A very stupid thought

So, the various copies of the Lotus 7, Caterham, Westfield, LoCost and so on. Go like shit off a hot shovel, acceleration is superb given low weight of the total machine. Motorbike on 4 wheels sorta stuff.

Electric cars accelerate very well indeed. Battery weight a bit of a problem.

Hybrids, when on their batteries, accelerate like electric cars, actually better given low battery weight.

So, when does someone put a hybrid into a Lotus 7 copy to gain the acceleration? Umm, yes, I know, different drive train and all but when does this start to happen?

37 comments on “A very stupid thought

  1. I doubt if an electric 7 would be heavy enough to connect all that torque to the tarmac. Such a car would wear out its tyres rather quickly.

  2. Pure guess – expertise in hybrids hasn’t reached maturity yet. probably go straight to electric considering the range of most drivers.

  3. Morgan have a lectric 3 wheeler called the EV3 launched 18 months ago, but they seem to have been playing silly buggers in search of govt funding.

    Allegedly you can buy one in Selfridges.

  4. A sports car that doesn’t go Vroom Vroom? It’s as silly an idea as driving one with a brunette beside you.

  5. Build it, and Richard Hammond will test it for you. I’m lining him up for my BSA Rocket 3 retro fitted with 3 rocket motors.

  6. Well dearieme most sevens have four pot engines so the vroom vroom is somewhat compromised although mine was not bad with the sidewinder exhaust, and especially in tunnels.

    But on balance I agree.

  7. They did, well not a hybrid but an all electric called the Wrightspeed X1, based on an Arial Atom.

    Beats anything in a straight line standing start.

    See YouTube for details.

  8. The biggest issues for the Caterham/Westfield type cars is that the drivetrains are pretty much straight lifts from production cars but with a bit of tuning.

    Most Hybrids tend to be front wheel drive, which complicates matters when converting the engines to the rear wheel drive Caterham/Westfield chassis. Also, I think its only Toyota who actually drive the front wheels by both fire and sparks, most others seem to drive the front end by engine, and the rear wheels by motors. On a Caterfield you’d effectively have to build them “backwards” with engine driven rear end and electric front, or convert them to front wheel drive, which would totally change the car. Also, you’d have the fun and games of finding space for all the batteries, control gear and full mechatronics needed to make it all work, versus the much simpler normal engine.

    As for Locost builders, most of them still think the 1.8 Ford Sierra was the pinnacle of automotive development…

  9. Well, looking at a 7 to electric conversion… the first problem your going to have is connecting one side of the front end to the other. The engine’s an essential part of the chassis.

  10. But… looking at it seriously. The 7’s a very quick car, rather than a very fast car. Anyone who’s ever driven one will appreciate the difference between quick & fast. So it’s not really how much power can be put down on the road – a twin turboed V8 proved that – but balance. Getting the CofG in just the right place & the suspension doing all the right things.

  11. What about an Isle of Man TT Zero bike setup? It would be good for just under 38 miles of madness followed by several hours on charge!

  12. Why bother, if you want lairy there’ll be loadsa cheap 2nd hand Fiesta ST and Focus ST engines to drop in them starting about now.

  13. Rhyds said:
    “Most Hybrids tend to be front wheel drive”

    What about the sort that are driven only by the electric motors, and just have the petrol engine as a generator to keep the batteries charged up? That way it’s easy to drive whichever wheels you want.

  14. “Anyone who’s ever driven one will appreciate the difference between quick & fast.” Oh go on; spoil us. What’s the difference?

  15. Weren’t the first Teslas highly modified Lotus Elise’s, so in essence it’s already been done.

  16. Hybrid engine with all ancillaries is too complex & expensive to maintain for the Seven buyers who want old style simplicity and inexpensive maintenance and repairs.

    If sufficient Seven types (demand) did want eg a Prius drive-train Quaife or similar would be making & selling (supply) a bell-housing adapter or gearbox to allow RWD.

  17. Pcar
    “Hybrid engine with all ancillaries is too complex & expensive to maintain for the Seven buyers who want old style simplicity and inexpensive maintenance and repairs”

    Dual-drive would be complicated, but if it’s only electric engines driving the wheels and the petrol engine just charging the batteries, that sounds easier than messing around with drivechains. There will need to be a box of electronics to govern the charging, but they don’t need to open that up.

  18. “Weren’t the first Teslas highly modified Lotus Elise’s, so in essence it’s already been done.”

