olv
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| posted on 4/4/06 at 12:28 PM |
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What's your cruising RPM?
I'm still torn over CEC or BEC. One minute i'm dead set on a car engine for simplicity, practicality/usability, cost and the fact
it's still going to be damn fast whatever is in there.
But then the idea of an R1 creeps in again and the thought of weight saving, 10,000 rpm and 6 speed sequential box becomes tempting.
My main concern about is a BEC is the useability of it. It's a given that it'd be incredibly fun when thrashing it, but what about when
you're not? What about if you're stuck in traffic, is the clutch a constantly tricky?
But most importantly when crusing over any distance. Is it correct that RPM is usually 6-7krpm at 70mph?
So what's your crusing RPM? ideally people running 3.14diffs and 15" wheels.
Finally, do 3.14 diffs mainly come from diesel sierras?
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Guinness
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| posted on 4/4/06 at 12:53 PM |
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I'm using a ZZR1100, 3.62 and 14" wheels with 185/60's on it, so not your ideal set up, but here's my 2p.
Yes cruising at 70mph on the dual carriageway / motorway is 7,000rpm, it's not bad. But, and it's a big but, that's not what
they're meant for.
Take the back roads, swapping up and down the gears, taking it to the red line, next corner appears quicker than you think, brake late, turn in, race
to the next corner.
Don't use the motorway. 37 tonne trucks are masssssssivveeeee when you are 4" from the floor.
Alternatively if you do use the motorway, resist the temptation to go from 70 to 100 plus in an instant!
Mike
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smart51
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| posted on 4/4/06 at 01:00 PM |
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My R1 engine is happy cruising at 4000. Sadly that equates to 41 MPH in 6th. 70 is at 6800 but who wants to use a seven on a motorway. On a twisty
B road I can be heard zipping up and down between 6000 - 9000 RPM in 2nd and the noise is glorious.
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jimgiblett
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| posted on 4/4/06 at 01:25 PM |
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On the motorway 6-7k revs 70-80 mph. Going above 7k revs effected the fuel consumption a bit dropping it from 30+ to 25 mpg.
Beenie Hat flaps a bit but ballistic sunglasses and earplugs keep everything pleasant so long as its not to cold.
Longest trip in a day Horsham to Harogate.
Planning 1800 mile trip this Summer 
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wildchild
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| posted on 4/4/06 at 01:26 PM |
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My bike (Kawasaki ZXR400) does about 7000rpm at 70 in 6th gear. From Mr Guinness's post I should probably expect my ZZR powered Seven to do
about the same.
In terms of noise, once you get up to motorway speeds on a bike, the wind noise is much louder than the engine. I imagine this is also the case in an
open car such as a Seven, unless you have a very efficient screen (and I haven't seen one on a Seven yet).
Wear a helmet and earplugs - at 70mph the wind noise is loud enough that you should theoretically only drive for 30 mins out of every 8 hrs to avoid
damaging your hearing.
In terms of reliability, it is what the engine is designed to do. It's no different to running your ford lump (or whatever) at 3000 rpm.
I don't see a problem 
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olv
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| posted on 4/4/06 at 01:56 PM |
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Of course 7s are not made for motorways and it's not really a plan of mine. It's just i don't want to not be able to use them simply
because it'd do my nut in so much
i'll just have to get a ride in one, hopefully i'll get a ride soon and that'll put the question to rest
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G.Man
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| posted on 4/4/06 at 02:13 PM |
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Olv, mine is pulling around 6500 at cruising speeds, but its not an issue, I was a biker, and thats what earplugs and intercoms are for
Opinions are like backsides..
Everyone has one, nobody wants to hear it and only other peoples stink!
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oioi
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| posted on 4/4/06 at 02:45 PM |
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i tend to cruise at about 4500rpm, which is jut shy of an instant ban 
there again i have lard up front so can happily sit at those sort of speed all day
That is the Curse of Speed which has plagued me all my life I am a slave to it. On my tombstone they will carve,
"IT NEVER GOT FAST ENOUGH FOR ME." - Hunter S Thompson
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Coose
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| posted on 4/4/06 at 02:53 PM |
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'OIOIIIIIIIIIII'!
As all the other BEC boys said, it's not a problem. Imagine you were used to driving a diesel that did 70 at 2500rpm, then got into a petrol
car. You'd think exactly the same, but then be used to it within a matter of seconds!
Avoid motorways if you can, and if you can't then just keep playing with other cars by squirting from 60 to 100mph (not that I would ever go
over 70 occifer). They don't expect it from a revvy little noddy car! 
[Edited on 4/4/06 by Coose]
Spin 'er off Well...
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welderman
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| posted on 4/4/06 at 03:09 PM |
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As the other bec's, i can drive around in 6th at 70mph 7000rpm.
I even passed a car at dinner time in 6th from about 30mph up to er ###mph. First time ive not dropped it down a few gears and give it some, was quite
impressed.
Thank's, Joe
I don't stalk people
http://www.locostbuilders.co.uk/forum/23/viewthread.php?tid=172301
Back on with the Fisher Fury R1
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Hellfire
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| posted on 4/4/06 at 04:22 PM |
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Go for the bike engine and avoid motorways - they're not twisty enough to have fun on.
Isn't 'fun' the reason you're building a car in the first place?
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JoelP
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| posted on 4/4/06 at 09:29 PM |
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my first drive in a 7 was from scotland to leeds, not fun on the a1 let me tell you  I tended to just stay in lane 1 behind lorries! Cant tell
you about crusing rpm, neither speedo works. Clutch would be annoying in heavy traffic but atleast its not heavy like a supercar's!
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Hellfire
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| posted on 4/4/06 at 09:51 PM |
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And that was in a CEC wasn't it Joel? At least in a BEC you can make it fun........
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kev R1
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| posted on 4/4/06 at 10:07 PM |
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don't know why people say that bec's are hard to drive in traffic, they're really not once you get used to the biting point of the
clutch, it's fine!!
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Hellfire
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| posted on 4/4/06 at 10:24 PM |
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Solution to that, is to get a bigger bike engine. I can honestly say that I've not stalled the ZX12R yet.
Phil
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smart51
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| posted on 5/4/06 at 07:27 AM |
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My bike clutch was a real problem - until I fixed it. Mount the clutch cable as close to the pivot of the pedal as you can. Mine is now fine. The
pedal is reasonably long, you can feel the biting point nicely and can pull away with almost no revs.
It is only if you have a really short travel pedal that you have problems and you'd have problems if you did that with a car clutch.
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