francy555
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| posted on 16/5/06 at 03:03 PM |
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Hayabusa powered Robin hood lightweight
Hayabusa powered Robin Hood lightweight
Hi, i'm building a robin hood lightweight and hope to power it using a Hayabusa engine which i already have.
I would like to know has this chassis and engine combination been tried before?
If so what problems where encountered during the build?
I would also like to know does anybody do a cradle to mount the hayabusa in a car?
Regards
francy.
Ps I'm new on this site so please be gentle!
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ned
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| posted on 16/5/06 at 03:42 PM |
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please don't do multiple posts, its not really the done thing. this section is probably the best area for you to post this particualr thread
in.
no idea on the question though I'm afraid!
cheers,
Ned.
beware, I've got yellow skin
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OX
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| posted on 16/5/06 at 04:21 PM |
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hi francy
i dont know of a robin hood with a busa engine but there must be some out there.
you might want to get a dry sump for the busa or a wetsump with swivel pick up from holeshot turbo's.
MK sportscars did my busa engine cradle.
have fun with your build and welcome
ox
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ChrisGamlin
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| posted on 16/5/06 at 05:22 PM |
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Im sorry to be so blunt with your first post and Im not sure what stage of build you’re at but if you want a busa or any other half powerful engine,
please reconsider and look for something other than an RH Lightweight chassis.
I have seen an RH Lightweight in various stages of build and to say its shockingly weak and poorly designed is a huge understatement in my opinion,
and from what I saw it would struggle to hold together with a moped engine let alone a Busa. 
When I saw a chassis part built a few months ago it was obvious how weak it was compared to a steel spaceframe chassis, especially in some of the most
important areas like suspension, drivetrain and passenger area. Having reached the stage of almost completing the chassis, the owner of the chassis I
saw is now of a similar opinion, initially the car was purchased as a potential light weight track / race car but he too now feels that it is not
suitable for use on track even with the improvements he planned to make to the chassis (foam sandwich as much as possible, properly bond the panels
together as opposed to just rivetting as RH suggest etc).
As an example the tub sides and transmission tunnel are all single skin ally of approximately 1.5mm thickness with the top “rail” of the
chassis just single thickness ally bent over as 3 sides of a square so not properly boxed, i.e. similar to an ally skinned Locost chassis side, but
without the steel spaceframe part to rivet the ally to! The diff also appears to be mounted by bolting it through a flat panel of 1.5mm ally that sits
either side of it, again I couldn’t see how it will cope with any serious power output without the diff ripping itself from the mountings. See the
pics below to see what Im on about
The suspension arms pick up on the bit of 2” box section ally you see in the pictures below, suspended through 2” squares cut into the ally sheet with
no obvious method of accurately locating it to get the geometry accurate without complicated measuring. This is the same on the front and the rear
suspension
Side Rail of chassis by the driver
Rear Diff Mounts
Rear Diff Mounts 2
Back End
I could go on as there were several other things I though were very poor or IMHO verging on dangerous, but I think you get the idea, and this was
being built by a pro race prep engineer so its as good as it will get
[Edited on 16/5/06 by ChrisGamlin]
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francy555
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| posted on 16/5/06 at 07:04 PM |
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Chassis strength
Hi chris, ox and ned.
Sorry for the multiple posts ned, had the first two on before i noticed the BEC section.
My chassis is almost built. The chassis is fully bonded together along with the rivets, this was recommended to me by Richard from RH.
I was thinking that the engine bay and passenger area were going to need some severe stengthening to take the hayabusa engine. However i don't
think the hayabusa engine is much heavier than the pinto the car was designed for but i do appreciate the power difference.
I recently bought a quaife reversing box on ebay and the guy i bought it off was very helpful to me once he had heard of my plans for the box. He
contacted MK engineering who also advised caution about what i was intending to do yet they were willing to make a cradle for me.
I agree with the poorly dsigned aspect of the kit, some of the panels i have recieved are some what suspect in terms of hole alignment etc.
I am aware that i will at least need to baffle the sump and make a few other modifications to the clutch change srings etc.
I intend to use the car for occasional fast road use and scare the living daylights out of myself and my 2 evo 7 driving mates.
