❔ QUESTION Mercedes-AMG M139

[Mh2000]

Does anybody know how Lotus will be detuning the I4 engine from 382 to 360 horsepower. Would be interesting to know for when the warranty runs out

 

[VL3X]

Does anybody know how Lotus will be detuning the I4 engine from 382 to 360 horsepower. Would be interesting to know for when the warranty runs out

Not sure what you mean by "how" but Lotus is obviously using a revised intake, exhaust, and tune. I expect there to be aftermarket reflashes available at some point to get it up to 500HP fairly easily... the engine can handle it, but heat management is always a concern with turbos and especially turbo mid-engine setups.

 

[ADC]

Something to keep in mind is that Lotus usually locks down their ECU, so probably going to require a piggyback tuning box, or a complete ECU swap (!!). I'm sure several tuning shops will be on the case once the i4 lands. Which will be Soon ™️

 

[lynchy73]

Does anybody know how Lotus will be detuning the I4 engine from 382 to 360 horsepower. Would be interesting to know for when the warranty runs out

The China I4 is listed at 480Nm and 400bhp. This suggests they are using the engine from the A45S (421bhp I believe), not the lower power setup from the A45. I would be shocked if they didn’t use the same I4 hardware Worldwide.

 

[ADC]

The China I4 is listed at 480Nm and 400bhp. This suggests they are using the engine from the A45S (421bhp I believe), not the lower power setup from the A45. I would be shocked if they didn’t use the same I4 hardware Worldwide.

The A45 and A45S run the same engine, just with different ECU maps. So yeah, it will be the same everywhere in terms of hardware, and the level of (de)tune is likely part emissions related, part not overshadowing the V6 on launch. Which is why is why the i4 is going to awesome 😁
As @VL3X said, the capacity of the cooling system is the thing to watch when attempting to dial it to 11.

 

[freefall_junkie]

I predict that Litchfield will crack the ECU and cooling issues and have a 450+ bhp i4 Emira running within 6 months of the first UK cars landing. Hugely tempting but for now I still want the V6. I expect Komotec will have upgrades for the V6 ready pretty quickly too as they have already done all the work on the Exige and Evora. I am thinking their 430 remap to open up the top end a little and raise the rev limit will be the sweet spot in price/performance for me.

 

[lynchy73]

The A45 and A45S run the same engine, just with different ECU maps. So yeah, it will be the same everywhere in terms of hardware, and the level of (de)tune is likely part emissions related, part not overshadowing the V6 on launch. Which is why is why the i4 is going to awesome 😁
As @VL3X said, the capacity of the cooling system is the thing to watch when attempting to dial it to 11.

I read an official document somewhere outlining the differences between A45 and A45S versions of the M139 (on this forum i believe). So far as i remember there are hardware differences (external/bolt on parts, not engine internals, I don’t recall exactly).

Here: https://www.9tro.com/media/cars/mercedes-amg-a45-cla45-twin-peaks?AspxAutoDetectCookieSupport=1 it mentions the following about some differences in the charge cooling:

"With a compression ratio upped from 8.6:1 to 9.0:1 and a 2.1 bar boost pressure the base version of the all-new M139 motor produces 387hp at 6,500rpm with 480Nm of torque from 4,750-5,000rpm on 1.9 bar of boost.

The S version makes a sensational 421hp at 6,750rpm with 500Nm of torque from 5,000-5,250rpm with 2.1 bar boost (M139 1.8 bar for base and S variants), achieved with a different ECU map as well as a larger, two-stage intercooler that works in conjunction with the low temperature circuit of the air-conditioning."

Anyway, regardless of whether the M139 comes with different hardware variants, if Lotus are willing to offer the I4 at 480Nm and 400bhp in some markets it bodes well for future upgrades from 360bhp to 400bhp at least (maybe Lotus approved).

 

[AlexB]

I predict that Litchfield will crack the ECU and cooling issues and have a 450+ bhp i4 Emira running within 6 months of the first UK cars landing. Hugely tempting but for now I still want the V6. I expect Komotec will have upgrades for the V6 ready pretty quickly too as they have already done all the work on the Exige and Evora. I am thinking their 430 remap to open up the top end a little and raise the rev limit will be the sweet spot in price/performance for me.

Yep - Litchfield do amazing R&D work so I have high hopes.

 

[Matt]

LOTUS said 2.0 for China will be 400HP, I am curious if LOTUS could achieve this number.

 

[ADC]

I read an official document somewhere outlining the differences between A45 and A45S versions of the M139 (on this forum i believe). So far as i remember there are hardware differences (external/bolt on parts, not engine internals, I don’t recall exactly).

Here: https://www.9tro.com/media/cars/mercedes-amg-a45-cla45-twin-peaks?AspxAutoDetectCookieSupport=1 it mentions the following about some differences in the charge cooling:

"With a compression ratio upped from 8.6:1 to 9.0:1 and a 2.1 bar boost pressure the base version of the all-new M139 motor produces 387hp at 6,500rpm with 480Nm of torque from 4,750-5,000rpm on 1.9 bar of boost.

The S version makes a sensational 421hp at 6,750rpm with 500Nm of torque from 5,000-5,250rpm with 2.1 bar boost (M139 1.8 bar for base and S variants), achieved with a different ECU map as well as a larger, two-stage intercooler that works in conjunction with the low temperature circuit of the air-conditioning."

Anyway, regardless of whether the M139 comes with different hardware variants, if Lotus are willing to offer the I4 at 480Nm and 400bhp in some markets it bodes well for future upgrades from 360bhp to 400bhp at least (maybe Lotus approved).

Yeah, fair enough, I was (not very clearly) trying to say that the engine itself is the same... I was ignoring the charge cooling and such because Emira is massively unlikely to share any of those with the A-series, for packaging reasons if nothing else.

I fully agree with your assessment of at least a 400 hp tune being a slam dunk, possibly via official channels at some later date.

 

[Stsainj]

It would be awesome if they could incorporate the new C63S E’s engine with mild hybrid and electric assist turbocharger!

 

[lynchy73]

It would be awesome if they could incorporate the new C63S E’s engine with mild hybrid and electric assist turbocharger!

The electric motors and batteries add a significant additional weight to the new C63, plus they need space, space that you likely don’t have in the Emira. The Electric turbo is maybe possible to package in an Emira, would add additional power and also reduce lag. However, I’d be happy with the elusive I4 Emira FE for now, or at least start seeing them in production and getting tested.