Posts of the Week

Hello Everyone;

After failing to buy an Emira three years ago due to delays, finally I was able to purchase a 2025 from the dealer lot. I got lucky that they had the color combination I wanted (Meridian Blue, Ice Gray interior), save for the wheels and calipers. I had sold my M3 CS few months back and had ordered an M2 CS. Received the allocation for it, and delivery was set for November. Then suddenly the strong driving enjoyment feelings I had test driving the Emira few years ago overtook my brain. As I read more and more of the postings here, I could not help myself and backed out of the M2 order, and purchased the Emira.

The car was delivered yesterday evening, and my first ~20 miles already put a huge grin on my face. I know I made the right decision. I am hoping to be a long-term participant on these forums.

Cheers!

Hey all - I've been a lurker on here for quite some time. I own a '98 RHD elise which is awesome and I've been highly considering an Emira for some months now. Last winter I ended up getting a 991.2 911 S instead of an Emira - which is a car that I absolutely LOVED. The 911 is insanely fast, fit and finish is unmatched and I really thought it was a long term fun car for me. The reality is that the first Cars and Coffee I rolled into with my 911 - I saw an Emira and immediately knew I'd be on the lookout to find one. After a couple months, I landed a Dark Verdant V6 Manual FE with 2k miles.

I didn't even test drive an Emira. I love lotuses and the reviews were enough for me - after my first drive yesterday, I was completely blown away. What I don't hear as much from reviewers is that this car is an absolute animal that BEGS for more through every corner. This car feels to drive the same way it looks. It truly is a drivers car and the chassis dynamics blow the 911 out of the water. The 911 is composed and extremely fast, the Emria feels a bit more feral and playful - exactly what I'm looking for.

Power wise - sizeable downgrade but I will tell you that the Emira has more than enough for street use! I'll miss the 911 on highway for sure, but it will more than make up for that on backroads.

Lastly - I fully wanted to upgrade the exhaust to go full titanium straight back(something like valvetronic perhaps), but after my first ride yesterday I am VERY unsure if I even want more or different sound. It sounds fantastic to me.

Here is a pic from when this car was for sale:

Got her wrapped in the GT4 color scheme! I was going to go with something more Nimbus Grey with highlights then I said, wth. Let's spice it up.

Hey guys, thought I'd put together a bit of a detailed look at how decreasing your pulley size will effect power and boost. Keep in mind this will also increase your MAT and overall temps.

I based this off of Merry Frankster evaluating Rotrex chargers over on MR2OC (so stealing a bit of his language).

I grabbed the below chart for the Eaton 1740 supercharger. Basically these charts give a description of the operational parameters of each supercharger. At any specific impeller RPM, the compressor is capable of producing a range of flowrate and pressure. This range is represented on the chart as the isocline for that RPM: 6k, 8k, 10k, 12k, 14k, 16k, 18k, and the service limit is rated at 20k RPM.


Do dive deeper we need to know the relation between these points and the engine's RPM
RPM (engine) = RPM (impeller) / ( P.D. (crank diameter) / S.C. (pulley diameter) )
The 2GR has a 142mm drive pulley (5.59055"). Since we're looking at SC pulley's in inches.

This brings us to the below numbers. Keep in mind everything above 7,200 engine RPM you NEED internal upgrades. Valve springs up to 7,600ish and rods above that. Another words, stock pulley is never going to reach 16,000 SC RPM, but it is possible with a 2.5" pulley on stock internals (temperature limiting, do so at your own risk).


The next step is to answer the question: How much air does the engine draw at any given RPM and boost level?
EDIT: Quick note, this is post is all calculated at sea level air pressures. Higher altitudes areas like Denver have thinner air and can safely go to smaller pulleys than running the same at sea level.

The mass of air drawn by a cylinder on its downstroke is:
Mass (air) = Density (air) x V(cylinder) x (Pressure ratio) x (Volumetric Efficiency)
Therefore the air drawn by the engine over time is 1/2 times this - (when talking about a four-stroke engine) - times the RPM.

Mass Flow Rate (air) = Air Density x Displacement x PR x VE X RPM / 2.

VE has been logged for estimates (seen below) but I'm using a 90% static number to simplify things.


From here we can map pressure ratio vs air flow for given RPMs. We overlay these for each RPM range to the supercharger efficiency chart.


