Dean
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 posted on 1/8/04 at 07:50 PM |
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Bec middie
Just wondering if it was possible to setup a bec in a mid-engine configuration with an automoitve drive shaft and irs? Just like the front engine bec
cars but with a mid-engine and a shortend drive shaft?
Thanks.
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liam.mccaffrey
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| posted on 1/8/04 at 08:19 PM |
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yes why not, if ihave understood you correctly
you can do anything you want inthis game its just the more different it is the longer it takes
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alister667
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| posted on 1/8/04 at 09:23 PM |
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Sounds like you're describing the Fisher Fury Menace (Mid ENgined ACE) - it's been featured in a few of the kit mags recently - it uses a
very short propshaft. I can't rememeber if it has IRS or not though.
http://members.lycos.co.uk/alister667/
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andkilde
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| posted on 1/8/04 at 09:30 PM |
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Hi Dean
That's the configuration I'm hoping to use myself. The Fisher Fury Menace uses that layout as do the Coram LMP and the new middy from
MK.
I believe we can do away with the driveshaft completely with a carefully designed flexible coupling -- I've been looking at industrial couplings
(as used between large electric motors and hydraulic pumps) but I'm thinking about simply purchasing a ready made piece from one of the
manufacturers).
I'm working on mastering SolidWorks at the moment so I can convert my napkin scratchings into something useful.
How far along in the process are you?
Cheers, Ted
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Sven
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| posted on 2/8/04 at 06:45 AM |
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me too, me too
quote:
Originally posted by andkilde
I believe we can do away with the driveshaft completely with a carefully designed flexible coupling -- I've been looking at industrial couplings
(as used between large electric motors and hydraulic pumps) but I'm thinking about simply purchasing a ready made piece from one of the
manufacturers).
Crikey. I hate to say me too, but 'me too'! Thinking about a 900+ (R1 GSXR1000, etc.) Jap inline 4 longditudanally(sp?) mounted behind
the driver (did I mention I'm looking at a single seater) with the output splined shaft directly coupled to a 3rd member via a flexible thingy
of some kind (TBD). Any help with ideas on the coupling would be tremendous.
Some of the Locost BEC builders appear to like the Land Rover Freelander diesel diff because it's IRS and it has a 3.182 ratio.
These diffs are like hens teeth in the US, so other options include a Mazda Miata but the ratio will be uncomfortable. I may consider a solid/live
rear axle and options include a Triumph GT6 (3.27:1) and a Ford Pinto (3.08:1), the latter sounding almost perfect with disk brake kits being very
affordable assuming the sucker can take the horsepower and the weight is reasonable.
For my application; going really fast on pretty smooth roads and at track days, I think a live axle would be just fine, but I do have a fully loaded
rear subframe for a Miata that might be useful assuming I can find reasonable final drive ratios for it.
I'm too cheap, by far, to spend $3200 on a Quaife differential, but that would be perfect if I wasn't so tight, ie: had a family to
feed.
I have Honda Civic front hubs, uprights/struts, which have the same PCD as the Miata, and I'd probably modify them to be suitable for the usual
unequal length a-arms with Yamaha R6 coil over shocks via a pushrod/rocker arm configuration.
Next steps for me is to obtain more parts for mockup, build a Staniforth string computer then do some AutoCAD and build a few balsa models of the
frame.
-Steve
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spunky
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 posted on 2/8/04 at 09:21 AM |
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You mean like mine, See archive
quote:
Originally posted by Dean
Just wondering if it was possible to setup a bec in a mid-engine configuration with an automoitve drive shaft and irs? Just like the front engine bec
cars but with a mid-engine and a shortend drive shaft?
Thanks.
The reckless man may not live as long......
But the cautious man does not live at all.....
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JoelP
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| posted on 2/8/04 at 05:58 PM |
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spunky, is that two sierra UJs bolted together? looks good, does it work well?
 
clutch adapter 2
[Edited on 2/8/04 by JoelP]
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Sven
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| posted on 2/8/04 at 06:16 PM |
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Yuh, exactly like that. So, in your opinion then, there is no need for a means to separate vibrations between the engine and 3rd member, assuming
they're both well mounted to the frame?
I assume a live axle would put the cat amongst the tree rats, then, as the whole axle needs the ability to move up and down.
FWIW, I'm still in the exciting thinking about it stage, although I have bought some cheapish parts, so I'm still open in most
respects.
Anything I should bear in mind that you can think of from your experience?
-Steve
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spunky
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| posted on 2/8/04 at 07:20 PM |
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Hi Sven, Joel, you're right, it is simply two UJ's bolted together.
Certainly does what its meant to do. The engine is mounted rigidly, so there is no movement, which would be a problem with such a short prop. the
advantage is the power transfer is very 'direct', the disadvantage is the engine vibes are passed through the whole chassis. That is only
really noticeable in the mirrors at certain revs.
I took a lot of time ensuring the allignment of engine and diff were perfect (this goes against the theory for 'normal' prop shaft
arrangements) but I wanted it balanced. there is no chance of oscillation on prop that length.
Sven, the only thing that springs to mind is mount the engine first and give the diff. mounts a bit of slack or slots. That way the coupling can be
torqued up fully without the risk of stressing any mounts.
Mine are slotted, giving around 3/8" to play with, as I plan on fitting an electric reverse and want to sandwich the flywheel between the UJ and
diff flange.
This idea can only work with IRS or De-Dion not live axle.
John
The reckless man may not live as long......
But the cautious man does not live at all.....
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Sven
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| posted on 2/8/04 at 09:17 PM |
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Thanks John. I thought about mounting the motor using stiff rubber engine mounts and the diff using rose/heim joints so it could be adjusted fore and
aft as necessary.
