What's the deal with E85

[Helios]

No prob if you choose to go warranty void and tuning. A must do is your headers you want longtubes catless, the power is in there

Don't do just tune. do it right & only once

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[WildHorse]

My 2018 stock tune was commanding 24.5 on 93,

That's a 12:1 CR correct? You'd figure 2-3 more with 11:1 CR?

 

[Bluemustang]

Again, stock tune will never advance the timing that high. Not even close...

Yeah. Also pretty sure you need a tune for 110 octane. Your typical 93 canned tune is not going to do it, other than the fact that it won't knock. I do know that a tune for flex fuel/E85 is not the same as a straight E85 tune. It's not nearly as aggressive. There's more to it than the max timing at the top of the curve. Timing advance across the entire rev range can make a difference.

 

[WildHorse]

Also pretty sure you need a tune for 110 octane

You don't need a tune for 87/89/91/94 so why 110? Stoich is the same. Won't the pcm keep adding timing till the knock sensors say stop that? Cause more timing = better efficiency. Well to a point anyways, cause if the piston head & combustion chamber design is optimized, 29-31* is all you need for max power / efficiency, assuming a 12.5 - 12.7 stoich at WOT & octane rating. Sorry for all the questions, just curious.

 

[Helios]

You don't need a tune for 87/89/91/94 so why 110? Stoich is the same. Won't the pcm keep adding timing till the knock sensors say stop that? Cause more timing = better efficiency. Well to a point anyways, cause if the piston head & combustion chamber design is optimized, 29-31* is all you need for max power / efficiency, assuming a 12.5 - 12.7 stoich at WOT & octane rating. Sorry for all the questions, just curious.

It will give timing to what the tables are maxed at, if your fuel allows for it. 110 is exceeding the stock tune for nothing (its only harder to burn)
You can max out the stock timing with 94, which should call for close to 27 degree soso. For a 2018+ GT

Octane is not a reference of horsepower, but a knocking safety. You use more octane to give more timing safely.
And using 87 into a 12+ compression engine is STUPID, no matter what everyone on this forum will tell you. Minimum of 91 always for gen3

Using 87/89/91 in your 18 ? Your not getting max performance. Simple as that

 

[Zinc03svt]

The big difference with E85 or 100-110 octane tuning is the average wot ignition timing. For example, stock tune might give you a 27 peak, but off the hit might start at 24 and slowly ramp up on quality 93 octane. A E85 tune will give you that 31-32 right off the hit and hold it through rpm band. Also, the better tuners adjust the VCT which adds more power. There is nothing to debate/compare here folks versus stock.

 

[Bluemustang]

You don't need a tune for 87/89/91/94 so why 110? Stoich is the same. Won't the pcm keep adding timing till the knock sensors say stop that? Cause more timing = better efficiency. Well to a point anyways, cause if the piston head & combustion chamber design is optimized, 29-31* is all you need for max power / efficiency, assuming a 12.5 - 12.7 stoich at WOT & octane rating. Sorry for all the questions, just curious.

Zinc pretty much hit on it. If you were to get a tune for 110 octane it would be much more aggressive than a stock tune or even a canned 93 tune. Commanding timing to ramp up quicker makes a big difference. On a 93 tune, or a flex fuel tune for that matter, it's not safe to ramp up timing like you would for a 110 octane tune or E85 tune. The stock tune and canned tunes are fairly conservative and safe.

Let me give an example. On the stock tune if you 93 octane in it, the pcm will recognize that there's no knock and will start adding to the specified maximum based on the tune parameters. So you will get more performance. But having the pcm add timing is different than commanding that higher timing off the bat. It takes time, fractions of a second that is costing you power potential. If your commanded timing is too much the pcm will pull timing (more than is necessary) and will have to slowly add it back in again, costing you more power.

The stoich is not as pertinent here because it's all based on lambda, which is what your pcm knows. If you use 93 octane or E85 the pcm is still operating at a lambda of 1 or ~0.85 for WOT fueling. So in theory 93 octane and E85 should make the same power. But the cooler intake charge (which improves volumetric efficiency) created by E85 plus it's higher octane rating allows you to tune it to take advantage. E85 can take gobs more timing and earlier in the powerband. Give it a hotter tune and you're in business.

Also, I've seen some things to suggest that E40 produces the most volumetric efficiency gain over gasoline, which should give you more torque potential. A straight E40 tune would be very fun. However, the super high octane of E85 might make this a moot point, especially in a forced induction application where that extra knock protection can be fully utilized. For NA applications this might be up for debate.

 

[WildHorse]

So basically it's just timing tables, stock tune is more conservative vs performance/race tunes on scaling timing. But they all seem to max out around the same total timing give or take a couple degrees.

 

[Zinc03svt]

So basically it's just timing tables, stock tune is more conservative vs performance/race tunes on scaling timing. But they all seem to max out around the same total timing give or take a couple degrees.

A stock tune would only max out 26-28 and not hold. Timing is cut on the shifts (factory drag mode cars not so much) so it looks like a roller coaster on a sheet. Plus any knock via fuel cuts timing. A E85/race tune would hold 31-33 degrees depending on tuner and holds it on the shifts. It is what helps make these a10’s n/a so quick with the wot drag shifts. Plus, as I mentioned earlier tuners can adjust the cam timing VCT for more power. 18 up gen3 are picking up 40 plus whp w/ decent E85 tuning.

5 plus degrees of timing on a 12 to 1 motor is substantial especially in the lower rpms.

 

[FruityJudy]

Ethanol will always make more power than gas at same octane rating also due to the oxygen it is carrying which has multiple benefits

 

[WildHorse]

Ethanol will always make more power than gas at same octane rating also due to the oxygen it is carrying which has multiple benefits

Then why do so many harp on E10 haha.

 

[FruityJudy]

Then why do so many harp on E10 haha.

Because the avg. person is pretty ignorant on anything that is not related to tv, internet, phone or facebook now days and only "know" the negative effects of it drying out orings and seals and destroying carburetors. There is "some" truth to this due to its hygroscopic nature.

 

[Helios]

Actually you would benefit from 93 having E10 rather than 0 inside. Thats why our 94 E20 is an excellent source for the gen3 coyote.

E85 is superior, even more if your at altitude where you begin with a handicap

I laugh when i hear stuff like ethanol is bad and search for no ethanol fuel at the pump, so much ignorance.

zinc explained it very well

 

[Helios]

I mix Shell 91 15:1 with VP X98. There's no 93 octane Shell here in Manitoba. There's a Husky that sells 94 octane but I recently found out it's not classed as a Top Tier fuel

Hm, for peace of mind seriously id just go with the husky 94. Buying VP to mix is not convenient and whoever told you its not top tier fuel prob don't even know that petrol supplier is most likely all the same around your town but they mix at the pump by itself adding additives. Thats almost always the case

Petrol has to be high quality.

 

[WildHorse]

and whoever told you its not top tier fuel prob don't even know that petrol supplier is most likely all the same around your town but they mix at the pump by itself adding additives. Thats almost always the case

Husky themselves said so. You can email and ask yourself if you don't believe me ;)

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