2876 replies to this topic

[Jvr]

It sounds to me like it's mostly software and cooling.  Lotus have been saying how conservative they've been with extra cooling provision, and Renault can keep coding up to the last minute, so I'm expecting it to come together in time, for Lotus at least.  Okay, for Grosjean.  Marussia too, who knows, they were quite good on reliability last year.

Marussia is using Ferrari engines this year so they are immune to Renault related problems.

[maverick69]

I wish I hadn't checked to see if anyone had done that.

 

Ideal!

 

Now I know what to buy the mother-in-law!

 

 

[oetzi]

 

I wish I hadn't checked to see if anyone had done that.

 

Ideal!

 

Now I know what to buy the mother-in-law!

 

 

 

http://www.lazyboneu...wel-Holder.html

 

[enotsne]

For those interested. Here are some of the changes Renault have made since Jerez.

Change of battery cell provider. The individual cells that make up the Energy Store have individual over-charge and over-discharge protection. These were proving unreliable due to thermal/vibration issues. Whilst the energy store is sealed in our fitment, I am informed the cells are now supplied by Panasonic.

Change to MGU-K to Crank drive gearing. The original torque multiplication factor was calculated to give a wider spread of torque on acceleration. Track testing found that this was causing traction dificulties and overloading the gearset and causing failure of the crank casing.

Change to turbocharger wastegate function. Renault had originally intended for the H to regulate Turbine speed in 95%+ of normal running. They facilitated this by allowing the H to pull charge (when the energy store was at capacity) to an air cooled heat sink. This strategy proved ineffective in certain environments and a more coventional wastegate is now being used to supplement the H.

Due to both the change in K gear ratio, boost control strategy and the energy store, most of the software relating to the charge and discharge cycling has been modified daily and continues to be refined. There are still issues relating to turbine speed control via H but these are mostly to do with fine tuning of the control software and the syncronisation between H control and wastegate control.

There has been swift progress and software related driveability now appears to be the main issue.

Edited by enotsne, 26 February 2014 - 07:22.

[FirstWatt]

For those interested. Here are some of the changes Renault have made since Jerez.

[...]

 

This is the best post in the whole thread. Such things cannot come from hearsay, you must be an insider.

Thank you for that.

 

Veeeery interesting that Renault originally has chosen to dump MGU-H energy into heat as soon as the ES is full (to control boost), albeit I'm at a loss why they are not able to balance MGU-K and MGU-H at any torque demand (i.e. dumping MGU-H into MGU-K, which is unlimited).

Energy dumped into resistors or with a waste gate is lost energy at the end. 

 

Also, the other things are totally logical explanations about what has been rumored.

 

Yes, now it boils down to software programming, and that hasn't to be freezed by end of February AFAIK.

 

Not that it's an easy task, I still believe F1 becomes a software/algorithm/simulation contest now.

Edited by FirstWatt, 26 February 2014 - 07:46.

[RoutariEnjinu]

For those interested. Here are some of the changes Renault have made since Jerez.

[...]

If this is true, this is exactly the best kind of insider info. The issues put like this, along with their responses to problems actually make me think more highly of Renault that I did before.

This seems plausible, and in giving you the benefit of the doubt, thanks. Hope you sort it all out soon.

The only bit I don't understand is it sounds like you were dumping excess electrical energy from the H to some sort of resistor pack heatsink, when I though H to K transfer was unlimited?

Edited by RoutariEnjinu, 26 February 2014 - 08:06.

[toofast]

Nice name.

[ollebompa]

For those interested. Here are some of the changes Renault have made since Jerez.

Change of battery cell provider. The individual cells that make up the Energy Store have individual over-charge and over-discharge protection. These were proving unreliable due to thermal/vibration issues. Whilst the energy store is sealed in our fitment, I am informed the cells are now supplied by Panasonic.

Change to MGU-K to Crank drive gearing. The original torque multiplication factor was calculated to give a wider spread of torque on acceleration. Track testing found that this was causing traction dificulties and overloading the gearset and causing failure of the crank casing.

Change to turbocharger wastegate function. Renault had originally intended for the H to regulate Turbine speed in 95%+ of normal running. They facilitated this by allowing the H to pull charge (when the energy store was at capacity) to an air cooled heat sink. This strategy proved ineffective in certain environments and a more coventional wastegate is now being used to supplement the H.

