[N54Society]

I'm getting tired of mixing gas when I have to fill up and planning my trips around it. Is there any way I could just pump straight E85?

I have an inline pump (I know, it's not rated for E85 but it works) and a custom E60-70 tune via MHD. I realize there is a point of diminishing returns with E85, ie no extra power can be had but it would really simply things if I could just fill up without worrying about that last 3-4 gallons being 91 pump gas.

Thanks

[stanlalee]

It just comes down to fuel demand. You may have to detune to keep fuel demands in check if you have a tune truly dialed in for e60-70 which works be counter productive. Fuel demand and poor gas mileage are the primary obstacles

[PR3CI5N]

No you can't. You'll get fuel mixture codes and most likely go into limp mode because your stage 1 LPFP will not be able to supply your HPFP with enough fuel. It takes an extra 3 mins to add a few gallons of 91 so your best bet is to continue mixing. Your cheapest alternative is to switch to the stage 2 LPFP and add TBI for straight E85.

[Nonecure]

Post a log so we can see where you are currently at. I love not having to mix anymore.

[N54Society]

Originally Posted by stanlalee

It just comes down to fuel demand. You may have to detune to keep fuel demands in check if you have a tune truly dialed in for e60-70 which works be counter productive. Fuel demand and poor gas mileage are the primary obstacles

So are you saying that if I run 100% E85, I would have to get detuned for the DME to demand less in order help the LPFP keep up with the HPFP?

Originally Posted by PR3CI5N

No you can't. You'll get fuel mixture codes and most likely go into limp mode because your stage 1 LPFP will not be able to supply your HPFP with enough fuel. It takes an extra 3 mins to add a few gallons of 91 so your best bet is to continue mixing. Your cheapest alternative is to switch to the stage 2 LPFP and add TBI for straight E85.

This is similar to the question above. By not touching the tune and adding more E85, how would the DME know to demand more fuel? Would it be the extra power I would be making just by simply adding more ethanol? I've never understood how this threshold is established.

As I understood it, the only reason why I got the stage 1 lpfp was because the tune would be demanding more fuel and therefore a secondary pump was needed to supplement the supply of fuel. God I'm such a noob.

Originally Posted by Nonecure

Post a log so we can see where you are currently at. I love not having to mix anymore.

I don't recall if this is one of my "best" logs but it's one of the latest ones. By best I mean I don't know if the road had an incline or not. It may have. Either way, let me know how it looks please.

http://datazap.me/u/vbp6us/log-14666...og=0&data=4-23

[Bimmer 808]

Originally Posted by vbp6us

So are you saying that if I run 100% E85, I would have to get detuned for the DME to demand less in order help the LPFP keep up with the HPFP?

I don't recall if this is one of my "best" logs but it's one of the latest ones. By best I mean I don't know if the road had an incline or not. It may have. Either way, let me know how it looks please.

http://datazap.me/u/vbp6us/log-14666...og=0&data=4-23

What IC are you running? IATs jump by 30 degrees.

[Nonecure]

I am jealous, your hpfp and lpfp looks really strong. I think you can trying increasing the amount of E85 and see how your system handles it. You need to have your tune adjusted first.

Your tune is currently too lean so you need to adjust that. When you run Ethanol, you need to run a little more rich. So with pure E85 would would want to target 11.8:1 afr. But since most stations aren't pure E85, target around 12.2:1 and you should be good. If your tuner doesn't know this, switch to someone else.

The DME will add more fuel automatically to keep your afr at the target level. I think your target is set too lean, so fix that first.

[talhagursoy]

Originally Posted by vbp6us

So are you saying that if I run 100% E85, I would have to get detuned for the DME to demand less in order help the LPFP keep up with the HPFP?

This is similar to the question above. By not touching the tune and adding more E85, how would the DME know to demand more fuel? Would it be the extra power I would be making just by simply adding more ethanol? I've never understood how this threshold is established.

As I understood it, the only reason why I got the stage 1 lpfp was because the tune would be demanding more fuel and therefore a secondary pump was needed to supplement the supply of fuel. God I'm such a noob.

I don't recall if this is one of my "best" logs but it's one of the latest ones. By best I mean I don't know if the road had an incline or not. It may have. Either way, let me know how it looks please.

http://datazap.me/u/vbp6us/log-14666...og=0&data=4-23

I would worry about the timing corrections more than E85 in this case...

