ChrisGamlin
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| posted on 14/10/05 at 08:57 PM |
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I'd maybe consider looking for one even lower (say a 4.6 Sierra if they do such a ratio?), that would bring it down to just over 150mph in top,
and with usual Locaterfield "aerodynamics" you'll need much more than 240bhp to get over 150mph let alone 170! 
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ChrisGamlin
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| posted on 14/10/05 at 09:07 PM |
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If I put in the original S2000 tyre size (225/50-16" ) then it says that it will theoretically top out at 175, but actual top speed probably
limited by aero rather than gearing , 175mph is about right considering 175mph/9000rpm = ~19mph/1000rpm in top - for a production car you wouldnt have
top gear any lower otherwise it would be useless for motorway cruising etc.
Not sure where your gear cal gets 200mph from tho 
[Edited on 14/10/05 by ChrisGamlin]
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G.Man
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| posted on 14/10/05 at 09:10 PM |
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quote:
Originally posted by chris mason
something's not right there, the supposedly top speed of the s2000 in stock form is just under 150mph
gear calc show's it has over 200mph.
hmmmmmmm 
Chris
6th is pretty much an overdrive on the s2000...
without turbo, nitrous, lots of tuning you would never get close to the redline in 6th
Top speed is achieved in 5th
[Edited on 14/10/05 by G.Man]
Opinions are like backsides..
Everyone has one, nobody wants to hear it and only other peoples stink!
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ChrisGamlin
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| posted on 14/10/05 at 09:13 PM |
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Secondary reduction sounds like the engine doesnt directly drive the clutch but instead is geared off it in much the same way as a bike engine.
Ignore the figures Ive posted above as I accidentally left the 4.6 diff in, so your 200mph is probably about right if using a 4.1 diff and not
including this secondary reduction. If including that 1.16 reduction, it appears to be geared for 170mph with stock tyres and diff, so similar to what
I said above really, about 19mph per 1000rpm in top.
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G.Man
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| posted on 14/10/05 at 09:14 PM |
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quote:
Originally posted by ChrisGamlin
quote:
Originally posted by kb58
I took that into account. A Hayabusa makes 100ft-lb torque at 7000rpm. A Honda K20 makes 150ft-lb at 6000rpm. So comparing "apples to
apples", gearing the bike engine down, and torque up, means the Hayabusa makes an effective 7/6 * 100 = 116ft-lb torque at 6000rpm. Yes the
bike engine is lighter by roughly 200lbs, or around 20% of the total car weight, but it still doesn't have the equivalent torque/pound as a
modern automobile engine.
[Edited on 10/14/05 by kb58]
What you havent taken into account is that the busa revs to 11k whereas the K20A only revs to around 8k(?). If you add that into the equation the
bike's high rev limit allows you to gear it much lower and still achieve the same top speed, say 11mph/1000rpm in top to achieve 120mph compared
to say 15mph/1000rpm for the K20A (although Im not sure the stock box would get you anywhere near that figure, probably nearer 20mph/1000).
Basically you need to look at torque at the wheels and ignore the engine torque. The lower gearing on the bike that is facilitated by the
higher revving engine means the engine torque is multiplied up more in the BEC than the car engine, so the resulting torque at the wheels figures for
both engines are very similar, but the BEC has the weight advantage still. In other words, if the bike and car were the same weight, they'd
perform about the same.
True, but the bike tranmission breaks 3 times as often, probably more...
Clutch isnt up to the job fgor long yada yada yada..
The Bikes BHP is a ficticious figure due to the over-rev it manages, look at the torque curve at those rpm's and that gives you an idea of the
impact a hill will have on that top speed... massive...
As for the £250 challenge, I raise you a £50 pinto..
Opinions are like backsides..
Everyone has one, nobody wants to hear it and only other peoples stink!
