matjas
|
| posted on 13/4/19 at 09:44 AM |
|
|
donor car/s and frame layout
Hi, been lurking for some time but finally registered and this is my first post ever so bear with me please.
I am an avid motorcycle enthusiast and mechanic with solid background in welding and general metal fabrication. The Locost thing has been with me for
a couple of years already but finally I decided to let it out. The biggest problem was always the lack of registration possibility in my country but I
decided not to make it a factor - when I make the car I will register in in Czech Republic or Latvia. The only option that seems feasible.
I want a car that will be pokey, fast but no track machine - If I want to travel to the mountains or make a cross country trip /circa 500km daily/ it
should be well possible in the Locost I am gonna build, hence the 150HP mark and 700kg seems like OK with me. Want to base the machines around readily
available components.
The only novelty I want to have in my car is pneumatic suspension with ground clearance adjustment. Have the project in mind and more on it later.
I am about to start gathering info as to my build and from what I managed to find out I have my mind set on two options as far as the components
go:
1. 2.0 Zetec 170HP NA engine, get rid of the loom and injection and use the CBR600 carbs /manifolds and fabrication of other parts seem like no
problem to me at all/, Sierra MK9 5 speed transmission, Sierra or Scorpio rear diff/live axle /I am gonna aim for independent suspension of all
wheels/. Engine management will be done by Nodiz simple module.
The 170HP should give plenty of poke to this small vehicle while keeping the running cost at a reasonable level.
Should I want more powah later on, the soft turbo up to 0.8bar with some decompression gasket should be an easy addition.
2. Mazda MX5 full system - 110-140HP available /lower power will be offset by a lower weight I reckon/, more modern setup, injection retained /better
fuel efficiency/. Turbo possible as well as the Zetec at a later stage. More sluggish 'out of the box' but as I said before: the lower
power will propel lower weight, so the road feeling should be similar - probably with much weaker low end grunt which I would hate.
If I am to be honest, due to my two wheeled background I have also thought about a motorcycle engine in the car... but actually have no idea how to
NEATLY go about the drivetrain in case of the chain driven bikes... and cheap shaft donors like K1100lt or newer k1200lt seem not to be up to power I
would like... also this is not really the drivers car with the bike engine in it... Not the leisurely type I am aiming for. But... who knows.
The question now is: I can fabricate the frame in my workshop quite quickly but what kind of frame should that be... Does the standard Sevenesque
frame project fit both of my envisaged donor types or do I have to accommodate changes already at this very early stage as far as engine, gearbox and
rear axle unit are concerned?
Also the rectatube in the project is 25x25mm /25.4 actually but never mind/ but what is the standard wall thickness??? 2mm? 2.5mm?
Has anyone tried welding the frame using actual 25mm seamless tubes for the sake of rigidity?
Best regards from Poland.
matjas
[Edited on 13/4/19 by matjas]
[Edited on 13/4/19 by matjas]
|
|
|
|
|
Ugg10
|
| posted on 13/4/19 at 10:22 AM |
|
|
For a front engine longitudinal bike engine the usual process is the replace the main drive sprocket with a rubber donut Cush element and then run a
prop shaft to a standard Ricardo rear diff (Sierra) however due to the secondary gearing on the bike through the rear sprocket you need a diff longer
that 3.5:1, ideally 3.2:1 or longer. The other issue is that most bike engines will be biased to the left to get the drive down the centre tunnel, ok
if you are in the U.K. as it offsets the driver weight a little but in Europe the engine will be where your feet and pedals want to be.
If I were starting a project I would look at the Midlana rear/mid engine seven style car. Put a Zetec st170 with gearbox in the rear and use bigwassa
oem wiring (search on here) to get it running as standard. A lot easier than getting a front engine - rear drive going these days unless you use the
mx5 complete. Worth looking also for reference at the Sylvia Vectis that used the whole MGF subframe, suspension, engine (160 he available plus a plug
and play emerald ecu) and gearbox in the rear and also the various exo cars like the exotech which uses the Zetec engine as well.
Just a few thoughts.
