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Anyone opinions using E85 for Track Days?

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I was talking with Shaun about this a while back. Apparently the direct injection on the gen 3 benefits way more from e85 than the port injection of earlier models. I saw 12 hp going from 91 to e85. We don’t get nearly the bump the gen 3’s do, but still worth the trouble for all the same reasons.

Yeah the direct injection can take a lot more timing than port injection, and its pronounced at low rpms on the coyote because the direct injection is mainly used below 3k rpm. So on a track not a big deal, but fun for a street car. The higher comp of the gen3's also generate a bit more gains up top than a gen2 though too.
 
Ale how do you see the fuel starvation any different between E85 and regular gas? before my in-tank transfer pump I'd starve at 3/4 tank which I would reach by the end of a flat out 20min session anyways. So at least for me the extra burn rate of E85 does not induce starvation earlier, the car was starving already on regular gas.
I re read my post. It wasnt clear lol.
The e85 run richer so u need much more volume than regular gas
u can struggling to pick up enough e85 when the fuel level is low.
Also,
Because you need always a 3/4 of tank.. you may have mileage issue.
Meaning if with gas u do ,i.e. 7 laps before reaching 3/4.of.tank
With e85 u may do just 4 laps before reaching that minimum level.
So if you go for the 5th lap u may "struggle"

Hope this makes it a little clearer
 
Resurrecting this thread because I found Flex Fuel at a Rudder's near Lancaster, PA about 16 miles from my home. Not a bad trip and lots of room to drive the trailer up to the pump and fill my 55 gallon drum.
I just tested some and it came out E70 but it's winter here. Pump says it can be anywhere from E50-E83. Would you expect the % to rise by summer?? I will test again in the spring but I was thinking about mixing race E90 with E70 just to get it higher in anticipation of my new motor install and tune. I hope to be able to predict how much E90 I need to keep the overall % around E80-85 so the tune remains consistent.
 

Fabman

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Resurrecting this thread because I found Flex Fuel at a Rudder's near Lancaster, PA about 16 miles from my home. Not a bad trip and lots of room to drive the trailer up to the pump and fill my 55 gallon drum.
I just tested some and it came out E70 but it's winter here. Pump says it can be anywhere from E50-E83. Would you expect the % to rise by summer?? I will test again in the spring but I was thinking about mixing race E90 with E70 just to get it higher in anticipation of my new motor install and tune. I hope to be able to predict how much E90 I need to keep the overall % around E80-85 so the tune remains consistent.
Yes the Ethanol % increases in summer. More Gasoline is added to the Ethanol in winter to make it light faster in cold weather.
I also thought about mixing pump e85 and race e85 but then it would become an expensive science project that I didn't really need so I just go 100% pump.
It's worked well for about 12 years. Just tune the car for the ethanol content that you are going to run and you're good to go.
Doesn't have to be exactly e85, I have run fuel down to the 70's without issue.
 

Mad Hatter

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If what I read is right, once you get over E60 the ability to add advance is about the same all the way to E85, but with E60 you will miss out on the cooling effects (kind of circular argument...). Which is my main reason for switching to Ethanol in the first place. Hoping to get my LU47 injectors in this week.
 

Boone

Professional Thread Killer
My '05 is true flex fuel. I can run any mixture of 93 octane and E85. In theory, it's Lambda = 1 at all time. I have a GM fuel sensor in my fuel line that tells a piggy back computer what the E% of the fuel in my return line is. This computer adjusts the signal to the injectors to compensate for the fuel mix. Great for a street car, and I purchased ten 5 gallon jugs that I take to the track full of E85 since availability can be sketchy. Unnecessarily complicated for a race car.
 

Fabman

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Thought I’d share this…

 

Dave_W

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Thought I’d share this…
Really like the actual math being done. I might take exception to one point - the claim that the cooling effect is greater (or more effective) for direct injection than port injection. There have been a couple Engine Masters episodes testing carb vs PI and PI vs throttle-body injection. In peak horsepower, both carb and TBI beat PI, and the main difference was intake air temperature. The scientific conjecture was that PI didn't give the fuel enough time to vaporize and reduce the intake air temp before reaching the combustion chamber. By mixing the fuel into the air at the start of the intake mainfold instead of the end, the travel time through the intake runnner allowed the evaporative cooling to take place, so the fuel-air charge actually ingested by the cylinder was more dense, making more power. When you spray the fuel straight into the intake valve opening, there's much less time for the droplets to evaporate and cool the intake charge. In the Engine Master testing, the difference in power was more noticeable at the top end - the dyno HP lines between PI and carb/TBI diverged more as rpm increased.

Thinking about it, if DI was effective at charge cooling, it's only happening in the cylinder when the intake valve is closed, so it would be reducing the peak cylinder pressure (Pv=nrT) and not increasing the mass of the intake charge. The carb & TBI cooling is happening in the intake manifold, reducing the absolute pressure / increasing vacuum in the intake and adding to the vacuum from the piston travel, and making the intake charge more dense, so more fuel-air mass should be entering the cylinder. More fuel & air means more power.

