turbovanman - u got pm
turbovanman - u got pm
Having a problem with the com setting i only have com 4and 5 to work with and my ostrich wants com 7 any idea?
Ok i think i might have got it now the Ostrich 2 has to be plugged in before opening MPtuner to reconize the Com port is open i now have an active Com 7 port open
ok, in talking with DodgeZ about scaling for E85, it brings up a good point. to scale for e85 and different injectors right now, you have to manually input an injector value that roughly 30% smaller than the injector you are going to run because you need 30% more pulsewidth.
is there something we could "check" to indicate when we are using e85 so that the injector size is accurate to what is in the car but is scaled for a e85 appropriate pulsewidth.
also, tying in the fuel pressure that is actually being used on the car to the scaling would be nice as well. like when running 72lb per hr injectors that are rated for 43psi, you need to type in a value that isnt the injector size when running them at 55psi.
i know there are values that can be inputted for this stuff in the fueling setup but it doesnt affect the scaling afaik.
also, being able to edit the afr values easier in the fueling setup would be nice. something like importing a .csv for these values would be awesome or being able to export the afr values to be used with another template.
thanks
Brian
Originally Posted by turbovanman
It is possible to closely monitor the adaptives as they will bias positive with the presence of E85. This can only be done when extremely accurate base curves are generated, with minimal error throughout all RPM and MAP ranges. When this is accomplished, it will will cause a nearly constant drift in learning and this shift should be applied to the open loop fueling. To give yourself some level of adjustment, add a transfer function that can provide an added level of adjustment/gain to open loop A/F conditions. A word of caution when using this approach - Don't add more E85 than the adaptive range can handle. Once the adaptives are railed you will get no further increase in fuel and thus the reason FFV vehicles light the MIL when too much Ethanol is used.
Hope this helps.
actually, i wrote "check" because i wanted a check box in the program to indicate that e85 was being used so that the injector value that we scale the tables for was the same as the injector size in the vehicle. right now, if e85 is being used and we are using, say, 72lb/hr injectors, we have to actually scale for something more like 50lb/hr to get enough pulsewidth to account for the increase in fuel needed for e85. this is further compounded by the fact that larger injectors are usually rated at 44(ish) psi of fuel pressure so not only are we fibbing on the injector size that the program is scaling for based on fuel type, we are also fibbing on the pressure that the injector is being run at in using the stock fuel pressure regulator.
lemme draw a little pic to illustrate what i am talking about.
i understand where you are coming from with applying E85 adaptive drift to the open loop fueling (pretty cool) but it was totally beyond the scope of my initial request for the current software/editor that we are using.
that said, this would account for minor variations in ethanol concentration, would it not?
Brian
Is the attempt to have a single offset for regulator pressure and one for injector offset??
This will be a multiplier and not an additive value, correct?
If the check box enables a single offset/gain you may want to make sure that it is used with the PW to be delivered rather than an offset to the PW tables. Any given user can calibrate the PW curves vs rpm based tables vs temperature compensation tables, etc.. differently. In these cases the offset will produce a different result for each unique method of calibrating. This will also avoid slope error steps when crossing the map values in the fuel tables.
The final value calculated after all compensation has taken place may be the best value to offset/multiply.
If you were to use the adaptives to fine tune/adjust the A/F ratio, you'd have to change the target A/F too... I'm not sure what stoich is for E85, but I'm fairly confident that it would be rich enough to be outside the capabilities of the stock, narrow band sensor... Anyone feel free to correct met if I'm off-base here...i understand where you are coming from with applying E85 adaptive drift to the open loop fueling (pretty cool) but it was totally beyond the scope of my initial request for the current software/editor that we are using.