[N54Society]

Originally Posted by Bimmer 808

What IC are you running? IATs jump by 30 degrees.

VRSF 7". Pretty sure it was a really hot day. It starts at 95F and ends at 109F for that run. ~14F delta.

Originally Posted by Nonecure

I am jealous, your hpfp and lpfp looks really strong. I think you can trying increasing the amount of E85 and see how your system handles it. You need to have your tune adjusted first.

Your tune is currently too lean so you need to adjust that. When you run Ethanol, you need to run a little more rich. So with pure E85 would would want to target 11.8:1 afr. But since most stations aren't pure E85, target around 12.2:1 and you should be good. If your tuner doesn't know this, switch to someone else.

The DME will add more fuel automatically to keep your afr at the target level. I think your target is set too lean, so fix that first.

Thank you! I'll pass this along to my tuner although I'm hoping he knows this already. Let's see what he says.

Originally Posted by talhagursoy

I would worry about the timing corrections more than E85 in this case...

Yeah good point. I'll point it out to my tuner.

[Nonecure]

Originally Posted by talhagursoy

I would worry about the timing corrections more than E85 in this case...

Running lean will cause timing issues, and he is very lean.

[bigdnno98]

A lot of Terrible information in here. OP contact your tuner.

[csu87]

Op fill up and see what your logs say. That's the only way to know for sure.

I run full e85

[Fred_Boosted]

The most common problem of running straight E85 is high pressure fuel pump, I would recommend those who want run straight E85 for long period of time or daily get a port injection system, it would be much more reliable.

[Fundguy1]

Range and difficulty finding pumps are my two downsides. E85 is cheaper buy you get less mpg and that results in less range.

[N54Society]

Originally Posted by bigdnno98

A lot of Terrible information in here. OP contact your tuner.

I contacted my tuner and he agrees lol.

Originally Posted by csu87

Op fill up and see what your logs say. That's the only way to know for sure.

I run full e85

I just filled up 3 gal of 91 and 13 gal of E85 (who knows the actual content). I'm going to do some logging in the mean time and send it to my tuner.

What kind of AFR are you seeing w/ straight E85?

Originally Posted by Fred_Boosted

The most common problem of running straight E85 is high pressure fuel pump, I would recommend those who want run straight E85 for long period of time or daily get a port injection system, it would be much more reliable.

My HPFP seems to be holding up fine though.

Originally Posted by Fundguy1

Range and difficulty finding pumps are my two downsides. E85 is cheaper buy you get less mpg and that results in less range.

I don't have that issue thankfully.

[bigdnno98]

Max power for ethanol is .86 lambda. In gas AFR that's 12.6. I know the n54 community actually targets more like a 12.8-12.9 AFR on e85 because of the DI the engine can run a little leaner than port injected cars. I prefer to stick to the 12.6 AFR on mine.

[csu87]

Originally Posted by vbp6us

I contacted my tuner and he agrees lol.



I just filled up 3 gal of 91 and 13 gal of E85 (who knows the actual content). I'm going to do some logging in the mean time and send it to my tuner.

What kind of AFR are you seeing w/ straight E85?



My HPFP seems to be holding up fine though.



I don't have that issue thankfully.

Get a handheld tester and test your ethanol content. If you are going to run e85, you need to know what it actually is.

As for AFRs, upper 12s is what I target.

[Chris@BoostConcepts]

Originally Posted by csu87

Get a handheld tester and test your ethanol content. If you are going to run e85, you need to know what it actually is.

As for AFRs, upper 12s is what I target.

you are also in Northern Colorado where the air is a bit thinner which requires less fuel. so you have a... well i wouldn't call it an advantage, but you have a different situation going on for your fueling requirement. even at 20psi you are fueling significantly less power then someone at sea level or near it in San Diego.

OP,

As for the information given, you should discuss with your tuner as he is the one who is working with your setup and will be the one who needs to make the changes to accommodate different mixes or straight e85. your LPFP setup (if healthy) should be able to handle straight e85 and the HPFP should be what limits your fueling ability. sounds like you are doing it correctly sneaking up on it. to determine where the tipping point is. as a side note, I grabbed a gas caddy 14 gallon tank with pump nozzle online and it fits nicely in the trunk (335i), could actually fit two probably, but I am also 40 miles away from the nearest station. I premix the gas in the caddy so I get almost two fillups per trip. helps alot. just need something elevated to put it on as it is gravity feed after you start the flow. very nice setup for $120.

