Redline

[LotusRising]

The key issue for this age of engine is likely to be the temperature limits on the pistons, head and exhaust manifold, the more power you are producing the higher the component temperatures. If these limits are raised the next would be the inertial forces on the moving components, which increase with the square of the speed so they get higher quite quickly. It will also get to the valve train limits when the valve springs aren’t strong enough to overcome the increased valve inertia and the valves don’t

Exactly what I was looking for. I really appreciate your reply.

 

[Leonard]

I agree with most of that. But I’m also concerned about the comments from some reviewers who imply the throttle response profile means it’s rather too easy to hit the rev limiter before realising you need to upchange.

I’m sure it’s something you’ll get used to, but if it feels like it needs a bit more rev range it’s going to be distracting. It’s not the power I’m concerned about, it’s the driveability.

Definitely.
That was why I was upset with the minor drop. In a manual car I want to feel the bhp peak out, not have it so linear that I'd be better off having a DCT

 

[xen]

The key issue for this age of engine is likely to be the temperature limits on the pistons, head and exhaust manifold, the more power you are producing the higher the component temperatures. If these limits are raised the next would be the inertial forces on the moving components, which increase with the square of the speed so they get higher quite quickly. It will also get to the valve train limits when the valve springs aren’t strong enough to overcome the increased valve inertia and the valves don’t close.

My read is that there isn’t any additional engineering required. It should (as far as I understand it) be a straightforward copy of the Evora 430 map.

In regions where environmental restrictions aren’t as strict it should be an easy model to launch (and in addition a decent profit driver as it’s largely the same car with a software change and high-margin carbon bits).

 

[hagen111]

One of the consistent criticisms is that the engine cuts off quicker than competitor engines and you lose the drama of that last thousand RPMs. Can anyone enlighten me on why lotus couldn’t run it up higher with this power unit?

Its supercharged. The beauty of a mechanical charger is there's no gap, it builds pressure immediately and from low revs. The downside, it makes no sense revving it up high...to much pressure and mechanical stress on charger and engine.

I loved the engine in my Exige V6 for its low rpm grunt and how smooth it is, and in fact it makes a very very fast car on the road.

Its a great supercharged engine!

People who complain about the lack of high revs, have no clue about engine/car design.

With regards 'due to emissions' claim: my GT3 revs up to 9000 with homologated emissions.

 

[TRX250EX]

(Nearly) always higher revving cars praised as better drivers cars, for example S2000, Elise with Yamaha developed engine, Ferraris Porsches Lambos, LFA, even best drivers car Mustang was GT350 with Voodoo engine...........

But it's not always a higher RPM engine will give more excitement, for example I owned both GT3 and GT2RS, around 2000RPM difference between them but GT2RS had more drama and more character in it and less boring over time, GT3 sounds alot better on the outside definitely but inside GT2RS for me felt more special....... This is one of rare cases I would say..... Did I wish Lotus did high revving engine? Absolutely will pay alot more for that, there's a reason why C8 Z06 have so much hype it's all due to that high revving Flat plane V8, even GT Blackseries have flat plane V8 but was considered by many boring engine in character due to lack of racing high RPM feel and sound.......

Supercharged engine is not worth going very high RPM on, hence I wished Lotus will come up with a big upgrade to this V6 making it more racing like, but since it's their last gas car I understand it's not worth the development cost to do it...... I have higher hopes for AMG I4 in future more than I do for V6 despite picking V6

 

[xen]

Its supercharged. The beauty of a mechanical charger is there's no gap, it builds pressure immediately and from low revs. The downside, it makes no sense revving it up high...to much pressure and mechanical stress on charger and engine.

I loved the engine in my Exige V6 for its low rpm grunt and how smooth it is, and in fact it makes a very very fast car on the road.

Its a great supercharged engine!

People who complain about the lack of high revs, have no clue about engine/car design.

With regards 'due to emissions' claim: my GT3 revs up to 9000 with homologated emissions.

Very broad statement (having no clue) to make when it’s easy to demonstrate you’re wrong. Some of the best engines produced in the last decade by engineers certainly more in the know than you have been high revving - that’s not a coincidence.