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G.Man
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| posted on 14/10/05 at 09:17 PM |
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quote:
Originally posted by chris mason
by using the secondary reduction as per the primary reduction on a bike it now brings out the top speed of the stock s2000 to just over 180mph at
approx 21mph per 1000rpm in top gear, now saying that the car will only rev to 7500 in top gear that wouldn't be too far off,
rpm in top gear always seems strange as some cars bounce of the rev limiter and some don't make it too it.
Chris
You got it chris, the S2000 wont hit the limiter in 6th let alone bounce off it...
But its still a great motor...
you are gonna love your new car more than the stealth...
PS. Race yer
Opinions are like backsides..
Everyone has one, nobody wants to hear it and only other peoples stink!
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_Aero_
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| posted on 14/10/05 at 09:27 PM |
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quote:
Originally posted by G.Man
The Bikes BHP is a ficticious figure due to the over-rev it manages, look at the torque curve at those rpm's and that gives you an idea of the
impact a hill will have on that top speed... massive...
So when Hellfire shows the dyno'd 152.5bhp at the wheels on a bike quoting almost 200bhp at flywheel (with ramair which there's
hasn't) this equates to say a 15% loss in transmission and resulting in a healthy 170+bhp at the flywheel. I think he may have something to say
about your superfluous adjectives...
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ChrisGamlin
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| posted on 14/10/05 at 09:28 PM |
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quote:
Originally posted by G.Man
The Bikes BHP is a ficticious figure due to the over-rev it manages, look at the torque curve at those rpm's and that gives you an idea of the
impact a hill will have on that top speed... massive...
Errrrrrrrrrrrrrrrrrrr
(in desperate need of a :bangshead against a brick wall: symbol)
quote:
As for the £250 challenge, I raise you a £50 pinto..
Plus another £50 for a useable gearbox I assume? :p
If you really wanted to Im sure you could find a £100 bike engine that would still muller it, but prices this low means its getting kinda pointless
now
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Andy W
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| posted on 14/10/05 at 09:35 PM |
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Are we talking about hills or mountains, being up some fairly steep hills in mine and they don;t seem to make much differance; even with a heavy
chassis.
Andy
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kb58
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| posted on 14/10/05 at 09:44 PM |
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I'll run the numbers end to end this weekend and we'll both see what's what.
I need to locate gear ratios for both the Hayabusa and RSX-S K20... shouldn't be hard to find.
quote:
Originally posted by ChrisGamlin
What you havent taken into account is that the busa revs to 11k whereas the K20A only revs to around 8k(?). If you add that into the equation the
bike's high rev limit allows you to gear it much lower and still achieve the same top speed, say 11mph/1000rpm in top to achieve 120mph compared
to say 15mph/1000rpm for the K20A (although Im not sure the stock box would get you anywhere near that figure, probably nearer 20mph/1000).
Basically you need to look at torque at the wheels and ignore the engine torque. The lower gearing on the bike that is facilitated by the
higher revving engine means the engine torque is multiplied up more in the BEC than the car engine, so the resulting torque at the wheels figures for
both engines are very similar, but the BEC has the weight advantage still. In other words, if the bike and car were the same weight, they'd
perform about 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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ChrisGamlin
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| posted on 14/10/05 at 09:45 PM |
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Andy, Im sure you realise but for the benefit of others, thats cos it makes absolutely no difference.
Once again its the torque at the wheels that determines how little speed you loose up a hill, and once again a high revving, low torque bike engine
with a low ratio gearbox will perform just as well as a torquemonster that revs to half the RPM with twice the torque.
Off to bed, my head hurts
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David Jenkins
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| posted on 14/10/05 at 09:46 PM |
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Oh no...
Not another "mine's bigger than yours" argument! We'll be up with the Cateringvan crowd soon!
These arguments are all pointless - a seven with a Morris 1000 engine is probably faster than the average tintop, and a lot more fun!
If you want a screaming engine that's a thrill a minute (but a PITA for a long journey) then get a bike engine - otherwise pick your favourite
car engine.
Each to their own thing...
David
[Edited on 14/10/05 by David Jenkins]
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ChrisGamlin
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| posted on 14/10/05 at 09:49 PM |
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Here's the busa ones....
