E85 Questions

[Mo-mo]

So I've been waiting for the numbers from burgers HPFP and had a few questions. I noticed a few of you are running E85 without said pump, with what seems to be just a jb4 map. So I'll just lay em all out, apologizes if this seems scattered, I thought of all this on the way to work.

1. Are there any other mods that you recommend besides JB4 for e85?

2. How are the power differences compared to premium 91 or 93 octane?

3. Has your fuel mileage improved at all?

4. If for some reason I need a fill up and can't find 85, can I just switch maps and put premium in?

5. Are you worried about damaging fuel related parts at all?

I'll probably think of something else, but it's early.

Thanks in advance

 

[cncBilly]

1. Intakes, secondaries and catback (personal choice).
2. E85 = higher map. Higher map = more noticeable power.
3. No. More noticeable power = heavier foot
4.Yes
5. No

 

[Mo-mo]

1. Intakes, secondaries and catback (personal choice).
2. E85 = higher map. Higher map = more noticeable power.
3. No. More noticeable power = heavier foot
4.Yes
5. No

I'm assuming that you don't have a hpfp, performance has been solid without altering the fuel system at all?

 

[AdrianG]

Depends on the fuel between 91 and 93, some 93 is garbage and some 91 is much better.

Your mileage will suffer somewhat while using higher ethanol mixes, but it's basically offset by the lower price. Realistically, I think if you were able to run 100% E85 (provided it is actually about 85% ethanol) you would probably save money on fuel, overall, but you would be filling up more often. Somebody else could probably verify or correct me on this.

You shouldn't need to alter anything to run an E30 mix, but a JB4/ECU tune and a couple other modifications can really help with performance. I recommend an ECU tune because I was totally plagued by an overboost condition setting in the factory ECU, despite the JB4. I do still recommend using a JB4 as it is a great tool, at the very least.

Switching maps with the JB4 is an option, if needed, a decent ECU tune should adjust automatically.

Minimal concern in regards to causing any damage.

 

[cncBilly]

1. Intakes and secondaries (personal choice).
2. E85 = higher map. Higher map = more noticeable power.
3. No. More noticeable power = heavier foot
4.Yes
5. No

I'm assuming that you don't have a hpfp, performance has been solid without altering the fuel system at all?

Correct. But if you go over E30 ish it won’t keep up.

 

[rpoffen]

You can run E30, but you need a tune to make use of it.
When I tried E30 on map 4, completely different car.

 

[Thomby]

Your mileage will suffer somewhat while using higher ethanol mixes, but it's basically offset by the lower price. Realistically, I think if you were able to run 100% E85 (provided it is actually about 85% ethanol) you would probably save money on fuel, overall, but you would be filling up more often. Somebody else could probably verify or correct me on this.

E85 has around 25-30% less energy than gas, so in a normal flex fuel car you lose about that much mileage, and would need the discount to be more than that to come out ahead. Maybe true some places in the midwest but I think in a lot of places it's more like 15-20% cheaper.

If the higher octane lets you advance timing enough to make up for the loss of energy, that would also swing the balance in your favor. Note that we're talking about making more power from the same amount of fuel, versus using the octane to up the boost (more air --> more fuel --> more power but no better mileage).

One thing I'm curious about is whether the JB4 will do the latter automatically -- I guess the test would be to run E30 on maps 1 or 2 and see if you lose power, or if it advances spark enough to make up for the lower energy fuel.

 

[AdrianG]

E85 has around 25-30% less energy than gas, so in a normal flex fuel car you lose about that much mileage, and would need the discount to be more than that to come out ahead. Maybe true some places in the midwest but I think in a lot of places it's more like 15-20% cheaper.

If the higher octane lets you advance timing enough to make up for the loss of energy, that would also swing the balance in your favor. Note that we're talking about making more power from the same amount of fuel, versus using the octane to up the boost (more air --> more fuel --> more power but no better mileage).

One thing I'm curious about is whether the JB4 will do the latter automatically -- I guess the test would be to run E30 on maps 1 or 2 and see if you lose power, or if it advances spark enough to make up for the lower energy fuel.

I figured E85 was as inexpensive everywhere else as it is here in Colorado. There's quite a price difference between E85 and 91 here.

 

[Thomby]

I figured E85 was as inexpensive everywhere else as it is here in Colorado. There's quite a price difference between E85 and 91 here.

According to E85 Prices (no idea how robust their data is), Colorado has 30-40% discounts, and I believe that's vs. regular. Looks like much of the midwest is 25-30% so worthwhile or at least breakeven, while most of the east cost is <15%, sometimes single digits. Now I'm curious how much power spark advance alone can recoup...

 

[turboAWD]

I believe the "required" mods list for full E85 (not a mix with normal gasoline) from BMS is

A) HPFP OR Fuel-It CPI kit.

For the tuning side, requirements:
B)
-CPI flex-fuel sensor
-jb4
-sxth ek1 / ek1-lite
-BMS "backend" flash map (in development)

I believe that's a "more or less guaranteed it will work". Some people (seemingly mostly in 2022 and newer models) on facebook have been able to run E85 without either of the mods listed in A), but a Lap3 tune instead. However, that seems to be, more or less, a "unicorn" situation - some cars can, some can't, and it's not officially supported by BMS, AFAIK.

For those that can't / don't want to leave things to chance, adding A and B should result in reliable E85 operation, AFAIK.

Please correct me if I'm wrong.

 

[Mo-mo]

Correct. But if you go over E30 ish it won’t keep up.

Ahh, alright then. I live in the midwest so I got corn juice everywhere, but not E30....I believe. So if I were to go for an E85 the hpfp is highly recommended it sounds like.

