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Old 07-23-2013, 01:38 AM   #876
Clark Turner
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I did see the tables you made. You have leaned out the high boost area a lot, I think it will be to lean now. I think the VE table needs a lot of work. But again. It may have been tuned that way because of a lack of fuel.
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Old 07-23-2013, 01:51 AM   #877
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I did see the tables you made. You have leaned out the high boost area a lot, I think it will be to lean now. I think the VE table needs a lot of work. But again. It may have been tuned that way because of a lack of fuel.
Can you check my logic please?

Carbibbles said on Romraider "So if your AFR was 13:1 in a certain spot and you wanted the AFR to be 12.5:1 in that spot, you would take 13/12.5 and get a multiplier of 1.04"

I've changed the AFR values in the AFR table to what they should be and I noted the changed cells. I then applied each individual multiplier to the "Speed Density Base Load Comp" table for those same cells.

So the fuel equation or the injector pulse width should still be near identical, I've just scaled both variables in a hope to achieve this. Next step is of course to safely test this. Have I gone the wrong way haha.
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Old 07-23-2013, 01:56 AM   #878
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I think the AFR targets are way to lean and I think the VE table is not correct. It would have to be tuned however. It would not be logical to have a VE table that ran 105 then 67 on boost at high rpm like that on your setup. Only on a car that maybe had a significant loss in VE at high rpm.

C
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Old 07-23-2013, 02:02 AM   #879
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I think the AFR targets are way to lean and I think the VE table is not correct. It would have to be tuned however. It would not be logical to have a VE table that ran 105 then 67 on boost at high rpm like that on your setup. Only on a car that maybe had a significant loss in VE at high rpm.

C
What AFR's would you run with when using E85? I would've thought my targets are on the rich side with this fuel.
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Old 07-23-2013, 05:06 AM   #880
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^ idk about e85, but that does seem lean to me. And your scaling for the map range seems off, 40psia when your only running 25psi boost. To help out you could try the ve tuning spreadsheet too.
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Old 07-23-2013, 06:37 AM   #881
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^ idk about e85, but that does seem lean to me. And your scaling for the map range seems off, 40psia when your only running 25psi boost. To help out you could try the ve tuning spreadsheet too.
Interesting, in Aus we tend to aim for around 0.8 lambda with E85 and stocky motors and lean it out for 2618 forged type stuff. Although with my stock EG33/GT35R combo I had that out to 0.85 and 450 odd whp.

But anway, you of course realise 38 psia = 25 psig, which is why the fuel map goes to 40 psia.

Might check out the VE spreadsheet although doesn't that require MAF to setup base values?
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Old 07-23-2013, 12:30 PM   #882
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bazza - you multiplied your VE map incorrectly. You adjusted your target fuel map correctly (although you may want to smooth it out and use richer targets in the midrange boost area), but you need to take the new value divided by the old value to get a multiplier "new_value/old_value" = multiplier for VE map. So if you had a fuel target of "6.5" and the new target is "11.8" you would get 11.8/6.5 = 1.82. Then apply that to the VE table cells that are in the same engine speed and psia areas.

Remember larger numbers in the VE map are more fuel, larger numbers in the open loop target map are less fuel. If you take fuel away from the open loop target table you need to add the same percentage of fuel to the VE map to maintain the same fueling.


The above calculations are inverted from tuning the VE map because the fuel target map is inverted (lower numbers are more fuel). The instruction you quoted me on is for tuning the VE map using wideband readings vs target afrs.



Jason
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Old 07-23-2013, 07:53 PM   #883
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bazza - you multiplied your VE map incorrectly. You adjusted your target fuel map correctly (although you may want to smooth it out and use richer targets in the midrange boost area), but you need to take the new value divided by the old value to get a multiplier "new_value/old_value" = multiplier for VE map. So if you had a fuel target of "6.5" and the new target is "11.8" you would get 11.8/6.5 = 1.82. Then apply that to the VE table cells that are in the same engine speed and psia areas.

Remember larger numbers in the VE map are more fuel, larger numbers in the open loop target map are less fuel. If you take fuel away from the open loop target table you need to add the same percentage of fuel to the VE map to maintain the same fueling.


The above calculations are inverted from tuning the VE map because the fuel target map is inverted (lower numbers are more fuel). The instruction you quoted me on is for tuning the VE map using wideband readings vs target afrs.

Jason
Thank you Jason - you've answered exactly what I was hoping you would. Also just to confirm one more thing. If I move the injectors from 575cc up to 650cc (as apparently this is what you do for E85 / ID1000??) do I again say 650/575 = 1.13 and then multiply 1.13 against the entire SD base load compensation table?
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Old 07-24-2013, 02:21 AM   #884
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Thank you Jason - you've answered exactly what I was hoping you would. Also just to confirm one more thing. If I move the injectors from 575cc up to 650cc (as apparently this is what you do for E85 / ID1000??) do I again say 650/575 = 1.13 and then multiply 1.13 against the entire SD base load compensation table?

Yes that would be the correct procedure for that change if you want to maintain the same final fueling and only adjust the injector scaling value to represent actual flow. Keep in mind that changing the injector scaling without actually changing injectors will alter the calculated engine load, the fueling will work out to be the same but it will have an effect on any engine load based tables. You want the injector scaling to be accurate to the actual flow (skewed for e85 of course) in order to have the ecu calculate accurate engine load values.

I usually end up with 750cc to 800cc on e85 and id1000s.
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Old 07-24-2013, 02:39 AM   #885
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But anway, you of course realise 38 psia = 25 psig, which is why the fuel map goes to 40 psia.
sorry that's my tired 1am math
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