If you want the equivalent of drilling out your carb jets, just install larger injectors. And fuel line ethanol sensors are cheap.
If you want the equivalent of drilling out your carb jets, just install larger injectors. And fuel line ethanol sensors are cheap.
nemsimphongthuy said:We know from tests GRM has done that E85 adds power, more power than racing fuel.
We also know that it's around 50 -70 Cents a gallon cheaper than premium and a lot cheaper than Racing fuel.
But if your car doesn't have Flex fuel capability is there a Grass roots way to gain the power benefits and cleaner burning?
If we used carbs you could just drill ( team) the jet (s) out 60% and be good to go. That is assuming the E85 you buy at your pump is 85% ethanol. Since it can legally be between 51%& 85% That's not a given. It will be 85% if you buy it from a racing fuel supplier, but I digress.
So it seems to me that first we need a simple way to test it. I have a test kit to determine specific gravity. Bit of a Science lab experiment and with glass test tubes etc. not exactly user friendly.
But with modern Electronics and the smart people we have here how difficult would it be to create a pocket sized fuel analyzer? ( Bonus points if it measures % water content)
The next problem I see is how to make older less flexible systems react to the need for up to 60% more fuel? Something to piggy back on existing systems.
I could swear I wrote exactly this not too long ago.
In reply to frenchyd :
It's a not too uncommon canoe tactic to copy an old post and repost it exactly or nearly so. OP, it would appear, is a canoe.
Keith Tanner said:If you want the equivalent of drilling out your carb jets, just install larger injectors. And fuel line ethanol sensors are cheap.
Installing bigger injectors seems straight forward enough for a Luddite like myself. But where do you input the data from the ethanol sensors?
Older ECU's don't have a OBD2 port. So are we just S.O.L. ?
Older ECU's can be tricked by modifying the signal from the oxygen sensor or the temperature sensor to adjust how much fuel the system puts into the engine.
If the temp sensor tells the ECU that the engine is warm, it will richen the mix to avoid detonation and to help cool it down. Temp sensors are ranged resistors, so adjust the range slightly and you can trick the ECU
If they don't use an oxygen sensor, then there's a manual adjustment that you can do.
In both cases, you get to manage the amount of ethanol yourself and adjust accordingly.
To make the most of E85, you'll want to up the compression ratio either with more static compression or more dynamic compression (adding a turbo or supercharger, etc.)
If you're running something like a MegaSquirt-II or later, then you just need the sensor and a few changes in code/wiring:
In reply to Stefan (Forum Supporter) :
Thank you,
Since the compression of Jaguar's post 1980 is 11.5-1 here in the states. (12.5-1 the rest of the world) It's really begging me to use E85
Jaguar gets away with such high compression by restricting total timing to 17 degrees compared to 40 degrees for carbureted cars
that seems straight forward except the temp sensor is analog? On a Lucas ECU do you know where I can input the data from the sensor, or do I start unsoldering the unit?
frenchyd said:Keith Tanner said:If you want the equivalent of drilling out your carb jets, just install larger injectors. And fuel line ethanol sensors are cheap.
Installing bigger injectors seems straight forward enough for a Luddite like myself. But where do you input the data from the ethanol sensors?
Older ECU's don't have a OBD2 port. So are we just S.O.L. ?
You output the ethanol sensor to a gauge. We're comparing this to carburetors and chemistry experiments. If you want an easy way to test the ethanol content of a fuel without test tubes, that's what the sensor can tell you. Using the information is up to you.
As for trying to trick your car using the temp sensor, the temp signal is a voltage (or a resistance, which kinda works out the same). You just substitute a voltage of your own.
FYI, the signal from the ethanol sensor is delivered in the form of a frequency for ethanol content. You could maybe hook it up to a tach :)
You need 30% more fuel, not 60%
In reply to Patientzero :
Fuel requirements depend on % of ethanol to gasoline. Pump E85 can be 51% - 85%
Keith Tanner said:FYI, the signal from the ethanol sensor is delivered in the form of a frequency for ethanol content. You could maybe hook it up to a tach :)
So an ethanol sensor gives you a different buzz depending on the alcohol[1] content of the fuel?
Yes, I know, I'll get my coat.
[1] OK, ethanol.
On a more serious note I guess one could use that output to drive a piggyback that modifies the signal going to the injectors. I'd probably want some feedback from the O2 sensor though.
The stock ECU already has that feedback. I don't remember how an O2 sensor reads E85, I'm a bit rusty there. But basically, you'd just want to scale fuel delivery in response to what the ethanol content is. I think that's exactly what JG's magic E85 box on his Corvette does.
In reply to Keith Tanner :
Doesn't E85 have a different stoich than gasoline? Something like 9.8:1 instead of 14.7:1, so your ECU will think you're massively overfueling and potentially trying to correct that back to where the OEM ECU thinks the AFR should be?
Of course that's assuming that your ECU has an O2 sensor, but I'd guess you have to look at something rather older to have FI and no O2 sensor.
In reply to frenchyd :
Correct and for 85% ethanol you would need 30% more fuel, less fuel for less ethanol content. Not 60%.
Other than maybe some weird Jaguar, I would expect just about any EFI system to have an O2 sensor.
IIRC, narrowbands don't read AFR, they read lambda. And that's basically fuel-independent, it's a direct measure of if you're at stoich or not - no matter what the AFR is. I'm pretty sure widebands are the same.
In reply to BoxheadTim :
Basically all O2 sensors work in lambda. Stoich is stoich no matter what the ratio is. Your ecu of choice converts the lambda output to AFR, so if you're tuning in gasoline scale you need to use gasoline AFR numbers because it's just a conversion in the background.
If you just tune in lambda it doesn't matter what fuel you use, 1 is stoich. Less is rich, and more is lean.
*Keith beat me to it.
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