---------------------------------------------------------------
1968 Ford Anglia 105e, 1.7 Zetec SE, Mk2 Escort Workd Cup front end, 5 link rear
Build Blog - http://Anglia1968.weebly.com
|
|
|
matjas
|
| posted on 13/4/19 at 10:34 AM |
|
|
Did not think about the bike engine canting as a problem , however it certainly is something to keep in mind. This could be offset by placing the bike
engine weight wise in the middle of the car and dividing the drive shaft in the middle so that it enters the middle tunnel at an angle.
In all honesty - if the notsosymmetrical  bike engine placement is an issue what about the weight distribution of the whole setup with the
engine/box at the back??? I am not keen on this setup really.
The bike engine is VERY tempting /I would opt for the CBR1100XX lump due to high HP numbers and excellent reliability/ + LOW WEIGHT, but wonder what
would be the everyday rideability and cruising with such high revving setup. Also, as you said, the diff should be really high input. Any idea where
to aim as far as diff is concerned? Only live axles come in play.
As much as reliability/tuneability and car like feel of the Zetec setup, the low weight and compactness of the XX engine is really something that
moves me towards this solution.
regards
matjas
|
|
|
Ugg10
|
| posted on 13/4/19 at 10:47 AM |
|
|
For a light weight car engine the two I would look at are the rover k series (160vvc) or the ford Zetec se / sigma engine. Both all alloy and with a
few mods the ford 1.6 can be made to rev to 8500 rpm and make 170hp (throttle bodies, ecu, ss4 cams, had rod bolts, gd valve springs, exhaust). Or
look at the Duratec but this is a tall engine and does not readily bolt to the rwd ford boxes but us available in the mk3 mx5 with a rwd gearbox but
the engine and box are at an angle to each other which may be an issue or will need engineering in. Rwd type 9 bell housings are available for the
Duratec and Zetec she from retroford in the U.K.
You could Aldo look at modifying the midlana chassis to accept a bike engine with chain drive but this would be an independent suspension. Search west
wales trikes for rear diff examples. This has been done in the Sylvia mojo iirc and again the exo cars have various examples from fireblade to bussa.
The original SDR Storm had a Aprilia RSVR twin mounted sideways and bolted pretty much directly to a diff (independent again) mounted in the rear.
For rear axles the English and atlas axles are the usual options iirc the atlas or Koln come in 3.44 ratio but happy to be corrected, lowest English
is 3.54. (Sierra independent came in 3.14 but these are rare, land rover freelancer diff are also popular with bike engines). Some have used the Volvo
340 in classic cars so may be worth a google what ratios they come in and how wide they are.
---------------------------------------------------------------
1968 Ford Anglia 105e, 1.7 Zetec SE, Mk2 Escort Workd Cup front end, 5 link rear
Build Blog - http://Anglia1968.weebly.com
|
|
|
matjas
|
| posted on 13/4/19 at 10:51 AM |
|
|
Many thanks mate. That is something for the starters.
And how about REVERSE in a bike powered Locost???
Could you also say anything about the framing version as in OP and material for the very frame?
regards
m
[Edited on 13/4/19 by matjas]
|
|
|
Ugg10
|
| posted on 13/4/19 at 10:59 AM |
|
|
Sorry, only used pre-built frames but a look at the Haynes/Locost/Midlana plans or find someone who sells flat pack chassis will give you a good
start.
---------------------------------------------------------------
1968 Ford Anglia 105e, 1.7 Zetec SE, Mk2 Escort Workd Cup front end, 5 link rear
Build Blog - http://Anglia1968.weebly.com
|
|
|
matjas
|
| posted on 14/4/19 at 10:06 AM |
|
|
a precut frame flatpack does not live on the Locost side of the things
still - the question is open what kind of the tubing should be used.
25x25mm and wall thickness???
has anyone used seamless precision tubing?
one question that arised - when creating the brake circuitry do you use any kind of braking power distributor to achieve the 70/30% braking power
front/back? of course servos and separate front/back circuits do get used in locost?
regards
matjas
|
|
|
JonBowden
|
| posted on 15/4/19 at 05:02 PM |
|
|
The tubing is mostly 1.6 mm (16 guage). The book suggests ERW tubing for the frame but seamless for the suspension parts.
I take it that you are thinking of a semi off road vehicle? If so, you might want to use bigger tubing.
I'd definitely suggest buying the standard locost books an possibly the Midlana book.
[Edited on 15/4/19 by JonBowden]
Jon
|
|
|
