Guest |99| Posted September 1, 2009 Report Share Posted September 1, 2009 Hi Ray, I have tuned my engine so that it is within a couple of % of the values in the AFT target table. This has been done without the AFT correction enabled. Can you let me know what would be the effect if I now enabled the AFT correction. Thanks Quote Link to comment Share on other sites More sharing options...
rayhall Posted September 1, 2009 Report Share Posted September 1, 2009 Chris, The engine would need retuning. The only cells that would be close, would be any you tuned at 14.7:1 The AFR correction should always be turned on before tuning. It makes tuning faster as the values in the fuel table are flatter. You can tune a cell at 3000 rpm and 100kpa and then copy that value over the whole table and the tune will be quite close for most engines. You then just have to fine tune some of the cells. With AFR correction turned on, the ECU uses the air fuel ratio you have in the target table to apply a correction to injector time. The basis formula is based on 14.7:1 air fuel ratio. 14.7 / Target AFR Value = Multiplication value. Example:- 14.7 / 12.5 = 1.176. The 1.176 is correction used to offset injector time to achieve the AFR value in the table, based on the number in the fuel table cell. It is possible to have a fuel table with just one rpm and load cell. The engine will run the correct air fuel ratio at all other rpm and loads. There is a video by Ben Strader from EFI-101 showing an engine on a dyno with one cell and a full table of cells. The power produced is the same and the air fuel ratios are very close. Using the target AFR table has other advantages. You can change the values in the table at any time after tuning and the engine will run the new air fuel ratio. No retuning is needed. Also this table is very good when tuning engines with big cams or multi throttle bodies. You set the fuel table axis to TPS, and then tune based on TPS only and the ECU looks up the AFR table to know how to adjust injector time as the load (manifold pressure) changes. No 4D or 5D tables are needed. Ray. Quote Link to comment Share on other sites More sharing options...
Guest |99| Posted September 2, 2009 Report Share Posted September 2, 2009 Thanks for the explanation and how the maths are done. Would the correct procedure for tuning then be to set all the Target AFR at one setting, say 12.0 which would be safe for most applications and then once the engine is tuned, adjust the AFR table points to achieve different AFRs, say 14.7 on light throttle or does it not matter what numbers are in the AFR table as long as they are sensible? Quote Link to comment Share on other sites More sharing options...
Guest |99| Posted September 2, 2009 Report Share Posted September 2, 2009 Just thinking a little bit further... If the WB CL is enabled will this affect the AFR correction calculation in that there may be a modifier acting on a modifier which will then be modified again when the IAT is enabled? Note: I have tuned the engine with the IAT enabled at the intial tune which was at about 15C. Quote Link to comment Share on other sites More sharing options...
rayhall Posted September 2, 2009 Report Share Posted September 2, 2009 Yes you could set the whole AFR target table to one value like 12.0 and tune the engine, then adjust the table later. Rather then having just one value in he whole table, you can set all the heavy load sites to values a bit richer while tuning. This will let you find the maximum timing that best suits an air fuel ratio close to what you will run after tuning. Wideband and narrow band closed loop control must be off when tuning. The reason for tuning is to find the correct base values for the fuel table. You do not want CLC messing with your tuning efforts. IAT Fuel correction must be on when tuning. You cannot turn it on later. The default values for this table should always be used and not changed. Using other values or having the correction turned off, will result is wildly changing air fuel ratios based on engine temperature. The comment I get is "The air fuel ratios were perfect on the dyno, and now they are all over the place". Enable the table and do not touch it, is the best advice. Also the position of the IAT sensor is important. On a turbo engine it must be after the intercooler. On non turbo engines in the inlet manifold plenum. Ray. Quote Link to comment Share on other sites More sharing options...
Guest |99| Posted September 2, 2009 Report Share Posted September 2, 2009 Would it be reasonable to say that if the engine is tuned properly with IAT enabled then turning on the WB CL after tuning will have no impact as everything will be tuned to the right AFRs across the load and rev range? Quote Link to comment Share on other sites More sharing options...
rayhall Posted September 2, 2009 Report Share Posted September 2, 2009 Yes that is correct. Functions like CLC wideband and knock control are there to make corrections due to some unexpected or long term change (engine wear). They are not for fixing bad tuning. Ray. Quote Link to comment Share on other sites More sharing options...
Guest Marcel B Posted September 21, 2009 Report Share Posted September 21, 2009 Ray , I (and I'm sure a couple others) would GREATLy appreciate if you do an indept , comprehensive "how to tune your engine tutoral on using the (many) features and tuning aids of the ViPec computer , and make it a sticky on the board. I would not have known about the use of the AFR correction feature if this thread wasn't started by Tinker.Is the above applicable whenusing any / all of the tuning modes ( Quick tune auto/man or the Quick Trim (Math key tuning function) ? also , after tuning , should the correction be turned off or can it remain on ? Quote Link to comment Share on other sites More sharing options...
Guest |306| Posted September 21, 2009 Report Share Posted September 21, 2009 Ray, My car has been running pretty well and it was tuned with AFR Correction turned off. If I turn it on, what will happen? Will it erase or change what I have done? Also, I am running the IAT sensor provided with my Vipec kit, I would just like to confirm that its settings should NOT be changed and should be fine as it is? I have had it on during this whole time tuning. EDIT: So closed loop should be turned on AFTER tuning, is this correct? Does my train of thought make sense? When tuning ensure: 1. IAT is on- don't change values 2. AFR correction is on 3. Closed loop control is off After tuning: 1. Keep IAT on 2. AFR correction on or off? 3. Turn closed loop on Thanks, Jeremy Quote Link to comment Share on other sites More sharing options...
