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SuziBlu
Joined: Mon Sep 14, 2009 11:30 pm Posts: 4268 Location: Eyre Peninsula
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 Posted: Mon Sep 26, 2011 1:43 pm |
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That equation you have given, is a famous one, used by many lecturers, it is a very complicated and hard to understand formula.
I gave up mental mathematics after teaching myself trigonometry, found out that calculators were far better than brain draining complications for the fun of it.
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Bad decisions make good stories.
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alien
Joined: Wed Mar 24, 2010 10:30 pm Posts: 16343 Location: Perth
Vehicle: '92 Sierra, 1.6efi, SPOA, 31s.
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Posted: Mon Sep 26, 2011 1:45 pm |
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=) the answer was suprisingly simple though...
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Ben_Sierra
az supporter
Joined: Wed Sep 30, 2009 11:30 pm Posts: 4472 Location: Perth
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Posted: Mon Sep 26, 2011 1:47 pm |
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Its 2W(0.5), where W is the Lambert W function. Thats the best you'll get without using a graphics calculator or similar...
The W function is a sum to infinity, so it'll take a while to calculate by hand,  although evaluation it as far as n=10 would get you pretty damn close I'd say, probably accurate to a few decimal places.
Its not solvable using normal methods. _________________ I want my old sig back 
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Ben_Sierra
az supporter
Joined: Wed Sep 30, 2009 11:30 pm Posts: 4472 Location: Perth
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Posted: Tue Sep 27, 2011 9:54 am |
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BTW, the solution is 0.407777....
_________________ I want my old sig back
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alien
Joined: Wed Mar 24, 2010 10:30 pm Posts: 16343 Location: Perth
Vehicle: '92 Sierra, 1.6efi, SPOA, 31s.
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Posted: Tue Sep 27, 2011 9:58 am |
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really? cos the solution i had was 0.25recurring... lol
so anyway, filled up today after the "big trip" on the weekend... got 10L per 100 bang on... there was only 10km of offroad driving in that too... the rest was 80-110km/hr with a few 115 moments. So i got better economy on the trip home than i did on the way down.
interestingly i filled up with 92ron once i got to the destination, so the trip home was on 92ron while the trip there was on 98 with injector cleaner added.
weird.
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Lil_Rat
Joined: Fri Jul 15, 2011 2:16 pm Posts: 177 Location: WA
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Posted: Tue Sep 27, 2011 10:19 am |
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alien wrote: really? cos the solution i had was 0.25recurring... lol
so anyway, filled up today after the "big trip" on the weekend... got 10L per 100 bang on... there was only 10km of offroad driving in that too... the rest was 80-110km/hr with a few 115 moments. So i got better economy on the trip home than i did on the way down.
interestingly i filled up with 92ron once i got to the destination, so the trip home was on 92ron while the trip there was on 98 with injector cleaner added.
weird.
Wind? Hills? Also wouldn't injector cleaner decrease the the efficientcy?
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atari4x4
az supporter
Joined: Mon Dec 11, 2006 10:30 pm Posts: 34842 Location: East Radelayed
Vehicle: SV420+SV620 Vitara's
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Posted: Tue Sep 27, 2011 10:22 am |
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you know what i put a dose of injector cleaner in the other week with a full tank of 98 & it burnt it like it was going out of style, last 2 fill ups have been back to normal. 
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alien
Joined: Wed Mar 24, 2010 10:30 pm Posts: 16343 Location: Perth
Vehicle: '92 Sierra, 1.6efi, SPOA, 31s.
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Posted: Tue Sep 27, 2011 10:34 am |
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weird huh... the injector cleaner i used was 10ml per litre... you wouldnt think that'd be enough to severely kill fuel economy?
wind won't have been a factor as i was travelling north/south and the wind changes in WA from easterly in the morning to west in the arvo. temps were similar also.
the only differences were the fuels and the injector cleaner.
as i said though, i'm noticing a power increase, even now since i filled up on 98 again its still there. Perhaps i had claggy injectors?
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JrZook
Joined: Tue Aug 08, 2006 11:30 pm Posts: 5517 Location: Holland Park
Vehicle: Awesome!!
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Posted: Tue Sep 27, 2011 11:12 pm |
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SuziBlu wrote: Talk power at the wheels, not engine power.
60kw*266% = 159.6kw
You could use this if you were trying to flog off some super dooper power increasing product but the context of the calc is wrong.
If you say you have increased power by 100%, you will have effectively doubled it.
Thus 60 -> 60+60 = 120kw
Increased by 200%
60 -> 60+60+60 = 180kw
What you have done is included the initial 100% (60kw) into the calc and thus it's 100% higher than what it actually should be.
Actual power % increase = (final - initial)/initial = (160-60)/60 = 1.66 = 166% _________________ Lil Foot!
http://tiny.cc/gtsw1
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SuziBlu
Joined: Mon Sep 14, 2009 11:30 pm Posts: 4268 Location: Eyre Peninsula
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Posted: Tue Sep 27, 2011 11:41 pm |
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JrZook wrote: SuziBlu wrote: Talk power at the wheels, not engine power.
60kw*266% = 159.6kw You could use this if you were trying to flog off some super dooper power increasing product but the context of the calc is wrong. If you say you have increased power by 100%, you will have effectively doubled it. Thus 60 -> 60+60 = 120kw Increased by 200% 60 -> 60+60+60 = 180kw What you have done is included the initial 100% (60kw) into the calc and thus it's 100% higher than what it actually should be. Actual power % increase = (final - initial)/initial = (160-60)/60 = 1.66 = 166% Whatever.
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Bad decisions make good stories.
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missmyljdaze
Joined: Tue Jul 05, 2011 7:16 am Posts: 2323 Location: perth
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Posted: Tue Sep 27, 2011 11:59 pm |
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SuziBlu wrote: off my head by midnight, lol yea goodo.
fixed it for you..........
stephen.
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atari4x4
az supporter
Joined: Mon Dec 11, 2006 10:30 pm Posts: 34842 Location: East Radelayed
Vehicle: SV420+SV620 Vitara's
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Posted: Wed Sep 28, 2011 12:15 am |
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first of all what are you classing as big tread?
I recently put on a pair of simex centipede copies & on the open road @ 110kph they chewed near enough to 4l/100km more than my goodyear MTR's do.
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stockman
az supporter
Joined: Thu Nov 05, 2009 10:30 pm Posts: 5319 Location: Canberra
Vehicle: 4wd
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Posted: Wed Sep 28, 2011 12:25 am |
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I got around 270-300ks on 31's on 10psi.
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sogone
az supporter
Joined: Mon Oct 25, 2010 11:29 am Posts: 2070 Location: Darwin
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Posted: Wed Sep 28, 2011 12:39 am |
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atari4x4 wrote: first of all what are you classing as big tread?
I recently put on a pair of simex centipede copies & on the open road @ 110kph they chewed near enough to 4l/100km more than my goodyear MTR's do.
Which are how tall Gus?  
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atari4x4
az supporter
Joined: Mon Dec 11, 2006 10:30 pm Posts: 34842 Location: East Radelayed
Vehicle: SV420+SV620 Vitara's
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Posted: Wed Sep 28, 2011 12:42 am |
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i guess they're about 30.6" i still don't have a tape measure... post one to me & i'm measure them
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