v8kid
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| posted on 29/8/05 at 12:07 PM |
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"official" mid engine locost?
Is there a need for an "official" midi locost? The mid engine forum has plenty of examples of very individual and ingenious solutions but
are they in the spirit of Lowcost?
Ha!! I can almost hear you say whats the need for an "official" midi we are doing very nicely thank you.
Well not all constructors who may want a midi have the level of experience and engineering 6th sense required. That limits the number of people who
might like to be part of this forum.
My thoughts on the Locost theme is that its popular because it gives specific guidance but at the same time allows the experienced constructor to go
his own way with different engines and suspension but linked to a common chassis.
Also Locost is a rallying point for like minded people to discuss common specific issues. Fair enough we are doing this right now but the midi section
is much more diverse and the lack of commonality means the best solution aint obvious. For example look at the discussion of lower wishbones failing.
Most middis just dont have that level of detail in common to discuss and find the best solutions for.
Without specific guidelines its easy to get diverted into non productive or energy sapping ideas. I take my hat off to the chaps that are producing
their own bodywork - I tried it once and gave up just cos its so dammed long a process. Another example could be the various builds which have adopted
the rear suspension subframes only to see the hardware for the commonly accepted independant setup become available.
Also an "official" locost midi is easy for clubs to recognise and arrange classification - in autocrossing, sprinting. hillclimbing,
concours - whatever. Second thoughts can I take the idea of concours back the thought makes my mind boggle.
My suggestion would be based round the original of scanty ally bodywork (easy to construct), simple tube chassis (easy to modify and build without
specialised equipment), car engined (for reliability), few specialist parts (for low cost).
Does the idea strike a bell or am I on my own?
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Marcus
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| posted on 29/8/05 at 12:33 PM |
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Due to the increasing lack of RWD donor parts, a Locost midi sounds like a good idea. I, for one, would probably look at this as a basis for my next
project. Having built a 'book' Locost, the idea of a midi appeals.
If you have any ideas, keep us informed.
Marcus
Marcus
Because kits are for girls!!
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Alan B
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| posted on 29/8/05 at 01:46 PM |
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quote:
Originally posted by v8kid
Is there a need for an "official" midi locost? The mid engine forum has plenty of examples of very individual and ingenious solutions but
are they in the spirit of Lowcost?..................
YES, absolutely......
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kb58
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| posted on 29/8/05 at 01:58 PM |
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It wouldn't be hard.
Take a Locost, shorten the hood/bonnet, open up the foot wells, put the gas tank up front. Lengthen the area behind the driver, and drop in a FWD
drivetrain. You could use all the same Locost construction techniques, even using the same nose, cowl, and fenders.
I had to laugh though, knowing even before I looked you'd be across the pond. While I think the concept would work out well over there,
there's a sad lack of custom car interest over here, which is kind of odd, living in "car crazy" California as I do.
[Edited on 8/29/05 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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v8kid
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| posted on 29/8/05 at 02:35 PM |
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Thanks for the interest chaps. On reflection I've posted a copy on the Chassis forum to see how important the concept of commonality is to the
front engined chaps. We shall see.
I have to admit to a vested interest in that the competition classes in Scotland for this type of vehicle are divided between road going kit cars and
competition cars (amongst other classes)
By having a recognised kit car (of which locost is one) I can compete in both classes by just changing the tyres!!
Also I think there would be benifits to newcomers ti the scene as I've already said.
Can hardly believe though there is a lack of interest in the states - most of the best practical and theory books I have are american - Ah well
another preconcevied idea gone phut!!
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gazza285
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| posted on 29/8/05 at 02:38 PM |
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quote:
Originally posted by kb58
Take a Locost, shorten the hood/bonnet, open up the foot wells, put the gas tank up front. Lengthen the area behind the driver, and drop in a FWD
drivetrain. You could use all the same Locost construction techniques, even using the same nose, cowl, and fenders.
[Edited on 8/29/05 by kb58]
It has been done that way before, and is exactly what I am planning to do when my "traditional" locost is finished.
