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Title: Big injectors with krkte modify, more rich? Post by: Michel94 on July 14, 2012, 04:20:06 PM Hi, if i put big injector (630cc) and modify krkte with this new injectors, the car will turn more rich than the stock? (i modify any other map)
Thx Title: Re: Big injectors with krkte modify, more rich? Post by: RS4boost on July 15, 2012, 09:02:15 AM If you calculate KRKTE right, the AFR will be the same as with your old injectors.
In a case of nonlinear injectors, you must have a look at FKKVS too. Title: Re: Big injectors with krkte modify, more rich? Post by: ABCD on July 16, 2012, 05:05:36 AM If you calculate KRKTE right, the AFR will be the same as with your old injectors. In a case of nonlinear injectors, you must have a look at FKKVS too. How exactlty is FKKVS used..could u throw some light. Thanks Title: Re: Big injectors with krkte modify, more rich? Post by: nyet on July 16, 2012, 09:10:54 AM I generally don't see a good reason to use FKKVS, unless you have a really f'd up fuel delivery system
Title: Re: Big injectors with krkte modify, more rich? Post by: RS4boost on July 16, 2012, 09:37:08 AM In FKKVS you can adjust nonlinear injectors to give a linear fuel output.
The X-axis of FKKVS shows the injection time in ms (=> load), Y-axis shows RPM. If the mounted injector is linear, the values in FKKVS are all set to 1. If the injector is nonlinear and gives you a lean or a rich AFR mixture in a area, you must adjust the values in the affected map region, to linearize it. Increase the values in a case of lean AFR to make it richer. Decrement it, if it is to rich and you want to make it leaner. Here an example for the original RS4 injectors, which gives a lean AFR in the low load area. To compensate this behaviour, the values until 1.5 ms are increased. (http://www7.pic-upload.de/16.07.12/jo14lhrx1pg.jpg) (http://www.pic-upload.de/view-15151507/FKKVS.jpg.html) Title: Re: Big injectors with krkte modify, more rich? Post by: nyet on July 16, 2012, 10:07:37 AM Here an example for the original RS4 injectors, which gives a lean AFR in the low load area. Are you sure they are truly non-linear, or is this just an injector latency issue? Title: Re: Big injectors with krkte modify, more rich? Post by: ABCD on July 16, 2012, 08:12:10 PM In FKKVS you can adjust nonlinear injectors to give a linear fuel output. The X-axis of FKKVS shows the injection time in ms (=> load), Y-axis shows RPM. If the mounted injector is linear, the values in FKKVS are all set to 1. If the injector is nonlinear and gives you a lean or a rich AFR mixture in a area, you must adjust the values in the affected map region, to linearize it. Increase the values in a case of lean AFR to make it richer. Decrement it, if it is to rich and you want to make it leaner. Here an example for the original RS4 injectors, which gives a lean AFR in the low load area. To compensate this behaviour, the values until 1.5 ms are increased. (http://www7.pic-upload.de/16.07.12/jo14lhrx1pg.jpg) (http://www.pic-upload.de/view-15151507/FKKVS.jpg.html) That sounds OK. But my point is that if the injectors have an issue, let it be there and to counter that we can directly change basic fuel maps. Sounds plausible? Function frame says: The pressure pulsations inside the fuel rail due to the injections pulses cause nonlinearities at fuel apportion. Further on there are deviations of linearity at very small or very large injection times, when the injectors do not open resp. close completely. The map FKKVS can be used for compensation of these influences. |