    The Elise had a ridged chassis. The 7 is a space frame construction. If you’ve driven one hard you’ll have felt the entire car flexing around you in response to acceleration & cornering loads. Quite how & where heavy rigid battery packs belong in a car built around an ICE & drive chain heaven knows. You could just end up with a horrible heap of ess-aitch-one-tee.

  19. Actually, the more I think about this the more impracticable it sounds. Much of the 7’s construction does two or three different things at once. It’s built to do what it does. By the time you’ve modified everything to accommodate an entirely different power/drive train, what you’ll have left won’t be a 7. It’ll be something else.
    So why not just go back to first principles & design a car around your preferred power source? You might get as lucky as Colin Chapman did with the result. Or you might not.

  20. Those comparing the Elise to the 7 aren’t quite grasping the issue.

    Effectively, an Elise has a FWD engine and gearbox package moved to the back of the car. So the engine is mounted transversely (across the car, east-west) and drives the wheels almost directly via a gearbox/diff combo like you find in most road cars.

    A Caterfield 7 has the engine mounted at the front of the car longitudinally (North-south) with a gearbox slung behind and a driveshaft running to a driven rear axle. While swapping the engine from an Elise on to a caterfield gearbox isn’t that hard adapting a FWD layout hybrid transmission to drive the rear wheels is much more difficult.

    Also, the other thing with hybrid powertrains is they depend on a hell of a lot of sensors and feedback from ABS or traction control systems. Problem is that Caterfields don’t come fitted with these so the hybrid control systems would need re-writing or the whole car would need re-designing to incorporate the extra kit.

  21. “So, when does someone put a hybrid into a Lotus 7 copy to gain the acceleration?”

    About 20 minutes before they end up in a field, upside down, on fire.

  22. On Saturday we saw around 20 Telsa cars coming down the Grimsel pass. Have no idea how they got to the top…

    @John Square brilliant!

  23. Dearieme, the difference between quick and fast is that the Lotus 7 won’t beat a Mondeo (or a Focus, or even a Fiesta) down an autobahn (not fast), but down a winding road, or away from lights, it’s incomparable (quick).

    Not the OED, just a driver’s definition. Also, by this definition a Reliant Robin might be quick away from lights (it weighs FA), but it doesn’t make the grade down winding anything, and it’s not fast either …

  24. @Witchie

    I never paid that much attention to Litus 7 style cars until one went past me on a Cornish road about ten years ago.

    The roads were as you describe above- windy, downhill, and naff all forward visibility.

    Some chap in a Caterham just strolled round me as if I was stationary and quickly became a dot on the horizon.

    I’ve wanted one ever since

    (Although a big draw is that I couldn’t fit the kids in….)

  25. @Rhyds
    It’s more basic than you describe.
    If you take the body panels off of a 7, you’ll see that the essential parts of the car are a dozen or more steel brackets the engine, gearbox & suspension all bolt to. The whole lot would fit in a small bag. The tubular spaceframe is just to keep all these bits in the right places relative to one another. The brackets are made to take an ICE of appropriate dimensions, gearbox ditto & whatever suspension set-up is preferred. A 7 looks like it does because the envelope accommodates the working bits and, just about, two bods & a small handbag
    There are no brackets to hang a battery pack or electric motor(s) from. These would be different brackets in different places needing an entirely new spaceframe* to connect them together.
    Essentially, it would be a different car.
    *The need to find somewhere for the battery pack & sticking to the racing car design philosophy of making all the bits do as many things as possible for the smallest possible mass means, inevitably, a rigid chassis rather than pure spaceframe.. CofG considerations imply something along the lines of a mid-engined ICE racing car. Not a 50s circuit racer.

  26. @ John.

    To be fair, an Ariel Atom went past me once and all I could think was “ooh that looks stiff and uncomfortable, but very direct steering”

    I was driving an Elise at the time.

  27. @Richard, August 13, 2017 at 8:50 pm

    Dual-drive would be complicated, but if it’s only electric engines driving the wheels and the petrol engine just charging the batteries…

    Prius is not dual drive. Electric motor powers flywheel as does the petrol engine. Thus, adapting for a Seven is mount longitudanly and attach bellhousing adapter prop shaft & and transaxle or RWD gearbox prop shaft & diff.

    Assuming you’ve found somewhere safe for batteries etc – a trailer?

  28. The kind of people who go for minimalist over achievement are not the kind of people who want electric.

  29. @Magnusw

    Heh- that made me laugh. I used to see an Atom around Bracknell, someone on the commute. Looked fun, if a touch indulgent.

    Now the (Chinese) middle aged lady who seemed to commute from on Basingstoke up the M3 in a Renault Twizy… that was madness (and probably illegal)

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