JB4 Thread for Lotus Emira AMG i4 (M139 Engine) – Tuning, Setup, Results & Support

[Andrew25]

To answer your question the more HP you produce, the more strain you put on the engine and it's components. So with the JB4, map 1 would be the most conservative, and map 4 the most agressive.

If you install a JB4 you are most likely voiding the warranty of your engine and drivetrain. However you should study the Magnuson-Moss Warranty Act (MMWA), if you live in the USA. Other things like electronics would most likely still have warranty unless they determined to be caused by the JB4.

Yet another fine reason for me to stay away from this kind of tuning, sadly. It’s super interesting, but voiding the warranty and having to replace stuff like that just isn’t within my budget (I suppose that 20-30k would be easy to reach). I might spend those money for racing a couple of times with a proper team instead, if I wanted so. But yes, that’s a totally different thing.

 

[1031ent]

Yet another fine reason for me to stay away from this kind of tuning, sadly. It’s super interesting, but voiding the warranty and having to replace stuff like that just isn’t within my budget (I suppose that 20-30k would be easy to reach). I might spend those money for racing a couple of times with a proper team instead, if I wanted so. But yes, that’s a totally different thing.

My personal opinion is JB4 maps 1 & 2 are probably safe for the additional HP to the engine. The I4 m139 engine came with 469hp in some Mercedes applications. I feel like you are safe from engine issues up to this HP.

As for the unit itself causing issues? I have no idea, but the manufacturer appears to be highly respected.

Personally I would wait until my warranty is up to install, because I like the piece of mind of knowing I am covered if any issues arise.

 

[Lotus F1]

My personal opinion is JB4 maps 1 & 2 are probably safe for the additional HP to the engine. The I4 m139 engine came with 469hp in some Mercedes applications. I feel like you are safe from engine issues up to this HP.

As for the unit itself causing issues? I have no idea, but the manufacturer appears to be highly respected.

Personally I would wait until my warranty is up to install, because I like the piece of mind of knowing I am covered if any issues arise.

It's an easy remove if needed for any warranty issue if required

 

[F1 SML8R]

Nothing easy about the i4 install. Multiple sources have confirmed the i4 (unlike the v6) is a royal pain in the @ss from an install perspective.

 

[Lotus F1]

Nothing easy about the i4 install. Multiple sources have confirmed the i4 (unlike the v6) is a royal pain in the @ss from an install perspective.

Perspective is needed. In the rare event you need warranty work comprehensive enough that the jb4 would be discovered, it can be removed in a few hours. To further simplify I made the intercooler sensor wire easy to remove from the JB4 without having to get to the sensor. Will only take me minutes.

 

[F1 SML8R]

Perspective indeed, the fact that you had to stray from the prescribed process and tweak to accommodate an easier install/removal, says it all. Don't get me wrong, for those of us that have quickjacks or a full blown lift, a nice full tool chest and time, it can certainly be done (throw in a side of bruised/scraped knuckles). However, most that have done it would NOT label this project as "easy".

BTW, not a dig at you, simply want to make sure any of our i4 brothers not familiar with this one aren't mislead into thinking it's easy like an oil change or air filter swap which most of us would likely describe as "easy". "easy", this one is not...

 

[Andrew25]

I represent, maybe, the best case of dummy user that never got his/her hands dirty on car mechanics and stuff. I would not be able to make sure something like the intercooler sensor wire is easy to remove, nor have I access to tools or anything needed. Also, I would need to fully trust the one doing the job. Maybe waiting for the warranty to be up is the better choice.

 

[Lotus F1]

I represent, maybe, the best case of dummy user that never got his/her hands dirty on car mechanics and stuff. I would not be able to make sure something like the intercooler sensor wire is easy to remove, nor have I

I'm sure you could, you just have to cut the jb4 boost wire and make two easy detachable connectors from that. Im no mechanic by any means and my tools are mediocre

 

[Lotus F1]

Perspective indeed, the fact that you had to stray from the prescribed process and tweak to accommodate an easier install/removal, says it all. Don't get me wrong, for those of us that have quickjacks or a full blown lift, a nice full tool chest and time, it can certainly be done (throw in a side of bruised/scraped knuckles). However, most that have done it would NOT label this project as "easy".

BTW, not a dig at you, simply want to make sure any of our i4 brothers not familiar with this one aren't mislead into thinking it's easy like an oil change or air filter swap which most of us would likely describe as "easy". "easy", this one is not...

None taken but when I say perspective I mean how often would you need to remove it completely for warranty work. The only time that you would really need to remove it is something catastrophic or major. In that event you could have it done in an afternoon. Even quicker if one just makes a quick disconnect for the one boost sensor wire.

 

[675430VME]

Perspective is needed. In the rare event you need warranty work comprehensive enough that the jb4 would be discovered, it can be removed in a few hours. To further simplify I made the intercooler sensor wire easy to remove from the JB4 without having to get to the sensor. Will only take me minutes.

No need, it will be discovered whether the unit is present or not if a serious warranty work is needed.

 

[Andy H]

I'm hoping that my the time my warranty expires in 2027, there will be an ECU unlock available. In the meantime, I'm in the too much hassle/risk for not enough gain camp.

I keep hearing mention of progress with the ECU here and there but still nothing concrete. I'm guessing the first ones will need to be done by the tuner but eventually perhaps we'll get a remote mapping solution.

 

[Lotus F1]

No need, it will be discovered whether the unit is present or not if a serious warranty work is needed.

Well according to Burger Motorsports and other similar units that is not the case. Due to its design and how it operates there is no way to know once removed