420A 93 oct vs E85

Inkdlyfe · Mar 17, 2020

So I've been running E85 on my daily but had to run 93 the other day cuz I almost ran out of gas but it seems like my car acted more responsive. Car is internally fully built. I have a Walbro 255 upgraded lines, and I also have a hahn port fueler running stock injectors and the high flow injectors Hahn supplied with the set up, my car is also running a aem fic 8. But its tuned on 93 not E85 yet. But can still runs amazing on E85 just I dont know seems like it got more ass behind it on 93. Any input ?

dsmcrzy · Mar 17, 2020

You tuned it on 93.... e85 requires more fuel compared to 93. So it makes sense that it ran better on 93.

AWD-Tony · Mar 17, 2020

It's running better on 93 because it's tuned on 93.

Inkdlyfe · Mar 17, 2020

It isnt nothing to retune it on e85 I'm just wondering what is better to run ?

AWD-Tony · Mar 17, 2020

With e85, you can increase boost and timing. Ethanol on a port injection engine cools the air before it goes into the combustion chamber. It’s basically 106 octane fuel but like stated above, you need about 40% more ethanol than gasoline. You’ll also want to change the fuel filter to a SS element as it will deteriorate paper & fiberglass. Also upgrade to anodized fuel rail.

Inkdlyfe · Mar 17, 2020

See that's all new to me. I was told just run larger lines and a bigger fuel pump?? I mean I been running e85 for about idk 5 months now never had a fuel leak or lean out... and I have a stock rail, fuel filter, etc. What else do I need to run e85 correctly and get the power out of it ? Minus the tune I can get that covered

AWD-Tony · Mar 17, 2020

What's your injector duty cycle on the current tune?

dsmcrzy · Mar 17, 2020

The 420a fuel rails are steel so you will be fine with the stock fuel rail.

Inkdlyfe · Mar 17, 2020

Yes even with the port fueler
And so what else would I need? Only the fuel filter? Or do I really need 2 pumps

dsmcrzy said:
The 420a fuel rails are steel so you will be

fine with the stock fuel rail.

tk106 said:
What's your injector duty cycle on the current tune?

silvreclips · Mar 17, 2020

Are the stock fuel injectors still being controlled by the stock ECU? How are you going to tune those for more fuel?

motomattx · Mar 17, 2020

Many times on E85 you would want to run less timing, the actual big advantage to E85 is the cooling properties of it and the mass of the fuel itself that you can burn.

Boomdeeze · Mar 18, 2020

motomattx said:
Many times on E85 you would want to run less timing, the actual big advantage to E85 is the cooling properties of it and the mass of the fuel itself that you can burn.

What? This is the first time I’ve ever heard that before..

motomattx · Mar 18, 2020

Boomdeeze said:
What? This is the first time I’ve ever heard that before..

Very true though. So this is the key aspect we need to understand here. And the part that is often overlooked is that the burn speed, the combustion speed, on ethanol blended fuels is actually faster than what we end up with on gasoline. So if we understand that, what this straight away should suggest is all things being equal as we move from gasoline to an ethanol blended fuel, we may need to retard the ignition timing, start the ignition event later. Of course the other aspect with ethanol is that it has some properties that make the engine much less prone to suffering from knock or detonation. And obviously this is one of the reasons that we as performance engine tuners are drawn to E85.

Burn speed of E85 changes dramatically with mixture, it burns much faster (needs less advance) at high power rich mixtures. At more typical mixtures it burns about the same as gasoline or slightly quicker.

Because of its high octane it will allow you to run more advance, that does not necessarily mean the increased advance gives more power. One of the most common mistakes tuners make is over advancing timing looking for that last little bit of power. That removes all your safety cushion for when things go bad (pulling a hill fully loaded on a hot day etc.) and boom there goes a head gasket or a piston.

If you make small incremental changes in timing 2 degrees will usually show a change if there is one to be had. And you have some means of comparing relative performance (dyno, time 0-60, max speed pulling a hill, Gtech or something similar) the engine will tell you what timing it wants. You are looking for what is called MBT (minimum best torque timing). It is the lowest ignition advance that gives you 99% of your max torque - best power. That is the safest tune and you give up only 1% of your engines max power 2-4 hp on most engines.

Inkdlyfe · Mar 18, 2020

silvreclips said:
Are the stock fuel injectors still being controlled by the stock ECU? How are you going to tune those for more fuel?

On a aem fic6

Boomdeeze · Mar 18, 2020

motomattx said:
Very true though. So this is the key aspect we need to understand here. And the part that is often overlooked is that the burn speed, the combustion speed, on ethanol blended fuels is actually faster than what we end up with on gasoline. So if we understand that, what this straight away should suggest is all things being equal as we move from gasoline to an ethanol blended fuel, we may need to retard the ignition timing, start the ignition event later. Of course the other aspect with ethanol is that it has some properties that make the engine much less prone to suffering from knock or detonation. And obviously this is one of the reasons that we as performance engine tuners are drawn to E85.

Burn speed of E85 changes dramatically with mixture, it burns much faster (needs less advance) at high power rich mixtures. At more typical mixtures it burns about the same as gasoline or slightly quicker.

Because of its high octane it will allow you to run more advance, that does not necessarily mean the increased advance gives more power. One of the most common mistakes tuners make is over advancing timing looking for that last little bit of power. That removes all your safety cushion for when things go bad (pulling a hill fully loaded on a hot day etc.) and boom there goes a head gasket or a piston.

If you make small incremental changes in timing 2 degrees will usually show a change if there is one to be had. And you have some means of comparing relative performance (dyno, time 0-60, max speed pulling a hill, Gtech or something similar) the engine will tell you what timing it wants. You are looking for what is called MBT (minimum best torque timing). It is the lowest ignition advance that gives you 99% of your max torque - best power. That is the safest tune and you give up only 1% of your engines max power 2-4 hp on most engines.

So going off the assumption that you tuned your car this way, may I as, what your peak timing is?

motomattx · Mar 18, 2020

Boomdeeze said:
So going off the assumption that you tuned your car this way, may I as, what your peak timing is?

My peak timing is pretty much the same as it was on gasoline, its just spread out across the rpm range differently, thats all.

Boomdeeze · Mar 18, 2020

motomattx said:
My peak timing is pretty much the same as it was on gasoline, its just spread out across the rpm range differently, thats all.

And that is?

motomattx · Mar 19, 2020

Without opening up the files I can say that its around 19 degrees or so under real boost.

Mello · Mar 19, 2020

If you remember what time do you have with E85 at MBT? It's not the 19º is it?

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420A 93 oct vs E85

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Inkdlyfe

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Inkdlyfe

AWD-Tony

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Inkdlyfe

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motomattx

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Inkdlyfe

Boomdeeze

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