ECMlink E85 Questions for ECMLink v3

[1GASonny]

Hey guys,

I’ve been reading a bunch and need to clear some things up. Right now my car is on pump gas tune (fic 1650, single walbro 450 pump) and was wondering what else is needed to make the switch to e85. I have a few Thornton’s near me that have e85 pumps but I know the ethanol content may vary- so with that being said should I :

get a flex fuel sensor ?
Target afr idle and wot for e85?
Base maps if any exist?

Engines built with 8.5.1 ratio on a s366 turbo

 

[1990TSIAWDTALON]

Change your Stoich, tune for 12.1 WOT and give her more timing. She is going to wake up!

 

[Vegas Smith]

You might want to get it dyno-tuned or have somebody help set that up for you. that's a lot of power to be learning how to tune e85. Flex sensors are convenient but I don't think anyone would call it necessary. As stated previously, target AFRs will be higher at WOT and timing will be higher. You wont find any formal base map but I guess you could look at other people's files and start there.

 

[donniekak]

If your pump gas setup is tuned well just adding a flex sensor and enabling the enrichment will get the fuel really close. You’ll have to move your current gas maps to the low octane maps and write in new targets for the high octane maps for e85.

 

[jakk220]

Mechanically, you should not need anything else to run E85. The car will run and drive just from changing global.

Remember that E85 does not knock. So when you tune you have to go by if its still making power on the dyno. You also need to account for your EGT's when tuning. Sure E85 is capable of a 12.3 AFR.... but how high are you EGT's that lean? I have killed turbos due to not accounting for that. My car is happy at about a 11.7 AFR at 35psi on an HX40.

Also remember that there is a viscosity difference between E85 and 93 octane that is not accounted for in ECMlink when the global suggestions are calculated. I have 1450 injectors and a 450 fuel pump and my global number is quite a bit richer than suggested because of this. The bigger the injector, the less this matters. Here is a chart that explains it a little bit more.

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[donniekak]

E85 knocks like any other fuel. Ask anyone trying to squeeze every last hp out of their tune what those spots on their plugs are.

 

[bastarddsm]

Yep, definately capable of knock. Jakk, you didn't burn a turbo down from a 12.3 AFR - something else was at play. As a rule E85 is pretty happy over a wide range of AFR on a gas scale 11-13:1 is pretty safe if, though 13 is getting on the lean side and should be avoided, but a few excursions into that territory won't be an issue. A full pass at 40psi and 14 AFR will probably burn it down though.

As for the injector flow it's not a big deal. E85 (.79) is about 7-10% more dense than gasoline(.72). Lucky enough for us the calculations in the ecu are really mass based, and in the end it's really not a big deal.

There's some relationship of flow, reynolds number, and pressure differential. Probably like Re is proportional to the sqrt of pressure differential. Re is density*velocity*nozzle dia / viscosity. Turns out the increase of viscosity cancels out the increase of density, and the mass flow stays the same. Neat how science works out like that.

 

[jakk220]

Yep, definately capable of knock. Jakk, you didn't burn a turbo down from a 12.3 AFR - something else was at play. As a rule E85 is pretty happy over a wide range of AFR on a gas scale 11-13:1 is pretty safe if, though 13 is getting on the lean side and should be avoided, but a few excursions into that territory won't be an issue. A full pass at 40psi and 14 AFR will probably burn it down though.

As for the injector flow it's not a big deal. E85 (.79) is about 7-10% more dense than gasoline(.72). Lucky enough for us the calculations in the ecu are really mass based, and in the end it's really not a big deal.

There's some relationship of flow, reynolds number, and pressure differential. Probably like Re is proportional to the sqrt of pressure differential. Re is density*velocity*nozzle dia / viscosity. Turns out the increase of viscosity cancels out the increase of density, and the mass flow stays the same. Neat how science works out like that.

Ok I worded that poorly... From my experience though with *most* E85 setups, the car will quit making power quite a bit before it starts knocking. So if you tune E85 by knock, you are doing more damage than you would with 93. Its not as simple as turn up timing until it knocks and back it down a degree. So your right I should not have said it wont knock, but more you should not tune by knock alone with E85.

