Lotus beyond the Elise chassis - what will happen?
Lotus beyond the Elise chassis - what will happen?
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theturbs

Original Poster:

949 posts

267 months

Thursday 21st February 2008
quotequote all
Was just mulling over this.

Lotus, although not quite enjoying financial bliss, has done ok out of the Elise chassis - plenty of cars sold in a number of markets, over a number of years. New variants continue to be released (2-11, Elise SC, etc.).

But eventually, this chassis will reach the end of its shelf-life, in the sense that the options will dry up for its ongoing development. Moreover, with Project Eagle and the new Esprit making the headlines, I for one am not clear on what is Lotus's strategy for the segment currently occupied by the Elise.

Does anyone have any thoughts on this? Is the Elise chassis a modern equivalent of the Seven chassis, that will continue ad infinitum? Will Lotus have to have a carbon-fibre chassis in the pipeline to take on the likes of the KTM X-Bow?


LivinLaVidaLotus

1,626 posts

232 months

Thursday 21st February 2008
quotequote all
Elise chassis weighs 65KG from memory (or the S1 did anyway), which is incredibly light for such a stiff structure. It'll live on for many years yet, and the manufacturing process for a long time as well, turning out a range of different chassis - which Lotus will no doubt milk for years, like only they can do. They will, at some point, come up with something more revolutionary no doubt (although maybe not in the chassis department), as that's where the big money is - coming up with something new, and wanted, and licensing it to other manufacturers - CF tub doesn't fit in to that category.

Scuffers

20,887 posts

305 months

Thursday 21st February 2008
quotequote all
LivinLaVidaLotus said:
Elise chassis weighs 65KG from memory (or the S1 did anyway), which is incredibly light for such a stiff structure. It'll live on for many years yet, and the manufacturing process for a long time as well, turning out a range of different chassis - which Lotus will no doubt milk for years, like only they can do. They will, at some point, come up with something more revolutionary no doubt (although maybe not in the chassis department), as that's where the big money is - coming up with something new, and wanted, and licensing it to other manufacturers - CF tub doesn't fit in to that category.
GLOL!

ever put one on the scales? they are slightly more than that!

as for stiffness, they are not that great either.

this is not to say they are rubbish, as a demostration of what's possible with extrusions, they are great, but there are better methods out there. CF is OK, but it's costs will never hit volume production prices, alloy steels are the way forward.

LivinLaVidaLotus

1,626 posts

232 months

Thursday 21st February 2008
quotequote all
Well, I'm just going off the info I have, which says the S1 chassis was 69.5kg in production form and 10,000 lb/ft/deg torsional stiffness, but I am willing to be corrected with some real world numbers smile

Twit

2,908 posts

295 months

Thursday 21st February 2008
quotequote all
For me the Elise chassis is at the end of its life now. Its still very competent and I love all the varients on the chassis but its had its day. From a Lotus point of view it will have to run a while as the focus has to be on the Eagle / Espirit development which will take priority. The future for lotus depends entirely on how they sell.

If they are decent sellers, and that is going to be purely dependent on price - if they try to go head to head with the likes of Porsche, high end BM and Merc, they will lose; it doesnt matter how good the car is - then there will be cash to think about the replacement for the Elise tub.

If the Eagle / Espirit don't sell well than administration beckons. Its that simple.

Either way we are a way away from a replacement despite the fact that its needed.

Gooby

9,269 posts

265 months

Thursday 21st February 2008
quotequote all
Blended composites has to be better than plain old steel alloys. They also have a fair amount of expertise in this area. What is required is Lotus lateral thinking to reduce production cost.

The given lotus weight for the chassis is 66kg and though it is not a stiff as a 911 chassis, it makes up for this in the light weight.

kevin ritson

3,423 posts

258 months

Thursday 21st February 2008
quotequote all
After 12 years it still gets great reviews and people still buy them. Lotus can afford to look at expanding their range and let the Elise sell itself for a couple of years - a whole new design won't find a load more buyers that they don't already have.

Monkey boy 1

2,066 posts

262 months

Thursday 21st February 2008
quotequote all
What's wrong with the Elise chassis ? it's a tried & proven design which AFAIK very few other manufacturers have copied. The concept may be a few years old now but the varients on that theme are endless. That's why it was designed that way.

Just think of the different chassis Lotus have used using this initial concept:

Elise Mk1
340R
Elise Mk1 GT
Elise Mk 2
Europa
VX220
2 Eleven

They are all different varients on the initial theme. Some with High sills, some with sill cut-outs, others with no door posts, others longer, others shorter.

Tooling costs are kept low, which must be good if Lotus are to make money.




theturbs

Original Poster:

949 posts

267 months

Thursday 21st February 2008
quotequote all
Monkey boy 1 said:
What's wrong with the Elise chassis ? it's a tried & proven design which AFAIK very few other manufacturers have copied. The concept may be a few years old now but the varients on that theme are endless. That's why it was designed that way.

