In reply to ZombyCougar Woofencamp :
What I’d love to know is if cars without the flex fuel emblem still are programmed to run on E85 but lack a simple sensor or something.
The flex fuel option listed for $100 When you remove the cost of the emblem and retail mark up that sure doesn’t leave much for actual hardware and installation.
LanEvo said:I remember reading that one problem with nitromethane is that you can’t see the flames in case of fire. Seems like scary stuff.
Nitro flames are visible. Methanol burns cool enough that its flames are not bright enough to be seen in sunlight.
frenchyd said:In reply to ZombyCougar Woofencamp :
What I’d love to know is if cars without the flex fuel emblem still are programmed to run on E85 but lack a simple sensor or something.
The flex fuel option listed for $100 When you remove the cost of the emblem and retail mark up that sure doesn’t leave much for actual hardware and installation.
Flex fuel used to have sensors. (Megasquirt is fully capable of reading them, and blending between pure-gasoline and pure-E85 fuel, timing, and boost maps, with the blend percentage user-definable)
Nowadays, they just monitor the fuel level sender for a dramatic change between shutoff and restart, which would indicate a refueling event If there is one, the PCM monitors how fuel trims swing after restart, and infers an alcohol content change based off of that.
frenchyd said:In reply to ZombyCougar Woofencamp :
What I’d love to know is if cars without the flex fuel emblem still are programmed to run on E85 but lack a simple sensor or something.
The flex fuel option listed for $100 When you remove the cost of the emblem and retail mark up that sure doesn’t leave much for actual hardware and installation.
The hardware isn't expensive - it's just the sensor. The different programming does not add cost at the retail end. That doesn't mean that the only thing you need to do is plug in the sensor, though.
I'm so excited to switch my Saab truck to e85.
Here's a question: does e85 require a larger exhaust system? I know it requires more fuel, and can make power gains with the same incoming air volume as compared to premium gas, but does that mean the volume of exhaust gases is larger, or about the same as with premium gas?
Does my question even make sense?
In reply to Robbie :
It does make sense, from an overthinking perspective, and the answer is no.
Knurled. said:In reply to Robbie :
It does make sense, from an overthinking perspective, and the answer is no.
In reply to Robbie :
As said it makes sense from an overthinking perspective.
Technically I suppose there is a tiny increase in volume but since they don’t make exhaust tubing in 64th inch sizes, I suspect if your tubing size is adequate now it will remain so with a 10% increase in horsepower.
The real power gain is when boost is added.
ps, don’t forget to richen it up
Knurled. said:frenchyd said:In reply to ZombyCougar Woofencamp :
What I’d love to know is if cars without the flex fuel emblem still are programmed to run on E85 but lack a simple sensor or something.
The flex fuel option listed for $100 When you remove the cost of the emblem and retail mark up that sure doesn’t leave much for actual hardware and installation.
Flex fuel used to have sensors. (Megasquirt is fully capable of reading them, and blending between pure-gasoline and pure-E85 fuel, timing, and boost maps, with the blend percentage user-definable)
Nowadays, they just monitor the fuel level sender for a dramatic change between shutoff and restart, which would indicate a refueling event If there is one, the PCM monitors how fuel trims swing after restart, and infers an alcohol content change based off of that.
So what you’re saying is even without the flex fuel option newer cars would adjust for alcohol levels in the fuel? ( or am I not understanding you correctly)?
In reply to frenchyd :
Well, it's Complicated. And I speak here only of GM products, since it seems like the majority of flex fuel vehicles on the road are GM. (Also almost all 3.0 Rangers, but nobody ever actually fixes those)
There's short term fuel trim, which is an immediate adjustment to fuel relative to the computer's mapping and changes several times per second. There's long term fuel trim, which happens in various map cells and is only adjusted if short term trims trend a certain way for very long, and will be used as a generic "starting point" for that cell for the short term to work on.
Calculated alcohol content is a kind of calculated mega-longterm trim, that is applied to EVERY cell. Sort of a giant blanket multiplier that is applied first.
That said. It is only vehicles with flex fuel that have this capability in the computer's firmware. And, I will allow, it doesn't really work all that well. Which is how I am familiar with it. It can get mucked up by refueling with the engine running, or a lot of cold starts and shutoffs, and you can wind up with a calculated alcohol content that is WAY off from what is actually there, and then the car will start throwing lean or rich faults, because when the combination of longterm and short term gets over 30% or so, the computer decides there's a problem. (And remember the alcohol content is a across the board blanket modifier and is assumed to be correct)
Also that said. People have run non flex fuel cars on E85. It will up the fuel trims to right on up around 35-40%, which will set a fault. It will also run lean when outside the cells where the car runs closed loop, namely cold start and wide open throttle. That's probably not good, although since many OE tunes run very rich to keep things cool, things might live okay in short bursts. Not in my car, though.
