NefMoto

Technical => Tuning => Topic started by: Jim_Coupe on December 01, 2016, 02:55:24 AM



Title: Injection time calculator ? Is there any method?
Post by: Jim_Coupe on December 01, 2016, 02:55:24 AM

When i tuned an 1.8T Me3.8.3 i used KFLF table to tune for more fuel.. But this was very time consuming and I had to flash the ECU so many times i lost the count. Is there any calculation sheet or similar where I can calculate the injection time so that i can be more close to reality to save some time.?



Title: Re: Injection time calculator ? Is there any method?
Post by: eliotroyano on December 06, 2016, 01:24:53 PM
When i tuned an 1.8T Me3.8.3 i used KFLF table to tune for more fuel.. But this was very time consuming and I had to flash the ECU so many times i lost the count. Is there any calculation sheet or similar where I can calculate the injection time so that i can be more close to reality to save some time.?

It can be done but it I think that maybe faster way (of course not so precise) to accomplish that task is to know AFR needed and apply appropiated percentage correction.


Title: Re: Injection time calculator ? Is there any method?
Post by: nyet on December 06, 2016, 01:53:19 PM
Any theoretical value isn't going to include a correction.


Title: Re: Injection time calculator ? Is there any method?
Post by: eliotroyano on December 07, 2016, 04:57:02 AM
Any theoretical value isn't going to include a correction.

I am really sorry, maybe I do not elaborate enough, but my comment is about with an AFR target in mind and knowing actual AFR in exhaust, a percentage correction can be applied to accomplish AFR targets.


Title: Re: Injection time calculator ? Is there any method?
Post by: nyet on December 07, 2016, 10:27:47 AM
I don't really understand why a spreadsheet would help anything.

You tell the ECU how to calculate airmass based on MAF readings (or pressure/RPM/VE), and you tell the ECU how big the injector is.

It does the rest.

What are you trying to calculate?

VE?


Title: Re: Injection time calculator ? Is there any method?
Post by: Jim_Coupe on December 11, 2016, 10:06:24 AM
Well.. Older ECUs like M3.8.3 is not that simple..  I recently tuned an 1.8T AEB Gt35 1300cc injectors m3.8.3 ecu..  I found it hard to dial the fuel in.. I guess i have to learn more about that.


Title: Re: Injection time calculator ? Is there any method?
Post by: prj on December 11, 2016, 12:43:27 PM
Well.. Older ECUs like M3.8.3 is not that simple..  I recently tuned an 1.8T AEB Gt35 1300cc injectors m3.8.3 ecu..  I found it hard to dial the fuel in.. I guess i have to learn more about that.

It is exactly as simple there. You just don't understand ECU's.


Title: Re: Injection time calculator ? Is there any method?
Post by: Jim_Coupe on December 13, 2016, 05:16:01 AM
It is exactly as simple there. You just don't understand ECU's.

Haha yoo funny..  ;D       

When adding extra fuel to lets say MS43 its not the same strategy as Me7.5 where you can use just tell the ECU what injectors and tell ECU what lambda you want... Well you have to enter injector constant there aswell but for tuning fuel in higher load areas in Me7.5 i find it more simple  via LAMFA and so on..


Title: Re: Injection time calculator ? Is there any method?
Post by: prj on December 13, 2016, 06:24:38 AM
When adding extra fuel to lets say MS43 its not the same strategy as Me7.5 where you can use just tell the ECU what injectors and tell ECU what lambda you want... Well you have to enter injector constant there aswell but for tuning fuel in higher load areas in Me7.5 i find it more simple  via LAMFA and so on..

It's exactly the same for both ECU's. It's simply airflow multiplied by a factor. Whether that factor gets derived from one map or 100 does not matter in the end.
You still don't understand how digital engine control works.


Title: Re: Injection time calculator ? Is there any method?
Post by: Jim_Coupe on December 14, 2016, 12:01:37 AM
It's exactly the same for both ECU's. It's simply airflow multiplied by a factor. Whether that factor gets derived from one map or 100 does not matter in the end.
You still don't understand how digital engine control works.

You are absolutley correct prj.. Thats why im asking u know. Thanks for pointing that out to me. I shall add a text in every post.. In case prj see this I know nothing about ECU.


Yes i know its a factor but i was asking if there was any good excel sheet or something to speed up the calculation. For example lets say i want to go from 255cc injectors to 1300cc + E85. I have started on my own sheet.. I´ll try and see where i land by just calculate in excel.




Title: Re: Injection time calculator ? Is there any method?
Post by: prj on December 14, 2016, 03:42:28 AM
You really don't need a spreadsheet to calculate (255/1300)*(14.7/9)