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ChrisGamlin
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| posted on 16/5/06 at 08:13 PM |
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Im pleased at least that you can see the shortcomings of it, obviously its mainly power and acceleration etc that puts forces through the chassis
rather than engine weight, cos a busa is much lighter than a Pinto! 
By the design I didnt really mean fit and finish as such because some of it is actually quite well manufacturered, its just the lack of strength that
concerns me most, and without putting some kind of spaceframe inside (so defeating the purpose) it I cant see there's a huge amount you can do
to significantly improve things unfortunately.
Good luck with it though
cheers
Chris
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russbost
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| posted on 16/5/06 at 10:02 PM |
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Have to say I'm surprised that someone of Robin Hoods size wouldn't have had the chassis checked out on a CAD package. I thought the idea
of the lightweight was good & original, but must say I can't see those diff mounts standing for much abuse (I've not had a close look
at the kit "in the flesh" . That said IF it can stand up to a standard Pinto it ought to withstand the standard 'Busa. The Busa is
about 100kgs lighter than a Pinto & gearbox & produces no more torque, although over half as much power again, but you've substantially
less weight to get on the move. It's the twisting action of the torque which tends to destroy diffs & their mountings. I'd be
interested to hear the final outcome of this!
Incidentally, I know 'Busas need dry sumping for serious use, but do they need it for road use too?
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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kb58
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| posted on 17/5/06 at 01:43 AM |
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quote:
Originally posted by russbost
... The Busa is about 100kgs lighter than a Pinto & gearbox & produces no more torque, although over half as much power again, but
you've substantially less weight to get on the move. It's the twisting action of the torque which tends to destroy diffs & their
mountings.
Yes but horsepower is horsepower. If you have one engine that makes 200ft-lb of torque, then replace it with a sportbike that makes only 100ft-lbs,
that seems like less torque. But then it goes through a higher ratio gear reduction because it's litterally spinning twice as fast... so that
100ft-lb turns into 200ft-lbs. It all goes back to the equation:
HP = torque * rpm / 5252
If you have half the torque but twice the rpm, it's all the same...
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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tks
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| posted on 17/5/06 at 06:14 AM |
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exept
driveability / rpm choice..
and thats the reason everything wich goes fast wants to have revs
because revs means speed choice...
in a corner or in a bend...
Tks
p.s. the ligth wight chasis could do with some lateral stiffness (seeing diff pics)
anyway, i only can think of a bit of twist in the diff and not of shearing of the ally plates...
The above comments are always meant to be from the above persons perspective.
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ChrisGamlin
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| posted on 17/5/06 at 05:35 PM |
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quote:
Originally posted by russbost
The Busa is about 100kgs lighter than a Pinto & gearbox & produces no more torque, although over half as much power again, but you've
substantially less weight to get on the move. It's the twisting action of the torque which tends to destroy diffs & their mountings.
I'd be interested to hear the final outcome of this!
Dont forget that at the back end, there will be SUBSTANTIALLY more torque applied to the diff by the busa than the Pinto could ever muster, because
its all multiplied up by the gearboxes.
EDIT: oops must read he complete thread first, totally agree with kb58 
cheers
Chris
[Edited on 17/5/06 by ChrisGamlin]
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bike_power
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| posted on 18/5/06 at 08:44 PM |
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Is there anybody apart from RH with one of these cars on the road yet, running reasonable power and done a few miles ?
I agree with the comments above, the chassis I saw didn't inspire confidence.
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ChrisGamlin
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| posted on 18/5/06 at 09:01 PM |
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The one Ive seen is now in a running state although I dont think its on the road. I too would be worried even more about the long term prospects of an
aluminium chassis that is very poorly designed to start with.
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Peteff
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| posted on 18/5/06 at 10:49 PM |
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the long term prospects of an aluminium chassis that is very poorly designed to start with.
Is this in your opinion or do you have anything to prove it ? I would be careful in blackening someones reputation with a damning statement if they
were in a position to take you to court and ask for proof of your allegations, especially if they had more money than you.
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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ChrisGamlin
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| posted on 19/5/06 at 05:01 PM |
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Step away from the soap box 
When commenting specifically on the RH I clearly said it was in my opinion, and in the last post, you missed out the start of the statement which said
"I too would be worried" which also confirms its my opinion Im expressing, nothing more.