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Alan B
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| posted on 29/8/05 at 03:05 PM |
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quote:
Originally posted by gazza285
quote:
Originally posted by kb58
Take a Locost, shorten the hood/bonnet, open up the foot wells, put the gas tank up front. Lengthen the area behind the driver, and drop in a FWD
drivetrain. You could use all the same Locost construction techniques, even using the same nose, cowl, and fenders.
[Edited on 8/29/05 by kb58]
It has been done that way before, and is exactly what I am planning to do when my "traditional" locost is finished.
This was something like my first thinking, and I seem to recall getting stuck around the rear arches/fenders area......it seemed to difficult to use a
wheel mounted rear arch/fender without a conventional wishbone type set-up...which is difficult with most FWD units...
Anyway, I'm sure it is possible, but does have it's challenges....
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gazza285
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| posted on 29/8/05 at 03:20 PM |
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Think about Sierra MacPherson struts. These are now commonly used instead of Cortina stub axles using a mushroom insert. Could not the same thinking
be aplied to using the MacPherson struts off a front driving car, giving you the double wishbone set up needed to get standard arches over the rear
wheels?
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TheGecko
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| posted on 29/8/05 at 03:25 PM |
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So if I actually stop revising my chassis design and just build the thing and prove that it works, people will queue up for a copy of the plans?
Hmmm... "The DIY Sportscar - A constructors guide" - $29.95 at good book stores everywhere  That would do just nicely
Seriously though, should I post some images of the (almost) final design?
Edit: to reply to gazza's post:
The problem with wishbones in a tranverse mid-engine layout is not the top balljoint. It's finding somewhere for the top wishbone to actually
go becaus ethe engine and gearbox are very much in the road. I still say just re-use the struts and be damned like me 
Dominic
[Edited on 29/8/2005 by TheGecko]
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Alan B
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| posted on 29/8/05 at 03:29 PM |
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Adapting struts is not the problem...it's finding room for a traditional wishbone that is hard.
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gazza285
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| posted on 29/8/05 at 03:32 PM |
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All part of the challenge, but it has to be said I was going to try and use the original struts.
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gazza285
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| posted on 29/8/05 at 03:40 PM |
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Sylva Mojo rear end using Fiesta uprights.
Fairly short bones mind, but how much travel do you really need?
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Alan B
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| posted on 29/8/05 at 03:40 PM |
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quote:
Originally posted by gazza285
All part of the challenge, but it has to be said I was going to try and use the original struts.
Definitely a good way to go.....
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cymtriks
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| posted on 29/8/05 at 05:08 PM |
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Look on the chassis section post!
I just posted three pics of my design on the chassis section thread and then I noticed the same issue here. Take a look.
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v8kid
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| posted on 30/8/05 at 07:32 AM |
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Wow chaps lots of nice designs out there!
Dominic has a good point proove it works and people will buy the plans - but what do people want?
Even in this short thread there is a huge diversity in ideas, strut, short wishbone, long wishbone, transverse, transaxle etc.
The beauty of the locost is that it can accomodate a wide variety of solutions from bike engines to V8's and from solid axles to fully
independant setups.
What we need is an adaptable design, simple and quick to construct without too many compromises.
I tried KB's idea of rearranging the sections of the book design - not as easy as it sounds but I'll persevere.
One of the major constraints is the type of engine transmission. Most front engine packages are wide which restricts the wishbone lengths and
transverse layouts are less available.
Interestingly Westfield have gone for transaxle and Lotus for transverse so no clues there.
Would there be general agreement that there should be wishbone suspension all round?
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Syd Bridge
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| posted on 30/8/05 at 08:29 AM |
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Looking at that Fiesta setup in the Mojo...and the strut setup itself is fairly universal among most manufacturers, some use a spigot for the strut,
and some a bolt-on.....
It would not be too difficult to make a dedion with end bracketry to hold the strut. No need for ball joints, as it would be held solid. Add a small
adjustable arm where the track rod goes, anchor the inboard end anywhere on dedion tube.
Anchoring this to the chassis then becomes a lot easier, and coilovers become a do-able alternative.
I've seen this somewhere before, but can't put a name to it.
Another project on the list??!!!
Syd.
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Fred W B
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| posted on 30/8/05 at 08:35 AM |
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Looking good guys, I like what Cymtrics has drawn, because it has no structure in the centre of the car. Many midi's have a transmission tunnel
type structure, only because the original seven style locost had it. You don't need it in a middy, rather put the strength down the sides where
it can be more efficient, and offer side protection.
