Gains from E85 (ethanol) on an N/A bolt on 370Z

Push370zzz · 09-21-2015, 09:45 PM

Quote:

Originally Posted by VitViper

Not bad at all for just changing fuel and minor retuning. In fact, I saw more gains with the fuel than I did with all the work and money spent on the Stillen intakes on the car. This was also done with stock injectors and a stock pump -- worked perfectly fine, holds a clean AFR all the way to fuel cut (7800 rpm). Fuel economy while cruising on the freeway at 75mph was actually the same if not 1-2mpg better than pump gas. Go figure.

Sorry, but there is absolutely no way that your car gets better gas mileage with E85 over E15 or less pump gas.

Chuck33079 · 09-21-2015, 10:31 PM

Quote:

Originally Posted by Push370zzz

Sorry, but there is absolutely no way that your car gets better gas mileage with E85 over E15 or less pump gas.

Right, doesn't e85 usually result in a pretty substantial drop in mileage? It's about 30% less energy by volume than pump gas and that's why you need more volume than pump, right?

synolimit · 09-21-2015, 11:02 PM

Quote:

Originally Posted by Chuck33079

Right, doesn't e85 usually result in a pretty substantial drop in mileage? It's about 30% less energy by volume than pump gas and that's why you need more volume than pump, right?

Per my tuner its 33%. This is why i was able to install GTR injectors and drive without issue on e85! At a rough guess of 14% rich that was in the clear to get to him 40 minutes away on the highway and side streets without so much as even a hickup.

FYI to anyone needing to install injectors at home and drive to your tuner.

Elmo370z · 09-21-2015, 10:52 PM

Thats what i thoughr

njobe89 · 09-22-2015, 06:51 AM

a reputable shop here in atlanta got back to me and the tuner from the shop stated that power can be made on uprev with e85. they quoted me around $500 for the tune as it would take a couple hours according to them. now i have to justify spending around $700 for maybe 10whp.

POS VETT · 09-22-2015, 07:20 AM

In the case of my GM truck, the drop in fuel consumption is way less than 30%. The drop in energy content is also less than 30%. The number 30% or 33% is used to size up injectors and fuel pump to give them cushion so that they work in a smaller duty cycle.

E85 has a much higher knock resistance and it burns at a lower temperature, these two traits allow the engine to run at near stoichiometric (i.e. leaner) and at very advanced ignition timing for a more complete burn producing a better use of the fuel. When a PCM senses a knock with E10, it backs off timing and injects more fuel to combat its destructive effects, meaning power output is lower and fuel consumption is higher, then the driver uses more throttle to compensate which makes the fuel consumption of E10 is now much closer to that of E85, or possibly, even less.

Push370zzz · 09-22-2015, 10:19 AM

Quote:

Originally Posted by Chuck33079

Right, doesn't e85 usually result in a pretty substantial drop in mileage? It's about 30% less energy by volume than pump gas and that's why you need more volume than pump, right?

Yes. E85 has about 72% as much energy as an equivalent gallon of gasoline. E10 should have about 96%.

Quote:

Originally Posted by POS VETT

In the case of my GM truck, the drop in fuel consumption is way less than 30%. The drop in energy content is also less than 30%. The number 30% or 33% is used to size up injectors and fuel pump to give them cushion so that they work in a smaller duty cycle.

E85 has a much higher knock resistance and it burns at a lower temperature, these two traits allow the engine to run at near stoichiometric (i.e. leaner) and at very advanced ignition timing for a more complete burn producing a better use of the fuel. When a PCM senses a knock with E10, it backs off timing and injects more fuel to combat its destructive effects, meaning power output is lower and fuel consumption is higher, then the driver uses more throttle to compensate which makes the fuel consumption of E10 is now much closer to that of E85, or possibly, even less.

The drop in energy content is very close to 30%. E85 is absolutely better for power, particularly in boosted applications, due to what you pointed out. That said you are just not going to get better or even close to the gas mileage you'll get on regular gasoline or E10.

http://www.edmunds.com/fuel-economy/...ison-test.html

https://en.wikipedia.org/wiki/Gasoli...lon_equivalent

Chuck33079 · 09-22-2015, 10:48 AM

Quote:

Originally Posted by Push370zzz

Yes. E85 has about 72% as much energy as an equivalent gallon of gasoline. E10 should have about 96%.

The drop in energy content is very close to 30%. E85 is absolutely better for power, particularly in boosted applications, due to what you pointed out. That said you are just not going to get better or even close to the gas mileage you'll get on regular gasoline or E10.

E85 vs. Gasoline Comparison Test

https://en.wikipedia.org/wiki/Gasoli...lon_equivalent

Right. So if someone is claiming the same, if not 1-2 miles per gallon improvement, they are in error since it would not be possible to get the same mileage on a fuel that has less energy by volume. Maybe he's looking at the mpg gauge which is now wrong due to different injectors?

I'm also unclear how someone can claim a power improvement from going to E85 without any timing adjustments. Can someone explain how that works? I'm at a loss.

njobe89 · 09-22-2015, 11:30 AM

Quote:

Originally Posted by Chuck33079

Right. So if someone is claiming the same, if not 1-2 miles per gallon improvement, they are in error since it would not be possible to get the same mileage on a fuel that has less energy by volume. Maybe he's looking at the mpg gauge which is now wrong due to different injectors?

