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masterj
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« Reply #60 on: January 17, 2012, 02:11:24 PM »
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Good info cold start with e85 gave me hell too! I never got it proper  Maybe we can look into some of those "flex fuel" GM's and see in comparison to their gas maps what they use for the alcohol mix maps. try a percentage of change to start? however i have no leads on e85 GM maps at this time, but someone else may? Hm... there has to be someone on this forum who has done proper E85 conversion...  |
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fredrik_a
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« Reply #61 on: January 17, 2012, 02:25:00 PM »
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Hm... there has to be someone on this forum who has done proper E85 conversion... Yes, you need to remember that in cold start conditions, the engine ignites basically only the petrol part of the E85 mix, i.e. the ethanol is just flushed through the engine unburned. This means that the enrichment for cold start is massive and that you can expect ethanol dripping out of the exhaut. I've done the conversion a few times as E85 is very common in Sweden, and heavy (I mean really heavy) enrichment is the only way to do it for cold conditions. Once the combustion chamber increases in temperature you can decrease the initial heavy enrichment as also the ethaniol will vaporize, not just the petrol. |
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« Last Edit: January 17, 2012, 02:28:06 PM by fredrik_a »
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masterj
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« Reply #62 on: January 17, 2012, 05:43:21 PM »
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Yes, you need to remember that in cold start conditions, the engine ignites basically only the petrol part of the E85 mix, i.e. the ethanol is just flushed through the engine unburned. This means that the enrichment for cold start is massive and that you can expect ethanol dripping out of the exhaut.
I've done the conversion a few times as E85 is very common in Sweden, and heavy (I mean really heavy) enrichment is the only way to do it for cold conditions. Once the combustion chamber increases in temperature you can decrease the initial heavy enrichment as also the ethaniol will vaporize, not just the petrol.
Can you tell me by how much should I enrich the AF mixture at 0C temperature (approximately)? Because up to the about 10-15C it is all good, but lower than that and hard start again awaits me... |
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« Last Edit: January 18, 2012, 01:22:47 AM by masterj »
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RC200
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« Reply #63 on: January 18, 2012, 04:02:06 AM »
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My S4 runs 100% E85 seamlessly since 2 years now. Here, E85 is 15% unleaded/85% alcohol in summer and up to 27% unleaded/73% alcohol in winter. On S4, there's a simple/cheap way of running E85, just set fuel trim to +25% in lemmiwinks, and the ECU will do the rest of the correction !! I usually get +3-6% on partial adaptation, and 0-2% on idling adaptation. That makes an overall correction of +28-31% max ... No engine startup problem at all in winter, no idling trouble. And add some timing if you want (you are not obliged), +7.5° in my case as I already have a MRC tune. Usually from +3° to +18° (yes I tried it in winter) !!! I notice nothing special above +10.5° except a strange phenomena: sometimes (when flooring the throttle) the timing is pulled to a default value of +12°, not nice. So +7.5° is fine in my case.   My car pulls more than 350rwhp. My MAF shows more than 326g/s on full boost (~1.3bar, 1.5 max) That's my cheap way of running 100% E85. |
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----------------------------------------------------------
EURO S4 B5 2.7T 07/1999 Ph2 8D50J9
VIN: > 8DZYA00xxxx
ECU 8D0 907 551D
K04, 750cc, Walbro 485LPH fuel pump, 4bars FPR, MRC map
Running 100% E85 with UniSettings adjustment. Timing +7.5°. >350 rwhp.
13.5L/100kms on highway, 16-19 mix driving.
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masterj
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« Reply #64 on: January 18, 2012, 07:43:29 AM »
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My S4 runs 100% E85 seamlessly since 2 years now. Here, E85 is 15% unleaded/85% alcohol in summer and up to 27% unleaded/73% alcohol in winter. On S4, there's a simple/cheap way of running E85, just set fuel trim to +25% in lemmiwinks, and the ECU will do the rest of the correction !! I usually get +3-6% on partial adaptation, and 0-2% on idling adaptation. That makes an overall correction of +28-31% max ... No engine startup problem at all in winter, no idling trouble. And add some timing if you want (you are not obliged), +7.5° in my case as I already have a MRC tune. Usually from +3° to +18° (yes I tried it in winter) !!! I notice nothing special above +10.5° except a strange phenomena: sometimes (when flooring the throttle) the timing is pulled to a default value of +12°, not nice. So +7.5° is fine in my case. My car pulls more than 350rwhp. My MAF shows more than 326g/s on full boost (~1.3bar, 1.5 max) That's my cheap way of running 100% E85. That's just a starting point  I've used Unisettings to adjust my fuel last autumn, but since then moved to real mapping. Now my idle maps are OK when warm. All I need is to adjust COLD START ENRICHMENT factors and that's it. |
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RC200
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« Reply #65 on: January 18, 2012, 07:55:29 AM »
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Strange, I didn't need some many tweaks for my S4. Maybe because my S4 is already MRC tuned ...
It was even a surprise for me to have a so perfect behaviour on E85 with only Unisettings trimming.
On the other hand, my 300zx required more work to run 100% E85:
_cold/warm start enrichment tables
_cold timing
_overall advance accross the rpm/load ranges
_small adjustments in all the corners
Cold startup in winter has been a nightmare to get it right (I mean: 1-2 seconds key turn ==> immediate startup)
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----------------------------------------------------------
EURO S4 B5 2.7T 07/1999 Ph2 8D50J9
VIN: > 8DZYA00xxxx
ECU 8D0 907 551D
K04, 750cc, Walbro 485LPH fuel pump, 4bars FPR, MRC map
Running 100% E85 with UniSettings adjustment. Timing +7.5°. >350 rwhp.
