Emira I4 ECU Flash Tuning is Now Possible (~510HP Turbo)

US region I4 (I don't know about others) alternator won't regularly charge a lithium battery due to emissions until it gets very very low on voltage (even then I don't know if the alternator will kick in). Just keep on battery tender everything will be fine, or drive car every day. Might be a regional ECU thing too...I had to switch back to AGM that does trigger the alternator since it runs lower voltage like the car is programmed to see. Weird stuff from AMG.
My battery has a Bluetooth app, so I will keep an eye on things and monitor what’s happening. I can top it up if necessary, but am quite curious to see if it’s charging during normal driving after hearing about these reported issues with Lithium batteries on the I4.

My battery is 60Ah, so it’s got plenty of capacity and should fair better than a smaller capacity unit.
 
Was he running it on an Emira I4/V6?

I was having some low voltage related issues on my Emira (all kinds of errors, that didn’t seem to reappear after I had kept the AGM battery fully charged with a trickle charger). So I thought I’d give this a try. It’s 60Ah, so plenty of capacity, it was cheap and a direct drop in replacement.

I’ve been running a small 20Ah version on my bike engined track car for a few months already. So far all good, and it out performs the SLA battery it replaced. Much stronger cranking and it’s never run low on charge (unlike the old SLA which was struggling). Weighs less than half the weight of the SLA too.

This battery has an app, can be powered on/off via the app and will turn itself off if the charge falls below a certain percentage. Can monitor battery temperature and charge percentage.
It's an i4. I have an i4 as well. Also, it's Kaz and he chimed in. Keep us posted. As he mentioned, his car was getting all kinds of errors related to low voltage. Also, he did confirm the weird AMG specific charging cycles at least for US cars. I do drive my car regularly. So, I'm curious to see if this works for you. I've run these batteries in all my cars. So, I was bummed when I heard about this AMG specific issue from Kaz.

To be clear, this is a NON-ISSUE on v6's.
 
I have compared the logs on both my stage 1 and JB4 Map4. JB4 will only achieve 2.2 or sometimes 2.3 at the very peak of the rpm whereas my stage 1 hits 2.4 as soon as 3000 rpm. That mid range feels day and night difference comparing to the JB4.

What's the status on your end for chip tuning? @Kaz
an Emira owner friend waiting for his spare stock ECU, once it comes things should move faster
 
Maybe by the time I actually get past my break in period, we will have map switch lol
 

Attachments

  • IMG_20251021_170119.webp
    IMG_20251021_170119.webp
    85.8 KB · Views: 43
Expecting 0-100 / 100-200 results from 500hp Emira, must be exciting!
 
Was he running it on an Emira I4/V6?

I was having some low voltage related issues on my Emira (all kinds of errors, that didn’t seem to reappear after I had kept the AGM battery fully charged with a trickle charger). So I thought I’d give this a try. It’s 60Ah, so plenty of capacity, it was cheap and a direct drop in replacement.

I’ve been running a small 20Ah version on my bike engined track car for a few months already. So far all good, and it out performs the SLA battery it replaced. Much stronger cranking and it’s never run low on charge (unlike the old SLA which was struggling). Weighs less than half the weight of the SLA too.

This battery has an app, can be powered on/off via the app and will turn itself off if the charge falls below a certain percentage. Can monitor battery temperature and charge percentage.
What's the brand of battery you went for and where did you get it from please
 
What's the brand of battery you went for and where did you get it from please
The battery is branded TET Lithium. I bought it locally in China. However, the charging from the alternator is not working well. I’m keeping an eye on it to try to understand what’s happening (there is a Bluetooth app so I can see the charge/discharge current and voltages when I’m driving) and see if there is anything that can be done to improve matters.
A lithium battery should work in an I4, but it would be best you regularly put it on a charger.
 
My Parts Manager finally received my new virgin OEM ECU spare from Lotus UK mothership… already shipped to tuner in Oklahoma to be read without/before car specific programming and then will sent back to marry and program to my car at local Lotus Service.

