chunkielad
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| posted on 31/1/05 at 07:48 PM |
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Top speed on FZR 1000
I am going to use the FZR 1000 engine in the car and have a 3.92 diff to use. Firstly, what sort of top end speed will I get and then, how does
chaning the Diff ratio change the acceleration/top speed?
i.e. is a 3.1 faster or slower in acceleration than a 4.5 (stupid figures I know!!!!)
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Wadders
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| posted on 31/1/05 at 07:51 PM |
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3.92 = mad acceleration, crap top end
3.13 = good acceleration, good top end.
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JoelP
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| posted on 31/1/05 at 08:10 PM |
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i cant tell you any specifics about that combination (fzr1000 with 3.92) but people often say that 3.62 is uncomfortable on motorways, hence the value
in the 3.38 and 3.14 diffs. I seem to remember that fireblades are better at coping with 3.62 than stuff like zx9s, which really benefit from longer
legs (ie 3.38 etc). i suspect that the fzx could be compared to r1s, but i dont know what they are most suited to.
is it a 3.92 LSD? if so, id sell it to a car engined user who wants good sprint performance, and look about for a 3.62 (LSD if you so choose). 3.62 is
probably better than a 3.92 for any use (i wouldnt be suprised if a 3.92 topped out on the wrong side of 110ish) hence sickening noise on a motorway.
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jambojeef
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| posted on 31/1/05 at 08:19 PM |
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My problem exactly!! I've downloaded this spreadsheet (cant remember credits-sorry!) was originally from an R1 but get your haynes out for your
bike and play with some figures - I've come to the conclusion that unles you're running a very revvy bike engine (Gixxer, ZX9R etc) then
the 3.14 diff has got to be way to go - when using the spreadsheet dont forget to put in corect primary drive ratio for your FZR - bikes drop down
from their crankshaft to the clutch basket unlike car engines whic are directly driven crank - clutch
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chunkielad
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| posted on 31/1/05 at 08:41 PM |
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quote:
Originally posted by JoelP
is it a 3.92 LSD?
No mate it's open (the free one from Shortie
quote:
3.62 is probably better than a 3.92 for any use (i wouldnt be suprised if a 3.92 topped out on the wrong side of 110ish) hence sickening noise on a
motorway.
I'm not going to do any motorway mileage really and I never go over 70!!!
My main concern is acceleration anyway so if a higher number is good for that, I'll stick with the 3.92!!
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JoelP
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| posted on 31/1/05 at 08:54 PM |
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fair points mate - you certainly cant sniff at a free diff! 
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Jon Ison
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| posted on 31/1/05 at 09:08 PM |
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1st thing you need to do is find out what reduction gears are in the bike box, i set the blade up to run just over 1000rpm per 10mph in top, 70mph on
motorway was a doddle at around 7000rpm with a top speed just over 130mph on a 3.89 diff with 15" wheels.
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chunkielad
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| posted on 31/1/05 at 09:09 PM |
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Joel - Any info on this from the manual?
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JoelP
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| posted on 31/1/05 at 09:12 PM |
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i shall look now...
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JoelP
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| posted on 31/1/05 at 09:33 PM |
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right then.
the bike as it stands has 17 teeth to 48 teeth, hence a final ratio of 2.82
combine that with a large back wheel, no wonder they have a cracking top speed. i dont actually know what, but id guess its geared to 165? someone
please correct me, its a 93 fzr1000.
so assuming you swap for a 3.9 diff, and a slightly smaller rear wheel (the bike has 24 inch diameter, my current wheels are 165 80 13, with a 23 inch
diameter) your top speed would become 113, assuning 165 is correct for the bike.
not sure what the rev limiter is on this bike (manuals bloody useless...), but i bet it would be screaming on a 3.92 diff at 70!
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niceperson709
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| posted on 31/1/05 at 11:01 PM |
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Don't know about the FZ1000 for sure but my FZ750 streetfighter cuts the rev limiter in at 10500 may be a bit lower on the 1000 because it has a
longer stroke in the engine , any way would probably be a good idea if you went for larger wheels to improve / tune your gearing in the absense of a
lower diff ratio.
best wishes
Iain
 
Rescued attachment 7of9-13S.jpg
Best wishes IAIN
life is not the rehearsal , it's the show so don't sit there thinking about it DO IT NOW
http://iainseven.wordpress.com/
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chunkielad
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| posted on 1/2/05 at 01:03 AM |
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I was thinking of 15s anyway so that should help - sorry for being thick but what would this give me? The tyres won't be ridiculously low
profile as I want to ensure some feedback from the tyers and no suprise loss of the back end
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JoelP
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| posted on 1/2/05 at 08:39 AM |
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no idea - its all guess work for me. Measure the diameter of the wheels and compare them to mine. Should actually compare rolling radius not diameter,
but i cant be arsed workingit out! 
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smart51
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| posted on 1/2/05 at 10:33 AM |
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measure the laden radius (height of the wheel centre from the road) rather than the diameter of the tyre. this gives a closer match to the true
turns-per-mile figure.
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