13.5L/100kms on highway, 16-19 mix driving.
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fredrik_a
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« Reply #66 on: January 19, 2012, 01:25:36 PM »
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Can you tell me by how much should I enrich the AF mixture at 0C temperature (approximately)?
I see you run quite rich already so that shouldn't be the issue. I usually see a need for about 3x crank enrichment @ 0°C ambient but it needs to be decreased gradually as the combustion chamber warms up quite rapidly. Keep in mind though that the after start enrichment is different for E85 than for regular petrol and that it's not linear. Also, you should not confuse cold engine enrichment (choke) with cold start enrichment as they are two separate things running in parallell. |
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« Last Edit: January 19, 2012, 01:36:00 PM by fredrik_a »
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leolux
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« Reply #67 on: April 18, 2013, 07:42:53 AM »
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Hi, all talkes about 6-8 dec on using e85 in what of RPM or LOad you mean it? At time i have only on full Load and High RMP change about 7dec with good result But how i can reedjust my Ignition Timings on idle and low load for perfect economy??? Leo |
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Acki
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« Reply #68 on: April 18, 2013, 07:49:59 AM »
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Raise ignition at constant drive till load won't lower. In winter you only get E70 at the fuel station because of cold start. GM flex sensor isn't very durable. From E100 cars I know that they start on gasoline (small extra tank for this) because ethanol won't evaporate very well at low temps. |
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overspeed
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« Reply #69 on: May 05, 2013, 11:21:26 AM »
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I´m from Brasil and we have E100 here since 70´s
You can easily start the engine if the temperature is above only 17°C (E100 didn´t vaporize lower than this, so it will be based on mechanical efect os the injectors to vaporize it) will just some tweaks in temperature correction maps to keep the engine runing in Warming withou problens
you can start the engine until about 7~8°C is you increase the fuel pressure (about 3,8Bar is what I saw in most brasilian flexfuel cars) and increase a lot the enrich based on IAT and TMOT.
Lower than 7°C is the problem... for these I recomend use 10% gasoline in the blend
There is no easy way to make "flex" convertions... you may want to use 2 prograns, one with E85 (or E100) and another for gasoline... keep in mind that using E85/E100 will require a lot more of DC in the injectros, and they can reach 100% easily if they are not big enough
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titi65
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« Reply #70 on: December 24, 2013, 08:12:48 AM »
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I've hard 2/3 points for E85 conversion:
-The injection angle might need to be adjusted.
-The ethanol is not vaporing "lineary" in temperature, so, when the engine get 80° the oil vapor recycling may devy the compensation in excess.
-The wall weeting maps has to be corrected (don't ask to me how, not tryed yet).
Sorry for my english, I'm french.
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titi65
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« Reply #71 on: March 14, 2014, 08:48:18 AM »
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But how i can reedjust my Ignition Timings on idle and low load for perfect economy??? Hi, Did you tried in low load to add or remove some ignition advance ? |
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Placebo
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« Reply #72 on: July 09, 2015, 08:35:09 AM »
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I know old thread but wanted to ask about best way to tune for E85 with a 1.8t using an M5.9.2 ECU.
I want to run 50-50 blend of E85 and regular. Fuel trims can compensate fine but I worry about running lean at WOT so I would like to alter the basic fueling setup. What should work best? adding ~15% (30% if running straight E85) across the KFLF map or altering FGATO from 1 to 1.15. Not sure I fully understand how the FGATO constant works but seems like it is a correction factor applied to the KFLF map, please correct me if this is wrong. Sounds like both methods would do essentially the same thing.
Thanks for whatever advice you wish to share.
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Placebo
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« Reply #73 on: July 09, 2015, 07:45:32 PM »
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Well, tried both methods for a little bit. Adding 15%to kflf seems to work ok. Fuel trims looked good at less than 5% and it leaned up to AFR high 11s at WOT. Had max 3 knock CF.
Did also try FGATO up from 1 to 1.15. Idle FT was 3% and adaptive FT was zero. Not sure if this is too good to be true. Logs show the part throttle FT briefly going to 0.8% for a bit then returning and staying 0%. AFRs looked reasonable on the gauge but did not try WOT nor logging AFRs. Need more info about FAGTO to understand better what it does before I trust this method.
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« Last Edit: July 09, 2015, 07:47:15 PM by Placebo »
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TeknoFi
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« Reply #74 on: November 15, 2022, 10:32:16 AM »
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Hey,
I'm playing with ethanol, without a sensor and it almost works already, but "ltft" (fra_w adaptation, partial throttle) is really, really slow to adapt.
I have mainly touched the values of FRAOMX, FRAORX, FRAODX, QUFRMX, FRMAX etc. so that I am not limited to +25%, but increased it to +34% at the beginning. Works good.
could someone tell me how to make longfueltrim / fra_w fast responsive. It doesn't make sense that it comes back to life only after 20 minutes of driving and it seems to happen in a completely random situation. Before that, it's just a straight line. fr_w runs normally at the same time. How to make it work quickly, and live often or continuously (however, not too quickly)? At the moment, the functionality is good if I switch off the frao and frau completely with nolra, and I don't change the fuel (krkte must be according to the fuel then) Now a super slow response of fra_w ruins the system.
My settings:
TVLRA 2 (second)
ZKFRAU 0.05%/sec <-already doubled from oem, can someone explain what does this do? I see in logs about 0.2% per second increases but problem is that its loooooong flat line before it moves.
What exactly are the limits ...MN/...MX/...RN/...RX that appear in these settings? (for frao,frau,rkat,rkaz), minimun, maximum and then again same for what? It has an upper and a lower, and both for the second time, why? What is the difference between the second pair? What determines in which situation one is used, etc.?
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