Due to both the change in K gear ratio, boost control strategy and the energy store, most of the software relating to the charge and discharge cycling has been modified daily and continues to be refined. There are still issues relating to turbine speed control via H but these are mostly to do with fine tuning of the control software and the syncronisation between H control and wastegate control.

There has been swift progress and software related driveability now appears to be the main issue.

A few questions if you have time and is allowed to answer.

What was the reason for trying the heatsink?Could not that energy be directly transfer to the MGH-K to some benefit?

Was the original gearing ratio more benificial had it worked or just a miscalculation? Or was the mistake in the crankcasing design?

Would greatly appreciate a answer

Edited by ollebompa, 26 February 2014 - 08:23.

[ollebompa]

Double post

Edited by ollebompa, 26 February 2014 - 08:21.

[Rinehart]

For those interested. Here are some of the changes Renault have made since Jerez.

Change of battery cell provider. The individual cells that make up the Energy Store have individual over-charge and over-discharge protection. These were proving unreliable due to thermal/vibration issues. Whilst the energy store is sealed in our fitment, I am informed the cells are now supplied by Panasonic.

Change to MGU-K to Crank drive gearing. The original torque multiplication factor was calculated to give a wider spread of torque on acceleration. Track testing found that this was causing traction dificulties and overloading the gearset and causing failure of the crank casing.

Change to turbocharger wastegate function. Renault had originally intended for the H to regulate Turbine speed in 95%+ of normal running. They facilitated this by allowing the H to pull charge (when the energy store was at capacity) to an air cooled heat sink. This strategy proved ineffective in certain environments and a more coventional wastegate is now being used to supplement the H.

Due to both the change in K gear ratio, boost control strategy and the energy store, most of the software relating to the charge and discharge cycling has been modified daily and continues to be refined. There are still issues relating to turbine speed control via H but these are mostly to do with fine tuning of the control software and the syncronisation between H control and wastegate control.

There has been swift progress and software related driveability now appears to be the main issue.

This is how you do an insider post. 

[jcbc3]

Which as all fine and good.

 

But I am also pretty certain that Renault and it's customers WILL call it 'catastrophic' if they are giving away just 5 or 10% to the other engines.

[undersquare]

Marussia is using Ferrari engines this year so they are immune to Renault related problems.

 

Ooops quite right.  Just a team I'm hoping things will come together for.

Edited by undersquare, 26 February 2014 - 09:09.

[oetzi]

Change to turbocharger wastegate function. Renault had originally intended for the H to regulate Turbine speed in 95%+ of normal running. They facilitated this by allowing the H to pull charge (when the energy store was at capacity) to an air cooled heat sink. This strategy proved ineffective in certain environments and a more coventional wastegate is now being used to supplement the H.
 

Will the inclusion of a more conventional wastegate cause any packaging issues for Renault supplied teams?

[Shiroo]

Nice name.

 

exactly my thought, though I accidentaly read it as enstone at first   such faux pas

Edited by Shiroo, 26 February 2014 - 08:48.

[enotsne]

Re the H to K transfer.
There are times when you can't (or wouldn't want to) transfer power from the H to the K but still need to limit turbo speed.

Think along the lines of a short burst of accel then slight decel then accel (such as feathering throttle for traction or in a switch back). The last thing the driver would want is for the K to feed power into driveline.

During those transitional situations Renault wanted to control the speed of the turbo by using the H to maintain shaft speed at or close to max rpm. It turned out (partly because of the driveability issues) that H was dumping to the heatsink far more than had been predicted or modeled. This was causing severe heat related issues in some cars at Jerez and the Renault 'patch' was to disable the H entirely and rely on the mechanical wastegate for the remainder of the test.

Obviously this resulted in dramatically increased lag and reduced performance but allowed some mileage to be put on the ICE.

In the interests of transparency it should be disclsclosed that we have had no first hand experience with the original spec PU used in Jerez.

Our running experience started with a version that had basic H functioning and limited K output.

Edited by enotsne, 26 February 2014 - 08:54.

[Markn93]

Great stuff.  A thousand 'thank you's for your contribution. 

[RoutariEnjinu]

Re the H to K transfer.
There are times when you can't (or wouldn't want to) transfer power from the H to the K but still need to limit turbo speed.

Think along the lines of a short burst of accel then slight decel then accel (such as feathering throttle for traction or in a switch back). The last thing the driver would want is for the K to feed power into driveline.

This makes sense.

