Out of a Seven, into the Elise….
As some of you will know I sold my Seven two years ago to buy an Elise. However I have stayed in touch with the L7OC through occasionally gate-crashing the N. Hants meeting. Simon Ray thought I was therefore in a good position to write an article for Low Flying comparing the two, and this is it. That’s assuming you accept technical articles from non-members, Roy…never mind I might win a free subscription… And before anyone at Dartford thinks this is a sales pitch for the Elise ….read on!
Note, I have not considered the C21 here, not because it’s a bad car, in some ways it combines the best of both, but it was not an option for me, not extreme enough. If I buy another car from Dartford it will be a Seven or may be a C21 Lightweight…how about it Jez? Strip out the trim from a C21 and use the VVC engine….perspex screen, no hood, just a tonneau. Aim for 450Kg…I’m in the queue!
Introduction.
The Seven and the Elise are both very much products of their time. The Seven’s spaceframe and stressed skin construction apes aircraft construction from the late 30’s, and the Elise’s bonded aluminium structure echos techniques first used on aircraft in the late 60’s. Already the cars appear sisters with only an age gap to separate them. There are major differences of course, construction, technology, front engine verses mid engine, bodywork and aerodynamics, and weight but the aim to provide a light weight, low cost(!), sports car is the key aim of both designs. Ironically the Seven saved the fledgling Lotus, and the Elise looks set to save the company again, so both designs and the men behind them deserve our thanks.
Of course, the testament to Chapman’s brilliance and Graham Nearn’s business sense is that the Seven is still around for me to make this comparison today and that far from being an ‘also ran’, the Seven convincingly holds its own against not just the Elise but against cars many times its price.
Construction.
The Seven uses the famous Chapman ‘body frame’ construction, basically a triangulated tubular steel space frame with stressed alloy structural skins riveted into position. This offers a very light weight, strong structure which is also easy to repair. The structure also offers some degree of crash protection as it deforms.
The down sides are corrosion (which is still much reduced compared with most conventional steel monocoque cars), fatigue and loosening of the alloy panels over the life of the vehicle. Having said this, localised repairs can be done successfully even though it may be necessary to completely dismantle the car to achieve them. Modern Caterham chassis have taken much of the loading from the alloy panels by extending the spaceframe to areas such as the transmission tunnel, increasing stiffness and extending life. Crash worthiness has been improved by added honeycomb structures in key areas.
The Elise uses a chassis manufactured of epoxy bonded aluminium extrusions. This gives the ultimate in torsional stiffness combined with low weight and excellent corrosion resistance, as all the aluminium components are anodised. Anodising electrochemically coats each aluminium component with a very hard layer of aluminium oxide which is impervious to most things.
The down side is that the whole structure is ‘lifed’, because it is made from entirely from aluminium which fatigues under any applied stress, unlike steel which has a particular threshold below which fatigue is not an issue. Lotus claim 8-10 years of hard use but the chassis itself is not easy to repair, so age and serious accidents result in a new chassis being required. At the front and rear of the chassis are two ‘crash zones’ designed to protect the occupants and be easily repairable. The front water radiator, its air scoop and the rear silencer are part of these structures. Replacing the rear silencer with a smaller lighter sports version is therefore not just an engine tuning consideration!
Onto this very stiff chassis are mounted two glass fibre ‘clamshells’ at the front and rear, and the door and sill structures. The doors are hung on the side protection bars, which are another substantial extrusion, Esprit style. The clamshells are designed to be easily removed for servicing etc, but easy is still measured in hours rather than minutes.
In terms of ultimate performance the Elise has the stiffer structure and it may well be safer in a major accident…but in terms of serviceability, repairability and performance verses cost the original Seven structure wins.
Suspension
Both cars use coil over shock absorbers at each corner, with double wishbone suspension at the front and an anti-roll bar. The Elise employs double wishbones at the rear offering independent suspension all round, whereas the Seven opts for either a live axle or De Dion setup, both of which offer a effectively a beam axle (non independent) solution.