A lot of what you pay for with "flex fuel" capability is different materials in the fuel system. The fuel pump and injectors are usually also larger capacity, but I don't see this being an additional expense to the manufacturer.
frenchyd said:In reply to LanEvo :What am I missing? I watch top fuel dragsters shoot flames out their pipes even during the day!!
Looks like I confused nitromethane with methanol.
frenchyd said:In reply to LanEvo : are you a no budget limited racer or performance guy? If so you are right you should always buy your fuel in sealed drums or cans. Because gasoline has the same variables.
I've got no personal experience, but I was under the impression that the proportion of ethanol in E85 varies more dramatically than octane levels at the pump.
I don't run turbo cars that are boosted within an inch of their lives, so octane ratings aren't all that meaningful to me. I just use 93-94 from Shell or Sunoco when I'm in the USA and PetroCan when I'm up at Mosport or Tremblant.
What a great answer and complete enough for me to understand your reasoning. Thank you
I’m new enough to all of this that I’d like to dig deeper if I may. For information I have a 2016 Ford 1/2 ton 4C4 V8.
I’ve been playing fuel mixer trying to find a magic elixir of fuel that will really give me performance. I’ve noticed there is a variety of mixes out there. My closest source of E85 has only about 30% alcohol while another station 5 miles away promises at least 51% alcohol. How do I find 85% alcoholic content?
Second I’m pretty sure the base gasoline stock they mix with E85 is pretty low octane. What if I add some 91 octane fuel? Will that improve the total octane enough? Or am I walking backwards? Losing the percentage of alcohol to gasoline?
Third When I use it in my MGUAR which will be supercharged and carbureted I’m thinking of using pump grade E85 since it will almost never see full throttle but switching to sealed cans/drums for racing. But maybe doctoring them up with a bit of Nitro and or toluene?
The idea is that under drag race applications I can start modest and add enough to make a difference as I gain knowledge and experience.
I can be a bit destructive since I have several engines and even more parts to sacrifice.
In reply to LanEvo :
It gets better with nitro. The flames you see shooting out of the zoomies is, I'm told, dissociated hydrogen burning in atmosphere. Nitro engines are run at a lambda value of around .5-ish so the engines don't melt down. (Stoich is around 2:1, but they are run closer to 1:1 fuel:air)
In reply to LanEvo : I’ve been using E85 in my new truck periodically. When I have E85 (from the pump) it really makes a performance improvement.
The first time I floored it with E85 I was on an entrance ramp. Both tires exploded with a loud squeal as they spun until the truck shifted to the next gear. I was shoved back into my seat and redline approached really quickly in that gear. Luckily I looked down at the speedometer because it was passing 85 mph and I still had about a third of the ramp to go. absolutely shocking how fast it made that truck go.
Since then I’ve really tried to find out what can about E85
Yes it will absorb water. So what? There is water in every gas tank in America!! Engines seem to run better in the rain don’t they? (assuming ignition is OK)
Octane variation? Yes but then so does gasoline. Probably a lot more than you expect. When I managed a station it wasn’t all that unusual to dump any extra from the tanker in another tank. I mean you get no credit if you send the extra back
Here is the deal though, ethanol has 114 octane. When dealing with boost the higher octane the more timing your engine can take and the power it will make
The only way to REALLY know what you are getting is to buy it from a supplier that guarantees what it is. If you want to draw a line in the sand you could buy 'real' e85, dilute it to ~e50, and then tune for that and hope that your tune is safe enough for whatever you're likely to get out of an e85 street pump.
For what it's worth, i started running e85 in my 90 turbo caravan after i got back from the $2016 Challenge. Judging by knock sensor activity, it has not matched up with 116 octane race gas. But, it still allows me to get 90% there with cheap gas from a regular gas station. It definitely has a unique appeal. The issue mostly comes from running a truly ragged-edge setup that you NEVER want to break, on a fuel that you don't really know the content of.
Also, as far as needing a larger exhaust, the sticking point is the word 'need'. If you change what's going into your combustion space to a higher proportion of liquid (fuel), you're going to end up with a larger volume of exhaust after it has all vaporized. There's also quite a bit of talk about e85 causing turbos to spool at lower rpms because of this increased exhaust volume. So, there is some effect. Whether your particular setup merits the effort/expense of an exhaust upgrade is pretty subjective. To me, turbo exhausts are one of those things where it pays off to go as big as possible the first time around, but doesn't really pay off to do it twice/in stages because a 2.5" exhaust isn't holding anyone back below 500hp anyway and the returns on a further upgrade usually arent the best return on investment you could get from a mod. I dont know if that makes sense.
In reply to Vigo :
That is the problem. Last time I bought race gas it was $9.00 a gallon. I found out later at the track. It had been on the shelf for over a year. I pulled back my timing and the engine was really doggy Probably a combination of stale gas and timing change. I didn’t ruin my engine but I didn’t run as I normally had
So gasoline even in a sealed container can have issues
as far as exhaust size goes there is a weight penalty with an increase in size in addition to a clearance penalty. On top of that too big can cost power especially at less than peak rpm.