I hope this way of communication is the future of getting information out to the fans, instead of to hungry journalists out to make names for themselves and spin the most shocking headline possible.

I'm going to assume you're genuine and wish you all the best. It sounds like Renault have done enough in time for homologation, and I suppose power speed and driveability will be unlocked as the mappings for all these different electronic systems become more refined.

[Shiroo]

Re the H to K transfer.
There are times when you can't (or wouldn't want to) transfer power from the H to the K but still need to limit turbo speed.

Think along the lines of a short burst of accel then slight decel then accel (such as feathering throttle for traction or in a switch back). The last thing the driver would want is for the K to feed power into driveline.

During those transitional situations Renault wanted to control the speed of the turbo by using the H to maintain shaft speed at or close to max rpm. It turned out (partly because of the driveability issues) that H was dumping to the heatsink far more than had been predicted or modeled. This was causing severe heat related issues in some cars at Jerez and the Renault 'patch' was to disable the H entirely and rely on the mechanical wastegate for the remainder of the test.

Obviously this resulted in dramatically increased lag and reduced performance but allowed some mileage to be put on the ICE.

In the interests of transparency it should be disclsclosed that we have had no first hand experience with the original spec PU used in Jerez.

Our running experience started with a version that had basic H functioning and limited K output.

 

great post, 2 great posts out of 2 posted in general

 

I wish good luck to my favourite team then 

Edited by Shiroo, 26 February 2014 - 08:59.

[bonjon1979a]

Wow , really great posts. Refreshing detail. Sounds like they've been busy

[undersquare]

@enotsne:  way to build a fanbase     

[ollebompa]

Re the H to K transfer.
There are times when you can't (or wouldn't want to) transfer power from the H to the K but still need to limit turbo speed.

Think along the lines of a short burst of accel then slight decel then accel (such as feathering throttle for traction or in a switch back). The last thing the driver would want is for the K to feed power into driveline.

During those transitional situations Renault wanted to control the speed of the turbo by using the H to maintain shaft speed at or close to max rpm. It turned out (partly because of the driveability issues) that H was dumping to the heatsink far more than had been predicted or modeled. This was causing severe heat related issues in some cars at Jerez and the Renault 'patch' was to disable the H entirely and rely on the mechanical wastegate for the remainder of the test.

Obviously this resulted in dramatically increased lag and reduced performance but allowed some mileage to be put on the ICE.

In the interests of transparency it should be disclsclosed that we have had no first hand experience with the original spec PU used in Jerez.

Our running experience started with a version that had basic H functioning and limited K output.

Great answer! Thanks!

Edited by ollebompa, 26 February 2014 - 09:17.

[undersquare]

So are the issues alluded to when using ERS not a big thing? Just software? Not structural?

 

Sorry to ask so directly, but you seem quite sure 

 

Sounds like it's just (mainly) installation if Lotus can fix it?

I didn't mean to sound sure at all sorry, hence 'it sounds to me like', it was just bits and pieces I've picked up is all.  Anyway enotsne has made my amateur speculation obsolete - change to Panasonic cells and the rest.  Lotus were talking about the extra cooling they've built in, so I think they'll benefit the most as it comes together.  Newey I predict will be his awesome stubborn self and keep prioritising aero so the PU will keep struggling.  Can't wait so see what happens tomorrow....

[RB1]

This is the best post in the whole thread. Such things cannot come from hearsay, you must be an insider.

Thank you for that.

 

Veeeery interesting that Renault originally has chosen to dump MGU-H energy into heat as soon as the ES is full (to control boost), albeit I'm at a loss why they are not able to balance MGU-K and MGU-H at any torque demand (i.e. dumping MGU-H into MGU-K, which is unlimited).

Energy dumped into resistors or with a waste gate is lost energy at the end. 

 

Also, the other things are totally logical explanations about what has been rumored.

 

Yes, now it boils down to software programming, and that hasn't to be freezed by end of February AFAIK.

 

Not that it's an easy task, I still believe F1 becomes a software/algorithm/simulation contest now.

 

I was wondering if the software was includes in the FIA's homologation.

 

Will they all still be fine-tuning their PU control systems throughout the year, maybe optimising for each race? or will it be fixed at some point?