Thanks for your suggestions.
-Steve
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Peteff
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| posted on 3/8/04 at 07:24 PM |
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I read somewhere about a joint using 2 sprockets with a piece of duplex chain round them. I can't remember where or when but it sounds like an
idea worth studying.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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spunky
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| posted on 3/8/04 at 07:34 PM |
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quote:
Originally posted by Peteff
I read somewhere about a joint using 2 sprockets with a piece of duplex chain round them. I can't remember where or when but it sounds like an
idea worth studying.
Interesting idea. I've used it for lashing together temporary drives at work, would have thought the torsional forces were a tad high as you
would be driving on half a link.
Spent a bit of time trying to find a Fenner coupling that would fit, either a tyre or star. Sure they would work but one with a high enough spec was
too big. pity as it would relieve some of the backlash and 'clonking' you get with a BEC.
John
The reckless man may not live as long......
But the cautious man does not live at all.....
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sgraber
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| posted on 3/8/04 at 11:52 PM |
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Dennis Palatov of DPcars.net is attaching his Hayabusa engine using rubber donuts from a BMW driveshaft... Does this help? (Since I have no practical
experience in these matters)
edit - oops link to http://www.dpcars.net it's the little silver beasty he's building...
[Edited on 8/3/04 by sgraber]
Steve Graber
http://www.grabercars.com/
"Quickness through lightness"
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ceebmoj
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| posted on 4/8/04 at 07:04 AM |
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Sounds a lot like what I am trying to build all though my work as staled some what. However I would be interested in swapping Ideas. The last thing I
did was have some plates laser cut so that I could mount bike front disks directly on to a sera diff.
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spunky
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| posted on 4/8/04 at 08:27 AM |
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quote:
Originally posted by ceebmoj
Sounds a lot like what I am trying to build all though my work as staled some what. However I would be interested in swapping Ideas. The last thing I
did was have some plates laser cut so that I could mount bike front disks directly on to a sera diff.
Thats what this forum does very well, im happy to share my experiences and swap ideas.
Steve- Had a good look at the DP1 site, hell of a car but somehow I don't think it is particularly 'Locost' 
John
The reckless man may not live as long......
But the cautious man does not live at all.....
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mangogrooveworkshop
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| posted on 4/8/04 at 09:54 AM |
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quote:
Originally posted by Peteff
I read somewhere about a joint using 2 sprockets with a piece of duplex chain round them. I can't remember where or when but it sounds like an
idea worth studying.
Chris Allison of Zcars does the bits for this type of drivetrain
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Hugh Jarce
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| posted on 6/8/04 at 04:03 AM |
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Some of the industrial transmission flanges are perfect for this. They come with a variety of splines/flanges/fixings and and the male and female
halfs are cushioned with a separate polyurethane "star". Some are designed to handle up to 500 hp and high torque figures.
The pay isn't very good , but the work's hard.
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spunky
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| posted on 6/8/04 at 05:54 PM |
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quote:
Originally posted by Hugh Jarce
Some of the industrial transmission flanges are perfect for this. They come with a variety of splines/flanges/fixings and and the male and female
halfs are cushioned with a separate polyurethane "star". Some are designed to handle up to 500 hp and high torque figures.
I agree they would be perfect. However I checked through all the cataloues at work and the couplings with a suitably high rating were all on the large
side
John
The reckless man may not live as long......
But the cautious man does not live at all.....
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sgraber
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| posted on 6/8/04 at 06:09 PM |
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ermm, if you look at the photo I posted above you will notice that the rubber piece being used by DPCars is a BMW bog stock part for the driveshaft
(320i?) and it is exactly what you are talking about but designed for a car....
Steve Graber
http://www.grabercars.com/
"Quickness through lightness"
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spunky
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| posted on 6/8/04 at 06:58 PM |
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They still must be around 5.5" diameter. very similar to the old Hillman Imp 'doughnuts' (English spelling) would have been too
tight for my installation without cutting chassis members.
Worth bearing in nind though.
John
The reckless man may not live as long......
But the cautious man does not live at all.....
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Mark Allanson
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| posted on 6/8/04 at 07:18 PM |
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quote:
Chris Allison of Zcars does the bits for this type of drivetrain
Its ALLANSON!!!!
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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ned
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| posted on 9/8/04 at 08:43 AM |
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that rubber donut looks exactly like the one on the girlfriends 316 compact. i noticed the other day when putting the spare wheel back on the car
under the boot.
Ned.
beware, I've got yellow skin
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Hugh Jarce
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| posted on 9/8/04 at 01:30 PM |
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quote:
Originally posted by spunky
They still must be around 5.5" diameter.
As Graber says they are made for the job but they are on the large side.
The industrial ones I had in mind are about 75mm to 90mm diameter. Yhe other thing to use is one of the metal to metal drag racing diff couplers. The
male would go on the motorcycle output shaft and the female bolts onto the nose of the diff in place of the flange.
 
Rescued attachment diff_coupler.jpg
The pay isn't very good , but the work's hard.
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MrFluffy
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| posted on 9/8/04 at 01:49 PM |
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cushioning
If your worried about the harshness of drive train, its worth noting that most bike engines have some sort of cush drive in the clutch hub (which will
be retained), along with the rear wheel. If it all gets snatchy after a year or so of abuse, worth checking that the cush drive hasnt broke up...
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malcolmstoddart
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| posted on 9/8/04 at 07:06 PM |
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task your local "Wyco" sales rep (or equivalent bearing supplier) with a headache tell him all the torque figures, rpm, angular
offset, shaft sizes, rolling diameters...etc... and he will come up with the goods, works for me at work anyway, when I can't be arsed to fathom
it all out...
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