David Jenkins
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| posted on 23/6/04 at 08:06 AM |
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I'm a bit concerned...
...by the large numbers of drivers who seem to be stuffing their bike-engined Locosts into the scenery! There have been quite a number recently, but
no-one's reported lately that they've put a car-engined car into the hedge.
Is it just the phenomenal acceleration in a light car, or is there a fundamental design issue that's making them very hard to drive? For
example, tyres that are too wide for the light-weight car? Or is it purely inexperience?
If the insurance companies latch onto this trend there'll be a "premium adjustment" in the coming months for the bike engined
cars...
David
[Edited on 23/6/04 by David Jenkins]
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Terrapin_racing
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| posted on 23/6/04 at 08:38 AM |
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A number of incidences I have read about were due to the drivers unfamiliarity with the power curve of the bike engine - now fitted to there car. One
guy was happily accelerating around a bend when the motor came on cam and he did a pirouette act writing the front end off!
This was his first run in the car 
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ned
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| posted on 23/6/04 at 08:42 AM |
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i'd tend ot agree with terrapin man..
a bike engine is revvy and the engine accelerates quickly thorugh the rev band. most of hte accidents i've come accross have been people getting
it round half way round or out of a bend.
most people know what to expect from a car engine, the engine doesn't accelerate as quickly normally but has more torque and possibly a better
torque/power curve than a bike engine. so perhaps a combination of experience and engine type would be my guess...
Ned.
beware, I've got yellow skin
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Terrapin_racing
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| posted on 23/6/04 at 08:48 AM |
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Makes me ask the question - how many bike engined builders have ever had a bike? I know loads of guys (but generally in motorsport) who have bike
motored cars but hae never ridden a bike!
Maybe thats why a few come off so badly at first??
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locoboy
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| posted on 23/6/04 at 10:40 AM |
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as a first time bec builder I too am a bit concerned by this I think the recent reports should serve as a warning that these cars are probably as far
removed as can be from a normal car driving experience and should be shown the respect they deserve.
I for one will be taking it steady in my CBR 1000 car ...............well round the bends anyway 
Isnt it the case that those most recently to stuff it in the scenery are people who have bought the cars not built them? Maybe there is a bit of car
self preservation in every builder which limits the number of risks they take..............................there is after all a lot of blood sweat and
tears involved in each and every home built car out there.
ATB
Locoboy
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ned
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| posted on 23/6/04 at 11:00 AM |
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col, i believe you're right. i also heard that insurance is cheaper if you built the car yourself, you're less likely to bend it as you
know how much effort was put into making it! its the people that buy cars other people have made that end up bending them quite quick it would
appear.
those that bend cars they made themselves are probably more likely to fix them themselves too and not let on to an insurance company if they can get
away with it! whereas those thaat just bought the cars wouldnb't know where to start, so settle with the insurance company instead.
Ned.
beware, I've got yellow skin
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spunky
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| posted on 23/6/04 at 11:23 AM |
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My insurance policy is for parts cost only in the event of a claim, no lobour costs are covered.
Has anyone had a BEC on a rolling road.
I'm very interested to know what the rearwheel torque figure is. The diff and smaller weels will all act as torque multipliers. I have a feeling
the figures could be surprising. Maybe some of the racer members know the maths involved...
John
The reckless man may not live as long......
But the cautious man does not live at all.....
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Jasper
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| posted on 23/6/04 at 11:24 AM |
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I would agree, you have to treat these cars with a lot of respect, I was driving home in the wet last Sunday, and just putting the pedal half way down
on a straight lit the back wheels up.
It's more like driving a true race car - progressive acceleration out of a corner, always break in a straight line, be smooth and flowing when
driving.
Though I would also add these cars do - on the whole - break away at the back end quite predictably. I think what happens to most people mid bend is
lift off overstear, go in a little bit strong, get scared, lift of the accelerator too fast, and the back end comes round. This is far less
predictable and snappy than regular oversteer.
I would suggest that EVERYBODY who has never driven a seven (esp BEC) or the like b4 goes on a track trainig day b4 going on the road, it really gives
you a good bit of practice in handling the car.