[oetzi]

I didn't mean to sound sure at all sorry, hence 'it sounds to me like', it was just bits and pieces I've picked up is all.  Anyway enotsne has made my amateur speculation obsolete - change to Panasonic cells and the rest.  Lotus were talking about the extra cooling they've built in, so I think they'll benefit the most as it comes together.  Newey I predict will be his awesome stubborn self and keep prioritising aero so the PU will keep struggling.  Can't wait so see what happens tomorrow....

Cheers. Agree about tomorrow, will be fascinating to see who can do what with the Renault. As for Newey, I know he has a history of extreme stubbornness, but he'll have to compromise if the car's still catching fire. Won't he?

[RoutariEnjinu]

I was wondering if the software was includes in the FIA's homologation.

It shouldn't be really. With restricted testing it requires nothing more than data analysis and a keyboard, and it's not like you can throw a thousand developers in the same file at the same time and stamp out the problem through brute force, as there needs to be continuity and coherence. It's an intellectual pursuit, more than it is a resource one.

If you can afford to make carbon fiber monocoques, and drive a fleet of lorries and motorhomes about, you can afford the best software engineers. This is assuming its the teams responsibility. If it's Renaults then aren't they allowed to dyno their engines indefinitely?

Edited by RoutariEnjinu, 26 February 2014 - 09:43.

[Newbrray]

For those interested. Here are some of the changes Renault have made since Jerez.

Change of battery cell provider. The individual cells that make up the Energy Store have individual over-charge and over-discharge protection. These were proving unreliable due to thermal/vibration issues. Whilst the energy store is sealed in our fitment, I am informed the cells are now supplied by Panasonic.

Change to MGU-K to Crank drive gearing. The original torque multiplication factor was calculated to give a wider spread of torque on acceleration. Track testing found that this was causing traction dificulties and overloading the gearset and causing failure of the crank casing.

Change to turbocharger wastegate function. Renault had originally intended for the H to regulate Turbine speed in 95%+ of normal running. They facilitated this by allowing the H to pull charge (when the energy store was at capacity) to an air cooled heat sink. This strategy proved ineffective in certain environments and a more coventional wastegate is now being used to supplement the H.

Due to both the change in K gear ratio, boost control strategy and the energy store, most of the software relating to the charge and discharge cycling has been modified daily and continues to be refined. There are still issues relating to turbine speed control via H but these are mostly to do with fine tuning of the control software and the syncronisation between H control and wastegate control.

There has been swift progress and software related driveability now appears to be the main issue.

 

 

What an introduction !!!

Now thats the way to make an entrance. (Madonna, Obama, Lady Gaga ....eat your heart out)

 

great opening post and thanks for the info.

[F.M.]

Re the H to K transfer.
There are times when you can't (or wouldn't want to) transfer power from the H to the K but still need to limit turbo speed.

Think along the lines of a short burst of accel then slight decel then accel (such as feathering throttle for traction or in a switch back). The last thing the driver would want is for the K to feed power into driveline.

During those transitional situations Renault wanted to control the speed of the turbo by using the H to maintain shaft speed at or close to max rpm. It turned out (partly because of the driveability issues) that H was dumping to the heatsink far more than had been predicted or modeled. This was causing severe heat related issues in some cars at Jerez and the Renault 'patch' was to disable the H entirely and rely on the mechanical wastegate for the remainder of the test.

Obviously this resulted in dramatically increased lag and reduced performance but allowed some mileage to be put on the ICE.

In the interests of transparency it should be disclsclosed that we have had no first hand experience with the original spec PU used in Jerez.

Our running experience started with a version that had basic H functioning and limited K output.

I take it you/your info comes from Enstone

[undersquare]

Cheers. Agree about tomorrow, will be fascinating to see who can do what with the Renault. As for Newey, I know he has a history of extreme stubbornness, but he'll have to compromise if the car's still catching fire. Won't he?

Yeah Newey will have to compromise won't he, I just suspect it will be one small reluctant step at a time.  Newey got away with under-cooling kers, but this time ERS is too big a part of it, one would think, yet he seems to have done it again.

