Sluggonaut
Goblin Guru
Availability is the only problem I've had with E85 when traveling outside my home area. At Goblinfest last year I had to drive 25 miles each way to fill my fuel cans.
Making HP. LNF, LSJ, LE5, LAP vs L61
- Thread starter Ross
- Start date
Fozda
Goblin Guru
What ethanol content are you tuned for? I want to switch to E85 but the inconsistency has me concerned.
Sluggonaut
Goblin Guru
I'm not sure what it was tuned for because I'm running the E85 tune that was already on the donor from ZZP. I've just been running pump E85. I did buy a test kit but haven't used it yet. I've been logging AFR's and haven't seen anything to worry about yet.
edit: I did send some logs to Al at ZZP before and after I figured out my wastegate adjustment issue and he thought everything looked good after moving everything over to the Goblin. His primary concern was AFR and he was happy with what he saw in the logs. My tune is posted on the forum so someone who knows more about it than me can probably answer that question better than I can. I'm assuming the tune is just more aggressive if you are tuning for high-quality E85 that is always a specific ethanol content.
edit: I did send some logs to Al at ZZP before and after I figured out my wastegate adjustment issue and he thought everything looked good after moving everything over to the Goblin. His primary concern was AFR and he was happy with what he saw in the logs. My tune is posted on the forum so someone who knows more about it than me can probably answer that question better than I can. I'm assuming the tune is just more aggressive if you are tuning for high-quality E85 that is always a specific ethanol content.
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Scott Geyer
Well-Known Member
Michigan has a good # of stations. Traveling could be tricky
Fozda
Goblin Guru
My thought was to just get a couple 55 gallon drums and fill them up at the pump and then tune it for that so that at least it's consistent. I believe the content depends on the weather so if I just wait until late spring to fill up it'll probably be pretty consistent throughout the summer. I just wish our ECU had flex fuel capability.
Ross
Goblin Guru
So a modern flex fuel car will adjust the tune quickly, as the new tank of fuel starts changing the O2 sensor's readings.
Our LSJ will do the same thing, just a lot slower than the modern cars.
The LSJ will adjust the tune using the Long Term Fuel Trims (LTFT) and the Short Term Fuel Trims (STFT).
If it were me, I would measure the E85, and then use HP Tuners to watch the STFT and LTFT being adjusted in real time.
If the last tank of fuel measures E75, and the next tank measures E50, then the trims will be adjusting a lot.
If you already have an E50 tune on your laptop, you could download that to the LSJ. If not, you can let the LSJ slowly adjust the tune.
The STFT has a limit, (20% or 30%) and can no longer adjust more, and then the LTFT can keep adjusting slowly up until it's limit.
The STFT and LTFT together only have a 50% adjustment limit.
If your LSJ is tuned properly, then your 50% adjustment starts from 0%. When I first used HP Tuners to see my trims, they were maxed out, and I had 0% adjustment left because my engine had air leaks in the intake and exhaust. Hence why I would watch it in HP Tuners, and watch your wideband, and then you know if your engine is running right. My wideband wasn't showing a problem, but luckily the 50% adjustment of the fuel trims was enough to correct for the air leaks. There was no room in the fuel trims to allow for a change in fuels.
Basically, if you drive conservatively for the first 10 miles after a new tank of E85, the LSJ will have adjusted the tune maybe 80%.
It might take 0 miles of driving, or it might take 80 miles of driving... the LSJ adjusts each cel in the table as you spend time at each RPM and load.
The STFT trims start adjusting within seconds, and the LTFT take minutes at each cel.
Our LSJ will do the same thing, just a lot slower than the modern cars.
The LSJ will adjust the tune using the Long Term Fuel Trims (LTFT) and the Short Term Fuel Trims (STFT).
If it were me, I would measure the E85, and then use HP Tuners to watch the STFT and LTFT being adjusted in real time.
If the last tank of fuel measures E75, and the next tank measures E50, then the trims will be adjusting a lot.
If you already have an E50 tune on your laptop, you could download that to the LSJ. If not, you can let the LSJ slowly adjust the tune.
The STFT has a limit, (20% or 30%) and can no longer adjust more, and then the LTFT can keep adjusting slowly up until it's limit.
The STFT and LTFT together only have a 50% adjustment limit.
If your LSJ is tuned properly, then your 50% adjustment starts from 0%. When I first used HP Tuners to see my trims, they were maxed out, and I had 0% adjustment left because my engine had air leaks in the intake and exhaust. Hence why I would watch it in HP Tuners, and watch your wideband, and then you know if your engine is running right. My wideband wasn't showing a problem, but luckily the 50% adjustment of the fuel trims was enough to correct for the air leaks. There was no room in the fuel trims to allow for a change in fuels.