Anyway, I think you'll find that I never mentioned any specific manufacturer in the statement you picked up on, I was just commenting that an
aluminium chassis, if poorly designed, would concern me in the long term (due to aluminium's inherent tendancy to fatique crack). People can
make up their own mind whether the RH falls into that category or not though.
[Edited on 19/5/06 by ChrisGamlin]
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Peteff
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| posted on 19/5/06 at 07:52 PM |
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Just thnking about your wallet, you didn't put any "in my opinions" in the last post. I think the thread title puts us in no doubt
which manufacturer you meant francy asked for a gentle opinion in the first post and as he already has the chassis, I don't think he wanted
to be told it's a crock. You did wish him luck with it though, so I suppose that's some concolation.
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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ChrisGamlin
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| posted on 19/5/06 at 09:31 PM |
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If RH sued everyone that typed a bad word about their cars on a kit car forum then the British justice system would grind to a halt and overflow
It is hard to fully appreciate its design without seeing one in the flesh but to put it into perspective, I honestly would refuse the offer to drive
or passenger in one purely because of my concerns about the structural integrity, which is something I dont think I'd say about any other kit
car I can think of. I certainly wouldnt extend that concern to the other RH cars in the range for example, which although possibly a little
agricultural in some of their engineering (in my opinion!) and not to my personal taste, at least seem to be fairly solidly built on the whole, and
the new "Hood" chassis they've recently shown actually looks fairly good in concept so could well be a great alternative to the
usual Locost chassis suppliers when its released.
At the end of the day maybe Im totally wrong about the Lightweight and it may prove itself to be a great design thats far
stronger than it appears and is as safe as any Locost-esque steel spaceframce chassis, but my uncle who's a welder by trade running a race car
prep company has also seen it in the flesh and if anything he had worse things to say about it than I did, so make of that what you will.
Anyway, it was all in my opinion and Im sorry if I offended francy but to me its a concern whether a design, which in my opinion appears extremely
weak compared to a Locost for example, would be safe and robust enough to use in anger on the road or track, especially one with 400bhp/ton! Because
of this I did feel the need to post in the way I did because I think francy should go into it with his eyes open to the potential pitfalls (which he
seems to be doing), especially as he's fitting such a powerful engine and obviously investing a reasonable amount of money into it. If I was
building something and others had fears over its strength or safety, Id rather those fears were aired so I could (if I felt necessary) make changes to
alleviate those concerns and satisfy myself that it was safe, rather than people not mention it for fear of upsetting me then finding out the hard way
that the fears were correct when having an accident or when something broke because of a poorly designed component.
cheers
Chris
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Avoneer
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| posted on 19/5/06 at 09:46 PM |
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And breath.
Pat
No trees were killed in the sending of this message.
However a large number of electrons were terribly inconvenienced.
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JoelP
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| posted on 19/5/06 at 10:04 PM |
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much more fun to build your own chassis from scratch, then theres no one to blame if it goes tits up!
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russbost
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| posted on 20/5/06 at 11:32 AM |
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quote:
But then it goes through a higher ratio gear reduction because it's litterally spinning twice as fast... so that 100ft-lb turns into 200ft-lbs.
It all goes back to the equation:
Pinto 1st gear ratio either 3.58:1, or 3.65:1, don't have ratios for 'Busa, but ZX9,10 & ZZR1100 are all similar @ 2.8:1
Hence the bike engine, which is starting out with less torque, has much less by the time it gets to the rear axle, so I'll beg to differ on this
one.
Leaving that & far more to the point, the Pinto has about a 3 ton flywheel, heavy crank & pistons & a heavy front pulley, the bike has
virtually no flywheel, minimal front pulley & light crank & pistons, hence the kinetic energy stored by the rotating mass in the bike engine
is far less than that of the car (even when spinning much faster, hence why bike engined cars are not the easiest things to pull away in without
plenty of revs. If you hold a Pinto @say 4000rpm & dump the clutch the instantaneous forces transmitted to the diff are massive, to produce the
same sort of forces from a bike engine you'd need to scream it to about 14000 & when you dumped the clutch it would probably slip cos its
wet. QED
I stand by my previous statement that a Pinto is going to transmit more (instantaneous) torque to the diff than a 'Busa is - any
questions?