So bigger isn’t always better
on top of that only at full throttle will it make any difference. Even road racing with small engines and relatively heavy vehicles the amount of time you are at full throttle peak RPM is relatively brief. So on a two minute lap with say ten corners you might be at full throttle peak RPM less than 20 seconds where a slight under sizing of your exhaust pipe would make maybe .02 seconds a lap difference. Unless you are a world champion class driver slight errors and misjudgments will easily add up to over ten times that.
E85 is perfectly good race fuel, but within a few limitations: The system needs to be able to handle some variation in ethanol content and you shouldn't be running right up to the limits of the fuel (and expected octane) but leaving a little bit of margin in there. Following that second one will keep you from ending up down on power when you get a tank of slightly less-good fuel, as the ECU won't end up having to cut things back to save the engine unless the fuel is significantly below what's expected.
In reply to rslifkin : You are right about that. Sooner or later the fuel you use be it race gas or E85 unless it comes fresh in sealed cans or drums will be subpar. That’s why most of the GRM crowd can’t build things to the absolute limit. We need a little safety net.
Jaguar V12s come with either 7.8-1 compression ratio and really good heads or 11.5 -1 compression ratio but lousy heads
while good E85 works with 11.5-1 compression and up to about 10 pounds of boost the fact I can’t trust always getting good E85 means I’ll take the 7.8-1 compression ration and good heads
There is another option with Jaguar California requires a cleaner exhaust and the way Jaguar did it is by retarding the timing more at lower RPM. i have a couple of California distributors and maybe I can make the 11.5 compression work with a California smog distributor
Enough to street drive it.
bentwrench said:Pump E85 is not a magical elixir, it's only regulated constraint is 15% gas (so it's not drinkable).
What grade of gas is not regulated. (my $5 says they don't use the best gas they have, they use the worst)
How high the water content is, is not regulated.
Every time you pull up to an E85 pump, you are rolling the dice as to what winds up in your tank.
This is fine for a passenger vehicle that has a flex fuel sensor.
However if you want to race and take full advantage of the E85 you will not be happy with pump fuel as it varies too much.
For race applications you will want fresh fuel from a sealed can for consistent power and jetting predictability.
You will also want to drain it between race weekends and put it back into that sealed container so it does not absorb water from the air.
Ethanol is delivered from the distillery in rail cars, the gas distributors do not have tanks for it they leave it in the rail cars stored on a siding.
The rail cars are not sealed and they breathe with the temp changes drawing in moisture.
The tanks at the gas station are not sealed and the ethanol picks up more moisture as it sits in that tank.
What you say is true both for Gasoline and for E85
Gas stations still have tanks underground and water gets into those tanks. Its OK because water reduces detonation and clean carbon deposits.
But Ethanol has 114 octane. And even blended with low octane gasoline will still produce a higher octane rating than pump gas.
And as for draining it after every event? You are confused. Methanol requires that not ethanol.
Methanol is corrosive, poison, and dangerous.
Ethanol is in beer wine and booze.
Vigo said:The only way to REALLY know what you are getting is to buy it from a supplier that guarantees what it is. If you want to draw a line in the sand you could buy 'real' e85, dilute it to ~e50, and then tune for that and hope that your tune is safe enough for whatever you're likely to get out of an e85 street pump.
For what it's worth, i started running e85 in my 90 turbo caravan after i got back from the $2016 Challenge. Judging by knock sensor activity, it has not matched up with 116 octane race gas. But, it still allows me to get 90% there with cheap gas from a regular gas station. It definitely has a unique appeal. The issue mostly comes from running a truly ragged-edge setup that you NEVER want to break, on a fuel that you don't really know the content of.
Also, as far as needing a larger exhaust, the sticking point is the word 'need'. If you change what's going into your combustion space to a higher proportion of liquid (fuel), you're going to end up with a larger volume of exhaust after it has all vaporized. There's also quite a bit of talk about e85 causing turbos to spool at lower rpms because of this increased exhaust volume. So, there is some effect. Whether your particular setup merits the effort/expense of an exhaust upgrade is pretty subjective. To me, turbo exhausts are one of those things where it pays off to go as big as possible the first time around, but doesn't really pay off to do it twice/in stages because a 2.5" exhaust isn't holding anyone back below 500hp anyway and the returns on a further upgrade usually arent the best return on investment you could get from a mod. I dont know if that makes sense.
Yes E 85 won’t match up to 116 race gas, because 100% ethanol is only 114 octane and at best only 85% of E85 is ethanol. The other 15% is lower octane gasoline.
However 116 octane race gas is at least 5 times more expensive. Now to be fair pump E85 may not even be that much ethanol. In some states it may be called E85 with as little as 30% ethanol.
In reply to LanEvo :
Thank you for reminding me about toluene. Didn’t it help improve fuel mileage ?
Current price of a gallon of toluene is around $150.00 but if I remember correctly a tiny bit massively improved power and fuel mileage. Maybe I can improve it to the point where E85 will get the same mileage gasoline does?
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