Is There a Market for a Mid-Engine Coupe Kit?

[dom9]

Off the back of the Stoneleigh thread, here: http://www.pistonheads.com/gassing/topic.asp?h=0&a...

I'm interested in knowing whether there is interest in a kit, mid-engine coupe. A modern Libra, if you like.

These guys do their Mini (and could potentially offer other bodies): speed3automotive.co.uk

But I can't really think of any others that are available new, from the manufacturer.

Ok, there are the MR2 body panel kits to turn the Mk.3 into an RS200 (which I like) but I believe they end up heavier than the original.

I'd like a bespoke chassis, be it a nicely designed spaceframe or a GRP monocoque (or AN Other). It must also be a handsome beast (I always liked the Libra).

There would seem to be plenty of cheap donors; MGFs, MR2s, Boxsters or even FWD cars like a Honda Type-R (could use a transverse layout or even an Audi/ Subaru in-line).

We have heard mention of perhaps one or two coming to market but it seems to be a segment that isn't well catered for. I know you '7' and Cobra drivers love the rain but surely a little coupe would be a better everyday car and could still be a lovely thing on the track, if the weight was kept down.

Yes, tooling costs etc are much higher than for open cars but if you can build a nice '7' copy for £10k and a New Else starts in the £30k region and Boxsters etc more (ok, I know these aren't coupes) then perhaps there is a market in the middle somewhere?

I have my Clio V6 (only 950 miles on the clock) insured for £40k now, so it doesn't really get driven (it looks like a house deposit to Mrs9) so I have picked up a little 106 XSi, which I am upgrading and refurbishing (documented in Reader's cars). Surely I could kill the two with one stone if a new, kit mid-engine coupe was available!?

Your thoughts are more than welcome... And yes, I realise I can buy a nice Mk.3 MR2 for £2k but if I want to build a kit and buy new...

[Equus]

Yes, subject to the usual caveat that doors and fixed roofs, and everything that goes with them (winding windows, heater/demist, hinge/lock mechanisms, weather seals, soundproofing) can be difficult and expensive to develop to an acceptable level in comparison to mainstream production cars.

[feef]

Make it a targa top and get the best of both worlds

[dom9]

Equus said:

Yes, subject to the usual caveat that doors and fixed roofs, and everything that goes with them (winding windows, heater/demist, hinge/lock mechanisms, weather seals, soundproofing) can be difficult and expensive to develop to an acceptable level in comparison to mainstream production cars.

Yes - I'd want all this, for sure. It shouldn't have to compromise too much.

feef said:

Make it a targa top and get the best of both worlds

I don't even want a sunroof (though obviously others might). Less rigidity, more complex/ expensive and will probably leak...

[Equus]

feef said:

Make it a targa top and get the best of both worlds

Can be, but you then need added cleverness to be able to store it in the car when running open, and they tend to rattle or squeak a lot as the seals and latches chafe against the main bodyshell unless everything is incredibly stiff.

Refer to the Fiat X1/9 for examples of both (excellent storage arrangement; prone to annoying squeaks from the seals).

[Stuart Mills]

A Smart Roadster perhaps, only the next size up. Rear engine, still looks fresh now, cheap to take a mould off, blown turbo examples are cheap. Draw a cross from above, chop into 4 and spread by 100mm?

[Equus]

Nothing wrong with the Smart Roadster at the size it is.

It would be nice to think that the industry is capable of coming up with something better than bad, cut-and-shut pastiches of someone else's designs, but perhaps I'm being excessively optimistic there, on the basis of recent evidence?

[300bhp/ton]

Equus said:

feef said:

Make it a targa top and get the best of both worlds

Can be, but you then need added cleverness to be able to store it in the car when running open, and they tend to rattle or squeak a lot as the seals and latches chafe against the main bodyshell unless everything is incredibly stiff.

Refer to the Fiat X1/9 for examples of both (excellent storage arrangement; prone to annoying squeaks from the seals).

T-top rather than full targa maybe?

Smaller panels and easier to retain rigidity.

I think this sounds interesting. And I'm a fan of the Libra.

For me though, any such kit would need to offer something more than an MGF/MR2 currently offers. A budget Elise or VX220 alternative maybe.

[rdodger]

As a former Libra owner I would say yes.

I looked at the spaceframe mini and wondered the same thing.

I would suggest you take a Libra and make some moulds and basically make a spaceframe Libra.

Maybe update the rear a little.

[kambites]

Someone could maybe make a targa which used the Elise screen and roll-bar cover and so could take the Elise soft and hard-tops? You can get an after-market heated Elise screen which would remove the need for de-misting blowers and it would be a simple way to be able to produce both a coupe and an open topped version.