I talked with Tom from Ecmlink a while back about the injector flow rates with E85 and what not and he said that I have to make the calculation to adjust for it on my own. I am no scientist, but that 11% adjustment made a big difference with my setup. I have noticed it in a few others as well. It threw off the VE table quite a bit without accounting for that 11% on 1450's.


I sent the turbo that blew to Justin and he said it was getting really hot and appeared to fail from EGT's. In certain areas the turbine was melting. Mine were 12.4 - 12.7 at the time. He also told me the same thing, people don't think about the EGT's when tuning with E85 and just lean it out a ton. Needless to say after richening it up, I haven't had an issue. This was not on a drag only car so its not like a few passes of this caused the issue. It was over time of (spirited) street driving and some track use. The turbo was on its first season when this happened and was brand new when I bought it. Every set up is different, but he should definitely keep EGT's in mind when going to 12's for the AFR.

I also don't set my car to kill and hope it lasts a few passes. I'm more about safe power.

Edit: ^^ not saying this is how you tune your cars but some do. I just mean that I keep mine conservative is all.

 

[donniekak]

Not sure what your setup is exactly but Holset’s in the bep housings are notorious for melting inducer tips.

 

[jakk220]

Not sure what your setup is exactly but Holset’s in the bep housings are notorious for melting inducer tips.

.55bep. I figured that wasn't helping things much.

 

[bastarddsm]

I don't think it's actually melting it. I was at a talk from a fomoco engineer a couple springs ago at the SAE conference. The talk was about the effect of the vanes in a garrett vgt, and how vane clearance and shape effected things. One thing they saw was certain conditions could cause a bunch of turbulence in the wake of the vanes. This would actually drive the turbine wheel tips into an oscilation, and cause them to fatigue and fail and look like what we think a melted turbine tip looks like. Theres a lot of things at play, but they don't melt off like we took a torch to them or anything.

 

[bastarddsm]

I talked with Tom from Ecmlink a while back about the injector flow rates with E85 and what not and he said that I have to make the calculation to adjust for it on my own. I am no scientist, but that 11% adjustment made a big difference with my setup. I have noticed it in a few others as well. It threw off the VE table quite a bit without accounting for that 11% on 1450's.

You gotta remember that your making some big assumptions here.
1. Your assuming that the E85 fuel didn't change the VE
2. Your assuming that the wideband actually reads the same on both fuels. (hint: they don't)

These two points are part of my dislike of speed density. We treat the ve map and wideband like it's some all telling/knowing thing, when in reality it's just a good guess is all.

Anyway, I'm sure there is a little change in the actual fuel mass flow rate, especially if you come from really heavy low viscosity gasoline, but it really should be mostly cancelled out.

 

[jakk220]

I don't think it's actually melting it. I was at a talk from a fomoco engineer a couple springs ago at the SAE conference. The talk was about the effect of the vanes in a garrett vgt, and how vane clearance and shape effected things. One thing they saw was certain conditions could cause a bunch of turbulence in the wake of the vanes. This would actually drive the turbine wheel tips into an oscilation, and cause them to fatigue and fail and look like what we think a melted turbine tip looks like. Theres a lot of things at play, but they don't melt off like we took a torch to them or anything.

Interesting... I guess I just assumed it was all due to heat. Is this something that can be prevented or is something that is just the design of the turbine wheel? I wonder if I have a picture of mine somewhere just to show what it looked like. It was a bizarre failure. Even Justin said he was having trouble actually determining what failed.

You gotta remember that your making some big assumptions here.
1. Your assuming that the E85 fuel didn't change the VE
2. Your assuming that the wideband actually reads the same on both fuels. (hint: they don't)

These two points are part of my dislike of speed density. We treat the ve map and wideband like it's some all telling/knowing thing, when in reality it's just a good guess is all.

