Talk me into/out of a JB4 stack

typedRew

Sergeant
Feb 25, 2019
412
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2009 335i xDrive
At some point, i'd like to add;

Meth injection
Nitrous

I know a jb4 also has lots of small fringe features that are things i'd like to add.

Max cool feature that runs cooling fan when in staging lanes on demand
2 step/anti lag for boost building on the line(auto), might be less stress/heat on the trans, also might help if I use larger upgraded turbos in the future and getting into boost without a loose converter
On the fly map switching, although I don't believe this lets you switch between 93 and e85 without flashing a new back end flash. Clarification?

Anyway, this winter i'm going to be doing some repairs and upgrades to the car and I just want to see if its worth adding the complication/cost for a few of these things or maybe more that i'm missing.
 
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Alex Vasilevskiy

New Member
Nov 18, 2016
6
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Cleveland OH
I'm running a stacked setup at the moment, FBO N54 with inlets and stage 2 lpfp, around E60 and added BMS meth kit this year. JB4 made it super easy to integrate meth and I got great results. You can switch between different boost maps and meth maps but to truly go between 93 and E85 requires a 2 min flash. For a car that's not tuned by a tuner and is essentially running basic maps I felt it performed pretty good. To give you some perspective on how the car is running, my best kill this year was my friends E85 2019 Mustang 5.0 with intake and ported manifold. In mexico did 4 pulls from 60 and 1 from 40 and ended up, according to him, putting 2-3 cars on him which surprised us both. Eventually when I upgrade turbos I will get in touch with a tuner but will still plan on leaving JB4 for its safety and CAN features. I know that many people dislike the JB4 but I have nothing negative to say about it and I've had it on my car now for 5 yrs. At that price point it's a great value for what it can do in my opinion.
 

typedRew

Sergeant
Feb 25, 2019
412
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2009 335i xDrive
I'm running a stacked setup at the moment, FBO N54 with inlets and stage 2 lpfp, around E60 and added BMS meth kit this year. JB4 made it super easy to integrate meth and I got great results. You can switch between different boost maps and meth maps but to truly go between 93 and E85 requires a 2 min flash. For a car that's not tuned by a tuner and is essentially running basic maps I felt it performed pretty good. To give you some perspective on how the car is running, my best kill this year was my friends E85 2019 Mustang 5.0 with intake and ported manifold. In mexico did 4 pulls from 60 and 1 from 40 and ended up, according to him, putting 2-3 cars on him which surprised us both. Eventually when I upgrade turbos I will get in touch with a tuner but will still plan on leaving JB4 for its safety and CAN features. I know that many people dislike the JB4 but I have nothing negative to say about it and I've had it on my car now for 5 yrs. At that price point it's a great value for what it can do in my opinion.

Thats a great comparison. Awd or rwd? Auto or manual?

When you have the back end flash, what settings do you run in the jb4? do you still use map1/2? Or does it have to be something specific?

Id like to ability to tailor the boost curve to my preference, and I think thats possible. Am I correct?

How much total boost are you running with the stack on that run against the 2019 5.0? Have you ever ran flash only?

From what i've seen, it seems like the jb4 cars are either obnoxiously faster for some reason or way slower and no in between.
 

Alex Vasilevskiy

New Member
Nov 18, 2016
6
5
0
Cleveland OH
Mine is a RWD Auto. In the JB4 you need to set it to option 4/2 so the JB4 knows you have a Back End Flash (BEF) on board for boost control. Each map has a different boost setting so since I have meth, I run map 3 and set the target myself through the meth additive option. Map 5 is still an auto tune map and map 7 is all out race. If you want to tailor your boost curve you can make your own through map 6 which allows you to set boost per RPM. When I ran the mustang I set my peak PSI around 21 but since I hadn't had a chance to dial in boost, it overboosted briefly to 22-23 psi when I shifted around 6300RPM from 3-4 and 4-5 shifts. I've never ran flash only so I guess I'm somewhat biased. What I will say though is some maps target boost depending on parameters like avg ign (maps 3 and 5) so if you are getting tons of timing corrections, the JB4 will automatically reduce boost and won't let you hit your full boost target as a safety feature which might explain some cars being slower.
 
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langsbr

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Apr 5, 2017
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I dont want to take anything away from the JB4, but I absolutely LOVE MHD flex fuel. If you aren't into mixing, or don't always know what your pump ethanol is, it's the best way to have hassle free ethanol. Infinitely variable interpolation and manipulation of boot, timing, and afr all on the fly. Super awesome product.
 