[Jvr]

Re the H to K transfer.
There are times when you can't (or wouldn't want to) transfer power from the H to the K but still need to limit turbo speed.
Think along the lines of a short burst of accel then slight decel then accel (such as feathering throttle for traction or in a switch back). The last thing the driver would want is for the K to feed power into driveline.
During those transitional situations Renault wanted to control the speed of the turbo by using the H to maintain shaft speed at or close to max rpm. It turned out (partly because of the driveability issues) that H was dumping to the heatsink far more than had been predicted or modeled. This was causing severe heat related issues in some cars at Jerez and the Renault 'patch' was to disable the H entirely and rely on the mechanical wastegate for the remainder of the test.
Obviously this resulted in dramatically increased lag and reduced performance but allowed some mileage to be put on the ICE.
In the interests of transparency it should be disclsclosed that we have had no first hand experience with the original spec PU used in Jerez.
Our running experience started with a version that had basic H functioning and limited K output.

Thak you for your insights, sounds like good progress has been made. I'd be interested to hear if limiting K operating window from the originally intended one reduces the expected max power output? Electrical engines are known to provide a rather flat torque range but I assume limiting the revs from the top end could also lead to reduced max power output from 160kW.

[oetzi]

Yeah Newey will have to compromise won't he, I just suspect it will be one small reluctant step at a time.  Newey got away with under-cooling kers, but this time ERS is too big a part of it, one would think, yet he seems to have done it again.

I think you may be right.

[Neophiliac]

Really good inside info. Let's see how R-teams get on in Bahrain-2. It seems to me that reports of Renault's imminent demise were at least somewhat exaggerated, even if the problems were quite catastrophic back in Jerez. Now I am thinking that there will be a raceable-ish engine in the back of the four affected teams come Melbourne, but key questions still remain unanswered:
- will it be anything like competitive with Merc/Ferrari unit in terms of output
- how is consumption? Will they be able to finish races without dropping 5 sec off the pace?
- reliability, reliability, reliability. Particularly a concern for Red Bull. Even as new components appear to have enabled running during tests, they have not been stressed enough to show whether they will last 4 GP distances at full bore. Even Mercedes are very cautious to declare victory on the reliability front as their extensive running keeps revealing problems here and there. Renault teams are and will remain far behind Merc in terms of getting that experience. If there are ongoing changes to components, they may not even be able to put any PUs though their full life cycle before testing ends.

[oetzi]

Renault teams are and will remain far behind Merc in terms of getting that experience. If there are ongoing changes to components, they may not even be able to put any PUs though their full life cycle before testing ends.

Will any of them manage that? According to (IIRC) Cosworth, a full testing cycle for one of these PUs would be ~4,500km. That's over 800 laps of Bahrain.

[Neophiliac]

Will any of them manage that? According to (IIRC) Cosworth, a full testing cycle for one of these PUs would be ~4,500km. That's over 800 laps of Bahrain.

Good point. Merc or Mclaren might manage, I guess, or get somewhere close - although they will need to put in some mammoth days in the upcoming test. But I suspect even getting to ~4000km will be way better than ~2000: in reliability testing it's almost the reverse of the law of diminishing returns for each extra km you can add.

[Alburaq]

Wow, great infos Enotsne. Thanks.
Is it possible to use super-capacitors that can receive the excess energy ?
Is the Renault PU powerful like many people say? 

Edited by Alburaq, 26 February 2014 - 11:42.

[RoutariEnjinu]

Wow, great infos Enotsne. Thanks.
Is it possible to use super-capacitors that can receive the excess energy ?
Is the Renault PU powerful like many people say?

That would be in violation of the energy store capacity rules.

[oetzi]

Good point. Merc or Mclaren might manage, I guess, or get somewhere close - although they will need to put in some mammoth days in the upcoming test. But I suspect even getting to ~4000km will be way better than ~2000: in reliability testing it's almost the reverse of the law of diminishing returns for each extra km you can add.

True, true. But that makes the (potentially) missing last few the most valuable of all.

 

I guess they've all run them to destruction on the dyno, and are monitoring degradation relative to that, and if it is matching real life they'll think they have a fair idea. But nothing makes things break like using them for real.

[Neophiliac]

True, true. But that makes the (potentially) missing last few the most valuable of all.
 
I guess they've all run them to destruction on the dyno, and are monitoring degradation relative to that, and if it is matching real life they'll think they have a fair idea. But nothing makes things break like using them for real.

... and if Renault dynos really are that inferior to the tools used by Merc/Ferrari, that comparison to simulation just goes out the window. They'll be flying blind into each successive event.

[Shiroo]

well would like to see answer on the question asked here again from enotsne but he might be at work at Enotsne at the moment :x so we need to wait.

Wondering if Newey will give a bit extra cooling, Lotus seems to have a upper hand going a bit more safe with extra cooling (though I wonder why the heck RBR did such mistake even if they had most info about the engine itself).