That regardless the fundamental point you’re missing is this has already been done and exists. The Emira engine in a 430hp state of tune (and higher reviving) is objectively better, performance wise, than one in a 395hp state of tune. Same with one in a 410hp tune that revs higher.

 

[Leonard]

Very broad statement (having no clue) to make when it’s easy to demonstrate you’re wrong. Some of the best engines produced in the last decade by engineers certainly more in the know than you have been high revving - that’s not a coincidence.

That regardless the fundamental point you’re missing is this has already been done and exists. The Emira engine in a 430hp state of tune (and higher reviving) is objectively better, performance wise, than one in a 395hp state of tune. Same with one in a 410hp tune that revs higher.

Indeed. I have no doubt the 400 bhp 6800 redline engine will be great.
As you say the 430nis already out there and is universally agreed as being a better more exciting evolution of the older 400 map

 

[hagen111]

Very broad statement (having no clue) to make when it’s easy to demonstrate you’re wrong. Some of the best engines produced in the last decade by engineers certainly more in the know than you have been high revving - that’s not a coincidence.

That regardless the fundamental point you’re missing is this has already been done and exists. The Emira engine in a 430hp state of tune (and higher reviving) is objectively better, performance wise, than one in a 395hp state of tune. Same with one in a 410hp tune that revs higher.

To my 'knowledge'...

High revving is 8000-9000 rpm, e.g. like a 458 Ferrari, S2000, GT3. Mostly all - no turbo's and especially no superchargers.

Hp is a function of Torque/Force times revs. So if you rev it up a bit and make it breath a bit better you easily get to 410 and 430hp on the Emira/Lotus engine. But still these engines run 'low' revs and it doesn't change the insights at all.

Everything can be changed to proof your point and most likely many examples to proof I am wrong.

But ever since I finished my education as an automotive engineer I still am of the opinion that the inherit design of a supercharged (and turbocharged) engine is to squeeze more air into the engine at lower Revs and create a very usable midrange power band, instead of having to rely on the air velocity created by higher revs to get enough air/fuel mixture into the cylinders. In the case of a turbo, this helps greatly in the re-use of heath from the exhaust gasses, which has a hugely beneficial impact on the efficiency and emissions of a fuel engine


My few cents...

 

[Leonard]

To my 'knowledge'...

High revving is 8000-9000 rpm, e.g. like a 458 Ferrari, S2000, GT3. Mostly all - no turbo's and especially no superchargers.

Hp is a function of Torque/Force times revs. So if you rev it up a bit and make it breath a bit better you easily get to 410 and 430hp on the Emira/Lotus engine. But still these engines run 'low' revs and it doesn't change the insights at all.

Everything can be changed to proof your point and most likely many examples to proof I am wrong.

But ever since I finished my education as an automotive engineer I still am of the opinion that the inherit design of a supercharged (and turbocharged) engine is to squeeze more air into the engine at lower Revs and create a very usable midrange power band, instead of having to rely on the air velocity created by higher revs to get enough air/fuel mixture into the cylinders.

My few cents...

No that is all very true.
But you can still have that low down shove and top end if the engine is capable of it.
The Toyota block probably isn't if we are being honest. But we do know that it works in 430bhp 7200rpm guise quite nicely and personally I'd like to have it if its an option

 

[xen]

To my 'knowledge'...

High revving is 8000-9000 rpm, e.g. like a 458 Ferrari, S2000, GT3. Mostly all - no turbo's and especially no superchargers.

Hp is a function of Torque/Force times revs. So if you rev it up a bit and make it breath a bit better you easily get to 410 and 430hp on the Emira/Lotus engine. But still these engines run 'low' revs and it doesn't change the insights at all.

Everything can be changed to proof your point and most likely many examples to proof I am wrong.