Just think of the different chassis Lotus have used using this initial concept:

Elise Mk1
340R
Elise Mk1 GT
Elise Mk 2
Europa
VX220
2 Eleven

They are all different varients on the initial theme. Some with High sills, some with sill cut-outs, others with no door posts, others longer, others shorter.

Tooling costs are kept low, which must be good if Lotus are to make money.
I'm not saying that there's anything wrong with the Elise chassis - I was inviting comments as to what the next steps might be for Lotus in this segment, given that all products have a lifecycle.

It may well be the case that the Elise chassis is evergreen in the same way as the Seven has proved to be, in which case the strategy will be one of continuous tweaking rather than radical change.




Edited by theturbs on Thursday 21st February 18:11

TIPPER

2,955 posts

250 months

Thursday 21st February 2008
quotequote all
I suspect that Lotus will continue with the basic Elise chassis for many years whilst researching alternatives. They'll only change it when there is a weight/manufacturing/cost benefit.
Personally I hope they continue with the Elise concept, I reckon they can get away with rebodying the current set-up but as ever I do hope they keep the weight down. Surely they could do an 800kg Motorsport mapped N/A Exige?

Scuffers

20,887 posts

305 months

Thursday 21st February 2008
quotequote all
Gooby said:
Blended composites has to be better than plain old steel alloys. They also have a fair amount of expertise in this area. What is required is Lotus lateral thinking to reduce production cost.

The given lotus weight for the chassis is 66kg and though it is not a stiff as a 911 chassis, it makes up for this in the light weight.
for mass production, steel is still the way forward... composities in mass production just are not there yet.

as for the 66Kg's (all be it with a steering rack installed):




Edited by Scuffers on Thursday 21st February 19:39

clanger

1,087 posts

289 months

Thursday 21st February 2008
quotequote all
Just like the wife's bathroom scales they weigh 10kg on the heavy side winksmile -having lifted one they do seem to be nearer the 90kg mark fully dressed... still an awesome piece of kit tho' smile

Gooby

9,269 posts

265 months

Thursday 21st February 2008
quotequote all
Scuffers said:
Gooby said:
Blended composites has to be better than plain old steel alloys. They also have a fair amount of expertise in this area. What is required is Lotus lateral thinking to reduce production cost.

The given lotus weight for the chassis is 66kg and though it is not a stiff as a 911 chassis, it makes up for this in the light weight.
for mass production, steel is still the way forward... composities in mass production just are not there yet.

as for the 66Kg's (all be it with a steering rack installed):




Edited by Scuffers on Thursday 21st February 19:39
So chassis minus steering rack is what? We have either proved a steering rack is heavy or the chassis is not 66kg....

I think the first thing to assess is weather the Elise is a mass production item. To my belief it is far from mass production, by a rough estimate I would say it was a low to medium production volume meaning tens per week, barely into triple figures.

If I were looking for the next gen elise chassis, the first place I would look is at the worlds best and people like ferrari, Mclaren and zonda use a carbonfibre tub. This isnt always easy, you need massive pressurised ovens to cure, hence they are a very low volume item. Mixing the expertise in extruded alloys with their expertise in injection moulding GRP with carbon fibre composite would give low weight, high rigidity and good lifespan.

I am confused as to why you would use a steel alloy chassis when every low to medium size manufacturer is going the same direction as lotus into aluminium extruded and composite, (Jaguar and Aston Martin etc)

Mass production is still using steel alloy but migrating to versatile chassis tech.

BUT you are the expert, why do you think steel alloy?

Scuffers

20,887 posts

305 months

Friday 22nd February 2008
quotequote all
Steel alloys (as in new stuff) offer far more strenght per KG than extruded ali, (and traditional pressed steel).

Yes the bonded ali exturion has it's place, and in low volume use, can be economic, but it's still relatively heavy for what it is (you can't change the sections profile within an extrution, so you end up having to make them as thick as the higher point of demand required.

An alloy stresses skin chassis would eb lighter and many times more ridgid.

Monkey boy 1

2,066 posts

262 months

Friday 22nd February 2008
quotequote all
Gooby said:
Scuffers said:
Gooby said:
Blended composites has to be better than plain old steel alloys. They also have a fair amount of expertise in this area. What is required is Lotus lateral thinking to reduce production cost.

The given lotus weight for the chassis is 66kg and though it is not a stiff as a 911 chassis, it makes up for this in the light weight.
for mass production, steel is still the way forward... composities in mass production just are not there yet.

as for the 66Kg's (all be it with a steering rack installed):




Edited by Scuffers on Thursday 21st February 19:39
So chassis minus steering rack is what? We have either proved a steering rack is heavy or the chassis is not 66kg....