I'm also unclear how someone can claim a power improvement from going to E85 without any timing adjustments. Can someone explain how that works? I'm at a loss.

if you just switch to e85 without a tune, you won't make any power. with the correct tune you are supposed to make power... not sure how other than it's higher octane rating than 93.

Chuck33079 · 09-22-2015, 11:53 AM

Quote:

Originally Posted by njobe89

if you just switch to e85 without a tune, you won't make any power. with the correct tune you are supposed to make power... not sure how other than it's higher octane rating than 93.

That's what I thought as well, but someone in here is claiming that he saw a power increase with zero timing changes. I was under the impression that the additional power from an E85 tune came from the additional timing you could run.

Push370zzz · 09-22-2015, 04:47 PM

Quote:

Originally Posted by Chuck33079

Right. So if someone is claiming the same, if not 1-2 miles per gallon improvement, they are in error since it would not be possible to get the same mileage on a fuel that has less energy by volume. Maybe he's looking at the mpg gauge which is now wrong due to different injectors?

I'm also unclear how someone can claim a power improvement from going to E85 without any timing adjustments. Can someone explain how that works? I'm at a loss.

They are mistaken if they believe that under similar conditions they are seeing similar fuel economy (much less an increase) with E85 over E10 or regular petrol.

E85 allows you to change the timing to a range not possible to run on standard gasoline due to knock. Without a tune to take advantage of it, you should not see any difference in power. It's like putting 94 octane in a Prius.

njobe89 · 09-23-2015, 12:36 PM

seems all e85 for n/a will make is 6-10whp. i ordered myself injectors and plan on getting the car tuned mid october. i might grab the plenum mod while i'm at it, so it will be hard to tell what i truly make from e85.

synolimit · 09-23-2015, 06:00 PM

Quote:

Originally Posted by njobe89

seems all e85 for n/a will make is 6-10whp. i ordered myself injectors and plan on getting the car tuned mid october. i might grab the plenum mod while i'm at it, so it will be hard to tell what i truly make from e85.

It'll be E70 by then. Id cut some power off those numbers.

njobe89 · 09-24-2015, 07:52 AM

Quote:

Originally Posted by synolimit

It'll be E70 by then. Id cut some power off those numbers.

we'll see what happens.. as of right now my plan is to get tuned by the 2nd week of oct.

synolimit · 09-24-2015, 08:18 AM

Quote:

Originally Posted by njobe89

we'll see what happens.. as of right now my plan is to get tuned by the 2nd week of oct.

Might get lucky, e85 tank might still have the good stuff

09-22-2015, 06:51 AM	#5 (permalink)
njobe89 A True Z Fanatic Join Date: May 2014 Location: Atlanta, GA Posts: 5,227 Drives: 2013 370z BS 6MT Rep Power: 174285	a reputable shop here in atlanta got back to me and the tuner from the shop stated that power can be made on uprev with e85. they quoted me around $500 for the tune as it would take a couple hours according to them. now i have to justify spending around $700 for maybe 10whp. __________________ 2 plus 2 times 2 = ? ... hint, it's not 8 Stillen CBE, Stillen Gen 3, TP's, Uprev tuned - 324whp/264tq

09-23-2015, 12:36 PM	#12 (permalink)
njobe89 A True Z Fanatic Join Date: May 2014 Location: Atlanta, GA Posts: 5,227 Drives: 2013 370z BS 6MT Rep Power: 174285	seems all e85 for n/a will make is 6-10whp. i ordered myself injectors and plan on getting the car tuned mid october. i might grab the plenum mod while i'm at it, so it will be hard to tell what i truly make from e85. __________________ 2 plus 2 times 2 = ? ... hint, it's not 8 Stillen CBE, Stillen Gen 3, TP's, Uprev tuned - 324whp/264tq

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Elmo370z A True Z Fanatic Join Date: Apr 2013 Location: st. petersburg Posts: 5,727 Drives: 09 nissan 370z Sp M6 Rep Power: 295379	Thats what i thoughr

09-22-2015, 07:20 AM	#6 (permalink)
POS VETT Track Member Join Date: Apr 2015 Location: Columbus OH Posts: 612 Drives: Z34\|C4LT4\|C6Z06\|V25 Rep Power: 3367	In the case of my GM truck, the drop in fuel consumption is way less than 30%. The drop in energy content is also less than 30%. The number 30% or 33% is used to size up injectors and fuel pump to give them cushion so that they work in a smaller duty cycle. E85 has a much higher knock resistance and it burns at a lower temperature, these two traits allow the engine to run at near stoichiometric (i.e. leaner) and at very advanced ignition timing for a more complete burn producing a better use of the fuel. When a PCM senses a knock with E10, it backs off timing and injects more fuel to combat its destructive effects, meaning power output is lower and fuel consumption is higher, then the driver uses more throttle to compensate which makes the fuel consumption of E10 is now much closer to that of E85, or possibly, even less.