Edited by Shiroo, 26 February 2014 - 11:47.

[oetzi]

... and if Renault dynos really are that inferior to the tools used by Merc/Ferrari, that comparison to simulation just goes out the window. They'll be flying blind into each successive event.

Well, maybe with one eye closed, anyway.

[pUs]

For those interested. Here are some of the changes Renault have made since Jerez.

Change of battery cell provider. The individual cells that make up the Energy Store have individual over-charge and over-discharge protection. These were proving unreliable due to thermal/vibration issues. Whilst the energy store is sealed in our fitment, I am informed the cells are now supplied by Panasonic.

Change to MGU-K to Crank drive gearing. The original torque multiplication factor was calculated to give a wider spread of torque on acceleration. Track testing found that this was causing traction dificulties and overloading the gearset and causing failure of the crank casing.

Change to turbocharger wastegate function. Renault had originally intended for the H to regulate Turbine speed in 95%+ of normal running. They facilitated this by allowing the H to pull charge (when the energy store was at capacity) to an air cooled heat sink. This strategy proved ineffective in certain environments and a more coventional wastegate is now being used to supplement the H.

Due to both the change in K gear ratio, boost control strategy and the energy store, most of the software relating to the charge and discharge cycling has been modified daily and continues to be refined. There are still issues relating to turbine speed control via H but these are mostly to do with fine tuning of the control software and the syncronisation between H control and wastegate control.

There has been swift progress and software related driveability now appears to be the main issue.

Really interesting. Thanks for sharing, don't hesitate to keep it up in the near future!          Excellent

[F.M.]

Nick Chester confirming Horner's comments on lack of (K)ERS experience at Renault:

"I don't think it's entirely fair because Renault Sport have tried hard to build up their expertise, and we've been prepared to help them as much as we can. Because we have such a long relationship with them, we have an open door and we'll help them whenever they need help and even suggest things for them."

Both teams have developed their own energy recovery systems in the past and are helping Renault overcome its current problems, which relate to the control and operation of the new V6 turbo hybrid.

With Friday's homologation deadline for power units effectively ending their development for the year, Chester re-iterated his belief that Renault's problems are being overplayed.

"I'm sure all Renault-engined teams would want them to be a bit further on. But we've had a very long working relationship with Renault, going back to '95 at Enstone. We know they're very strong mechanically, they're making a lot of progress and I'm sure they'll get there. A lot of the work now is going to be software and operations."

[wingwalker]

Woah, and the post of the month award goes to... 

Thnaks so mcuh, enotsne.

[eREr]

well would like to see answer on the question asked here again from enotsne but he might be at work at Enotsne at the moment :x so we need to wait.

Wondering if Newey will give a bit extra cooling, Lotus seems to have a upper hand going a bit more safe with extra cooling (though I wonder why the heck RBR did such mistake even if they had most info about the engine itself).

Even Merc tested several variations of engine cover in Bahrain, so it seems not just Renault PU creates lots of hot air. New opening is huge compared to original one:

 

[kraduk]

Will the inclusion of a more conventional wastegate cause any packaging issues for Renault supplied teams?

 

I remember button talking about the sound of the wastegate does that mean merc have one also?

[Zava]

Nick Chester confirming Horner's comments on lack of (K)ERS experience at Renault:

[...] A lot of the work now is going to be software and operations."

perfectly in line with what enotsne said.

[bonjon1979a]

Even Merc tested several variations of engine cover in Bahrain, so it seems not just Renault PU creates lots of hot air. New opening is huge compared to original one:

 

 

They were testing variations of the cover because they'll be running in different temperatures throughout the year and wanted to see how different each one was. They didn't have to run the large one because of overheating as evidenced by the fact they returned the smaller one. Just testing out the various configurations.

[GhostR]

Even Merc tested several variations of engine cover in Bahrain, so it seems not just Renault PU creates lots of hot air. New opening is huge compared to original one:

 

 

It's not just the opening in your green circle that changed. Look to the left and right from the bottom edge of the circle. those side openings have also changed shape.

[Alburaq]

Yes it's the Merc 'max heat' bodywork spec. All air outlets are bigger...
Lotus wanted to start with conservative air outlets. They'll probably refine them later. 

[Hanzo]

Very interesting posts in this thread  

[study]

Interesting Judge post tonight