Chris

[Jwdominick]

don't listen to the naysayers, I have been 100% e85 for quite some time, back with jb4/be mhd and now 100% MHD.

[csu87]

Originally Posted by Chris@BoostConcepts

you are also in Northern Colorado where the air is a bit thinner which requires less fuel. so you have a... well i wouldn't call it an advantage, but you have a different situation going on for your fueling requirement. even at 20psi you are fueling significantly less power then someone at sea level or near it in San Diego.

OP,

As for the information given, you should discuss with your tuner as he is the one who is working with your setup and will be the one who needs to make the changes to accommodate different mixes or straight e85. your LPFP setup (if healthy) should be able to handle straight e85 and the HPFP should be what limits your fueling ability. sounds like you are doing it correctly sneaking up on it. to determine where the tipping point is. as a side note, I grabbed a gas caddy 14 gallon tank with pump nozzle online and it fits nicely in the trunk (335i), could actually fit two probably, but I am also 40 miles away from the nearest station. I premix the gas in the caddy so I get almost two fillups per trip. helps alot. just need something elevated to put it on as it is gravity feed after you start the flow. very nice setup for $120.

Chris

Yes, but anyone can run straight e85 regardless of their location. They will just have to tune it correctly, which is why I suggesting logging and seeing where he is at. If hes running too lean, back off via tuning a little until he gets to a safe tune that he can run full e85 on.

[N54Society]

Originally Posted by bigdnno98

Max power for ethanol is .86 lambda. In gas AFR that's 12.6. I know the n54 community actually targets more like a 12.8-12.9 AFR on e85 because of the DI the engine can run a little leaner than port injected cars. I prefer to stick to the 12.6 AFR on mine.

That's what my tuner told me too. He said you can run a little leaner on E85. Do you think I'm in the 13s because the E-content is lower than advertised?

Originally Posted by csu87

Get a handheld tester and test your ethanol content. If you are going to run e85, you need to know what it actually is.

As for AFRs, upper 12s is what I target.

I'm going to test it out for the first time tonight and report back.

Originally Posted by Chris@BoostConcepts

you are also in Northern Colorado where the air is a bit thinner which requires less fuel. so you have a... well i wouldn't call it an advantage, but you have a different situation going on for your fueling requirement. even at 20psi you are fueling significantly less power then someone at sea level or near it in San Diego.

OP,

As for the information given, you should discuss with your tuner as he is the one who is working with your setup and will be the one who needs to make the changes to accommodate different mixes or straight e85. your LPFP setup (if healthy) should be able to handle straight e85 and the HPFP should be what limits your fueling ability. sounds like you are doing it correctly sneaking up on it. to determine where the tipping point is. as a side note, I grabbed a gas caddy 14 gallon tank with pump nozzle online and it fits nicely in the trunk (335i), could actually fit two probably, but I am also 40 miles away from the nearest station. I premix the gas in the caddy so I get almost two fillups per trip. helps alot. just need something elevated to put it on as it is gravity feed after you start the flow. very nice setup for $120.

Chris

Yeah I'm going to incrementally increase it rather than in one shot. I think CSU has a good point in testing the content too. I'm not very far from E85 stations so I should be ok without the caddy although it seems to be a great idea for those that are far away from the tap.

Originally Posted by Jwdominick

don't listen to the naysayers, I have been 100% e85 for quite some time, back with jb4/be mhd and now 100% MHD.

I'm just going to work my way up so that my tune can take full advantage of the increased E85. On hindsight I should have gotten the stage 2 (or now Chris' setup - his wasn't out then).

Originally Posted by csu87

Yes, but anyone can run straight e85 regardless of their location. They will just have to tune it correctly, which is why I suggesting logging and seeing where he is at. If hes running too lean, back off via tuning a little until he gets to a safe tune that he can run full e85 on.

Do you think being in the low 13s AFR is too lean for 100% E85?

[Nonecure]

Originally Posted by vbp6us

Do you think being in the low 13s AFR is too lean for 100% E85?

Lambda 0.867 or 12.7 is the leanest you want to run on full E85. Your log was mid to high 13's, which is way too lean.