AMG Emira

[Snorkel]

What do you guys think about the ability to keep the engine cool in the back of the Emira? Lotus has of course a lot of experience with mid engine cars, but this power plant is also new to them. So, any thoughts about heat management of this turbo engine? 

[Nipper]

On 19/07/2021 at 17:54, dvq said:

I too have been trying to see if there are any physical differences between the M139 in the A45 and A45S and there aren't a whole lot of resources out there. Was trying to get P/Ns for parts in the head and couldn't find much. If there would be any major differences, it would likely be in the head or exhaust manifold. It's most likely just a difference in mappings.

I've been thinking about this too, there are significant differences between the C63 and E63 which both use the same engine. Mercedes use different pistons in the C63.

 

However, even 360hp out of a 4 pot will need to be beefed up for reliability so who knows. It's certainly a question I want an answer too. If the I4 is in any way a cheaper version of the full fat A45s version, then this car won't be for me. 

[TomE]

17 hours ago, Snorkel said:

What do you guys think about the ability to keep the engine cool in the back of the Emira? Lotus has of course a lot of experience with mid engine cars, but this power plant is also new to them. So, any thoughts about heat management of this turbo engine? 

Russell Carr said heat management was a key design challenge and I think they're well aware of the heat-related issues and limitations on Evora, particularly the constraints it placed on upgrading power.

There's some discussion elsewhere that this is why the bulkhead between cabin and engine bay has been moved forward to give more engine bay space at the expense of less rear cabin space compared to Evora.  The side scoops, whilst referencing the Evija design, are also much larger than the Evora ones.

[Snorkel]

Yes, I also saw the bigger side scoops + the shape of the bodywork seems to help suck the air right into the scoops. On YT, there is a video made by 'Lotus Malaysia' and one of the co-workers at GW explains how the wind flows through the splitter (you can also see the front radiator through the bumper) and leaves from the hood. Also, when they move to the rear of the car, it seems that the rear window has an opening on the underside. As the wind flows over the roof, it can enter the engine bay also from  there. But I certainly hope that's enough. That AMG turbo is going to create a lot of heat, so cooling will be key. I also read something about an electrical waterpump (more flow on high demand)... Maybe that's also not bad for keeping everything cool. But what about idling in traffic? I read some posts about the Evora where people mention the temperature gauge going up, but then the fan kicks in to keep it under control. Hopefully they get the job done with the AMG. 

[Evotion]

This one?

A Closed-Up of the Lotus Emira

Ha, my son and myself on the right talking to the Lotus guy - spooky 😊

They must have edited out the bit where I laid on the floor in front of the car with a thumbs up and a big grin.

 

[Snorkel]

Yep, that's the one 😃

[Porter]

Very interesting screenshot from the A New Dawn documentary. Looks like an M139 in testing in an Evora test mule. The positioning and exhaust design are particularly interesting.

 

See this cutaway model for reference - looks like Lotus are using a close-coupled catalytic just after the turbo hot side exit, similar to the A45. 

[Evotion]

For those of us, who are un-technical, like me, what does that mean for the engine and flow?

Is this to keep heat down to a minimum?

[Porter]

It's for emissions. A closely coupled catalytic converter heats up more quickly on cold start than one that's further down the pipe. Some manufacturers were even doing pre-turbo catalytic converters for a while in the mid-2000s in an attempt to improve cold-start emissions. Placing the catalytic converter after the turbo is always better for spool-up of the turbine though, and thankfully most manufacturers have now standardized on engine packaging and exhaust routing that places the turbo (or turbos) as close to the exhaust ports as possible. That's the reason for the "Hot V" architecture of many recent V6 and V8 designs.

[snowrx]

Can Lotus slap a fan on the flange next to the catalyst outlet for some active aero? 😁

 

[Snorkel]

Is it just me or is this a very sexy engine? I find it very attractive. 😃

[mg4lotus]

It's the peek-a-boo bits that are probably doing it for you.

Just out of interest, does it have a cam belt or a cam chain?