Brian
Mike
"The Constitution is not an instrument for the government to restrain the people, it is an instrument for the people to restrain the government - lest it come to dominate our lives and interests." - Patrick Henry
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- Edmund Burke
It is for the scaling of the cal from the get go. It isn't going to be an added feature for the cal (but that would be nice). I am not sure how much you have played with MP tuner but it has a scaling feature that lets you choose your injectors and map sensor. It then rescales the correct tables for you. Well you have to tell it how big your injectors are. In which case the stock, +20s and +40s are all known by their flow at 55psi of fuel pressure. When using other injectors such as 72lbs injectors it is really 72lbs at 43.5 psi of fuel pressure. So when you bump it up to 55psi they are more like 81lbs injectors. It would be nice to have it figure out what your injectors are really flowing on the scaling "window". I know when I first messed with it I put 72lbs when it should have been 81lbs.
basically add in some of the math
http://www.witchhunter.com/injectorcalc1.php4
Once you do the rescale the injector size and MAP size are saved in the template file. The target AFR uses that information to come up with it's line for guessimated pulse width for the AFR you want.
That is great, the problem is when rescale for e85. You kind of have to lie to it get it rescaled correctly. so....
To rescale for 72 lbs injectors you have to first upsize them for the new PSI.
72lbs@43.5psi = 81lbs@55psi.
Then you have to add roughly 30% more fuel. So...
81lbs * 0.7 = 57.6lbs
To get my 72lbs injector work out correctly for e85 I have to scale for 57.6lbs. Remember MPTurner saves what you used to rescale for in it's AFR target calculations (or at least that is the way it looks to work).
When setting up your target AFR there are a bunch of options which include E85 fuel. I can't see how this is calculated correctly when the injector size is incorrect. In the "fueling setup" for the target AFR what is "Inj Rating (bar)" Does this mean what are the injectors rated to flow but in bar instead of lbs? Also on the table for typing in what AFR you want, is there anyway to highlight a bunch of cells and then type in your number?
you are incorrect.
http://www.e85mustangs.com/tuning.html
2022 Viper runs 9s
Mike, you are correct and this is why normal application adaptives are not permitted to adjust for +/- 50%. This would go beyond the A/F range of the standard sensor and why it was advised not to use more E85 than what the adaptives can properly adjust for. As sensor technology improved, including the use of extended range sensors, the adaptive window grew as a result. Early adaptives were limited to +/-25% while later adaptives are at +/-33%. If an E85 mixture is being used (somewhere between 14.7:1 and 9.7:1) then consideration must be given to avoid exceeding the O2/adaptive adjustment capability.
I hope this helps.
Scaling the way you are talking about (for E85) is really only valid for the 3 main fuel tables.
For example, look at the Prime PW table. You don't want to scale this table by simply adding 30% for E85. It might get you close, but in theory, it's not right. Because E85 vaporizes very differently from gasoline. So, the volume of fuel you want in the manifold on startup should be different than what you get by simply scaling for the energy content in the fuel (which is where the 30% figure comes from).
The other PW tables have similar issues as they are mostly related to start-up and warm-up.
Also, you would NOT want to scale the navigator output for E85 since it would then give you an 'equivalent' fuel economy (instead of a true fuel economy).
That's the intended purpose of adding the fueling lines to the 3 main fuel tables. So, that you can make changes like these and adjust accordingly.
Now, in the case of fuel pressure changes, that scaling can and should be applied to all the PW tables since it (mostly) has the same effect as changing injector size. Of course, there are some limits to that as well - the spray pattern and latency change with pressure. But, within a reasonable range it should be valid.
So is the information on this page incorrect?
http://www.e85mustangs.com/tuning.html
I read that as. If the computer thinks it is seeing 14.7 from the o2 (1.0 lamda) but it is running e85 it is 9.7. No? I am also thinking more of running straight e85 or straight gas. Not a mix.Understanding Air/Fuel ratios
This article assumes you already understand the concept of the air/fuel ratio (AFR), but if not, familiarize yourself by visiting this Wikipedia link. You may have already read that E85 has a different stoichometric air fuel ratio than gasoline's 14.7. The stoich AFR for E85 (at 85% Ethanol) is 9.76. The stoich value represents an ideal perfect burn of the fuel usually used at part throttle conditions. Full throttle conditions require a richer mixture than stoich to prevent the dreaded detonation, or pinging.
However most AFR gauges you can purchase to display a numerical value of the AFR, are showing you values for gasoline. This is where it can get tricky, and it's important to understand how this ratio works on both gasoline and ethanol-based fuel.
