Philippe
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| posted on 31/12/05 at 09:28 PM |
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Mid engine collective base
I would like to second the call made by some of you ,V8Kid for instance, to somehow nurture for the Locost middy a common building element comparable
to that of Ron Champion's Locost. I don't understand how with all these car engineers writing in so many forums we cannot find YET a
formal set of drawings. Who is going to amend Champion's drawings and sell them to us amateurs? Thanks.
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derf
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| posted on 31/12/05 at 11:00 PM |
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Hopefully you will.... 
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kb58
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| posted on 1/1/06 at 02:36 AM |
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It sounds like you're wanting to come up with universal plans...
While well intended, I don't think it'll happen, there's just too many of us who want to do it "our way" with the parts
we have on hand. I really can't see one solution being heralded by all.
Most of these small independant car designs that actually happen seem to come from one person, or a group with a strong leader. Once in production
people modify it to their own needs.
I doubt we could even agree on what doner car to use, I mean, what's the budget that can be accepted by everyone... the answer's all over
the place. Then, what world car would be used (so everyone can build it)? Just these two items are real show stoppers since the answers are
different everywhere.
It may a fun exercise, but I just can't see us subborn types agreeing on anything! I mean, look why we're all here, it's because we
don't like any existing cars...
[Edited on 1/1/06 by kb58]
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
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kango
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| posted on 1/1/06 at 04:59 AM |
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I can't even find a body!
I am planning my next car as a VW GOLF midmount, but need a body to determine wheelbase ect. Then to make up drawings as I go along is no problem.
Once a basis is established surely everybody will start suggesting improvements.
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akumabito
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| posted on 1/1/06 at 12:44 PM |
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I don't really see the problem with a "universal" set of plans.. look at the Locost.. no two are the same, yet they are usually all
based on the same set of plans. Sure, you could design the thing with a particular (commonly found) engine in mind, but people could still change
things anyway.. i see no reason why a middy shold be any different in that from a Locost..
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andygtt
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| posted on 1/1/06 at 01:14 PM |
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How many cheap front engined rear wheel cars are there to use as a basis for a 7 type?
And how many mid/ rear engined cars are there available to use as a basis for a midi?
Reality is that to build a locost midi you much do much more design to adapt a front mounted engine to fit the rear.
So its a more work and engineering on a midi and therefore much less easy to design a generic chassis.
However IMO the biggest challenge will be the body.... it seems with Midi's there is not a generic shape like the 7 that people like.
Although saying this having looked at the La Bella I recon we could be moving towards some real locost midi's.
Andy
please redefine your limits.
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Spyderman
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| posted on 1/1/06 at 02:02 PM |
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quote:
Originally posted by andygtt
How many cheap front engined rear wheel cars are there to use as a basis for a 7 type?
And how many mid/ rear engined cars are there available to use as a basis for a midi?
Reality is that to build a locost midi you much do much more design to adapt a front mounted engine to fit the rear.
So its a more work and engineering on a midi and therefore much less easy to design a generic chassis.
However IMO the biggest challenge will be the body.... it seems with Midi's there is not a generic shape like the 7 that people like.
Although saying this having looked at the La Bella I recon we could be moving towards some real locost midi's.
I think Andy has summed it up, although many points could be argued. There is as yet no one car that has inspired such a vast amount of copying as the
Lotus Seven has. And look how long it took before the copies became main stream! At that rate there will be a standard midi clone to utilise and
modify by about the year 2015.
Spyderman
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Philippe
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| posted on 1/1/06 at 02:39 PM |
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Mid engine rear engines
What I meant buy generic mid engine chassis blueprint was a tube frame locost type from which all types of rear mounted engines could be adapted. What
Sylva, Meerkat, Onyx call mid engines are not typically mid engines they are rear transaxles (sitting above the rear axle). To me a mid engine is a
Porsche spyder, a Matra, a GT40 with the engine hanging somewhere in between the rear and the front wheels. Rear transaxles are perfect but they
should not be called mid engine; this confuses the issue. As for the body, I really see no reason why one should entirely depart from the traditional
Seven look. Look at Sylva's magnificent specimen from the front you would think that you are looking at an ordinary seven.