Guest Dave-Kriedeman Posted September 21, 2009 Report Share Posted September 21, 2009 Ray , I (and I'm sure a couple others) would GREATLy appreciate if you do an indept , comprehensive "how to tune your engine tutoral on using the (many) features and tuning aids of the ViPec computer , and make it a sticky on the board. I would not have known about the use of the AFR correction feature if this thread wasn't started by Tinker.Is the above applicable whenusing any / all of the tuning modes ( Quick tune auto/man or the Quick Trim (Math key tuning function) ? also , after tuning , should the correction be turned off or can it remain on ? No offence intended, What you must also be aware of is that making such details freely available would have impact on ViPEC Dealers whom make a living from selling, installing and correctly tuning these ECU's. Fair enough a general over view of the features etc, but an indepth,comprehensive guide would be an unfair thing to the Dealers. "THIS IS ONLY MY OPINION" Quote Link to comment Share on other sites More sharing options...
rayhall Posted September 21, 2009 Report Share Posted September 21, 2009 Jeremy, After tuning: 1. IAT correction must stay on 2. AFR correction must stay on 3. Closed loop narrow or wideband can be turned on. Quote Link to comment Share on other sites More sharing options...
rayhall Posted September 21, 2009 Report Share Posted September 21, 2009 Marcel, I will make a step by step guide to using the tuning tools. I also will help with questions on tuning, but do not have the time or motivation to write a book on tuning. A book would be what is needed to cover all the possibility and try and pass on years of tuning experience. People like Dave, know just how hard this experience is to gain. It comes from years of tuning, and many hours of hair pulling. The quickest way to learn the basics is to do some courses at EFI-101. This will get you started in the right direction, but will not give you knowledge on tuning each engine type. EFI-101 use a V88 on one of the cars used in their classes. None of the tuning tools are used. The courses are to teach tuning that can be used on all ECU brands, so the tools are not used. Quote Link to comment Share on other sites More sharing options...
Guest Marcel B Posted September 22, 2009 Report Share Posted September 22, 2009 Marcel, I will make a step by step guide to using the tuning tools. I also will help with questions on tuning, but do not have the time or motivation to write a book on tuning. A book would be what is needed to cover all the possibility and try and pass on years of tuning experience. People like Dave, know just how hard this experience is to gain. It comes from years of tuning, and many hours of hair pulling. . Ray , this would be greatly appreciated , as I would be part of the process , but I would not be doing the actual "final" tuning on the dyno. This would be done by my friend who is a well respected and proven local builder / tuner who has a lot of experience building and tuning rotarys , but none with this model ECU. The quickest way to learn the basics is to do some courses at EFI-101. This will get you started in the right direction, but will not give you knowledge on tuning each engine type. EFI-101 use a V88 on one of the cars used in their classes. None of the tuning tools are used. The courses are to teach tuning that can be used on all ECU brands, so the tools are not used. I would if I could , but I just do not have the time right now as I am much too busy at work(like U Ray ) . Presently I am not really interested in getting into a the "nitty gritty" of the tuning process , I spent a lot of time and energy building my car , I just want to have it tuned and running RELIABLY .It is for these reasons that I would much prefer to have someone who knows what they are doing ,handle the job . On the other hand though , from the technical aspect of things , I want to know my ECU "inside out" so I can figure out stuff when ever I need to because i am the only person who does any work on the car. Quote Link to comment Share on other sites More sharing options...
Guest Marcel B Posted October 15, 2009 Report Share Posted October 15, 2009 Hi all , anymore on this :?: Quote Link to comment Share on other sites More sharing options...
rayhall Posted October 15, 2009 Report Share Posted October 15, 2009 I will start next week. Ray. Quote Link to comment Share on other sites More sharing options...
Guest Marcel B Posted December 5, 2009 Report Share Posted December 5, 2009 Ray , have you found the time yet Quote Link to comment Share on other sites More sharing options...
Guest |229| Posted December 16, 2009 Report Share Posted December 16, 2009 When tuning with "autotune" do i need to turn off WB and lambda? Or does it do this itself when using autotune.. Quote Link to comment Share on other sites More sharing options...
Guest |99| Posted December 17, 2009 Report Share Posted December 17, 2009 Closed loop lambda should be turned off. Quote Link to comment Share on other sites More sharing options...
Guest |229| Posted December 17, 2009 Report Share Posted December 17, 2009 also when using the autotune? I have read nowere in the manual that it should be turned off. I just came to think of it because when tuning with the Apexi FC O2 feedback needs to turned of.. But i will turn it off in the vi-pec software also when tuning it. What AFR should it be when cold.? 0 degrees. Quote Link to comment Share on other sites More sharing options...
rayhall Posted December 18, 2009 Report Share Posted December 18, 2009 Closed loop wide or narrow band must be turned off when tuning. It may not be in the manual, as it is expected a tuner would know that any form of closed loop air fuel ratio is used to make corrections after the engine is tuned, and will only cause tuning problems if turned on. The AFR correction table is used by the Quicktune as a lookup table. This table while tuning, is an open loop table. Ray. Quote Link to comment Share on other sites More sharing options...
Guest |229| Posted December 19, 2009 Report Share Posted December 19, 2009 I know it must be turned off, learned that with my PFC. But have never used built in autotuning before, and thinking when built in it may turn of the things that needs to turned off before working correctly... But that was not the case, so will turn it off each time. I need to learn this so there will be stupid questions. I'm sorry for that. Quote Link to comment Share on other sites More sharing options...
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