E70 vs E85
Thread Starter
Joined: Jun 2005
Posts: 2,265
Likes: 671
From: Oskaloosa, Iowa
E70 vs E85 I'm considering running E85 and trying to decide if my original fuel system plans are good enough. During the process of research I also found that although E85 is readily available here it's usually closer to E70.
My setup is going to be a single dw300c 340 lph pump and was thinking siemens mototron 60 lb injectors. I'm only looking to make 550ish rwhp through the 4l60e. Stock bottom ls1 with 228r cam and D1x at 8 pounds. E85 wasn't in my original plans and probably not needed for my power level, but since it's so readily available here and I'm new to tuning it might be beneficial for the added detonation resistance if my fuel system plans will be enough.
During my research I found that there is a pretty big stoichiometric difference between E70 and E85. I don't know how much difference that actually makes in tuning though? Since E70 is what is actually available here and I tuned for it how much of a problem would it create if I actually got E85 or the other way around?
Is all of this worth it at my power goals? Will the single 340 lph pump and 60 lb injectors actually meet the demands of E85 at 550 rwhp through an auto with forced induction?
My setup is going to be a single dw300c 340 lph pump and was thinking siemens mototron 60 lb injectors. I'm only looking to make 550ish rwhp through the 4l60e. Stock bottom ls1 with 228r cam and D1x at 8 pounds. E85 wasn't in my original plans and probably not needed for my power level, but since it's so readily available here and I'm new to tuning it might be beneficial for the added detonation resistance if my fuel system plans will be enough.
During my research I found that there is a pretty big stoichiometric difference between E70 and E85. I don't know how much difference that actually makes in tuning though? Since E70 is what is actually available here and I tuned for it how much of a problem would it create if I actually got E85 or the other way around?
Is all of this worth it at my power goals? Will the single 340 lph pump and 60 lb injectors actually meet the demands of E85 at 550 rwhp through an auto with forced induction?
Thread Starter
Joined: Jun 2005
Posts: 2,265
Likes: 671
From: Oskaloosa, Iowa
I'm trying to wrap my mind around this...The wide band doesn't care what the stoich of the fuel is because it reads lambda? It converts that lambda reading to an AFR reading with no concern for stoich. So regardless of fuel type I can use that AFR reading in terms I'm familiar with using pump gas and shoot for the same AFR target as I would for pump although I'm running E70? The biggest issue would be detonation from too much timing with lower than expected octane if I don't test the fuel?
The important thing is to change the target stoich in the tune from 14.7 for pump to the stoich of the fuel im running. The wideband will still read in terms I'm familiar with using pump it will just take more fuel to get there?
Last edited by BCNUL8R; Oct 30, 2017 at 12:09 PM.
Joined: Aug 2007
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From: Turnin' Wrenches Infractions: 005
My two widebands are like that yes. They convert stoich to 14.7. It doesnt matter the fuel, if it displays 14.7 you are hitting the mark. This is my first go round with e85 so I dont know all the ends and outs. When i changed stoich for MS109 (105 octane) and turned the trims on it still hit target AFR. Im not sure what or how much that stoich setting changes fueling. I will be learning soon. After its tuned, i will re-enable the trims with a 14.7 stoich and see how the computer responds. My understanding has always been narrowbands are fixed to a certain degree....so I dunno.
Thread Starter
Joined: Jun 2005
Posts: 2,265
Likes: 671
From: Oskaloosa, Iowa
I'm new to tuning altogether. I've got a few months before I will actually be tuning on the car to learn. I'm reading books and researching now. I'm trying to decide if e85 is actually beneficial or ads more complication for the novice tuner lol.
Depending on your base pressure you might be out of pump and possibly injector at that power level.
SBE LS1 w/224 Cam here. Walbro 450 and 80 # injectors. At 8 lbs of boost about 600 rwhp on E60 I have hit 90% injector duty cycle.
SBE LS1 w/224 Cam here. Walbro 450 and 80 # injectors. At 8 lbs of boost about 600 rwhp on E60 I have hit 90% injector duty cycle.
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Have you heard that it's E70? Or have you tested it and found it to be E70?
When I first started to run E85 a few years back, my research led me to believe the same thing. When I started buying it, I would test each batch. And I found it to be very very close to E85 every time. It was so close, I never had to change the tune. Now I don't bother testing it, although I probably should.
When I first started to run E85 a few years back, my research led me to believe the same thing. When I started buying it, I would test each batch. And I found it to be very very close to E85 every time. It was so close, I never had to change the tune. Now I don't bother testing it, although I probably should.
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Verdad Gallardo Thread Starter
Joined: Jun 2005
Posts: 2,265
Likes: 671
From: Oskaloosa, Iowa
Have you heard that it's E70? Or have you tested it and found it to be E70?
When I first started to run E85 a few years back, my research led me to believe the same thing. When I started buying it, I would test each batch. And I found it to be very very close to E85 every time. It was so close, I never had to change the tune. Now I don't bother testing it, although I probably should.
When I first started to run E85 a few years back, my research led me to believe the same thing. When I started buying it, I would test each batch. And I found it to be very very close to E85 every time. It was so close, I never had to change the tune. Now I don't bother testing it, although I probably should.
Due to the crappy fuel system of the GTO and the fact that I'm only going to be running 8 pounds or so of boost I've decided to stick with 93 pump for now. I like the simplicity of a single drop in fuel pump and 60 lbs injectors on pump. I didn't like the idea of a dual pump boost reference setup just to run 8 pounds of boost.
I was under the impression that switching from gas to e85/e70 will change the burn temp to cooler? for example, gas stoich is 14.7 but when e85 is used, since it burns cooler will read lower (richer on the wideband) at ~9.5? i'm planning on running e85/e70 and gathering parts (already have 255lph walbro) and just got 42.5lb injectors and will tune the IFR via hptuners.
also subbed for input
also subbed for input
Yes, it will burn considerably cooler. That can be both good and bad. On a hot summer day under a heavy load, the engine will run nice and cool. But it will be hard to start when it's near freezing.
The burn temp won't effect stoch. Different calculation and method of measurement.
The burn temp won't effect stoch. Different calculation and method of measurement.