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

[Milk242]

I never got the chance to hear @675430VME car with the jb4 but I can attest that the Mach 5 downpipe paired with his (I think is a custom) SS exhaust sounds extremely good for an i4. So much so that I also bought the downpipe.

 

[Aforst]

That's great! 400 hp US version?
At crank, right? Thank's for sharing!

JB4 just arrived. Gonna mount it this week. Already installed the MACH5 GPF off, sports cat. It was a PITA to remove the original one..

400HP US version. Power figures are at the wheels. Hub dyno. Supposedly a stingy dyno that.

 

[675430VME]

Yeah! Even with just the Mach5 downpipe, the sound at full throttle is already amazing — aggressive and sharp! And the pops during gear shifts and deceleration are absolutely out of this world. I can only imagine how insane it would sound with an upgraded rear muffler too.. hehe :-D

If noise is not a concern for you, I would go for a well design SS straight pipe. Cheapest, lightest, and sounds really badass through out the whole rpm. Some of the new straight pipes come with modified valve control so NO CEL as well.

 

[675430VME]

400HP US version. Power figures are at the wheels. Hub dyno. Supposedly a stingy dyno that.

Stingy but more accurate

 

[675430VME]

Advice: Updated to firmware V3 Alpha, mobile app can no longer connect to the JB4 unit. Working with Burger to find a solution.

 

[ManuelB]

Advice: Updated to firmware V3 Alpha, mobile app can no longer connect to the JB4 unit. Working with Burger to find a solution.

Thanks for the feedback! Using JB4 PRO with the BT dongle installed at JB4?

 

[675430VME]

Thanks for the feedback! Using JB4 PRO with the BT dongle installed at JB4?

The regular JB4 app and BT. Has anyone been using V3 Alpha?

 

[1031ent]

If noise is not a concern for you, I would go for a well design SS straight pipe. Cheapest, lightest, and sounds really badass through out the whole rpm. Some of the new straight pipes come with modified valve control so NO CEL as well.

Which pipes come with the modified valve control?

 

[675430VME]

Which pipes come with the modified valve control?

You can do both as straight pipe or with muffler, either way you need a valve controller to bypass CEL.

 

[Andrew25]

Hey sorry for the beginner’s question but can fitting the JB4 threaten the health of the engine? I’m not planning anything crazy, no ethanol or something, just trying to compensate for those 40bhp that we in the EU were stolen.

 

[virtualmacho]

Hey sorry for the beginner’s question but can fitting the JB4 threaten the health of the engine? I’m not planning anything crazy, no ethanol or something, just trying to compensate for those 40bhp that we in the EU were stolen.

Anything that changes anything can potentially threaten the health of the engine. Not limited to adjustments in fuel trim and ignition timing, piggybacks will also introduce additional wiring, which means increased risk of melting wires or disconnecting couplers that can result in damage. Understanding how the unit fools the stock ECU, and taking care of the wiring (heat, abrasion, tension, etc.) should reduce the risks of damage, but will never bring it down to zero.
Most piggyback users consider these risks vs their own risk appetites to decide. I thought that the JB4 harness was reasonably protected, if kept away from hot surfaces. (The OBD2 cable is another story)