The Caterham suspension is well proven and has undergone much fine tuning over the years. The result is that the current car is well optimised for grip and ride comfort in it’s standard form. The chassis is generally set up to be neutral , or produce mild understeer, with power oversteer available on demand. Thus a responsible driver is unlikely to come unstuck, even if they are a comparative novice. The car will even tolerate lifting off in mid corner. Irresponsible, unskilled heavy right foot merchants will spin, ( I speak from experience) but you quickly learn how to avoid it, usually without any damage other than to one’s ego!
The Elise chassis has been the subject of much praise and indeed most of this is justified. At low speed it feels bumpy compared with a Seven but as speed increases the car comes into its own. Not only is the ride comfort at speed exemplary, grip and traction are also first rate. The feel and feedback from the steering is also faultless. Under most conditions the car is far easier to drive than the Seven and certainly much less tiring on a long journey. At 100mph the car is more stable than many cooking saloons of twice the weight, whereas the Seven always feels a little ‘light’, more nervous. This is largely down to two aerodynamic devices. Air from the radiator is blow over the windscreen to produce downforce at the front of the car, whilst under car air is expanded through a venturi at the rear to produce rear downforce. This is aided by the moulded in rear spoiler.
However, the Elise chassis is not without its problems. I had four sets of dampers on my car before I got a set which worked properly, the original fitments were so noisy it sounded like a guy with a hammer was hitting the floorpan!. In addition the front suspension has limited travel (something addressed by Caterham on the latest Sevens ) plus the springs are quite soft. At speed the aerodynamic downforce lowers the front by another few millimetres…the result is that ride heights are critical if bottoming on bad bumps is to be avoided. Lotus have addressed this by redesigning the springs but my Jan 1998 car had the old setup so this was another warranty job. Watch out for early Elises with a cracked front number plate, a sure sign of running too low!
Another downside is that the mid-engine layout produces snap roll induced oversteer on the limit and this is not always clearly telegraphed. This trait is common to all mid engined cars not just the Elise but the problem is exacerbated by the Elise’s aerodynamics, which create high down force on the front of the car at speed and the high position of the engine, dictated by the use of what is effectively a front wheel drive layout powertrain. Thus the handling balance shifts from mild understeer through neutral to oversteer. If the road is wet and your speed is high in a turn, or you are over zealous with the throttle, the tail will step out. If you lift off the tail will step out as weight is transferred to the front. Although the steering response is quick so is the onset of oversteer. You are now in the realms of something which is not novice friendly and explains why John Lyon was not keen on the Elise as a teaching vehicle. To create more rear downforce would require extensive remodelling of the rear bodywork and the styling compromise was not deemed acceptable.
Under normal circumstances the Elise beats the Seven in most areas, but on the limit it can be another story. Needless to say very few Elise drivers will ever find this limit on a public road, the car is too good for that. Track days are a different thing though. Certainly on the short ‘loop’ at the top of Curborough I couldn’t get enough speed for the car to do anything untoward unless provoked, but I wouldn’t be so sure at say Thruxton. Take a change of underwear if its raining!
Engine and gearbox.
Being all aluminium the ‘K’ series does not have a particularly pleasing tone (anodyne is a good word), and in the Seven this is masked by inlet, exhaust, road and transmission noise, which I personally feel is a ‘good thing’. In the Elise the engine note is about the only thing you can hear, and it does not really suit the sporting feel of the car. Hence the many retrofittable exhaust systems for the Elise, which are great as long as you don’t get rear ended in a traffic accident (see above). Indeed, the slight whine from the Elise gearbox makes the car sound almost electric on the overrun, more milk float than thoroughbred. I now understand why some owners have fitted big audio systems to their cars..they can’t stand the sound of the engine!
The Elise has the last laugh though when touring because it is quiet enough to talk (albeit in a raised voice!) to your passenger, and your ears are not ringing after a 5 hour drive!
Performance and fuel economy.
As the Caterham and the Elise now both use the Rover ‘K’ series in its various forms the comparisons are quite interesting.