Anyway, I'm sure there is a little change in the actual fuel mass flow rate, especially if you come from really heavy low viscosity gasoline, but it really should be mostly cancelled out.

In my case my car was never tuned on a 93 octane VE table. When I switched to SD, the car was already on E85. I just compared mine to the normal VE of other cars with a similar setup and it just was not matching up. Adding some fuel via the global and then lowering the VE table made it look much more normal.

The fuel was getting there, but the table was really high under boost before the changes were made to the global. For some reason, it seemed as though that fuel mass flow rate was more prevalent in my car than others. Believe me when I say I checked everything else as a possibility. I spent over a month on the issue. I had every fuel component off my car and replaced or tested them. Everything down to the fuel lines.

You are right with the assumptions though. I always question my wideband all the time and am learning not to trust it alone. Which is why I am becoming more of an advocate of monitoring EGT's as well.

 

[1990TSIAWDTALON]

I broke 2 shafts in BEP .55's with HX40s, but only on E. On gas they were fine. A bigger hot side helps in that situation. Justin and I have talked a lot about the issue.

 

[donniekak]

I don't think it's actually melting it. I was at a talk from a fomoco engineer a couple springs ago at the SAE conference. The talk was about the effect of the vanes in a garrett vgt, and how vane clearance and shape effected things. One thing they saw was certain conditions could cause a bunch of turbulence in the wake of the vanes. This would actually drive the turbine wheel tips into an oscilation, and cause them to fatigue and fail and look like what we think a melted turbine tip looks like. Theres a lot of things at play, but they don't melt off like we took a torch to them or anything.

Makes sense if you think about the velocity needed to shove a bunch of exhaust through a tiny nozzle.

 

[1GASonny]

So what do you guys mostly pay attention to when tuning e85?

 

[bastarddsm]

Put it about 12:1 AFR on a gas scale, mid teens for timing at High rpm. Then tweak it at the track or dyno looking for power improvements. I'm in the 40psi 700+hp area though. Lower boost/power will likely be leaner and more timing.

Mine at least seems to be relatively insensitive to AFR. 12 +/- .5pt on the gas scale seems to be the sweet spot

 

[Kevin Jewer]

If you get knock on E85, you're well past the point where you screwed up. I've been up to 1200 hp and ~65 psi on pump e85 and have never seen knock, but I run it richer than the rest of the world does which could be a factor. People run it way too lean IMO. Alky fuels are only knock resistant due to their cooling properties, and the more fuel you use, the more cooling it can do.

I've tuned too many cars on E85 to count, some percentage of which have been good back to back tests of changing only the fuel (known injector flow on ethanol etc). If the VE table is right on gas, it will also be right on E85, with everything else mathematically correct (admittedly that's a tall order in most cases). Which implies, at least to me, that any differences in WBO2 reading or changes to VE are negligible. The biggest monkey wrench with e85 tuning that is for some reason not widely known is the change to injector flow mentioned above. The 5-15% drop in injector flow vastly outweighs any other minute differences. Methanol won't have the viscosity issue with injectors, but it should have more of any issue with changing the VE, and I just haven't seen it in actual operation on intercooled cars (there's a good reason why). It's good to know about all of the potentially sources of discrepancies, of course. But there are enough real issues to worry about without getting into minute differences that just don't add up to anything meaningful in actual operation. Just my 2 cents of course.

 

[Brandon Mau]

I'm with Kevin and run it richer than most. My target AFR is 11.2 and the car is very happy with peak timing at 13.3* 8500 RPM and up. On the dyno the 10hp it gained leaning it out at 11.7-11.8 just did seem that important to me running higher egts. You do see cases where guys have run some crazy high timing even in the 20*'s. From the guys I have all talked to they say the 4G63's max efficient timing is 18 anything past that they say is worthless basically (again remember every engine is going to be different). All the big power guys running 7-8's I have talked to not one pushes more than 14* peak timing. The more efficient the setup the less timing it will need. Overall what I am saying is make your power with more boost not timing. Everyone has there own way of doing it from experiences and what works best for there setups.