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cornishrob
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| posted on 1/1/06 at 08:21 PM |
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In my opinion i think bolting a front front combination of engine and gearbox in the arse end of a car working in the same manor is more a case of
where to put the mounts dependent on the exact engine rather than having to design something bespoke for each specific engine.
im pretty sure that a rover k series in a 214, a 2.0 mondeo zetec and a toyota celica 3s GE engine would all fit and work in near enough the same way
so that their fitment wouldn't be a major issue. Just like its not an issue when building a front engined locost.
The only forseeable poblems would be clutch and throttle cables. and the gearshift cables. these would have to be made to measure but its not a big
price to pay for the engine being in the back.
I think a general chassis design which could be addapted to suit individuals cars and engine choices would be a good starting point and i think there
would be a lot of interest in it.
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derf
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| posted on 1/1/06 at 11:49 PM |
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I think that the bigger problem is the bodywork. If you look at the Meerkat and the la bala, both have locost type frames, but they are going through
lots of work to get the bodywork done, probably as much as it took to get the cars built and running. With the book design the hardest body part to
manufacture is the nose and the scuttle, and those are readily available through suppliers. The rest is just aluminum rivited to the chassis.
Kurt got lucky and started with a mini body and just built his frame to match.
If someone could come up with a simple body then I think it would not only be feasable to design a standard middie frame. Maybe use an existing front
bumper with aluminum sides and rear like the book locost has. I have seen a few middie sevens on the computer, but the elongated rear, ans shortened
nose just doesnt look "right"
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TheGecko
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| posted on 2/1/06 at 01:32 AM |
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quote:
Originally posted by Philippe
What Sylva, Meerkat, Onyx call mid engines are not typically mid engines they are rear transaxles (sitting above the rear axle). To me a mid engine is
a Porsche spyder, a Matra, a GT40 with the engine hanging somewhere in between the rear and the front wheels. Rear transaxles are perfect but they
should not be called mid engine; this confuses the issue.
OK, now you're pressing one of my hot buttons! Have a look at a few FWD transaxle arrangements first and then make a judgement about where
the engine sits relative to the axle line. For example, here's a small photo of the right hand end of my donor Corolla drivetrain:
[img][/img]
As you can see the only parts of the engine hanging over the axle line are the alternator and the intake plenum. All of the rest of the engine is
forward of the axle line - in fact the engine block leans forward about 10 degrees.
If transverse mid-engines are not "real" mid-engines, then you're excluding the MR2, MG-F, Elise, NS-X, and Lamborghini Muira &
Urraco from your idea of mid-engined. If an inline drivetrain arrangement is what you call "real" mid-engined then you are going to have
very great difficulty getting anything like a "Seven" look as the proportions just won't work. Have a look at the OX7 in my photo
archive for just such a beast.
quote:
As for the body, I really see no reason why one should entirely depart from the traditional Seven look. Look at Sylva's magnificent
specimen from the front you would think that you are looking at an ordinary seven.
As I've saidd a few times on this board, I have built a model to check this and it is possible to come close to traditional Seven proportions
with a transverse mid-engine arrangement. Here's my 1:10 scale model, built around real measurements of an actual donor drivetrain.
 
Gecko model with silver sides
Now all I have to do is stop spending so much time on here , get back into the garage and finish it.
Dominic
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kb58
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| posted on 2/1/06 at 04:43 AM |
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Yup, what he said ^. If you define "real" mid-engine cars as the engine ahead of the rear axle, then all the car's noted do in fact
qualify.
I guess I'm including my own "mid-engine" Mini to meet that definition too.
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
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Philippe
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| posted on 2/1/06 at 10:23 AM |
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Mid engines rear engines
In reply to Dominic.
What is mid engine is of course a matter of appreciation. I take your illustration as legitimate but maintain my point that transaxles have blurred
the lines regarding what the notion of weight distribution in mid engines should be. This is not a "hot button for me". I have seen a
picture of a conventional mid engine Locost with a very long rear engine hood...it looked terrible. I much prefer what Sylva is doing. This is a point
that I would concede: for a true mid engine arrangement to look balanced the whole chassis of the Locost should be lengthened.
Where are you at in your own project. Do you read your mail?
Philippe.
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cymtriks
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| posted on 2/1/06 at 10:38 AM |
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My suggestion
See my design on this thread.
http://www.locostbuilders.co.uk/viewthread.php?tid=30627&page=3
A key part of the design is the use of 4x2 section around the engine bay which frees up this region by being strong enough without any diagonals which
often get in the way of suspension and driveline.