Basically, if you drive conservatively for the first 10 miles after a new tank of E85, the LSJ will have adjusted the tune maybe 80%.
It might take 0 miles of driving, or it might take 80 miles of driving... the LSJ adjusts each cel in the table as you spend time at each RPM and load.
The STFT trims start adjusting within seconds, and the LTFT take minutes at each cel.
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Ask the experienced tuners on HPT what they think of GM’s “virtual” flex fuel.
If all it’s doing is adjusting fuel trim, is there any benefit to running It as flex fuel, other than the possibly cheaper fuel? Without timing adjustments is there any power increase? I guess maybe the cooling effect helps a little?
If all it’s doing is adjusting fuel trim, is there any benefit to running It as flex fuel, other than the possibly cheaper fuel? Without timing adjustments is there any power increase? I guess maybe the cooling effect helps a little?
Ross
Goblin Guru
The old LSJ will adjust fuel trims. A modern GM flex fuel vehicle is a whole new thing that I am not knowledgeable on.
I would have a proper ethanol tune on the LSJ, (timing included) and then let the fuel trims do the gas station fuel supply differences.
Sorry, I thought you were talking about it being able to adjust for all ethanol contents, not just the variance in E85 or whatever particular E blend.
TravMac
Well-Known Member
So there's a few things here that are interesting from a few folks. I love my E85 setup, so maybe can shed some light with what I've come across.
The fuel doesn't exactly end up cheaper in most cases, but there are benefits to running it. When I say in most cases, it's all about cost per mile. E85 is less energy than regular pump gas, so you end up using more. Your energy deficit from E85 to pump gas is somewhere about 25%, so quick math at the pump can usually tell you what is the better deal. I used to play this game all the time in my suburban: that was half for value of pulling up to the yellow handle, and half if I was planning on towing something.
Speaking of towing, there's the E85 benefits. The octane rating on E85 is much higher than most all pump gas, so anyone running a boosted setup (or in my suburban case, towing and extra load on the motor) can benefit purely off the lack of detonation potential. That said it is MUCH cheaper than premium in almost every case. The issue being that premium tends to be better controlled and more readily available.
E85 can make more power when properly tuned, but this enabled by the octane rating and being more aggressive with timing. The "blend" at the pump can vary in Michigan from somewhere around 51% to somewhere around 83%. The pump usually tells these as a service announcement of sorts to consumers that I can't quite remember the numbers so these may be a tad off. This also depends on time of year when it's winter or summer for different blends to efficiently run in the cold.
In any case, I've ran a lot of E85 and always had it be +75% from the pump. Maybe that's luck, or Meijer has a great stock of corn. Either way that's why I stopped buying 5 gallon buckets of E85 specific race fuel and started going to the pump for it. It works just fine, and they are around Michigan everywhere. The Goblin seems happy to run off it too!
The fuel doesn't exactly end up cheaper in most cases, but there are benefits to running it. When I say in most cases, it's all about cost per mile. E85 is less energy than regular pump gas, so you end up using more. Your energy deficit from E85 to pump gas is somewhere about 25%, so quick math at the pump can usually tell you what is the better deal. I used to play this game all the time in my suburban: that was half for value of pulling up to the yellow handle, and half if I was planning on towing something.
Speaking of towing, there's the E85 benefits. The octane rating on E85 is much higher than most all pump gas, so anyone running a boosted setup (or in my suburban case, towing and extra load on the motor) can benefit purely off the lack of detonation potential. That said it is MUCH cheaper than premium in almost every case. The issue being that premium tends to be better controlled and more readily available.
E85 can make more power when properly tuned, but this enabled by the octane rating and being more aggressive with timing. The "blend" at the pump can vary in Michigan from somewhere around 51% to somewhere around 83%. The pump usually tells these as a service announcement of sorts to consumers that I can't quite remember the numbers so these may be a tad off. This also depends on time of year when it's winter or summer for different blends to efficiently run in the cold.
In any case, I've ran a lot of E85 and always had it be +75% from the pump. Maybe that's luck, or Meijer has a great stock of corn. Either way that's why I stopped buying 5 gallon buckets of E85 specific race fuel and started going to the pump for it. It works just fine, and they are around Michigan everywhere. The Goblin seems happy to run off it too!
Scott Geyer
Well-Known Member
Guys at ZZP said you can gain a good 40hp. They recommend changing the fuel pump
People that
How are you checking the ethanol content? Flex fuel sensor or test tube?
