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.