Primary Reduction - 1.596
1st - 2.613
2nd - 1.936
3rd - 1.529
4th - 1.284
5th - 1.134
6th - 1.040
revs to about 10,800rpm
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Jon Ison
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| posted on 14/10/05 at 09:49 PM |
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Its personal choice, I for one wouldn't be swayed from a BEC for a fun road and track car, as for hills ?????
Slack hill on way too Matlock, some will know it.......
my 900cc blade and 1100cc bird as yet too be beaten up it showing outrageous speed at the top and leaving Subaru's and the like in its wake, its
steep, its long, the engine just pulls n pulls......and that's without much of a run at it as those that know the hill will know its 40mph run
up too it and a regular mobile camera spot in the 40 limit, you'd think they would cotton on and wait at the top.......
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ChrisGamlin
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| posted on 14/10/05 at 09:52 PM |
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I think youve missed the point David, I cant speak for anyone else but Im not arguing which is better, just making sure that when people make a
decision on what they think will perform best for them, they do it using the correct calculations and figures!
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_Aero_
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| posted on 14/10/05 at 10:11 PM |
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Chris Head/wall banger for you to use...
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Bob C
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| posted on 14/10/05 at 10:17 PM |
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The "torque vs BHP" argument crops up wherever there are petrolheads & motormouths & are usually circular with the odd
misconception...
The answer lies in good old 'o' level GCE physics,
power = force * velocity
or
power = mass * acceleration * velocity
There's no gearing factor in that equation. And it says that at a given speed the acceleration is determined by mass and the power available.
Period.
The common misconception is due to the "peaky" nature of "power tuned" race engines, a less powerful engine with a wider
torque spread can be faster because a) there's no doldrums where the next gear up is off the cam already and b) you spend less time messing with
gears instead of accelerating. So folk say "torque is more important than power". Which is daft.
cheers me dears
Bob
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G.Man
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| posted on 14/10/05 at 10:44 PM |
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quote:
Originally posted by _Aero_
quote:
Originally posted by G.Man
The Bikes BHP is a ficticious figure due to the over-rev it manages, look at the torque curve at those rpm's and that gives you an idea of the
impact a hill will have on that top speed... massive...
So when Hellfire shows the dyno'd 152.5bhp at the wheels on a bike quoting almost 200bhp at flywheel (with ramair which there's
hasn't) this equates to say a 15% loss in transmission and resulting in a healthy 170+bhp at the flywheel. I think he may have something to say
about your superfluous adjectives...
The point is here, torque gives you an idea of the speeds possible, BHP gives an idea of how exciting that getting there will be...
Combine that how exciting with a weight factor and the BEC will always give the most excitment...
The CEC will always give the best day to day use...
Its like race vs road.. different characteristics suit different needs...
just like a duke 999 is more exciting than a BMW 1000... but which one would you want to use for 1000 miles...
Which is the better bike...
PS. I was a BSB chief technician I know a little about bikes... maybe a smidge more than most, and have certainly seen more on the dyno than almost
anyone here...
Opinions are like backsides..
Everyone has one, nobody wants to hear it and only other peoples stink!
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kb58
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| posted on 15/10/05 at 02:33 AM |
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Yup, I'm convinced. It doesn't matter what rpm an engine runs at, it only matters what power it generates, at any rpm.
Running the numbers through CarTest was very enlightening. I created two "Super-7" cars.
Car1: Hayabusa, 160hp, 100ft-lb torque, 1200lb test weight, 40% on front tires. Geared so top speed was 140mph.
Car2. Honda K20C, 200hp, 140ft-lb torque, 1400lb test weight, 60% on front tires, geared so top speed was also 140mph.
Here's where the big difference hit me... shift time. In the CEC I left it at the default of 0.4 seconds, but with the BEC I cut it to 0.2
seconds. That made all the difference.
End result, the BEC, thanks to the fast shift time, reached 1/4 mile in 12.8 seconds, with the CEC trailing at 13.1.
Very interesting.