Weehe

Specialist
May 21, 2019
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I have been using JB4 with MHD BEF for my N55 for years. I've tuned the BEF to my car and have not needed to adjust it for 2 years. I will say I am 90% happy with this setup. The only issue I have with JB4 is that you have to tune it for the rpm you go WOT. Most of the time that is ~3k rpms for me, and I have dialed the duty bias in great. The issue is that if I got WOT at 4k rpms I over boost like crazy, run out of fuel, limp mode. This is a common issue. This is the only reason I'm considering flash only tuning from a pro tuner. Once I learn how to tune boost I'll do it myself.
 
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Terry@BMS

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Jan 23, 2017
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I dont want to take anything away from the JB4, but I absolutely LOVE MHD flex fuel. If you aren't into mixing, or don't always know what your pump ethanol is, it's the best way to have hassle free ethanol. Infinitely variable interpolation and manipulation of boot, timing, and afr all on the fly. Super awesome product.

We have a BEF map that is compatible with the MHD flex tables for those who want to run it, although the JB4 includes a lot of the same functionality already via it's autotuning maps and flex fuel integration.
 
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langsbr

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Apr 5, 2017
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We have a BEF map that is compatible with the MHD flex tables for those who want to run it, although the JB4 includes a lot of the same functionality already via it's autotuning maps and flex fuel integration.

Oh cool, I saw you were developing it but didn't know it had become fully supported. My friend was debating on getting a jb4 and he was holding off because of flex fuel. I'll let him know it will work with it. I had mentioned the virtual flex fuel the jb4 has had for some time. He also wants the 2 step, gauge override, etc. Sounds like a win!
 

Terry@BMS

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Jan 23, 2017
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Oh cool, I saw you were developing it but didn't know it had become fully supported. My friend was debating on getting a jb4 and he was holding off because of flex fuel. I'll let him know it will work with it. I had mentioned the virtual flex fuel the jb4 has had for some time. He also wants the 2 step, gauge override, etc. Sounds like a win!

Yes with everything integrated in to one system in the JB4 it's a lot easier and safer to use all of those features too.
 

CNM135i

Specialist
Nov 14, 2018
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M135i PWG
@CNM135i might have something to add?

~2 years since I gave up working with JB4 - I am sure a lot has happened since then. One major change is the change back to integrated (for the F-series) so my criticism will no longer apply. However, a piggyback will, in my opinion, never be a 100% solution for tune (hope I am not starting a war) haha
 
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typedRew

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Feb 25, 2019
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2009 335i xDrive
~2 years since I gave up working with JB4 - I am sure a lot has happened since then. One major change is the change back to integrated (for the F-series) so my criticism will no longer apply. However, a piggyback will, in my opinion, never be a 100% solution for tune (hope I am not starting a war) haha

If you don't mind digging a little deeper, i'd love to hear your experience.

I'm usually one to use the simplest most comprehensive option to avoid overcomplication. But in this case it seems like the jb4, while adding complexity, is mostly that.

I do plan on having a custom back end flash 'real tune' but I know a lot of people who use the base bef with success. I'm using MHD exclusively now with success and no complaints.
 

Bnks334

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Dec 1, 2016
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If you don't mind digging a little deeper, i'd love to hear your experience.

I'm usually one to use the simplest most comprehensive option to avoid overcomplication. But in this case it seems like the jb4, while adding complexity, is mostly that.

I do plan on having a custom back end flash 'real tune' but I know a lot of people who use the base bef with success. I'm using MHD exclusively now with success and no complaints.

Once you've done a "BEF" the JB4 isn't really doing much except adding a confusing layer into the mix. JB4 at that point is then useful for its other features such as steering wheel controls and meth control etc. If you're not using any of that stuff then not much point in spending extra on the JB4.
 

ShocknAwe

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Jan 24, 2018
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Charleston, SC
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N54/3 1er ///Mutt
I used JB4 with a backed for years on my N54 1er. Great system. Map switching and steering wheel controls are great. Also quite liked the on the fly throttle sensitivity settings and wastegate control.

I only switched to flash only as that's my tuners preference (Hydra) for the N53 setup.

I really miss the steering wheel controls, code readouts, error clearing. Also miss the map 4 safety. I felt more protected with the JB4, but not sure if that's really the truth.

I also liked the ability to auto ignore the TPMS. I had to specifically code that out when I switched to flash only. Not hard, but the JB4 is DAMN CONVENIENT.