 

[Mo-mo]

I figured E85 was as inexpensive everywhere else as it is here in Colorado. There's quite a price difference between E85 and 91 here.

91 in Iowa is over 4 bucks a gallon, E85 is under 2.

 

[CraigS]

One thing to keep in mind if you live in a cold area: below about 10 degrees F e30 doesn't idle well at cold start. It will start but it's often rough and takes a bit. After 15 seconds, all is fine. Jb4 or lozic ecu (i have both) don't correct for this as far as I know. I believe they only alter things at high throttle inputs and the idle fuel maps remain stock. I don't think the hpfp would help you there either. Does anyone know if theres a way to get the flex fuel sensor to tell the jb4 to alter idle fuel maps based on e percentage?

I had thought I could get away with e15 with cold intake temperatures but no such luck, excessive timing pulled.

 

[cncBilly]

Ahh, alright then. I live in the midwest so I got corn juice everywhere, but not E30....I believe. So if I were to go for an E85 the hpfp is highly recommended it sounds like.

Start by adding about 4 gallons of E85 to the rest of 93 or 91 if thats what you have. I’m in Kanerdu we use litres so I do an approximately 20 ltrs e to 40 ltrs 93.

 

[Mo-mo]

One thing to keep in mind if you live in a cold area: below about 10 degrees F e30 doesn't idle well at cold start. It will start but it's often rough and takes a bit. After 15 seconds, all is fine. Jb4 or lozic ecu (i have both) don't correct for this as far as I know. I believe they only alter things at high throttle inputs and the idle fuel maps remain stock. I don't think the hpfp would help you there either. Does anyone know if theres a way to get the flex fuel sensor to tell the jb4 to alter idle fuel maps based on e percentage?

I had thought I could get away with e15 with cold intake temperatures but no such luck, excessive timing pulled.

yeah being in the midwest this may not be ideal to try

 

[GennyGuy]

So I've been waiting for the numbers from burgers HPFP and had a few questions. I noticed a few of you are running E85 without said pump, with what seems to be just a jb4 map. So I'll just lay em all out, apologizes if this seems scattered, I thought of all this on the way to work.

1. Are there any other mods that you recommend besides JB4 for e85?

2. How are the power differences compared to premium 91 or 93 octane?

3. Has your fuel mileage improved at all?

4. If for some reason I need a fill up and can't find 85, can I just switch maps and put premium in?

5. Are you worried about damaging fuel related parts at all?

I'll probably think of something else, but it's early.

Thanks in advance

1. Get CPI to run high amounts of ethanol.

2. The more ethanol, the higher the power difference. Full E85 will net a substantial power margin over 91/93 octane.

3. No, it will be far worse.

4. Yes.

5. A healthy concern is never a bad thing, but no, I don't think that I am damaging anything.

 

[Thomby]

2. The more ethanol, the higher the power difference. Full E85 will net a substantial power margin over 91/93 octane.

The more ethanol, the more *potential* power difference, if you increase boost/timing (or compression ratio) to take advantage of the increased knock resistance.

Just adding more ethanol on the same map won't do anything, in the same way that premium's extra octane in a car designed for regular won't help by itself.

 

[GennyGuy]

The more ethanol, the more *potential* power difference, if you increase boost/timing (or compression ratio) to take advantage of the increased knock resistance.

Just adding more ethanol on the same map won't do anything, in the same way that premium's extra octane in a car designed for regular won't help by itself.

Sure, but you won't be running the same map as 91/93 either if you're adding ethanol or even posing this question. The question assumes JB4 ownership, which includes multiple maps, and instructions as to which map to use depending on setup and ethanol amount.

And the second part of your comment is not necessarily true. While most cars may not see a discernible difference, that's not true of all cars. Hyundai vehicles can all run on 87 octane, but some vehicles are advertised as having increased performance if premium fuel is used. This is on stock vehicles, no map switching required.

Car and Driver did an article a few years back also which proves the same thing.

Here you go: Is Premium Gas Worth It? We Test High Octane on 4 Popular Vehicles

 

[turboAWD]

One thing to keep in mind if you live in a cold area: below about 10 degrees F e30 doesn't idle well at cold start. It will start but it's often rough and takes a bit. After 15 seconds, all is fine. Jb4 or lozic ecu (i have both) don't correct for this as far as I know. I believe they only alter things at high throttle inputs and the idle fuel maps remain stock. I don't think the hpfp would help you there either. Does anyone know if theres a way to get the flex fuel sensor to tell the jb4 to alter idle fuel maps based on e percentage?

I had thought I could get away with e15 with cold intake temperatures but no such luck, excessive timing pulled.

I believe the new jb4 bef (back-end-flash) via sxth ek1(-lite) is making some changes to make that less of an issue when on full E85.

 

[GennyGuy]

One thing to keep in mind if you live in a cold area: below about 10 degrees F e30 doesn't idle well at cold start. It will start but it's often rough and takes a bit. After 15 seconds, all is fine. Jb4 or lozic ecu (i have both) don't correct for this as far as I know. I believe they only alter things at high throttle inputs and the idle fuel maps remain stock. I don't think the hpfp would help you there either. Does anyone know if theres a way to get the flex fuel sensor to tell the jb4 to alter idle fuel maps based on e percentage?

I had thought I could get away with e15 with cold intake temperatures but no such luck, excessive timing pulled.

The cold start issues sounds like it's just ethanol being ethanol. I live in a cold climate and have to contend with the same. I had car on E60 and it was 8F. Hesitated and then started right up. Hesitation was only like 2 seconds however, doesn't linger. This was on LAP3 ecu, not sure if it makes a difference.