I think the first thing to assess is weather the Elise is a mass production item. To my belief it is far from mass production, by a rough estimate I would say it was a low to medium production volume meaning tens per week, barely into triple figures.

If I were looking for the next gen elise chassis, the first place I would look is at the worlds best and people like ferrari, Mclaren and zonda use a carbonfibre tub. This isnt always easy, you need massive pressurised ovens to cure, hence they are a very low volume item. Mixing the expertise in extruded alloys with their expertise in injection moulding GRP with carbon fibre composite would give low weight, high rigidity and good lifespan.

I am confused as to why you would use a steel alloy chassis when every low to medium size manufacturer is going the same direction as lotus into aluminium extruded and composite, (Jaguar and Aston Martin etc)

Mass production is still using steel alloy but migrating to versatile chassis tech.

BUT you are the expert, why do you think steel alloy?
interesting to see that the Left Rear weighs ZERO Kg confused

stevie111s

123 posts

266 months

Friday 22nd February 2008
quotequote all
spot the 3 pads in use, dummy!

Gooby

9,269 posts

265 months

Friday 22nd February 2008
quotequote all
Scuffers said:
Steel alloys (as in new stuff) offer far more strenght per KG than extruded ali, (and traditional pressed steel).

Yes the bonded ali exturion has it's place, and in low volume use, can be economic, but it's still relatively heavy for what it is (you can't change the sections profile within an extrution, so you end up having to make them as thick as the higher point of demand required.

An alloy stresses skin chassis would eb lighter and many times more ridgid.
Your point of view relies on single material production. I would propose that a composite of materials would be uses to achieve a greater affect.

They also have the VVA (variable vehicle arch) which (according to Tony Shute) is being used on many cars, I suspect that would fall into your catagory of steel alloy or possibly Aluminium alloy.

Lotus have considerable expertise with composites. Have you looked at the front crash structure, (silly question)it is a very clever piece of design, a number of different weves of fibre are used in order to absorb impact energy is specific ways. Very light, very strong (in specific directions) and still a functional structural support.

Typically a lotus chassis is the true structure of the car and unlike most other manufacturers the body work does not make up a considerable aspect of the cars structural rigidity, that is why thie chassis are always so good. This also provides a good structural base to make many different body styles which can just be draped over the car.

Carbon fibre is developing cheaper techniques for large component design. Looking at other industries, high end cycle frames are using composite techniques. The main frame is typically a carbon fibre, but high stress items such as chainstays are aluminium alloy.

Perhaps my model of looking at other tech sectors is an outdated point of view but I dont see other manufacturers using steel chassis. The aircraft industry dont use steel but much of that is due to new combat requirements of stealth, the commercial aircraft sector are staying with aluminium and composites, the cycle sector use steel alloy frames in a specialist area but typically it is a "retro" feel of bike. Motorbikes are still using a steel tubular chassis, but for that application, I suppose it is an ideal material for the reasons you stated.

I suppose the best way to understand the direction Lotus are going in is to look at the Eagle and Esprit when they come out. Seeing as lotus have not developed a chassis (for thier own production) since the mid 90's, that would be the true indicator.

What chassis was proposed on the M250? .. .

Edited by Gooby on Friday 22 February 11:15

Esprit

6,373 posts

314 months

Friday 22nd February 2008
quotequote all
stevie111s said:
spot the 3 pads in use, dummy!
Or spot that there could be a fourth one and that since you only need three points to define a plane and that the chassis under its own weight is effectively an infinitely rigid structure, it's entirely possible that there could be a 4th pad in use, but completely unloaded wink

fatboy111

308 posts

248 months

Friday 22nd February 2008
quotequote all
Monkey boy 1 said:
What's wrong with the Elise chassis ? it's a tried & proven design which AFAIK very few other manufacturers have copied. The concept may be a few years old now but the varients on that theme are endless. That's why it was designed that way.

Just think of the different chassis Lotus have used using this initial concept:

Elise Mk1
340R
Elise Mk1 GT
Elise Mk 2
Europa
VX220
2 Eleven

They are all different varients on the initial theme. Some with High sills, some with sill cut-outs, others with no door posts, others longer, others shorter.

Tooling costs are kept low, which must be good if Lotus are to make money.
Lotus have produced a number of cars on the Elise chassis, but with very small chassis variations.

It surprises me that Lotus haven't utilised the flexible nature of the chassis further (i.e, extending the chassis with longer extruded sections; widening, etc). The flexibilty kinda was one of the points to an extruded chassis, but I feel Lotus haven't maximised the potential...

S Works

10,166 posts

281 months

Friday 22nd February 2008
quotequote all
...yet. I strongly suspect that the Eagle & Esprit will utilise VVA as alluded to by Gooby, which is (as I understand it), basically an extension of the Elige chassis concept to do just that.