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E85 max power lambda value copare gas pump fuel

Understanding AFR

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Dear all,

i will use modelled fuel from ECU g4+ from my Mitsubishi lancer evo9, id1300cc, turbo pressure 1.65b, flex fuel e85

I search some information and experience from you about lambda value (max power lambda value) for pump gas and e85 for turbo engine

For pump gas Stoich ratio is 14.7 / lambda 1. For cruising i will use lambda 1 and for full boost 1.65b i will use 0.73 lambda

For e85 Stoich ratio is 9.8 / lambda 1, for cruising i will use lambda 1 and for full boost 1.65b i dont know yet may be around 0.8 lambda

do you have some test what is the best lambda value for e85 in full bosst for the max power?

Thanks in adavnce

dyno will tell you, yet generally similar lambda as 98, unless there was it was excessively rich on 98 to combat knock then it will be a bit leaner on e85

Scott is spot on - The ideal lambda value is not fixed and will vary from engine to engine. That being said, E85 tends to respond well at the same lambda targets as pump gas under high load. You can actually run leaner on E85 many times because you won't be relying on the cooling aspect of an overly rich mixture in order to prevent knock.

In general on E85 I'll be in the vicinity of 0.80-0.82 and on pump gas I might be more likely to be in the region of 0.78-0.80. While you're running reasonably high boost on pump gas with 1.65 bar, I'd be surprised if you aren't giving away some power running at 0.73 lambda. The dyno will be the true answer to your question though.

any reason power starts to drop off if we run a mixture that's to rich?

Depends on the fuel, but petrol/gasoline and E85 will burn slower and cooler if over-rich - both reduce potential power.

I know this is a very old post but to Andre I have a question. You say e85 responds very well to Similar lamda targets as pump gas. Would you say a blend of E50 would respond just as well to pump gas lambda targets since it has more petrol than e85? Not a lot of info I can find online about tuning E40-E60. I'm just trying to capture most of the ethanol benefits by running say E50 without running my injectors or fuel pump to maximum duty cycle like I would using e85. Thank you for any insight.

From what I have experienced engines produce most power at the same lambda value regardless of the fuel type... Doesn't matter how you mix fuels with each other as long as lambda value stays the same... But that's just my experience...

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