But ever since I finished my education as an automotive engineer I still am of the opinion that the inherit design of a supercharged (and turbocharged) engine is to squeeze more air into the engine at lower Revs and create a very usable midrange power band, instead of having to rely on the air velocity created by higher revs to get enough air/fuel mixture into the cylinders. In the case of a turbo, this helps greatly in the re-use of heath from the exhaust gasses, which has a hugely beneficial impact on the efficiency and emissions of a fuel engine


My few cents...

Totally agree with you. Thing is we’re comparing the same engine. One map revs higher and produces more power. Wanting that out the gate or hoping for a version with that tune doesn’t qualify a person as clueless or having no clue.

 

[IanO]

My read is that there isn’t any additional engineering required. It should (as far as I understand it) be a straightforward copy of the Evora 430 map.

In regions where environmental restrictions aren’t as strict it should be an easy model to launch (and in addition a decent profit driver as it’s largely the same car with a software change and high-margin carbon bits).

Yes, to get back to the Evora max rpm is likely to be an emissions issue, to go above that to 7500, 8000 or 9000 rpm, which I think was the direction the original poster was looking for, then significant engineering is required.

For the 430 tune I don’t know which euro 5 markets lotus sells into and if the volumes support homologation costs.

I’m also not sure if it was ever offered in the US so I don’t know if the 430 would meet US emissions, hopefully some of the forum members would know.

 

[IanO]

With regards 'due to emissions' claim: my GT3 revs up to 9000 with homologated emissions.

Yes, it is definitely possible to meet the emissions with a high revving engine as Porsche and others have proved but the engine needs to be designed and developed to support this and at the time Toyota was working on the design of the V6 it is likely that Euro6d emissions had not even been defined.

The engine in the new Gordon Murray T50 revs to over 12,000rpm but I’m not sure that is affordable for Lotus to fit in the Emira

 

[TomAce]

Is there a diagram on the net where you can see maximum speeds in each gear for the Emira six-speed manual?

I'd like to know how fast you can go in second gear for example. I have been to the Dolomites last weekend and there a lots of slow hairpin curves where it really depends on the gearing. My M2 did a great job regarding this, second gear is short enough to have some fun and I didn't need first gear at all. That's different to the Porsche Boxster Spyder guys who had to downshift to first in order to get the engine at speeds where they deliver some power...

 

[RENDERMAN]

They can but didn't "due to emissions," or so we're told. They're just keeping the V6 redline at 6800 for now until a future GT or sportier version comes out and then they'll simply bump the redline to ~7200 and claim it has more power.

Pardon me sir, but how high can an electric motor rev?

 

[kitkat]

Is there a diagram on the net where you can see maximum speeds in each gear for the Emira six-speed manual?

I'd like to know how fast you can go in second gear for example. I have been to the Dolomites last weekend and there a lots of slow hairpin curves where it really depends on the gearing. My M2 did a great job regarding this, second gear is short enough to have some fun and I didn't need first gear at all. That's different to the Porsche Boxster Spyder guys who had to downshift to first in order to get the enigine at speeds where they deliver some power...

If the 6 speed mt gearbox is geared the same as the Evora GT:



EDIT: This graph is likely wrong as I can't find the final drive for the Evora GT

 

[TomE]

Should be the same as Evora GT gearbox and gearings. The supercharger gives you strong pull from 2000/2500rpm upwards and 2nd is good for over 60mph without bumping into the redline.

On alpine roads you should be OK in 2nd apart from the very tightest and steepest hairpins.

 

[kitkat]

Seems that the Emira 2nd gear is 6 mph off from the GT4’s infamously tall gearing.

 

[NicolasB]

If the 6 speed mt gearbox is geared the same as the Evora GT:

This doesn't seem correct. That looks more like a Cayman GTS chart. Thought 2nd was good for ~65mph?

 

[kitkat]

This doesn't seem correct. That looks more like a Cayman GTS chart. Thought 2nd was good for ~65mph?

You're right, I'm having a hard time finding the actual final drive, I think I used a wrong final drive.

 

[Eagle7]

If the Emira can do 180 mph as Lotus claims, they must have stretched out 5th and 6th to reach that speed at 6,800 rpm. It's going to be interesting to see what the actual gear ratios are when that information becomes available.