Basically the Elise weighs some 200Kgs more than an corresponding Seven, but the reduction in power to weight is somewhat nullified by the Elise’s terrific traction off the line, better aerodynamics and (I suspect) reduced transmission power loss. The Elise has wide spaced gear ratios and an overdrive 5th gear whereas most ‘K’ engined Seven have Caterham’s own ultra close ratio 6 speed gearbox. The Elise can get away with its ‘cooking’ MGF gearbox due to the good torque response of the engine coupled with lowish drag at speed and the efficiency of the Honda sourced gearbox. The Seven partially gets away with its brick like shape because of its small frontal area, but over 80mph the 0.6Cd starts to become felt, whilst there is no doubt the combination of the 6 speed box and the Sierra differential consume quite a bit of power, despite the 6 speed’s top gear being ‘straight through’. A live axle K series car (if it exists) should be better, but best case this is probably still around 20%. The Elise transmission loss seems to be around 18%.
There is no doubt that the Seven with the standard 1800 K series engine is faster in acceleration than the Elise and not far behind in terms of top speed. However, the telling statistic is that the Elise rarely returns fuel consumption figures much worse than 32mpg and can achieve 40mpg during fast touring if one is careful. As I drive the Elise some +7K miles per year at my expense this is a noticeable improvement….even more so now we are post budget! This was one reason why I bought the Elise.
Of course Chapman did produce an aerodynamic Seven, the Eleven, which if fitted with a modern K series would probably knock the Elise into a cocked hat!…ie 450Kg or less, 0.30Cd, etc. I thought this was the route Caterham might go with the C21, but it was not to be quite. The C21 ended up as a mini TVR, not an aerodynamic bodied Seven.
Controls
Gear Change
Probably one area where road testers most disagree is over the quality of the Elise gearchange. The lever looks long and ponderous, but the gate is actually quite narrow. It is not a shift which responds to brute force. It would appear that the shift change quality varies greatly car to car, and is also related to the most publicised Elise problem, the notorious ‘red hose’. In a good one the change is actually quite reasonable, although never as quick as the Seven, where the gear lever goes ‘straight into’ the gearbox. The Elise lever operates down two, two foot long, cables so it’s at a disadvantage to start with. I actually rebuilt the gear linkage on my car, taking great care to align everything, apply plastic grease to all the correct areas etc and it made a noticeable difference but the biggest improvement was by fixing the clutch problem I had from day one…the ‘red hose’.
Clutch
I’ll mention the red hose problem here because this is the second major annoyance (after the dampers/springs) I have had with the Elise. The Elise has a hydraulic clutch, operated via a 4 metre length of red plastic hydraulic line. This is clipped to the radiator water pipes which run the length of the car. In hot weather the pipe can expand and as a result the ‘throw’ of the clutch is reduced and therefore drags. Although there are those who claim the red hose problem does not exist, Lotus have changed to a braided stainless / Teflon hose in production. I fitted this type of hose to my car myself because I couldn’t get any sense out of Lotus at the time, and the problem is fixed. Many cars with sticky gearboxes have this problem. Some early cars also had gearbox faults with jumping out of 5th gear a common problem, but then so did the MGF. It was a Honda/Rover problem.
In defence of Lotus, most of the problems I experienced were down to their suppliers, Koni, Rover, etc. The ‘red hose’ fiasco was entirely down to them, however and as the problem was also known on the Esprit since about 1984, it was very annoying that it should have been carried over onto the Elise.
Although I am aware that the Caterham 6 speed box has not been without its problems these have tended to be ones of excessive noise rather than total failure. Likewise generally the clutches on all Sevens are very robust and capable of sustaining the most appalling abuse!
Steering
Both the Seven and the Elise have beautiful steering responses. The response of the Seven is very dependant on the type and size of tyres fitted, whilst at present the Elise tyre choice is with Pirelli and Michelin, with Yokohama rumoured to be testing. The front of the Elise is very light and rapid turn-ins with cold tyres provoke terminal understeer but generally the response of the car is superior to the Seven owing to the mid engine layout, with the resultant tendency to spin on the limit. You need to keep a firm hold of the wheel too, because the wheels can tramline on bad surfaces, particularly under braking, and snatch the wheel if you are too relaxed.