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ChrisGamlin
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| posted on 20/5/06 at 11:52 AM |
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quote:
Originally posted by russbost
Pinto 1st gear ratio either 3.58:1, or 3.65:1, don't have ratios for 'Busa, but ZX9,10 & ZZR1100 are all similar @ 2.8:1
Hence the bike engine, which is starting out with less torque, has much less by the time it gets to the rear axle, so I'll beg to differ on this
one.
........
I stand by my previous statement that a Pinto is going to transmit more (instantaneous) torque to the diff than a 'Busa is - any
questions?
Yep
You're forgetting the primary reduction gear in the bike engine which means the gears are actually much lower than just looking at the actual
gear pairs. For example, on a busa 1st gear is 2.6:1 but the primary reduction is 1.6:1 so overall 1st is the equivalent to 4:1
At the end of the day if a Pinto put as much torque through the drivetrain as a Busa, then it would accelerate as quickly. OK there's always a
weight difference but if you could get a Pinto car down to say 550kgs, I would be my house on a 550kg busa whipping the crap out of it under
acceleration
BTW I can see what you mean about everything in a Pinto being heavier inside so might transfer more instantaneous shock, but when dumping the clutch
like you mentioned, the limiting factor is always going to be the tyre grip so its not as though the diff has to absorb all that energy and stop the
momentum dead, it just means the tyres break traction more easily. If the rear brakes were on solid and you dumped the clutch then yes the Pinto would
load up the diff mounts far more as the diff would have to resist all that extra momentum, but all the time the tyres can spin I think this would be
the limiting factor on any instantaneous load when pulling away sharply, not the weight of the rotating parts in the engine.
cheers
Chris
[Edited on 20/5/06 by ChrisGamlin]
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russbost
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| posted on 20/5/06 at 12:49 PM |
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First, apologies to Francy for hijacking his thread, but I think this is an interesting & informative discussion.
Yes, hands up, I admit I'd forgotten about the reduction gear - BUT ............
Busa, about 80lbs/ft, believe this is about right? Pinto around 100lbs/ft. 80x4.16 (the overall 1st gear of the Busa) =332.8lbs/ft 100x3.65 (1st on
the Pinto) =365lbs/ft
Hence the Pinto transmits more torque (particularly instantaneous torque) to the rear axle. The reason the Busa engined car accelerates faster is that
it's lighter & has around 80 Neddies more under the bonnet, we've now moved away from torque & got into power differences.
However I do agree (Hurray!!!) that the Busa is obviously transferring more energy overall than the Pinto otherwise it wouldn't be
quicker if the cars were the same weight. But, the Pinto will deliver that initial chunk of twisting force more viciously.
Are we all now agreed?
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ChrisGamlin
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| posted on 20/5/06 at 01:00 PM |
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Yep sorry for the hijack
A busa also produces 100lb/ft so does leave it higher than the Pinto in that example, but whether its more or less I dont think it would be
significantly different either way, so I guess it comes more down to the fact that the busa will produce more force for a greater proportion of the
time?
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russbost
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| posted on 20/5/06 at 01:05 PM |
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Perhaps the answer is some stronger diff mounts - better safe than mashed!!!!!
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ChrisGamlin
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| posted on 20/5/06 at 01:07 PM |
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Which leads us nicely back on topic, because its the diff mounting method on the Lightweight that is one of the things that concerns me
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tks
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| posted on 20/5/06 at 01:14 PM |
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@PETEFF
Its totall b**chips in my opinion!
If we are in a free country we can say what we want i didn't saw the chasis yet but a bit of a designer knows that 2 ally plates won't
with stand a seasonfull braking accelareting.. at least nog for 10years!!
Robin Hood can have more money, but they would be dump to take it to the court
because then the buyer could do the same and tell them that its crap what they sell and not even mentioning the riscks of it!
the biggest thing what you should think about is WHO made the statement.
whas it the queen of england?
whas it a important person?
whas it a proffesor of alloy?
i like it (and its spanish) to tell the true of your feelings to this chap, imagine he build and it falls apart and he had a accedent the minimum what
we can do is underline the extra risks/advantages
because remember one thing where there is more advantage there is also a more risk!!
i agree with chris
Tks
The above comments are always meant to be from the above persons perspective.
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