All AFR's regardless of fuel type work off of a common number called Lambda. A value of 1.0 in Lambda represents the stoich for any fuel. Gasoline is Lambda 1.0 at stoich. E85 is Lambda 1.0 at stoich.
If you already have a standard gasoline AFR meter hooked to a wideband O2 sensor, you can still use the displayed gasoline AFRs in determining your engine's true AFR. For example, if your gasoline meter is showing 14.7, then we know this is Lamda of 1.0. The equivelent on the E85 side is around 9.7. Therefore you can conclude that the 14.7 you see on the gauge is a true AFR of 9.7. This allows you to effectively use existing gasoline AFR components or software to tune an E85 Mustang without buying special equipment. Simply use the same target AFRs on your gasoline gauge that you normally targeted for gasolline.
2022 Viper runs 9s
Sounds like it needs to scale twice for e85 then? Once to rescale for the bigger injectors and then again to adjust the 3 tables to e85?
2022 Viper runs 9s
At the least, yes. Then the 'other' PW tables will need tweaking individually. Again, the 30% figure will probably get you close (closer then doing nothing anyway). But, it will likely need further tweaking from there for cold start and warm-up.
In addition, E85 needs 2 different adjustments in the 3 main fuel tables - 1 for the fuel specific gravity, and one for the AFR. The AFR is the larger driver, though. The specific gravity is important because our injectors flow a specified volumetric rate, but the AFR is actually a mass balance. Gasoline is typically around 0.73, but ethanol is closer to 0.79. So, there should be an adjustment for that as well. Though, it's small enough that if you neglected it, the adaptives should compensate.
that's a good idea. just fyi, you can do some simple copying in that screen by highlighting and using the ctrl-c and ctrl-v key combinations. also if you select a range of cells and press ctrl-i it will interpolate between the first and last cell. you need to be very deliberate, btw, when do the key combinations, i.e. press the ctrl key and hold, press the c key, release the c key, release the ctrl key. i need to fix that logic in the next version so it works smoother.
ok so scaling everything that is scaled for injector size is bad for e85. thats fine. i understand that.
my intent of taking more information into account when dealing with different pressures, fuels, injector size was so that the injector information in the calibration information section was correct rather than having to do external calcs to fool the program into giving you the values you need.
im ok with doing everything manually, i just have to write additional information down so that i dont forget what i actually based a calibration around.
Brian
I think what he means there is that when you add E85 that the afr will shoot to a lean amount higher than the adaptives can handle thus making the ecu "give up" on trying to correct it. With the sensor that has more range when you add e85 the afr doesn't shoot outside the range so the ecu can correct it.
Ian Adams Function>Form 1990 shadow scrapped, too rusty:( 1991 Spirit R/T Scrapped, parts sold:( 1989 Turbo Caravan Daily beater with built-[I]ish [/I]engine slowly evolving into weekend turbo beater.
Oh, like just adding e85 but not rescaling the computer?
2022 Viper runs 9s
yea, he was talking about the newer flex fuel vehicles that dont have an ethanol sensor.
Ian Adams Function>Form 1990 shadow scrapped, too rusty:( 1991 Spirit R/T Scrapped, parts sold:( 1989 Turbo Caravan Daily beater with built-[I]ish [/I]engine slowly evolving into weekend turbo beater.
I know I've mentioned this before, but is there a reason we can't just put a multiplier into the system to scale the final pulsewidth and remove some of the complexity? For example, just before the pulsewidth is loaded into the timer compares multiplying it by a scaling factor. So, if you went from say factory 25lb/hr to 50 lb/hr injectors you would divide the pulsewidth by 2 as it's being loaded. Same would happen if you raised or dropped your fuel pressure, just tweak the multiplier. I get that there may be some inherent loss of precision, but I don't think it would be much worse than the accumulated errors possible with multiple table scalings.
That would remove a lot of other tweaks and playing with tables just to fix fueling. It wouldn't have anything to do with dead time, but we never adjust that anyways. I'm not sure it totally fixes the e85 issue, but it might make it simpler to tackle.
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