The only way I see to take advantage of any cooling effect from DI is to increase the compression ratio of the engine (or increase boost pressure) past were you would get knock without the cooling, and use the cooling effect to reduce peak cylinder pressure to under the threshold for knock. Still, there is less time for the cooling to happen, especially at high rpm, so I'm not sure hof effective that would be. In the Ford test of the DI 3.5 Ecoboost referenced in the video, I think most of the power gain was probably from octane number increase of E85 compared to E10, rather than charge cooling. I could be wrong, though.
 

TMSBOSS

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Dave

I follow Engine Masters also. Shouldn’t we all? LOL. They recently did a test between port injection and carb systems. The carb made more power. Temp sensors showed cooler air fuel charge entering the combustion chamber. Like you said, it takes time for the fuel to evaporate and cool the charge.
I am seriously considering E85. Several stations in my area have it at the pumps. Higher octane, cooler temps and cheaper gas are hard to ignore.
 

Boone

Professional Thread Killer
Since I set my car up as Flex Fuel, I'm giving away tons of power by running only 9.5:1 compression. For a "purpose built" E85 motor, I would have run 11:1 compression ratio with boost. With an 11:1 CR, I could see 800whp at under 20psi. NA motors can easily run 13:1 CR with E85, and that's where the advantage lies.
 
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I recently came across this question myself, as the tuner I may go with said he will only tune a road race car if it's on E-85 or race gas.

The issue for my application was he said I needed to install a different fuel pump as well as injectors if I wanted to run E-85 safely. Roughly ~$1,400 in parts, so figure about $2000 if I had a shop do the work. From there, my next issue was the nearest E-85 station is roughly a 40 minute round trip for me. Compared to race gas averaging $12 gal, the initial extra cost of going E-85 would take 34 track days to pay for itself. Not to mention the extra annoyance of spending 40+ minutes to get the E-85, lug around the carrying containers, etc. Meanwhile, race gas is readily available at all of the tracks I go to. My car isn't powerful enough to need the cooling benefit from the E-85.

I'm sure some day I will convert the car to E-85, but for now the extra initial cost to get the car setup for it and the recurring annoyance of having to deal with getting the fuel ahead of time is a no go for me.
 
I recently came across this question myself, as the tuner I may go with said he will only tune a road race car if it's on E-85 or race gas.

The issue for my application was he said I needed to install a different fuel pump as well as injectors if I wanted to run E-85 safely. Roughly ~$1,400 in parts, so figure about $2000 if I had a shop do the work. From there, my next issue was the nearest E-85 station is roughly a 40 minute round trip for me. Compared to race gas averaging $12 gal, the initial extra cost of going E-85 would take 34 track days to pay for itself. Not to mention the extra annoyance of spending 40+ minutes to get the E-85, lug around the carrying containers, etc. Meanwhile, race gas is readily available at all of the tracks I go to. My car isn't powerful enough to need the cooling benefit from the E-85.

I'm sure some day I will convert the car to E-85, but for now the extra initial cost to get the car setup for it and the recurring annoyance of having to deal with getting the fuel ahead of time is a no go for me.
My tuner has a fair bit of experience with E85 and did not require a fuel pump upgrade but I'm not sure what you have to start with. I also would not do E85 if I had to carry it in a bunch of jugs. I will have a 54 gallon drum in the trailer that I take to my closest flex fuel station about 30 min away and fill up. Since I mix race E85 with pump flex fuel that allows me to not only have the 54 gallons mixed and ready but I also mix a few jugs so I probably have almost 70 gallons at the track when I get there.
 
1,041
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I recently came across this question myself, as the tuner I may go with said he will only tune a road race car if it's on E-85 or race gas.

The issue for my application was he said I needed to install a different fuel pump as well as injectors if I wanted to run E-85 safely. Roughly ~$1,400 in parts, so figure about $2000 if I had a shop do the work. From there, my next issue was the nearest E-85 station is roughly a 40 minute round trip for me. Compared to race gas averaging $12 gal, the initial extra cost of going E-85 would take 34 track days to pay for itself. Not to mention the extra annoyance of spending 40+ minutes to get the E-85, lug around the carrying containers, etc. Meanwhile, race gas is readily available at all of the tracks I go to. My car isn't powerful enough to need the cooling benefit from the E-85.

I'm sure some day I will convert the car to E-85, but for now the extra initial cost to get the car setup for it and the recurring annoyance of having to deal with getting the fuel ahead of time is a no go for me.
The only thing I changed on my E85 tune was the injectors. I have 2 gas stations within 10 min of my house with E85 and one 5 min from where I work.
 
The only thing I changed on my E85 tune was the injectors. I have 2 gas stations within 10 min of my house with E85 and one 5 min from where I work.
Same thing here.. i've been on E85 exclusively since 2012. Yea i did replace my O2 sensors a couple times and a set of injectors and my valves are not the prettiest when you do a bore scope but for stock Gen 1 pistons and rods with boss heads (thats 11.5:1 since they have slightly more CC than Boss pistons) they are holding up well!!! thank you e85 for no detonation even on the hottest days.
 

Fabman

Dances with Racecars
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Same thing here.. i've been on E85 exclusively since 2012. Yea i did replace my O2 sensors a couple times and a set of injectors and my valves are not the prettiest when you do a bore scope but for stock Gen 1 pistons and rods with boss heads (thats 11.5:1 since they have slightly more CC than Boss pistons) they are holding up well!!! thank you e85 for no detonation even on the hottest days.
And at half the cost of racing gas….It’s a no brainer in my book
 

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