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Re: Dyno results

Posted: 15 Jun 2011 19:16
by Tinus lotz
4.8 is n yster!!!!

Re: Dyno results

Posted: 17 Jun 2011 07:07
by Sias
Tinus, ek stem saam! Maar as jy na die oorspronklike grafiek gaan kyk, sal jy sien die syfers is omgeskakel van krag op die wiele na krag op die flywheel. Die grafieke wat ek opgesit het, is alles nog krag op die wiele. Dus as jy na Patrol4.8 se grafiek kyk, is die krag op die wiele 129kW by 5163rpm. By 3000rpm gee sy kar 120kW by die flywheel, wat omtrent 80kW by die wiele is - as ek nou die grafieke reg lees...
Die V8 wat ek nou in het, gee 109.5kW op die wiele by 3000rpm - dis 160kW by die flywheel. My grafiek gaan net tot by 3000rpm, so ek weet nie hoe lyk dit by 5000.
Ek dink die ratverhoudings is te lank, hulle kom nie by 5000rpm uit met myne nie! :lol:

Re: Dyno results

Posted: 17 Jun 2011 10:41
by Tinus lotz
Sias ek v erstraan al hierdie dinge maar daar is genoeg kole daar!! Ek het n GTI om mee te jaag en n patrol v ir. Overlanding ens die prob leem wat ek het met ander motors insit is gaan my patrol nie in n Land rover v erander nie. ?
Ek het geen probleem met dit nie maar wil eerder die voertuig los soos die dolfyn vreters hom ge bou het sodat alles hou en ek elke trip begin en klaarmaak
Julle manne met die omskakelings gaan groot en ek wil graag ook n paar kw by he maar nie iets breek nie :mytwocents:

Re: Dyno results

Posted: 17 Jun 2011 13:31
by dieselfan
You should always use kw on the wheels as kw on the flywheel is almost impossible to calculate. I've yet ti see one dyno get it right. The use the so called flywheel figures as it looks higher and customer smiles more. Think about it how do they work out the flywheel power?

Re: Dyno results

Posted: 17 Jun 2011 19:52
by Kagiso II
ƒ☻╩┐┴♂☻σ├ and then get the square root of that, devide by the number of angine revolution against the number of wheel rotations in the given time span - ideally 6-seconds [then x 10 give the p/minute]

en as jy daai glo, saql enigiets glo :rolling: :rolling: :biggrin: - GENIET die naweek manne.

Re: Dyno results

Posted: 18 Jun 2011 11:48
by Theuhan
Oom Mac jy ken mos baie mense reel bietjie vir ons n Dino dag, ek sal ook graag wil sien wat maak die lex

Re: Dyno results

Posted: 18 Jun 2011 12:40
by Kagiso II
O K - youre ON - Give me a suitable Saturday between 23 July {incl) & 6 Aug - BUT Exclding 30 July]

The date with the MOST votes will be the one..

Re: Dyno results

Posted: 19 Jun 2011 22:46
by dieselfan
Kagiso II wrote:ƒ☻╩┐┴♂☻σ├ and then get the square root of that, devide by the number of angine revolution against the number of wheel rotations in the given time span - ideally 6-seconds [then x 10 give the p/minute]

en as jy daai glo, saql enigiets glo :rolling: :rolling: :biggrin: - GENIET die naweek manne.
Seriously though, they measure KW on wheels as they can, to get flywheel you would have to know the exact mechanical losses of the gearbox, axles etc. They use a % of 25 as the norm but EACH car is DRASTICALLY different, some have less resistance some heavier components.

The reality is look at KW on the wheels thats what counts.

Re: Dyno results

Posted: 20 Jun 2011 07:54
by Peter Connan
Dieselfan I basically agree that it is power at the wheels that matters.
However this approach is useless for determining whether your engine is performing to spec, unless that dyno has been used to check several supposedly identical cars.

There are dynos that attempt to measure the resistance of the gearbox by measuring the time it takes the dyno to slow down with the car in gear but the clutch disengaged. Off course it is still not entirely accurate because of tire slip etc.

Here on the highveld air pressure also plays a variable role, so that is another factor which needs to be "estimated". :thumbdown:

Re: Dyno results

Posted: 01 Jul 2011 22:11
by tour de frans
How do you think they measure wheel power ,there are loses to.

Sias,daai eerste grafiek is nie wiele nie,dis flywheel.Kyk na die vertikale skrif links op die grafiek.109kw op die flywheel is nie krag nie.Hoekom rev hulle die engine net tot by 3200rpm?Die 425nm lyk ook nie reg nie(jammer ek klink negatief,ek is alles behalwe dit.)Daai goeie torque syfer is torqueconverter slip.Maw die engine rev op daai oomblik hoer as wat die dyno lees.
Check dit weer.
Groete
Frans