Ducks and runs for cover......
Cheers
Fred WB
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v8kid
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| posted on 30/8/05 at 09:34 AM |
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Ah yes forgot about that side protection - should have remembered too as there was a close shave at one of the events this month - half the drivers
seat was demolished with the impact. driver okish (colarbone).
What about these ugly cages westfields seem to sprout?
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kb58
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| posted on 30/8/05 at 02:03 PM |
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quote:
I tried KB's idea of rearranging the sections of the book design - not as easy as it sounds but I'll persevere.
It's easy in concept, but still a lot of work to design - but very straightforward. My point was that the same Locost approach could work for
this, and using the pre-exisiting fiberglass parts means not having to make anything in composite.
Regarding the rear suspension arms, they design themselves. What I mean is, yes the engine's in the way, so don't go there. In other
words, rotate the a-arm so one arm is practically a trailing link, while the other goes straight inward, behind the transmission. That's what I
did on Kimini so I know it works.
Yes a DeDion could package well, once it's figured out how to miss the transmission case.
I very much vote for using complete, transverse, FWD drivetrains, That's where all the cars have gone and it only makes sense to use
what's out there. It also makes it much faster, simpler, and cheaper then adapting other transmissions to the engine.
[Edited on 8/30/05 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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kb58
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| posted on 30/8/05 at 02:19 PM |
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quote:
Originally posted by Fred W B
Looking good guys, I like what Cymtrics has drawn, because it has no structure in the centre of the car. Many midi's have a transmission tunnel
type structure, only because the original seven style locost had it. You don't need it in a middy, rather put the strength down the sides where
it can be more efficient, and offer side protection.
Ducks and runs for cover......
Cheers
Fred WB
In my car, I have a center tunnel. Removing it would not have allowed the seats to sit any closer since they touch already. It's a convienent
place to mount the shifter (for us left-drive types) and run all the hoses, pipes, and wires.
I agree putting more structure to the outsides helps torsional rigidity but since, in my case at least, I have little to no room between the seats and
the shell, ther's no room. The Mini is a small car! OTOH for a clean-sheet-of-paper design I see your point.
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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sgraber
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| posted on 30/8/05 at 06:08 PM |
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My intention was to build a low cost middy, and I am still on track to do that. The bodywork phase is, wthout a doubt, the most difficult part of the
project.
Regarding the chassis and specifically the packaging of FWD components into the rear compartment: My solution was to build a deDion around the back of
the transaxle. I wanted a solution that could be built without any machining. And one that would capitalize on the strength of the original strut
mounting points of the upright. So I rotated them 90d to the back. I like the simplicity of the deDion. I think it was the best solution for a person
of my limited fabrication and design skills.
Steve Graber
http://www.grabercars.com/
"Quickness through lightness"
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MikeR
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| posted on 30/8/05 at 09:28 PM |
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good god - blooming obvious idea - you don't have to keep the 'upright' upright!
Never thought of that!
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Fred W B
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| posted on 31/8/05 at 05:55 AM |
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Steve - Great idea, I like that a lot.
To get this to work, the body issue has to be sorted. As stated, it will have to be easy and cheap to make, and look good.
We have to look at things like the Ariel Atom for inspiration.
Image deleted by owner
I think the shortened nose/long boot modified 7 look is terrible. But then maybe the original 7 look only looks good because we are used to it? Every
other car that we think looks good has a streamlined look.
Fred WB.
[Edited on 31/8/05 by Fred W B]
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Alfalfameister
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| posted on 31/8/05 at 10:51 AM |
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quote:
But then maybe the original 7 look only looks good because we are used to it?
True, true... I'm not Brit, so to me, the Seven is not a "classic" looking car and all that. However, I'm still making one
because it should be a real thrill to drive.
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crbrlfrost
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| posted on 31/8/05 at 04:55 PM |
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I have to agree with fred. Sometimes structural elements can be quite satisfying to the eye and easily formed panels (out of flat stock such as Al)
can be made very attractive. But then again I'm a sucker for the atom, so excuse my bias. Cheers!
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