In common with the Seven the Elise is quite sensitive to tyre pressures, and an accurate gauge is a must.
And while we are on the subject of tyres the Elise has no spare and no provision to carry one either, instead you get a can of Tyreweld. Having had three punctures in three months with the other cars in the family this is not something I am very happy with…you don’t even get a jack or wheel brace. At least the Seven allows you to carry a spare even if it is an option on the low spec. cars.
Handbrake
Oh and before you ask..the Elise has a handbrake which works…a first for Lotus and of course the Seven now has a handbrake you can reach…a first for a Seven!
Living with the cars.
The Elise is just sensible enough to be an everyday proposition, although I think I might be worried about ‘unwanted’ attention when parked. The main advantage of the Elise is the greatly enhanced cabin space, coupled with just the right amount of air conditioning with the top down. Another reason for buying the Elise..you don’t get blown to bits.
The downside is that you do not feel as ‘at one’ with the road and the elements as you do in a Seven, but it’s certainly not boring! Check out a 1.9 BMW Z3 if you want a nap! The Seven is probably more fun over all but it is hardly a car for everyday use although I did use one as my only transport for about 2 years at one point so if you are determined enough it can be done. Certainly the car is reliable enough to use everyday.
The Elise cabin has a stripped out look (which I like) and this extends to the seats. They are not that comfortable, particularly if you do not have much built in padding. I note the new VVC Elise has better seats so there must have been a lot of sore bums at Hethel during Elise testing.
In contrast, all the individual Seven seats have been models of comfort. Lotus should have consulted Caterham on that one, most definitely!
The Elise ‘Stack’ instruments are very neat, but the LCD display is very hard to read in sunlight, particularly if you are wearing sunglasses. The Seven instruments are more messy, but more informative and easier to read. By the way, I hate the latest Caterham switches which light up all colours at night. The overall ‘green’ glow was much better.
Finally the Elise heater. I mention this because a) Seven owners think Elise owners are soft because the car has one fitted as standard and b) several magazines commented on how powerful the heater was. Not true in my experience. The ‘K’ series engine is so efficiently cooled by the massive radiator in the Elise that little extra hot water is available for the heater. Also there is virtually no heat from the engine bay. On a cold day in a Seven your top half freezes whilst the lower half cooks. In the Elise all of you freezes…Of course you could blank the radiator, but that interferes with the Elise aerodynamic package. Yes officer, I crashed because my heater wasn’t working… I can see it all now!
Notice I don’t mention the hood…both cars should be driven alfresco. For what it’s worth both hoods are a compromise. Because of its better refinement the Elise is rather more tolerable with the roof on.
In terms of ease of use both are a pain.. avoid if at all possible!
Servicing and Reliability
Both cars are maintainable by a competent DIY mechanic, although for warranty and resale reasons I have been using a dealer to service the Elise, a first for me. Needless to say I am not exactly happy about the quality of service or the prices they charge. Are you reading this Guy?
The Seven is easier to maintain overall because its layout is less extreme, as I have said before it’s the only front engine, rear wheel drive car I know where you can work on the engine and gearbox by removing the bonnet. I hate working on mid engined cars…you feel like you have been put on a rack, fortunately the Elise has proven totally reliable so far (once the teething problems were resolved) so I will probably continue with the once a year visit to the dealers.
Likewise a properly assembled and maintained Seven should be totally reliable too. When Sevens breakdown it is generally down to inexperienced DIY rather than any real flaw in the design or components.
To sum up
For everyday use, long journeys and low fuel consumption its got to be the Elise. For fun and performance its got to be the Seven. To quote a well known motoring mag, ideally you need both!
It really is that close!
And as for the owners…they are both a mad bunch although I would say the Seven contingent are more interested in the technical aspects of the car rather than the ‘pose’ value.
The final word must go to my wife, who is not a big car fan and hated the Seven when we met. Although she likes going out in the Elise, she still looks at every passing Seven with affection. When funds permit I am sure we will own another! Praise indeed.
Jon Pippard 12/3/99
For Heather and Paul…..get well soon.