We're looking for where each of these overlaps its correlated isocline. Given data above, we know that the stock 3.0" pulley takes an engine speed of 7,513 RPm to hit the 14,000 isocline. So 7,000 engine RPM comes in near the 13,000 SC RPM point. From here we follow it down to the mass air flow.


This roughly correlates to 1425 KG/hr of airflow. Convert to Lbs/Min and we get 52.36. As a general rule you can multiply this by 9.5-10.5x for maximum horsepower achievable. So lets use 10x.
This means the stock SC configuration generates enough airflow (hypothetically) for up to 524bhp. The dotted red cross lines indicate the SC's draw on the drivetrain. Our intersection is at the 32 kW draw line, which is roughly 42hp. Brining our hypothetical hp down to 482BHP (506BHP capacity if using 10.5x the Lbs/min airflow) Again these are general rules and not set in stone numbers.

Now, for the important part, how does changing pulley size effect max airflow, and resulting HP change. I repeated the process above for pulley size 3.0" (green) to 2.5" (Red) with 0.1" increments for the other colors. X over limits that are unsafe for stock internals.


From here we look at (roughly) where the airflow falls for each pulley size at 7,000 rpm.


So lets look at hypothetically dropping from a 3.0" (green) to a 2.7" (orange).
Mass Flow Rate (KG/hr) moves from 1425 to 1575ish, a 150 kh/hr increase (5.5116 lb/min) Using our HP 10x rule estimation, this is a 55hp gain.
The supercharger parasitic draw increases from 32kW to 44kW. (16hp draw)
Meaning our net increase in airflow minus parasitic draw is ~39 HP gained from the pulley change alone.

Now if you build the engine (or want to risk ruining yours) and shift max RPM up to 8,000 we can see this drastically increases flow, essentially shifting things to the right. The SC becomes less efficient and as can be seen by the kW isoclines (parasitic draw), so you do see diminishing returns between both RPM and increased boost, along with the fact you need to account for temperature and all your engine internals.


Hopefully JB4 / VF / Komotech, etc can work with smaller pulleys and we can see some moderate steps up in performance for some of you guys!

Thanks for attending my Ted Talk.

RA Forged Wheels

Fronts are 20x8.5 +43. Rears are 20x10.5 +36.

Mr. Wolfe said:

If they go with a hybrid system, I hope they go very light on the ICE. Not gonna lie, this news makes me a little nervous.

Mr. Wolfe

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An absolutely engaging conversation, the most impactful ever on the Emira.
Looking from the proverbial 50,000 ft. view:
- legacy Lotus leadership has been replaced by Geely (EV) loyalists
- 400 or more Hethel staff now have new free time
- Lotus financials are presently dismal, focusing developmental costs
- 2030 emissions regulations are triggering prepatory moves now
- a 2027 'whatever model' intro means 2028 deliveries
- the Emira was niche from get-go, will not see 10,000 units globally again
- a small-volume, expensive v8 push by an EV mfgr. seems implausible
- all prices going forward are headed north (see niche comment)
- Emira sales now are trending south, and a 180 turn unlikely
- hybrid is the (mass market) future one way or another
- are US market preferences the tail wagging the global dog?
- if you have an Emira love it, or get one soon. Choices are changing.
- those wanting rare exotic collectible status are getting their wish
- the new will be different, exclusive, rare for more money
- enjoy the moment (see US/Canada delivery thread trend chart)

"It will have the strong embedded Lotus DNA"

My guess is some form of water ingress.

Here's my brief personal take on this issue:

If a vendor spends years being rude and dismissive to people over email, they shouldn't be surprised when those same people stop giving them the benefit of the doubt when discussions come up in public forums. Americans in particular will go out of their way to "hit back" at someone who has been rude to them. That's why well-run American companies will simply never do it.

If you're going to run a company that sells globally, even an earnestly engineering-focused company, you need to be willing to do good customer service and support (including pre-sales support) as an ongoing commitment. Engineering merit is only one of the criteria for success, it doesn't earn the business on its own.

The vendors that are most consistently and vocally supported by individuals here on the forum (and on other platforms) are typically those who have given excellent customer service experiences, not necessarily those with the most extreme or perfect or well-marketed product lines.

Just my $0.02.

Rorie said:

Anyone know if there has been a shipment since July 15th? I think my VIN ends in 11187 and is coming to Canada. Thanks.

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30 cars arrived recently for the US but nothing for Canada. I will add the 30 cars in a couple of days.

Edit: the 30 cars that arrived on 8/20 has been added to the tracking sheet.

the knob has entered the chat