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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G.Man
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| posted on 15/10/05 at 08:18 AM |
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But you can always spend £3000 on an elite sequential box for the CEC
Opinions are like backsides..
Everyone has one, nobody wants to hear it and only other peoples stink!
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smart51
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| posted on 15/10/05 at 08:27 PM |
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quote:
Originally posted by Bob C
The answer lies in good old 'o' level GCE physics,
power = force * velocity
or
power = mass * acceleration * velocity
There's no gearing factor in that equation. And it says that at a given speed the acceleration is determined by mass and the power available.
Period.
The thing with Olevel physics is that its a bit basic. Sure, the physics is correct, power does = m * a * v but you have missed out something
important.
The peak power of an engine exists at only 1 engine speed. Acceleration uses lots of engine speeds. It is the "area under the curve" of
the engine that determines vehicle acceleration - a sort of average engine power. Diesel, car petrol and bite petrol engines of the same power have
the same hieght of power curve but the width is different. Instead of 800 - 4500 for a diesel or 800 - 6000 for a CEC, a bike will deliver 1000 -
12000. OK so none of the engines are any good at the bottom end but acceleration from 0 to whatever uses the whole of the engines dynamic range.
Gearshift times also help the BEC plus the fact that you need fewer shifts in a 0 - 60 sprint.
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G.Man
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| posted on 16/10/05 at 03:04 AM |
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smart makes an excellent point...
The car will have a different torque spread and wide ratio box, whereas the bike engine will use more revs and a closer ratio box so that you can keep
it on the boil....
Was the same with my 250 kart... we got 60bhp out of the honda CR250 and revved them to 12,000 rpm, much more than any crosser would...
but all the power was from 9000-11,000 with about 1k of over rev...
Boy was that exciting to drive, but drop out of the rev band and you were dead in the water...
Same applies to the bike motor really, below 4-5k they are nasty, above that all hell breaks loose, and its the noise and delivery that makes it so
exciting...
Opinions are like backsides..
Everyone has one, nobody wants to hear it and only other peoples stink!
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tks
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| posted on 16/10/05 at 01:53 PM |
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mhhh
you cant compare very well,
and when you compare you need to let it be on 1 point only.....
also its all about priorities, Sound, Clutch
Cornering,PETROL CONSUMPTION....
Also from 1 figure you cant say nothing....
sow peak BHP isn't use full, max rpm isn't usefull..
we will need 2 Dyno Figures to be able to see and compare 2 engines....
what if you have an engine that has torque but only deliver it between 2000 and 3000Rpm.. and out of that zone it has 50% less..? wouldn't be
very usefull?
also when you switch to next gear..you fall down in revs... and thats the point where i think an Bike Engine picks faster up.....
at the end its all about F=MxA...
@ any engine speed used on the test
the avarage value of the 2 will make one faster as the other...
also we need to consider the acceleration of the engine speed it self!
how much time does it take for an car engine to rev to 6000? and howmuch for an bike to 6000? or to 12.000?
i think its clear an CEC for the ROAD..and an BEC for competition...
i personally think BEC are much more graggile than CEC not only because the engine wich it fits of the CEC it should be able to make
200.000miles...
how much you give an BEC??
Tks
The above comments are always meant to be from the above persons perspective.
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G.Man
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| posted on 19/10/05 at 09:37 PM |
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A bike engine has a close ratio box compared to a car engine...
The rev range is greater but in relation to what that does to the performance its much of a muchness...
The real score is the weight loss that makes the torque requirement that much less so the bike engine results in a much more exciting delivery in most
cases...
Okay, my cossie would have been more than a match, and actually worked out cheaper than a zx12r with dry sump, goodrich hoses and aeroquip fittings,
but when you look at the cheaper r1 or blade engines the picture is far less clear cut...
there will always be fans of both, and fans of either...
Opinions are like backsides..
Everyone has one, nobody wants to hear it and only other peoples stink!
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Jon Ison
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| posted on 19/10/05 at 10:04 PM |
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I'm not so sure 330bhp of cosworth would be "more than a match"
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