tompat3463
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| posted on 1/4/13 at 03:31 PM |
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does this look right ? final drive ratio
as the title really.
Im building a blade engined mini with engine in the front running 12" wheels and I want a top speed of around 110mph for a decent drivable car
with plenty acceleration.
 
Description
so does this spread sheet look right ??
TIA Alan
[Edited on 1/4/13 by tompat3463]
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froggy
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| posted on 1/4/13 at 04:12 PM |
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70 mph is going to be pretty painful at 8500 rpm . When I ran my kitten with the tl1000 I had it geared for 70 at 6500 which I could just about live
with but it struggled over the 1/4 with high 15 second times . Dropped the gearing to 10mph per 1000 rpm and it did 13.8 and sub 5 seconds to 60 but
cruising speed was 50mph .
[IMG]http://i144.photobucket.com/albums/r187/froggy_0[IMG]
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mark chandler
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| posted on 1/4/13 at 06:16 PM |
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What sized tyres ?
FYI 185/60/13 on a 3.65 diff will hit 125mph at max revs
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loggyboy
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| posted on 1/4/13 at 06:27 PM |
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Is it for a lawnmower?
No way you need that many gears that close together. Either the ratios are incorrect or the sums are.
Mistral Motorsport
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bigrich
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| posted on 1/4/13 at 06:54 PM |
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Looks off to me. Diameter of wheel/tyre seems wrong. 3.62 diff should be enough for 120 at max revs
.JPG)
A pint for the gent and a white wine/fruit based drink for the lady. Those are the rules
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ReMan
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| posted on 1/4/13 at 09:10 PM |
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Looks right to me
What size tyres?
www.plusnine.co.uk
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loggyboy
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| posted on 1/4/13 at 09:27 PM |
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So you start in 1st, accel to about 45mph then shift to 2nd and go only 17mph before changing 3rd, then only 16mph to 4th then only 10mph to 5th and
then 11mph to 6th and only 13mph in 6th before you reach redline.. your gonna spend more time changing gear than anything else.
[Edited on 1-4-13 by loggyboy]
Mistral Motorsport
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ReMan
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| posted on 1/4/13 at 10:07 PM |
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That's BEC's for Ya!
Cpmpared with mine, using the Gear Calc on the sticky:
smaller wheels but a taller diff it still looks right for a Blade
www.plusnine.co.uk
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tompat3463
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 posted on 2/4/13 at 10:05 AM |
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thanks for the replies people.
its spreadsheet is a calc that is on the westgarage website. its setup for a cbr900 (893)
ive set the wheel diameter at 18" as I will be running 12" wheels and unsure of tyres still tho I think a 18" dia will be roughly
right.
the indy blade I owned topped out at around 120mph and yes cruising at 70mph was strange will the engine running high revs but I beleive thats the
price U have to pay for a quick low end accelerating car.
the spreadsheet is availiable to anyone if you go on the westagare website so please feel free to do the sums for me
im looking for quick 0-60 for a laugh and a giggle round the country roads not looking to break land speed records.
I just want to ge a good idea of sprocket sizes to order by doing these calcs.
the main issue as mentioned iun a previous post of mine is that limited space in the mini engine bay means a smaller diff sprocket is favourable
(45tooth beeing around 230mm with chain)
but doing it will a 45tooth means using somewhere in the region of 14t gearbox sprocket and I wouldnt want to go any smaller ie. 12-13tooth as is
would be hellish for the chain !!.
Im in no way an expert on these things but I think the spread sheet looks right TBH.
any more info will be greatly appreciated.
THANKS ALAN
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MikeRJ
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| posted on 2/4/13 at 01:17 PM |
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quote:
Originally posted by tompat3463
thanks for the replies people.
its spreadsheet is a calc that is on the westgarage website. its setup for a cbr900 (893)
ive set the wheel diameter at 18" as I will be running 12" wheels and unsure of tyres still tho I think a 18" dia will be roughly
right.
It will be closer to 20" if you are planning on using 165/60R12 tyres.
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