And I also don't think that many people realise just how quick these cars are. I was following Hicost down a piece of straight, dry dual
carriageway on Sunday, we came out of a roundabout and he completely floored it (I could here the dump valve through ear-plugs, crash helmet, and my
exhaust!). I went for it too and he couldn't shake me off, that's +400bhp cossie against 140bhp ZX9 - BTW he came up with some lame excuse
abou the roof slowing him down 
And yes, I would also agree that if you built it, you get use to it and you tend to drive it slowly at first incase anything falls off!
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locoboy
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| posted on 23/6/04 at 11:24 AM |
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agreed, i guess the moral of the story is build it and dont bend it!
ATB
Locoboy
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pbura
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| posted on 23/6/04 at 12:17 PM |
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I wonder if BECs could use a bit more roll stiffness in front to induce a little initial understeer at the limit. Not like a plowing Detroit monster,
but just enough to allow the driver to make a decision whether to back off or to intentionally break the back loose.
Pete
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David Jenkins
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| posted on 23/6/04 at 12:39 PM |
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Would narrower front wheels have a similar effect?
DJ
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greggors84
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| posted on 23/6/04 at 01:22 PM |
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Wouldnt you want less roll stiffness at the front to induce understeer?
Chris
The Magnificent 7!
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pbura
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| posted on 23/6/04 at 02:48 PM |
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quote:
Originally posted by greggors84
Wouldnt you want less roll stiffness at the front to induce understeer?
I believe that the problem may be that the BECs have less weight at the front than a book car, making the rear want to break away sooner than the
front. To compensate, less grip would be wanted at the front (or more at the rear).
David J has made an excellent point in that this could be done with the tires: they could be narrower (or the backs wider), more tire pressure could
be used, or a less grippy compound.
The other way would be to increase roll stiffness at the front. This puts more load on the outside tire so it doesn't grip as well.
It seems sort of a waste to give up cornering power at the front, so probably the best course would be to make sure everything has been done to
maximize rear grip first. Second choice (IMO!) would be to alter roll stiffness because this would reduce the overall roll angle of the car, giving a
little more help to the rear.
Pete
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David Jenkins
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| posted on 24/6/04 at 07:08 AM |
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I was giving this some thought last night, as I was sitting on my (delayed ) train...
How many people building ANY Locost has had much experience in driving rear-wheel-drive cars? Being an old fart I had a driving license for 7 or 8
years before I drove a FWD car (apart from the odd trip in a mini), so all my 'foundation skills' were learnt in an assortment of RWD
cars. The last commonly available RWD car with no driver aids was probably the Sierra (I'm excluding the BMWs, as they've never been
'cars for the masses' and use gadgetry to keep you on the road).
There are certain RWD skills you just HAVE to learn if you want to commit your life to a fast corner, such as getting the speed right before you turn
in, not upsetting the balance of the car in the middle of the corner (e.g. by lifting off, braking or changing gear), and powering smoothly through
the turn. FWD cars have a totally different technique - when I did a day out at Silverstone I found it difficult to change gear mid-turn in a Pug 306
GTi...it went against all my previous experience!
I wonder how many of these bike-engined accidents are caused by lack of RWD experience combined with the 'coming on cam' surge that you
get with these engines.
Maybe there isn't a basic design flaw with the BEC cars after all - just a need for new drivers to build up their RWD skills before they hit the
pedal hard.
Just a thought - a.k.a. 'ramblings' - better get ready for work now...
David
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theconrodkid
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| posted on 24/6/04 at 08:47 AM |
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think you should do a bit of karting,that teaches you how to get out of trouble,i had a couple of BMW 3 series,had to treat them with respect in the
wet
who cares who wins
pass the pork pies
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Jasper
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| posted on 24/6/04 at 08:53 AM |
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David - nail on the head time, that's why I went and had tuition and did track days b4 I started larging it on the road. I'd never had a
RWD car before - or at least not one that I drove fast. Totally different driving experience - my wife will also agree with this, totalled my 525 BMW
(diesel estate) in the wet on a bend 4 months after passing her test and only ever driving FWD.
I think the BEC's just accentuate and existing problem - loads of power, lightweight car, RWD.
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Mk-Ninja
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| posted on 24/6/04 at 09:16 AM |
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Must admit Im driving mine very cautiously at present not knowing where the limits are, and I have driven loads of RWD cars in the past.
Im looking forward to a couple of track days and I guess it would help if one of them was a bit damp to get a feel without loads of grip.
