some questions...

[lazer]

im planning to buy jb4 for my 2012 135i n55

i only have catback and bms intake so im confuse with the iso form. what is it? do i need this mod?

and if i understand, to run e85 low mixture i need the flexfuel wire? or i cant run it

thanks im new with this car and i search on the forum and still dont be 100% secure

[hawkm3]

Iso is the firmware jb4 runs Now, if you buy a jb4 pretty sure it already comes with iso 5 like mine did. And no you don't need a flex fuel wire, you can run up to 40% e85 just monitor how the car does

[e36addict]

All JB4's ship non-ISO. You have to do the mod to the circuit board and update the firmware accordingly. If you want to safely run over 20-30% E85 you need the flex fuel wires. Some new JB harnesses have the FF wire integrated into it now, so you wouldn't have to get it separate. I'd call BMS. Also, read this thread to learn everything..

http://www.n54tech.com/forums/showthread.php?t=13189

And the ISO thread

http://www.n54tech.com/forums/showthread.php?t=17800

[loesch]

So I'll create the quorum since the first guy is completely wrong. E36addict is correct.

[potxoli]

Since we are asking newb questions, here is another. Everything I've read in the ISO thread says the main benefit is "buttery smooth" power delivery. That sounds like a must have. However this ISO thing has been out for 2+ years, yet they still don't ship with it? I find it kind of odd that one needs to buy something for $500, take it apart, desolder/clip electronics off of it, attach it to a windows computer and reflash it, just to get something that everyone says is better than stock.

Why don't they ship with it?

[lazer]

With the regular jb4 n flex fuel wire...how many %e85 i can put without upgraded the fuel pump? I think bms said 40 on map 5?

[lazer]

But do i will notice a good gain?

[hawkm3]

Originally Posted by e36addict

All JB4's ship non-ISO. You have to do the mod to the circuit board and update the firmware accordingly. If you want to safely run over 20-30% E85 you need the flex fuel wires. Some new JB harnesses have the FF wire integrated into it now, so you wouldn't have to get it separate. I'd call BMS. Also, read this thread to learn everything..

http://www.n54tech.com/forums/showthread.php?t=13189

And the ISO thread

http://www.n54tech.com/forums/showthread.php?t=17800

If this is true why is it that my jB4 had iso written on it and I've been running 40% e85 since day one when I installed it

[hawkm3]

And my average ignition and timing advance have been great monitoring my car while on 40% e85

[hawkm3]

Wait hold up, I didn't see yours was an n55 I have an n54 is there a difference in the way they work

[loesch]

Originally Posted by Ralph1M

Wait hold up, I didn't see yours was an n55 I have an n54 is there a difference in the way they work

Honest mistake. Yeah. Big difference in firmware. Terry still hasn't taken ISO out of beta and still ships JB4s with integrated firmware from 8/17/2012.

[loesch]

Originally Posted by potxoli

Since we are asking newb questions, here is another. Everything I've read in the ISO thread says the main benefit is "buttery smooth" power delivery. That sounds like a must have. However this ISO thing has been out for 2+ years, yet they still don't ship with it? I find it kind of odd that one needs to buy something for $500, take it apart, desolder/clip electronics off of it, attach it to a windows computer and reflash it, just to get something that everyone says is better than stock.

Why don't they ship with it?

Only Terry Burger knows the answer to that one. He dodges the question if asked.