NefMoto

hey all,

simple question( may not be such a simple answer) but i have been playing with e85 recently and basically have come down to the conclusion of ( in this one area of topic) krkte for fuel instead of anything else( like fkkvs for example, which is atm set to all 1's)

as of right now i just used lemmeiwinks to add some fueling(+ 14. % in the primary channel) and now have my STFT and LTFT's at -1.6 and -2.3 respectably( with around .81 to .83 lambda at WOT to redline ( without lemmewinks adjustment about +15 on both)

so i was wondering if anyone had any insight as to how to go about adjusting krkte for the change? is there a given formula? i understand how to calculate krkte as a base to get started with injector change, but not much as far as adjusting for so much added fueling.

any insight would be much appreciated thank you!

Never use lemmi

My KRKTE scaler (you just multiply) for E85 is 1.403. This is under the assumption that the ECU was originally tuned for E5, which is the norm in Europe, not sure about the rest of the world.

A little formula, adapted from FR

KRKTE [ms/%] =  Airdensity x Vhzyl / (0,00167 x AFR x Kfuel xQstat)


airDensity = 1.293 g/dmˆ3 Air density (0 °C and 1013hPa)
Vhzyl [dmˆ3] Piston displacement of a cylinder in dmˆ3
Qstat [g/min] Valve constant for n-heptane
Kfuel = density correction for gasoline/ exotic fuel based on n-Heptane
AFR =  Air/Fuel constant at combustion for Lambda = 1.0
Normmk = 0.001667 min/ms Adaptation of units

Note that you must calculate Kfuel from density relaed to n-Heptane.

I use it with sucess in Brazil when tunin E100, E05, etc.

In the past VW calebrated FKKVS to avoid changing KRKTE when Brazil changed to E22 (now it is E27 on regular fuel)

thanks

let me ask this a different way..... SIMply, how do i adjust krkte based on LTFT's?

just that simple part... dont worry about fuels or anything...thanks!

Just follow it exactly (assuming your TVUB is correct).

Add or remove x% from KRTKE depending on LTFT.

Hi, just admit that we have changed the injectors, we calculate krkte, but how to find tuvb, I did not have when buying the injectors



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If you do not know the correct TVUB you're in trouble.

no I do not have it, for cons I have the flow for 2.5ms
so I calculated for 1g of fuel at 12.4V
Do you think I'm far from it with this method?


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Thank You! im pretty sure it is. cars been within 3% total( stft and ltft) deviation from zero fro about 1 yr now on 93 octane.. just changed to e85 and been making adjustments accordingy just never new how to adjust krkte without using the gueesing game after the ballpark values

TUVB is the reference time for 1g of fuel if I am not mistaken, I say this because we have the value TIMIN which corresponds to the minimum quantity for lambda 1


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no TUVB is injector latency.

And your definition of TIMIN is wrong as well.

this can be computed an example it is in french but I found this

(https://uploads.tapatalk-cdn.com/20180730/d65a78ba68d17a4ad0045564e8191e3b.jpg)(https://uploads.tapatalk-cdn.com/20180730/c1b21c1b64aaf9a467ae34dad1de9af7.jpg)(https://uploads.tapatalk-cdn.com/20180730/9bd4d74af08f1401cbef4d4566f0246f.jpg)(https://uploads.tapatalk-cdn.com/20180730/6219dfbb3dcf7a333aa6ea47add44c20.jpg)


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Also it is TVUB not TUVB.

it's the same for me just the letters displaced due to the change of language used to know english and french


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I have the obvious example at Citroen, same injectors, same ecu engine of different generation, TVUB / TUVB are different, I understood thanks to the document that tvub changes according to the chosen mofset because it influences the driving intensity of injectors, so it is better to calculate it


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By intensity do you mean the speed at which the injector solenoid opens?

this is what is explained and demonstrated in the pdf, I am not at my home, I will post it when I return, however it is in French.


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Hi, here is the pdf

so are you just trying to argue for no reason?? pdf and bs aside... tvub is still info from the injector manufacture.. end of story... tweaking them is just one way of making adjustments, but that doesnt mean coming up with your own values based on black magic pdfs that still come to the fact full circle that you need the injector specific times on ms per specified voltage


.....so why are you going so hard to start an arument your not going to 1 win 2 with the one person who doesnt need to pull out data sheets to tell you your wrong?

hint...its not me!

also thanks for trashing my question originally... just close this thread.... you answered( nyet) my question long ago

no worries, regarding the manufacturer, in my case Bosch does not provide this information, some dealers for off-road use do the flow tests and depending on the use provide this info. that's just why your post has deviated.


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hi lepatron972 you don't find answers in chiptuners???  :P

This is why you buy injectors that you have datasheets for, and not some random ebay crap

personally I buy from the manufacturer and as most often they are injectors series, there is no data sheet. the Bosch injectors that I have me, the technical service bosch refused to give them these info



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Hi, I only saw your message yesterday, I'm on vacation and no computer with me. the MED17 operates in torque demand regulate by monitoring, the architecture is modulated by the couple of memory.


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