Gordon
I'm sure I've got one, just don't know where I've put it
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David Jenkins
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| posted on 24/6/04 at 09:48 AM |
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quote:
Originally posted by theconrodkid
think you should do a bit of karting,that teaches you how to get out of trouble
That makes a lot of sense.
I'd love to have a go - but there's only the commercial 'works outing' type places near where I live. Don't know if
they would let me just go and drive around for an hour without being involved in a group. I don't want to race - just play silly beggars for a
while!
Might give them a ring, though...
David
[Edited on 24/6/04 by David Jenkins]
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Alez
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| posted on 24/6/04 at 09:58 AM |
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This is the formula that made me crash:
RWD +
big BPH / ton +
inexperience_with_ (RWD + big BPH / ton)
No more, no less. Everytime I drove the car I was feeling so safe and able of controlling the situation (sideways roundabouts LOOKED like fun )
that I'd push limits slowly but steadily. I had never driven something so powerful yet so stable and noble. What I had yet to learn is that when
you lose your front end in one of these you cannot back up, it's just game over!
The reason why people crash these and not car engined Locosts is because of the huge BPH / ton factor, not many car engined cars you can compare to
around, there are many more BECs than turbo Cosworths around!
To sum up, after my "experience" I TOTALLY agree with Jasper and also I must admit I'm a complete dumbass!
[Edited on 24/6/04 by Alez]
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David Jenkins
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| posted on 24/6/04 at 10:07 AM |
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quote:
Originally posted by Alez
To sum up, after my "experience" I TOTALLY agree with Jasper and also I must admit I'm a complete dumbass!
Alez, you'd better get some practice and training before you get too excited by the new car...
David
[Edited on 24/6/04 by David Jenkins]
[Edited on 24/6/04 by David Jenkins]
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blueshift
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| posted on 24/6/04 at 01:13 PM |
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I keep nearly crashing my mx5, good practise for not crashing the locost when it's finished.. I hope.
not going to be a BEC but 220lbft from the v8 will demand enough respect.
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David Jenkins
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| posted on 24/6/04 at 04:02 PM |
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quote:
Originally posted by Syd Bridge
Has anyone considered that with a lightweight bec, the tyres need to be a good deal narrower than a heavier auto engined car?
Never mind BECs! I've fitted Yoko 185/70 x 13" partly because I think they suit the car, but also because that's what Caterham use
on their cheapest models - and whatever you think of Caterhams in many other respects, they do handle amazingly well!
I also expect them to be a lot more forgiving when making stupid mistakes - to let go more progressively than big fat sticky tyres.
(That's what I hope, anyway...)
David
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pbura
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| posted on 25/6/04 at 03:01 AM |
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quote:
Originally posted by Syd Bridge
Trust the seppo brain bank...
Geez, Syd, keep going on like this, and no one will know that you can be a very nice guy!!
OK, next time you're out hobnobbing with the goober-smoochers, why don't you pose this question to your idols:
"Car 1 has a 650/650 front to rear weight distribution, and Car 2's is 450/650. How should Car 2 be set up differently than Car
1?"
They may mutter in their salads about Newton, but chances are they'll come up with bigger tires in the back and/or a heavier anti-roll bar in
the front.
And WTF's wrong about that?
Pete
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spunky
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| posted on 25/6/04 at 08:53 AM |
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Syd.
Not wishing to 'blow feathers up yer arse'
to use a roughneck phrase. But I watch your posts with interest and have to say that you and a selection of other members do appear to post from
genuine knowledge/exerience.
So a question....
Am I asking for trouble...
Mid engine with a front axle weight of 220Kg. 195/60/ tyres on 14" rims.
Softly sprung with softish damping.
Weight distribution 60/40 back to front without driver?
Just curious on your take before I push the car into a Lincolnshire dyke...
John
The reckless man may not live as long......
But the cautious man does not live at all.....
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gys
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| posted on 25/6/04 at 08:56 AM |
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quote:
Originally posted by Syd Bridge
Also, if the builders on this site spoke to the tyre manufacturers and asked for their recommendations, you would be surprised at what came back. The
widths suggested would be far narrower than most are currently running.
You obviously did, and what did they recommend you? Based on a car with...
Man kann ein Auto nicht wie ein menschliches Wesen behandeln – ein Auto braucht Liebe...
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