[Stuart Mills]

I love the Smart Roadster, the Libra and the X19 with its clever use of stow space. Even a rear boot behind the engine, mine had the bags to fit in too. Lovely car design.
However for a new kit Coupe to be a real commercial success and to justify the huge set up costs it needs to be seen universally as breathtaking. Not easy to achieve but obviously the better the car the more demand. Kit coupes will always be compared to main stream offerings and so the successful kit car has to offer something extra, maybe performance or a unique roof system or some other feature not available on the high street. Without this the product needs to be competitively priced by comparison to the big boys or amortising may not happen unless a lower cost set up is found. Taking moulds of a Libra, Smart or X19 and adding cutting edge style or something unique may be the only way to ensure you don't lose your shirt off your back. Not like me to be pessimistic but whilst I always encourage new products there has to be a word of caution.
Maybe Italo would be kind enough to offer a sketch as a start point.
(how do you stick the dash above the e in coupe?)

[Equus]

300bhp/ton said:

T-top rather than full targa maybe?

Smaller panels and easier to retain rigidity.

The problem tends to be the rigidity of the bodyshell rather than that of the targa panel. The targa panel is pretty much unstressed, so nothing there to cause it to distort. It's the windscreen frame moving relative to the rollover support, due to limited torsional stiffness, that causes the issues.

It doesn't take much to set up squeaks and rattles, hence the obsession with very high torsional stiffness figures amongst the major manufacturers - despite what the bar room experts would have you believe, it's refinement, not handling, that's their primary concern.

FWIIW, my biggest beef with the Libra was the number of bangs and clonks you got when driving it, compared to the Elise. Mainly due to the clamshells on the Libra, I think - the Elises are obviously 'permanently' fixed to the chassis using rubber isolating bobbins, which obviated this issue.

kambites said:

Someone could maybe make a targa which used the Elise screen and roll-bar cover and so could take the Elise soft and hard-tops? You can get an after-market heated Elise screen which would remove the need for de-misting blowers and it would be a simple way to be able to produce both a coupe and an open topped version.

But would you really want a coupe (or targa) with no air con, much less no heater blowers, in competition with modern mainstream production cars?

Edited by Equus on Thursday 5th May 18:11

[jas xjr]

that kit that used the mgf was interesting. especially as they are unloved on the second hand market.

[rdodger]

Already done Stuart!

[Equus]

^^^ Xanthos GT. Basically a Lotus 23 with an Elise windscreen and Elise hardtop as a sliding canopy.

Making the sliding hardtop work with side windows might be tricky, though.

jas xjr said:

that kit that used the mgf was interesting. especially as they are unloved on the second hand market.

I wonder if the Sylva J15 could be made to work as a coupe, with the Elise screen and gullwing doors-cum-targa-panels?

eta: forgot; they're doing open versions with Elan screens already, aren't they?

Edited by Equus on Thursday 5th May 18:37

[rdodger]

J15 too small really.

The Libra was good because it was more practical than the Elise having more storage space. It was possible for 2 people to tour for a week including camping gear.

The roof panel lifted out and stored behind the seats. It carries a spare wheel under the front clam.

It was and still is a great looking car.

[Equus]

rdodger said:

J15 too small really.

Yes, you're probably right.

I was always a fan of the Costin-Nathan, but I guess that cars like that, the 23 and the J15 are a bit too extreme for everyday comfort.

[dom9]

rdodger said:

Already done Stuart!

Like that!

Glad this thread seems to be gaining some traction and good discussion!

Do modern 1,200cc bike engines make good torque? Perhaps a way to keep weight Dow and differentiate it!

[300bhp/ton]

Equus said:

300bhp/ton said:

T-top rather than full targa maybe?

Smaller panels and easier to retain rigidity.

The problem tends to be the rigidity of the bodyshell rather than that of the targa panel. The targa panel is pretty much unstressed, so nothing there to cause it to distort. It's the windscreen frame moving relative to the rollover support, due to limited torsional stiffness, that causes the issues.

Maybe we are at cross purposes here. But a T-top would have a permanent bar connecting the windscreen to the rollover support. And make for an easier more rigid structure.

Equus said:

kambites said:

Someone could maybe make a targa which used the Elise screen and roll-bar cover and so could take the Elise soft and hard-tops? You can get an after-market heated Elise screen which would remove the need for de-misting blowers and it would be a simple way to be able to produce both a coupe and an open topped version.

But would you really want a coupe (or targa) with no air con, much less no heater blowers, in competition with modern mainstream production cars?

Edited by Equus on Thursday 5th May 18:11

i personally wouldn't want air con of any type on a vehcile like this.

[Equus]

300bhp/ton said:

Maybe we are at cross purposes here. But a T-top would have a permanent bar connecting the windscreen to the rollover support. And make for an easier more rigid structure.

A T-top adds a little torsional rigidity, but not that much

300bhp/ton said:

I personally wouldn't want air con of any type on a vehcile like this.

But then you're not exactly renowned for your mainstream tastes.

I wouldn't, either, if it was an ultra-light, Costin-Nathan/Lotus 23 coupe sort of thing, but for anything with pretension toward everyday usability, it would be essential for me and most of the modern-day motoring population, I'd say.