Chassis stiffness is double the book design, the wheel covers are the same all round, there are only two body panels, front bonnet and engine
cover.
It's very similar in concept to the Riot car.
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JC
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| posted on 2/1/06 at 11:08 AM |
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Here we go again!!!. IMHO, it is possible to come up with a 'common' MIDI design - IF you are prepared to make some compromises. As I
have found out, stick with Uncle Henry for the donor and away you go. I am getting around the bodywork issue by not having much! But I don't
see why a design like mine couldn't have a 'locost' nose cone and end up looking like a Sylva Riot. For what its worth, I would
consider selling plans but am still some way off completing my car, before which it would be a brave person to have my plans!!!!
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TheGecko
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| posted on 2/1/06 at 01:39 PM |
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quote:
Originally posted by Philippe
What is mid engine is of course a matter of appreciation. I take your illustration as legitimate but maintain my point that transaxles have blurred
the lines regarding what the notion of weight distribution in mid engines should be. This is not a "hot button for me".
I have no real desire to get into an argument about what does or doesn't constitute mid-engined. I'm not even really sure what
you're trying to say about "blurred lines" and weight distribution? Yes - a transverse mid-engine layout will have a more rearward
mass centre for the drivetrain than a longitudinal one. So?
Other than BMW's foolish advertising campaign about "Perfect Balance" (apparently maintained despite changing fuel, passenger and
luggage loads) I don't think many people really believe that there's anything magical about 50:50 weight distribution. If anything, a
moderate rearward bias will tend towards more even wheel loads with weight transfer under braking, instead of forcing the front brakes to do all the
work.
Like I said, if you want to redefine the work of various manufacturers around the world and tell them that their "mid-engined" cars are
actually "rear-engined" then you'd better start a letter writing campaign. Me? I'll stick with the cheap, common, reliable
(and powerful) transverse drivetrain that I already have. I guess I'll have to put up with the problem that my wheelbase will be 400-500mm
shorter than a longitudinal mid-engine would be - the improved handling from that is disadvantage I'll work around. The lighter chassis weight
because of that shorter length will be a problem too I suppose. The fact that the fuel and driver/passenger will be quite close to the CofG,
minimising CofG disturbance with changing loads? Horrors!
If you want to try to wring power and reliability out of 70-year old air-cooled flat-4 design because it meets some sort of "design
purity" than enjoy. More power to you says I. However, coming here and telling us (effectively) that we've got it all wrong is not going
to get you a lot of support or assistance.
quote:
Where are you at in your own project. Do you read your mail?
Phillipe, I do read my email - I have one from you that hit my inbox at about noon on New Years Eve. Inexplicably, I've been doing other things
in the interim. I will send you a reply when I have a chance to finish writing it. An observation - you come across as a pushy son-of-a-gun. Maybe
you're not - I don't know. Ease off a bit.
Dominic (who probably shouldn't write replies when he's had a few glasses of wine but... what the hell)
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Alan B
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| posted on 3/1/06 at 12:19 AM |
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How did I miss this thread?
Anyway, thanks Dominic...you pretty much said all that I would have said.
Back to the main topic....standardisation is tough...almost everyone says it's a good idea.....but, on the proviso that it mirrors their own
views..
The only way I see of there being an "offical" mid-engined locost is by someone building one and publishing a book or publishing
plans....then if it takes off.......a de facto standard is created.....not unlike what Uncle Ron did.
Until that we are on our own...and IMO, because we prefer to be..
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TheGecko
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| posted on 3/1/06 at 05:05 AM |
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Hmm, just re-read my reply in the cold light of day and it does sound a little short-tempered  I'll leave it as is though, since editing it
after the event always seems a little dishonest.
On Alan's point - standardisation is indeed tough and, I believe, made more so because the all-in-one nature of a transverse FWD drivetrain
enforces the inter-relationship of a number of dimensions. With a front engine Locost the relevant dimensions are mostly on separate components
(engine, gearbox, axle) and their inter-relationship is somewhat less critical (and also amenable to some manipulation and adjustment).