TravMac
Well-Known Member
Both ways actually. Was really curious just how good the expensive GM sensor in an '05 truck really was. Turns out they were expensive for a reason. The new sensors are much more cost effective, but that's technology advancement for ya.
Also yes, you do need to push more fuel to even get the car to run right. Fuel pump and injectors are basically a requirement with E85. Easy swap, easy power, not many long drives for the Goblin (honestly really curious to see my mileage once I hit the streets to cruise around given all the changes I have from stock).
Sluggonaut
Goblin Guru
I'm getting around 14-16 MPG on my E85 setup.
edit: I guestimate this is equivalent to me getting about 22 MPG on gas which seems to be around the average for a Goblin. My wife's Equinox is a NA Ecotec that gets about 26 MPG on gas and about 18 MPG on E85. So the 15%-25% estimates of reduction in mileage for E85 are closer to 25% in my limited experience with an Ecotec.
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Tinkles
Well-Known Member
A standalone ECU and flex fuel sensor is always an option for your pump E85 woes. Pump E85's allowed inconsistency sours it for me. I plan on running Ignite Red(E90) and my local A&A Auto Parts carries VP race fuels. With the non-pump E85 you do not have the variance in ethanol content and I like that a lot.
E85 also helps to make power by having a really high oxygen content(~33% for VP E85) and it also cools the air charge better than a non-ethanol fuel. Making the decision to run E85 is pretty simple in my opinion, especially in a boosted vehicle.
E85 also helps to make power by having a really high oxygen content(~33% for VP E85) and it also cools the air charge better than a non-ethanol fuel. Making the decision to run E85 is pretty simple in my opinion, especially in a boosted vehicle.
There are but they really do not benefit the performance minded people. IIRC pump E85 is allowed to be anywhere from ~50% to 85% ethanol witch makes a flex fuel sensor and flex fuel capable ECU extremely beneficial.
I have a link just a little further down that can help extend your drives, but it does unfortunately require some rearranging of parts.
Ross
Goblin Guru
So tell me how you really feel.
Why do you feel that way? Who is Paul? What does his wrap look like?
PS, We really do need a rear suspension redesign. Upper and lower A arms. The goblin has so much more potential.
Maybe they are talking about Paul Clark aka Carproblem.
PS, We really do need a rear suspension redesign. Upper and lower A arms. The goblin has so much more potential.
Maybe they are talking about Paul Clark aka Carproblem.
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Rauq
Goblin Guru
Still get a kick out of like 500 out of over 1,000,000 Cobalts built being turned into Goblins (0.05%). Maybe 60% are SS? But then again at least 1/4 were salvage or total beaters to begin with... Same argument goes for folks complaining there's no more Cobalts around to turn into Goblins.
I also get a good lol out of folks asking $10k for Cobalts with major issues. Good Goblin donors can still be had for a fraction of that if you put a small portion of the effort that it takes to build one into the search for a donor.
Regarding handling, I wouldn't argue that an SS/TC was a great handling FWD car for its time, and I wouldn't argue that front Macpherson in the rear is less than ideal, but a Cobalt and a Goblin are completely different animals. An unmodified Goblin suspension setup is still way more performance than I can effectively utilize.
And I only drive my Goblin slightly less than the S2000 it replaced. To each their own
I like listening to the ZZP guys and for the most part I'm entertained by their antics, Goblin jokes included. We're a teeny tiny market, but a greater percentage of Goblin owners are spending real money on the Ecotec platform than Cobalt owners.
I also get a good lol out of folks asking $10k for Cobalts with major issues. Good Goblin donors can still be had for a fraction of that if you put a small portion of the effort that it takes to build one into the search for a donor.
Regarding handling, I wouldn't argue that an SS/TC was a great handling FWD car for its time, and I wouldn't argue that front Macpherson in the rear is less than ideal, but a Cobalt and a Goblin are completely different animals. An unmodified Goblin suspension setup is still way more performance than I can effectively utilize.
And I only drive my Goblin slightly less than the S2000 it replaced. To each their own
I like listening to the ZZP guys and for the most part I'm entertained by their antics, Goblin jokes included. We're a teeny tiny market, but a greater percentage of Goblin owners are spending real money on the Ecotec platform than Cobalt owners.
Desert Sasqwatch
Goblin Guru
These guys don't have any bias in this discussion, uh huh. Maybe they shouldn't be bad mouthing the Goblin since we do spend good $$$ with them. And they are definitely missing the point of the Goblin, since many of them are built from Cobalts that will NEVER be able to drive again. I'd bet a good 1/3 of the builds fall into this category. And show me a Cobalt that can stay with (or embarass) any of the 'super car' category vehicles for the price we spend on building one - around $25K.