turbo time
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| posted on 1/3/08 at 04:17 AM |
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Middy BEC... Considering ATV/ Quad Parts?
So here's what I've had on the drawing board lately. When thinking about this, it helps to think of it as a shifter kart combined with
something like a Peel P50 that I'd like to use to go back and forth to work with a few days a week for fun.
-Very small single seater
-Mid Engine (right behind driver)
-Bike Engine (R6, R1, whatever I end up with for cheap/free, etc...)
-Transverse mounting, keeping chain-drive
-Size undetermined, but assume about 70" wheelbase, around 40" track...
-Target weight below 700 lbs (there will be some compromised things like noise insulation & lexan windows)
So you get the basic idea. I'm up in the air on some specifics, like what hubs/brakes/suspension components I'll be using exactly.
I'm looking at lots of options, I like ATV-size wheels for this purpose, and there are some available D.O.T. approved tires with on-road tread
patterns. Also, I noted that ATV's generally have reverse, decent front hubs and brakes. I'm not sure exactly what most of the suspensions
are, however. I haven't found many good pics. Most look like swing axles, but I'm told there are some with IRS, which might offer a good
chance to steal driveshafts, A-arms, etc. When I say borrow A-arms, I mean just that. I wouldn't be borrowing all the suspension travel or
anything, and I would be using my own spring rates/shock valving, designed for road use. This thing would have the normal locost 4" of ground
clearance.
I'm just brainstorming here until I can get a chance to go to the powersports place and crawl around in their showroom under their quads and
take a bunch of pictures.
If you've got any ideas for something like this, how I might want to go about it, help me out.
And no, I don't give a crap about safety, so save your thoughts about how it might be dangerous, of course it will... I'm not going to buy
a G-wagon, or hummer to putt around town with so I can "feel safe" like all my asshole neighbors.
Edit: Done a bit more research, and it looks like going longitudinal, losing the chain, and eating the extra weight and longer wheelbase might be an
option now if I get too lazy to pull apart a diff to keep the chain. A lot of these are torquey, they have fairly stout transmissions, most all of
them do look to have reverse (one honda even has a fully manual trans, but the kicker is that it can be shifted entirely push-button, that'd
make running shift linkage easy ). I guess the question then, which I can now frame, is would it even be worthwhile, or possible to try and mate a
better bike engine to one of these trans (which have some shortcomings) for the above advantages, or skip it and keep the bike trans at all costs. And
the problem in the back of my mind is whether or not a lot of the wear parts, like if I were to use ATV hubs, would they stand up to 80mph speeds? I
know quads are built durably and to offroad, but not to go 80mph for an hour or 2 straight. I don't know if these should or shouldn't be
concerns.
[Edited on 1/3/08 by turbo time]
The Projects: www.absurdcars.com
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bilbo
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| posted on 1/3/08 at 08:54 AM |
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This little fella was posted on here a while back. Is this the sort of thing you are thinking of? It was something I was considering for my mext
build:
 
Rescued attachment dh-3.jpg
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Build Diary: http://bills-locost.blogspot.com/
Web Site: http://locost.atspace.com
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SeaBass
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| posted on 1/3/08 at 11:31 AM |
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Drysdale... A nice little machine.
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Hammerhead
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| posted on 1/3/08 at 02:48 PM |
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I think this type of car is the future!
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hillbillyracer
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| posted on 1/3/08 at 05:08 PM |
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I work on utility spec (what farmers use) quads a fair bit & while as you say the engines are pretty torquey most havnt got all that much power,
the 500-800cc machines might have about 50bhp.
Mating a performace barrel & piston to the ATV crankcase & gearbox may well be possible as many quad engines were developed from 2-wheeled
bike motors. With the exception of Polaris most ATVs have a combined crankcase & gearbox.
Most Suzukis had a dedicated ATV engine which is quite long with two output shafts at the back (but no diff) for an IRS set up & an output forward
for the front diff if you fancy 4WD. Later Suzukis have a more convetional single output shaft at the rear (& another forward on a 4WD) that you
would need to use a RWD diff with, Yamahas, Kawasakis older Hondas are built in a similar fashion.
About 15 years ago Honda started to change their engine layaout from the 2-wheeler based OHC engines with the crank left/right across the frame to a
pushrod engine with the crank laid front/rear. The electric shift Hondas that I know use this layout & it'd be difficult to fit a different
barrel & head to that pushrod crankcase. The electric shifts were a fair bit a of trouble to kick off & though better still have a bit of
bother, the box itself is the same as a manual & it's the electric side that's to blame.
Chains have long since given way to shaft drive & IRS is much more common now, solid rear axles used to be almost universal.
Many ATVs are also automatic now but most use the variable pulleys & belt like an old DAF car which although far better than you might think may
not appeal. Almost all the Polaris bikes use this set up & go up to an EFi 800cc twin but it makes for a bulky setup.
You may find things different if you have a look at sports quads, they may well be better suited to what you want.
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