There is an example in the design of my rear suspension. I'm re-using the donor struts, converted (cheaply) to adjustable coil-overs. Thus I
only need a simple bottom wishbone. By careful tweaking of chassis member sizes and positions I ended up with a symmetrical wishbone i.e. I can use
the same wishbone on either side. This means I can make one jig instead of two for this critical component and be confident that left and right will
be identical. However, all of this hinges on the particular dimensions of the AE101 Corolla drivetrain I'm using. I think the next model
(AE112) might be the same but am quite confident that none of the other FWD Corolla variants (AE80, AE92, ZZE122) will be. And that's just from
the same manufacturer and one who has a reputation for not changing things much. Adapting a Nissan/Honda/Mitsubishi/Suzuki/whatever strut layout
would require quite a cascade of interconnected changes.
Funnily enough though, I have encountered similar problems lately with the Locost design. I've been exchanging correspondence with a builder
who is using the same Holden Gemini (Chevette to the rest of the world) front suspension uprights as me and he remarked on the difficulty of
"getting it all to line up" on the Locost chassis, including some photos of outriggered wishbone brackets etc. That sent me searching for
Cortina upright dimensions to compare with. The bottom line is that the Gemini upright is of similar height (between balljoints) to the Cortina but
the axle line is about 25mm lower i.e. closer to the bottom balljoint. That, coupled with 15" wheels with a larger rolling radius than the Book
Escort 13" ones, means the chassis end of the wishbones all need to sit about 45-50mm higher than Book (or the clearance under the bottom
chassis rails needs to be 50mm more - great for that "off-road" look! ). Things get tricky then because the book front end has a lot
of related angles (L-assembly, FU1, FU2 etc) that all assume the brackets will go in certain places. I can only assume that the various adapters for
using Sierra uprights closely emulate the Cortina dimensions. Heaven only knows what results builders in the US are getting with S10 or Mustang or
Pinto spindles?! It would certainly explain some of the "interesting" wishbone brackets I've seen in photos.
Expecting the reader of a book to make these sort of design changes is a bit much - particularly when the design is presented as a fait
accompli without any theory or design principals explained. Arguably, presenting that sort of theoretical material is not the role of a
"cook book" type manual anyway. I get the impression that Keith Tanner's new "Cheap Sportscar" book delves into this
area a little (bump steer etc?) but how far do you go? If I publish my design, do I need to provide reams of theory to support any design changes by
the reader (almost impossible) or take the Champion approach and leave 'em to their own devices? I don't find either satisfactory and I
don't see a simple solution. I have some thoughts about a software tool (perhaps a "solver" type Excel spreadsheet) where you could
plug in all of the required donor part dimensions and out would drop an adjusted set of chassis plans. That should be easy to write - not! It took
me hours drawing and re-drawing to get my front suspension the way I want it and many more hours again for the rear end. No easy answers here.
Anyway, enough rambling from me. I'll still probably publish my design in one form or another when it's done but it'll never be
anything like a universal set of mid-engine plans.
Dominic
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kb58
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| posted on 3/1/06 at 05:18 AM |
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Exactly, Dominic, well said. This is what I was saying, that everything is connected to everything else. To come up with a design that works for
everyone is impossible. The best approach is to make it generic enough that various drivetrains and uprights can be fitted to it. And use either no
composite or pre-existing Locost part!
[Edited on 1/3/06 by kb58]
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
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derf
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| posted on 3/1/06 at 05:36 AM |
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Thats one reason i think that the locost is such a good way to go for rwd engines, the bodywork is very simple, and the 2 parts that are complicated
are redily available from suppliers.
To be honest the geko design is probably the best design for a middie that would be easy to build for the masses I think Ive seen yet. I know that
steve is looking at bussiness plans for the labala, but if successful he could publish the book plans for a mid engine car, and make his money selling
bodywork to fit, but then that defeats the biggest selling point of the book 250lb to build the car, which is impossible.
To me it looks like the geko uses mostly book bodywork, and is built around your engine, however if you could extend the rear to fit a wide range of
donors, even if you use book front suspension, and go with a dedion rear and standardize the rear... i dont really know i followed the book dimension
as best i could, but since UK cars dont exist in the uS Ive had to modify my car to suit my donor, out of necessity. i dont really see whay the big
problem would be especially if the larger rear structure takes up a good majority of the stress to the rear, and can still support the engine's
weight.
If anything here doesnt make sence chalk it up to americanisms in action...
oh yeh, and keiths book is on my must read list, it goes into alot more detail on the final assembly than rons does, it pretty much picks up where the
original book leaves off.