I'll be interested in seeing if there's a way to set up two flashes I can switch between using MHD, a DD and kill mode.
 

CNM135i

Specialist
Nov 14, 2018
60
18
0
Ride
M135i PWG
If you don't mind digging a little deeper, i'd love to hear your experience.

I'm usually one to use the simplest most comprehensive option to avoid overcomplication. But in this case it seems like the jb4, while adding complexity, is mostly that.

I do plan on having a custom back end flash 'real tune' but I know a lot of people who use the base bef with success. I'm using MHD exclusively now with success and no complaints.

Your car is an E-series so better get some input from those guys (I didn't see that when I posted my comment).
 

Milan

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Dec 24, 2016
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jebi se
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your mom
Unpopular opinion: Once you start adding things like PI you aren't really staying "flash only". In my experience the JB4 manages these a lot better than MHD with all the addons.

I think flash only is great for the FBO guys but once single turbo, the JB4 provides way too much functionality to overlook
 

scrllock

Sergeant
Dec 17, 2018
267
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2011 335xi
Some, though unless you're using meth/PI I still don't think it's worth the cost.
When Terry says " a lot of the same functionality already via it's autotuning maps and flex fuel integration." that really just means if you buy the MHD flex fuel, the JB4 won't break it. Its own inherent "virtual flex fuel" can't adjust timing, etc. and so if you switch from pump gas to e85, you still have to re-flash without the MHD FF module. This is something Terry seems to avoid talking about in direct terms, as it's really not what people expect from a flex fuel solution. Like most of the features, it requires a BEF to work 100%.

Personally since I don't need a boost controller and I have the hardware for DI-only e85, WMI/PI control isn't needed, so there's not many reasons to justify the install. Revving gauges on startup I guess? Wireless logging is nice but the mhd adapter will be shipping soon. I also wanted something simple, which meant no secondary fuel injection, no piggybacks wired through unsealed grommets causing odd issues I have to track down later, etc.

Lastly, if you're beyond FBO, you're probably working with a tuner, and their opinion is going to matter a lot more than mine. Just my $.02.
 

CNM135i

Specialist
Nov 14, 2018
60
18
0
Ride
M135i PWG
My videos explaining my meth setup running a Torqbyte controller and showing how the meth fail work


 

Terry@BMS

Sergeant
Platinum Vendor
Jan 23, 2017
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Some, though unless you're using meth/PI I still don't think it's worth the cost.
When Terry says " a lot of the same functionality already via it's autotuning maps and flex fuel integration." that really just means if you buy the MHD flex fuel, the JB4 won't break it. Its own inherent "virtual flex fuel" can't adjust timing, etc. and so if you switch from pump gas to e85, you still have to re-flash without the MHD FF module. This is something Terry seems to avoid talking about in direct terms, as it's really not what people expect from a flex fuel solution. Like most of the features, it requires a BEF to work 100%.

Personally since I don't need a boost controller and I have the hardware for DI-only e85, WMI/PI control isn't needed, so there's not many reasons to justify the install. Revving gauges on startup I guess? Wireless logging is nice but the mhd adapter will be shipping soon. I also wanted something simple, which meant no secondary fuel injection, no piggybacks wired through unsealed grommets causing odd issues I have to track down later, etc.

Lastly, if you're beyond FBO, you're probably working with a tuner, and their opinion is going to matter a lot more than mine. Just my $.02.

There isn't a requirement to reflash when running pump vs. E85 mixtures with the basic BEF implementation. Timing is indexed on load which the JB4 can control back to the DME. The timing to load targets are set so you can run a lower boost profile on pump gas and get appropriate timing levels. But using the new MHD Flex option we've been able to make the back end flash maps a lot stronger for those who run different fuel mixtures often. So for $99 extra or whatever I tell customers why not. You've already invested more than that in the sensor and analyzer at that point.

Regarding how the JB4 would benefit a car like yours the two biggest things for people is usually ease of tuning, eliminating the need of a custom tuner, especially for those running larger turbos that usually require a lot of WGDC fiddling to get right over a wide range of climate conditions, and the extra safety systems. I continue to see flash only cars pushing 18:1 AFR in one bank or fuel trims with a huge variance, and the owner having no idea unless they happen to be logging AND review the log. If the JB4 encounters situations like that (and others, low fuel pressure, boost too high, etc) it aborts the run and flashes an indication to the dash for you. We've saved countless N54 motors using the technique and as the motors age it's becoming even more critical to catch problems in real time not when reviewing logs later after a bunch of runs.