg
Originally Posted by Bt12 View Post
SeanWRT, so our car is running 14-15 psi stock? Do you know any standard tunes that boost it closer to 20psi or is there a reason the m2 N55 is not able to safely and reliably run at that level?. I run 93 octane where I am
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