Tuner already has the 2019+ MG1CP002 ECU I sourced from ECU Store. Will post updates for people interested in this adventure in a separate post. Plan to transport my car to Oklahoma for Dimsport dyno and road testing since colder weather coming anyway.

So shiny!

IMG_1519.webp


IMG_1518.webp


IMG_1520.webp
 
The battery is branded TET Lithium. I bought it locally in China. However, the charging from the alternator is not working well. I’m keeping an eye on it to try to understand what’s happening (there is a Bluetooth app so I can see the charge/discharge current and voltages when I’m driving) and see if there is anything that can be done to improve matters.
A lithium battery should work in an I4, but it would be best you regularly put it on a charger.
This is off topic but many posts you can find, basically the I4 Mercedes alternator will not properly charge a lithium battery because the voltage is too high for it to trigger the alternator logic, it is looking for low AGM voltage. It won't even charge the stock AGM battery till it dips below 70% to save on emissions - really stupid. I got a Braille AGM works great
 
The battery is branded TET Lithium. I bought it locally in China. However, the charging from the alternator is not working well. I’m keeping an eye on it to try to understand what’s happening (there is a Bluetooth app so I can see the charge/discharge current and voltages when I’m driving) and see if there is anything that can be done to improve matters.
A lithium battery should work in an I4, but it would be best you regularly put it on a charger.
Have a chat with @Kaz. He shared in one of his posts how the i4 alternator has some weird charging cycle for fuel efficiency reasons. Essentially, it was partially designed to work with the M139 hybrid version of our engine and only charges at cold start-up, in track mode and on decal/braking if I recall correctly. The whole thing was like too crazy to believe, but it does seem to be the case. That's why he got rid of his AntiGravity battery. I was bummed, because i've run this battery in all my cars, except this one for this reason. Oh, and you are correct. As long as you put the battery on a tender every night, you'll be fine.
 
My Parts Manager finally received my new virgin OEM ECU spare from Lotus UK mothership… already shipped to tuner in Oklahoma to be read without/before car specific programming and then will sent back to marry and program to my car at local Lotus Service.

Tuner already has the 2019+ MG1CP002 ECU I sourced from ECU Store. Will post updates for people interested in this adventure in a separate post. Plan to transport my car to Oklahoma for Dimsport dyno and road testing since colder weather coming anyway.

So shiny!

View attachment 72268

View attachment 72269

View attachment 72270
that is the sexiest piece of metal I have seen in a long time...incredible how this small metal object can unlock so much happiness and joy in our lives (!!)
 
Have a chat with @Kaz. He shared in one of his posts how the i4 alternator has some weird charging cycle for fuel efficiency reasons. Essentially, it was partially designed to work with the M139 hybrid version of our engine and only charges at cold start-up, in track mode and on decal/braking if I recall correctly. The whole thing was like too crazy to believe, but it does seem to be the case. That's why he got rid of his AntiGravity battery. I was bummed, because i've run this battery in all my cars, except this one for this reason. Oh, and you are correct. As long as you put the battery on a tender every night, you'll be fine.
So basically any lithium battery will not work on the Emira correct?
 
So basically any lithium battery will not work on the Emira correct?
They will work just put on tender, but it won't work like standard battery that recharges when you drive, it will always be on the bare limit of having charge and cause some CEL eventually - but for a track car just keep it plugged in all fine. And yes any lithium since they are higher voltage and that is what causes issues.
 
They will work just put on tender, but it won't work like standard battery that recharges when you drive, it will always be on the bare limit of having charge and cause some CEL eventually - but for a track car just keep it plugged in all fine. And yes any lithium since they are higher voltage and that is what causes issues.
Thx for the heads up!
 

Create an account or login to comment

Join now to leave a comment enjoy browsing the site ad-free!

Create account

Create an account on our community. It's easy!

Log in

Already have an account? Log in here.

Back
Top