9XX Ethanol - E85 tuning or EFI E85 flex fuel conversion

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kistinie
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9XX Ethanol - E85 tuning or EFI E85 flex fuel conversion

Post by kistinie »

In France and many other EU countries E85 is far cheaper than regular fuels. E85 is also high octane so perfectly adapted to 9xx HC engines.
Corrosion can be a problem but my experience for my Range Rover 3.9 EFI and Triumph TR3A is that it is not a critical issue.
Two main options are possible for the Elite/Eclat/Excel :

- Re-Jetting the carbs. A by far easier, less expensive and origin respect option
- Convert to injection with dual mapping, or better, install an ethanol sensor, create a flex mapping to become full flex fuel

So has someone re-jetted the Dellorto carbs for Ethanol, E85 fuel or gone for injection with flex mapping ?
If no, how many could we be interested in the project to ease and rise the quality level of this upgrade ?

Thank you, and best thoughts from Vichy (France) !

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bash
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Re: 9XX Ethanol - E85 tuning or EFI E85 flex fuel conversion

Post by bash »

My main issue with e85, if Im correct, is that although the octane rating may be higher the energy produced is lower, so you end up using more fuel to get the same power, which somewhat defeats the so called "green" credentials of using it. Please correct me someone if Im wrong.
Bash
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kistinie
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Re: 9XX Ethanol - E85 tuning or EFI E85 flex fuel conversion

Post by kistinie »

1,48 more fuel is needed to get the same same stoichiometric AFR with E85. For MPG, you usually need 10 to 20% more. But you get lower CO, and less Nox. So yes, greener fuel and here in France, 1,7 € for Premium fuel, 0,7€ E85 ...

My RRC needs 11L/100Km on 95 Ron, 14L on E85
Our Prius, 5,5L/100 on 95, 6 to 6,5 on E85

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bash
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Re: 9XX Ethanol - E85 tuning or EFI E85 flex fuel conversion

Post by bash »

Im not having a pop here, I appreciate that ethanol in fuels is here to stay and I agree that we need to get used to it so your aim to get our cars ready is very timely, but green campaigners always quote emissions from the exhaust but conveniently forget about the emissions created by its production, not to mention that food is used when people are starving. Anyway, back to your original point.
I think that we would need fuel injection to get around all the different fuels. Is there a way that the different grades can be automatically detected ?

Bash
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bash
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Re: 9XX Ethanol - E85 tuning or EFI E85 flex fuel conversion

Post by bash »

I ask this question because in the usa e85 is allowed to vary between 55 and 85 percent ethanol, so how is huge variation safely catered for by the management. If this is the same in europe I dont see how a carb setup could cater for it because bigger jets would be needed to make it work with e85, but then if it actually was only in fact e55 it would be running hugely rich.
Sorry to be a pain, anyone else got any thoughts.
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Lotus-e-Clan
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Re: 9XX Ethanol - E85 tuning or EFI E85 flex fuel conversion

Post by Lotus-e-Clan »

bash wrote:
Mon Oct 11, 2021 00:07
I ask this question because in the usa e85 is allowed to vary between 55 and 85 percent ethanol, so how is huge variation safely catered for by the management. If this is the same in europe I dont see how a carb setup could cater for it because bigger jets would be needed to make it work with e85, but then if it actually was only in fact e55 it would be running hugely rich.
Sorry to be a pain, anyone else got any thoughts.
Bash
Re: retention of carbs. This isn't going to affect my motoring space anytime soon (fingers crossed!) and I have no experience of running high ethanol fuel, but one approach (analog-cobbled experimental approach) would be to run an O2 sensor with a dash display and have switchable igniton maps. Switch to the more advanced ignition map as indicated by weakened AFR values and vice versa. Not sure if there are any available, but a standalone AFR-controlled ignition ECU would be nice to have, or use a full EFI ECU for ignition only. But I guess this ignition-centric solution could be limited in scope if fuel quality varied hugely.

For me, my current mileage is so low that expensive high octane E5 fuel is no hardship, and to be honest, even when I did a decent mileage commuting (in classics) I used 97 -99 as a norm.
Peter K

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bash
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Re: 9XX Ethanol - E85 tuning or EFI E85 flex fuel conversion

Post by bash »

Im about to put an injected self tuning 4 barrel unit from fitech on my car ( v8 powered ) which is partly tuned using a wideband lambda, amongst other 'stuff', but even that cannot cope on its own without making changes. Even though this is self tuning you can actually change almost everything on a hand held unit. On initial setup you have to put in the engine displacement, 215 ci, in my case, but if e85 ish is used, because of the fact that it uses 30 percent more fuel the only way around it is to tell you ecu that the engine is 30 percent bigger, roughly 285 ci in my case, and then it will cope ok. ( 3.5 litres to 4.7 litres ) As long as the injectors are within thier duty cycle that is.
As you can tell, Ive spent abit of time on this.
I can save two maps, but for me, I will be sticking to petrol. However, Its still worth thinking about if e85 becomes commonly available here, which it isnt, but I suspect a fishing expedition here ?

Bash
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