[Evotion]

2 hours ago, Snorkel said:

Is it just me or is this a very sexy engine? I find it very attractive. 😃

Just you.   You need help 😃

 

[Stands Up]

Hi, I am Snorkel and I am an Engine Addict

[Everyone]

Hi, Snorkel.

[Snorkel]

Hmm... If it's just me, why is there a whole crowd that says: "Hi, Snorkel"?? 😂

This sounds more like a lot of other people with the same problem... unless they've put me in the "cargo bike group". 🤔

[Evotion]

It was a general special needs group 😄

I do kinda get it. Not with engines but cars like my old Integrale, F-Types in the right colour, classic Ferraris...  they transcend the normal.

I saw an Alfa Stradale once....    that can make you weep with joy.

[Porter]

5 hours ago, mg4lotus said:

Just out of interest, does it have a cam belt or a cam chain?

It's chain-driven. Interestingly, the timing chain drives a cog which drives the input gearing on each cam.

 

The input gearing on each cam timing control assembly is also directly geared to the one on the other cam, so there is always a physical reference keeping the cams tightly in sync with one another. This is in contrast to systems that are only driven by the chain per cam, which then has the dual job of both driving the input gear and establishing the per-cam timing reference. In addition to preventing the cams from ever being out of time with each other, this AMG system should have less variable force on the timing chain per engine cycle and I expect would have a far longer service life for the chain.

Edited July 27, 2021 by Porter

[Frickin_idiot]

On 26/07/2021 at 20:31, Porter said:

Very interesting screenshot from the A New Dawn documentary. Looks like an M139 in testing in an Evora test mule. The positioning and exhaust design are particularly interesting.

 

See this cutaway model for reference - looks like Lotus are using a close-coupled catalytic just after the turbo hot side exit, similar to the A45. 

Nice spot

[DanR]

That engine is set-up for AWD. Wonder if Lotus has plans for an AWD Emira?

[Bravo73]

Highly, highly unlikely. (ie no!)

[Evotion]

10 hours ago, DanR said:

That engine is set-up for AWD. Wonder if Lotus has plans for an AWD Emira?

Nah. Too much weight, too expensive to change everything, and maybe not even enough time now.

Their future EVs might...

[KusaKusa]

Now that I think about it, I can't recall any application of the M139 engine that's not AWD. Any cases where it's used only FWD? Maybe those models can bring us closer to an actual horsepower number.

[Porter]

22 hours ago, KusaKusa said:

Now that I think about it, I can't recall any application of the M139 engine that's not AWD. Any cases where it's used only FWD? Maybe those models can bring us closer to an actual horsepower number.

I suspect the quoted figures have been crank output, not wheel HP. 

I'm also interested to see how the 2WD DCT does in the real world. That's a lot less driveline lash to cope with compared to AWD, so it would likely have different shift logic than the AWD application.

[Likuid]

The AMG throws a real kink in my plans. I wanted to get a manual Emira, but if the AMG will eventually exceed the V6 in power and completely replace it (which sounds like is the plan someday) I am not sure what to do. If I am losing the manual then I would rather it be DCT than torque converter, but at the same time the sound of the V6 and having one of the last manual production cars that may ever be made is appealing.

Edited July 29, 2021 by Likuid

[Evotion]

My recommendation for everyone a bit unsure is to buy the V6.

Own it for 2 years, hopefully not even lose much on it due to rarity and desire, and then get what will then be, by then, a new powerful AMG DCT 4-cyl.

Makes sense to me.

[Nass]

@Evotion Where I am and the market I am in , that will be a 30-35% depreciation hit if lucky (can be a 40-45% hit if unlucky) as the brand is unkown and the dealership changed owners a number of times during its history in the country. keep in mind that these numbers are with the "premium" charged for the first edition cars, almost 0% chance to get it at MSRP.

but believe me if they do the same thing they did with the Evora 400 and charge 95,000 GBP for it, it will drive reasonable people to other marque and barely have any sales (which is what happened) and the cycle will repeat again.

your scenario is the dream scenario but will lotus be able to implement that their dealerships (private business) to sell at MSRP and not gouge them out of the competition? that is the real question. because once you start hiting that 75k+ range a lot of competition starts to enter the equation.

Edited July 31, 2021 by Nass