[Edited on 3/1/06 by derf]
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TheGecko
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| posted on 3/1/06 at 06:29 AM |
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quote:
To me it looks like the geko uses mostly book bodywork, and is built around your engine, however if you could extend the rear to fit a wide
range of donors, even if you use book front suspension, and go with a dedion rear and standardize the rear...
Derf,
Two things:
- it's Gecko. You know, the little, quick lizards with sticky feet. Named after the little, quick sportscars with sticky feet
- I realized after I sent my last sermon that I hadn't put in the bit I was going to about de Dion. A de Dion rear (like Steve's La
Bala) on a transverse FWD package could get closer to a universal solution. It does assume the builder can fabricate a de Dion tube to suit their
particular donor parts but, if they're building a car, they should be able to do that! I started out drawing de Dion's - the strut rear
just looks like less fabrication. The strut layout is a lot more component specific however.
quote:
oh yeh, and keiths book is on my must read list, it goes into alot more detail on the final assembly than rons does, it pretty much picks up
where the original book leaves off.
I'll have to order a copy of Keith's book I think, just to round out my collection if nothing else Seriously though, I've yet to
see a negative comment about it. High cost of all low-volume imported books here is the real problem. Local price (from
Pitstop Books) is $50 + postage. At the current exchange rate thats about US$37 - about twice what Amazon sells
it for. Of course I could order it from them but international shipping adds up quickly too and I don't get it overnight I should've
put it on the XMas hints list for wifey to get for me
Anyway, if I get a chance tonight, I'll finish a render of the rear end of the chassis and post it here, possibly with a de Dion alternative if
I can find the drawings. Then the cognescenti can pass comment on my design "expertise".
Dominic (who is now going to go back to pretending to work whilst web surfing)
[edited because I pressed Post before I'd finished]
[Edited on 3/1/2006 by TheGecko]
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Ratman
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| posted on 3/1/06 at 10:34 AM |
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I like the Gheko chassis because it uses a full FWD strut suspension. If there is a std Midi Locost then it must use everything possible from a donor
car. Rear wishbones or de-dion are just too hard to make. So, if using a typical FWD car as a donor, the load pickup points are pretty much the same
for 80% of the likely donors. The chassis should just be the least possible number of tubes that link everything together and provide good strength
and torsional stiffness. The main problem is the front end. Where do you get a wishbone front end from these days? I guess might as well take that
from the original Locost then. or.. (and I don't like this idea really) but several Jap vans have double wishbone front ends, common stud
patterns and removable steering arms. Main disadvantage is that they are designed for about 200mm of ground clearence.
- Brian.
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kb58
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| posted on 3/1/06 at 04:21 PM |
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I'd use Miata donor parts for the front suspension, and the preferred FWD parts for the rear. Miata parts because they're widely
available, getting cheap, and are fairly light. Use all of it, the uprights, brakes, and rack.
[Edited on 1/3/06 by kb58]
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
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crbrlfrost
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| posted on 3/1/06 at 06:51 PM |
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Perhaps instead of a universal middie car, a universal middie bracket (aka chassis) would be the goal. Engine bay big enough to allow use of most
transverse FWD powertrains in both 4's and 6's (someone would inevitably shove an 8 in there), basic boxed front section to allow
variations in double wishbone suspensions, and the basic mounting point areas in the rear for McPherson/Chapman links. In the locost way of doing
things, people would redo the rear for a DeDeon or SLA, but as long as the primary structure is still there. I like the rear section of cymtriks
design as it allows a wide variation of options without cutting into the primary tubes, and a front box is just that. Bodywise it could be made with a
wide passenger compartment (either using a backbone structure with a wide center tunnel, or a more twin tube style structure) so as to use the Al
sheeting as body work (ala lotus 340R or the like) or someone could go through the rigors (better men than I) of a complete body plug. Naturally a
basic suspension layout and parts could be included in the drawing set for those less interested in doing it themselves. But to make a long story
short, it would just be a rigid base structure to start from with a lot of latitude build on. Just a thought. If only I could get 2cents each. Cheers!
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derf
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| posted on 3/1/06 at 09:21 PM |
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no thats pretty much what Ive been saying from my 1st post in this thread.
Anywhoo, Mr Geeko, sorry about getting the name wrong (), my insurance is done by Geico so I should have gotten the name right after all the
commercials Ive seen over here
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