I've been hearing of a few people doing this as of late. Basically a full tank of 93 with a gallon of e85. Saposedly it just helps resist detonation. Is there any truth to this? I know e85 is a much better fuel in terms of resisting detonation then 93, but would just a gallon with lets say 10 gallons of gas be enough to actually help any? Next summer I plan on changing the fuel system and making the switch to e85, but in the winter months/spring I'm going to start tuning my car myself. And if this actually works I'd start putting some in when I plan on messing with nitrous just to make it a little more safe since it's all on me now. So is this something that has some truth to it?
putting a "splash" of e85 in with a tank of 93?
- Thread starter ctgreddy
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Ive heard of people doing it before but usually it was to help pass emissions since adding a gallon or two of E85 to a tank will lean it out some.
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yes exactly they do it to help pass emission testing
so to put say 50/50 93/e85 in the tank would this work? im wondering also will i have to add some fuel to my tune in order to not run lean?? can someone tell me what there wideband shows at WOT when running e-85.. sorry man not trying to steal your post i think we kinda have the same idea with trying to run some e-85 and 93 until we get the fuel system swapped for full e85
I do it all the time in my Coyote car. The Coyotes are always in closed loop and the fuel trims can take care of adding enough fuel if you put 2-3 gallons of E85 in to bump up the octane. Now obviously your Cobra (and most other cars) is in open loop at WOT so your WOT fueling will lean out a little. Depending on how rich it is currently tuned to, the E85 splash may cause it to be 'too lean' according to most but the extra cooling and octane will help make up for it. At cruise in closed loop the fuel trims will take care of it.
I've found that adding 3 gallons of E85 to my tank changes the fuel trims by around 5-6%, so you will most likely run 5-6% leaner at WOT. If you are currently tuned to 11.0:1 at WOT on gasoline, your air/fuel will go to around 11.5-11.6 which is still in the acceptable range. If you have a more aggressive tune and it's at 12.0:1 currently, you will now be in the 12.6-12.8 range which would make me a little nervous. Now if you are talking about just adding a gallon or two, obviously the change will be a smaller %.
I've found that adding 3 gallons of E85 to my tank changes the fuel trims by around 5-6%, so you will most likely run 5-6% leaner at WOT. If you are currently tuned to 11.0:1 at WOT on gasoline, your air/fuel will go to around 11.5-11.6 which is still in the acceptable range. If you have a more aggressive tune and it's at 12.0:1 currently, you will now be in the 12.6-12.8 range which would make me a little nervous. Now if you are talking about just adding a gallon or two, obviously the change will be a smaller %.
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Are you talking about your Coyote or another car? A 50/50 mix would be too much IMO (that would be about a 15% change in stoich). I've run up to 4-5 gallons of E85 (the rest 92 octane) in my Coyote on my old Bama 93R tune and I saw 3-4 degrees more timing due to less knock activity. Fuel trims were adding about 10% fuel at cruise and WOT. The fuel trims learn almost immediately. No issues.
No i was refering to my Cobra. its tuned around 11.4-11.6 WOT so adding 6-8% more fuel in my tune would make up for the 50/50 mix then?? i have adv 3 sct so i can add some fuel to the tune.
thanks for the help
thanks for the help
No, if you do a 50/50 you would need to add something like 15%. The 6-8% was for just maybe 3-4 gallons of E85 added. If you are close to being at the edge of your fuel system I would be very careful adding more than 10% though. Do a lot of datalogging.
ok makes sense, im just wondering how much the 50/50 mix will help.. currently i have 255 intake 255 inline and 60s.. i need to see where my inj duty and pump is currently, its making 527whp
ill be sure to data log alot when trying this
ill be sure to data log alot when trying this
I put a 50/50 mix in my car and it ran like crap
Yeah, a 15% change in the stoich is a pretty big change. I'm guessing you didn't change the tune at all? Ran like crap all the time or just at WOT? I'm guessing that if you gave it time the fuel trims would figure it out at cruise, but what do I know, LOL.
So basically, if you add 2-3 gallons for a full tank then it will have greater knock resistance and allow a couple degrees more timing, assuming the tune is correct as far as afr's go.
So in theory, I(or anyone) could run 93 tune with all 93 on my cobra with say 21degrees of timing which is normal for my mods and 93. Then when I want to spray a 75 shot, instead of taking away timing I could just put in 2-3 gallons of e85 along with 93 and put the adequate fuel jet in to get the afr where it needs to be safely, Without pulling any timing but still being safe.
So in theory, I(or anyone) could run 93 tune with all 93 on my cobra with say 21degrees of timing which is normal for my mods and 93. Then when I want to spray a 75 shot, instead of taking away timing I could just put in 2-3 gallons of e85 along with 93 and put the adequate fuel jet in to get the afr where it needs to be safely, Without pulling any timing but still being safe.
Theoretically, yes. I've never had a nitrous car so I don't really know. I would think that for something as small as a 75 shot it should work fine.
it ran like crap all the time. imo you guys are going to blow your engines, not trying to be a dick
Sounds like all the Coyotes should be doing this if the above information is correct. I mean why not if you can get more timing safely.
It worked/works well in mine. I guess I would say 'your results may vary', but it's worth a shot. I started with about a 20% E85 mix. I tried around 30% and didn't see any benefit over the 20% mix so I usually just splash in 3 gallons or so. This is especially useful when you stop at a gas station that only has 91 octane premium. In that case I usually put 4 gallons of E85 in.
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You know most regular fuel is already at least a 10% blend and the government has been trying to pass a mandate for 15%. Closed loop driving is probably not a problem but if you run a lot of boost and are tuned on the edge adding a leaner fuel to the mix is only going to make things worse for you. Why risk burning down a cylinder for a few points of octane to resist detto when lean fuel is just as dangerous? You are not gaining anything.
It's like this:
Add E85 to increase protection from detonation: Detonation damage=hole in piston
Leans out fuel in the process: Too lean of mixture damage=hole in piston.
The end result is the same.
If you are I would add a few points to your WOT fuel table just to be safe.
It's like this:
Add E85 to increase protection from detonation: Detonation damage=hole in piston
Leans out fuel in the process: Too lean of mixture damage=hole in piston.
The end result is the same.
If you are I would add a few points to your WOT fuel table just to be safe.
Mixing E85 in with pump gas on anything under an 11 GT Stang is probably a recipe for a boat anchor and more than likely not the greatest idea for the 11+ 5.0s either. The newer computers in the 11+ 5.0s can compensate for a hell of a lot more that our 03-04 Cobra computers can.
Buy some Torco for extra add on the go safety and then save up for a fuel system and tune for E85.
Buy some Torco for extra add on the go safety and then save up for a fuel system and tune for E85.
Coming from the guy that claimed he ran 50/50 mix already and I would bet you didn't change the tune at all or had a wide band hooked up. Now you are the lucky one that didn't blow your engine. This is why we are on here to gain knowledge on how to do this safely and with benefit. Not trying to be a dick just saying
No I didn't have a wideband hooked up of have it tuned. It didn't clean out anything and my car doesn't run any better
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