What fuels/mixes do you run and for what reasons?

My time with race gas was mostly high octane unleaded VP fuel mixed with pump 93.

I also would run VP racing maddative unleaded octane booster at full mix amount with non race gas. However I found it would turn my spark plugs an autumn gold red color so I stopped using it.

All in all I had to drift away from the unleaded race gas due to difficulty to utilize on the street, difficulty of obtainability, and price.

I have never really been fond of e85 through the years. I dislike the MPG and the fact that you have to dump twice as much fuel in to have the same bang as normal gas all just for the reason of cold IAT so that you can pretend the octane is higher and it’s the reason you make more hp despite you turning the timing up through the roof. It’s lack of availability everywhere. The cost alone of redoing my entire fuel system again to send double as much fuel and installing a e85 % sensor in the gas tank with a computer that’s properly tuned to pull and add timing based on the e85 % due to it being different % every time you go to the pump. Last the simple fact e85 attracts water like a magnet!

What and how do you use your fuels?

 

I designed my system from the beginning to be E85 compatible (all aluminum lines and appropriate fittings - less than $100 complete) and it didn't cost any more than if I planned to run gas but at the time I had no intention to switch to E85. My goal was 91 oct/meth inj but I planned ahead. Now my car is set up as a flex fuel car so I can run whatever is handy at the time of need.

Yes, the computer uses a flex fuel sensor and automatically switches and blends the two different fueling tables based on the alcohol content. Now I have no worries about what fuel to use and where I'm at in the city. This is a great thing certainly nothing to complain about.

I agree that E85 can be a PITA to get for some but if it's easily available it may be worth it for some people.

Why do you have an issue with timing on E85? Timing is simply a number. The timing is set to where the car makes the most HP and makes it safely. My car made 950hp @ 14*...so what.

E85 around here ranges from $1.89/gal to $2.50/gal and we have two gas stations in town that carry it...

I think your hate of E85 is clouding your judgement of the benefit of what E85 can bring to the table to a high HP car. There are technical/chemical advantages that E85 has over race gas that give it a huge advantage. The below is a snippet from a conversation I had with an engineer about E85 when I started to use it.

******
Three metrics are important, one is critical temperature, the second is critical pressure, and the third is Autoignition Temperature. When you take a combustible to its critical temperature and pressure, it is capable of autoignition. The critical points and autoignition temperature for E85:

Critical Temperature:
Ethanol — 465.4˚ F

Critical Pressure:
Ethanol — 62.5 BAR

Autoignition Temp:
Ethanol — 685˚ F

E-85 is a country mile beyond any gasoline mix you can buy anywhere today.

When attempting to pick compression ratios and boost levels, you want to stay below about a 45:1 operating compression ratio. You do the calculation as follows;

Compression ratio x boost (measured in BAR)= operating compression ratio

For example, 11:1 compression with 30lbs of boost. 30 lbs of boost is actually 30 PSIG + ambient. That comes to 45.7 psi. 45.7/14.5 gives us 3.15 BAR. 3.15 BAR x 11.1:1 compression gives us 34.98 or an operating compression ratio of 35:1.

With an ethanol critical pressure of 62.5 BAR, we are way safe. Where is the line you don't want to cross? For ethanol, you are plenty safe (properly fueled) up to 44 or 45 BAR operating compression ratio.
*****


ks

 

@KEVINS
work that has to be done, fuel availability, cost, MPG, change

I don’t hate on e85 or have a problem with it or any real complaints. It’s just I feel like they are using ethanol addition as a substitute for watering down your gasoline based on profit margin (if you know about water injection it will make sense to you).

 

When gasoline goes up E-blends are a bargain. You will have to calculate your MPG change and see where the cross over is, but "E85" is often 2/3rds the price of 91 octane and that's an easy choice for my combinations.

Pump E85 here is 50% pretty much year round, and I have a station that sells it close by. I built the 78 to take it, including a larger fuel tank, stainless lines and rated components, fuel pump and injectors big enough to hit the goals on up to 75% ethanol. Ford infers rather than using a sensor, so I do get a little rough run on first start when it's figuring out the E blend. But on that engine even NA it makes more power than 91, and I only see a minor range reduction. If I stop somewhere that doesn't have it I just put in pump gas and don't worry about it. When I put the turbos on I am planning boost control, I will just turn the boost down so I can run regular gas.

Part of the benefit with E85 is the ability to run more optimized timing without a fear of detonation. When I had my Raptor it would pull timing at cruise on pump 91, running hard off road it would really tank the timing, especially on hot days. When I switched to E-blend it would run all the timing all the time and I saw less than 10% fuel economy difference in that piggy. E made a ton of sense, more performance, very minimal range reduction and with 36 gallons I didn't care. Off road weekends I would stick 20 gallons in the bed and blend it when I topped off since the remote stations often only carried 85 or 87 octane.

The Mustang is more difficult, E85 is a much better deal with the blower. But that car has a 15 gallon fuel tank, and I notice a much larger difference in range with it. It does not infer alcohol, so I have to change the tune to change the fuel, so if I am somewhere without my laptop and have to put in standard gasoline it runs rich until I can swap the tune. It has enough fuel table self-correction not to be dangerous, but I am also careful not to get into boost. The car will run fine on 91, and when fuel prices are down I just run 91 all the time. If I blend I just estimate the stoic and then dial it in with a log. The safety of E is worth it and I don't road trip the car that often. It also passes emissions a lot easier on E-50. When I do the "mid service life" restoration on that car I will figure out how to fit a larger tank and up my line sizes.

I am a big fan, if you have the fuel capacity and can use the fuel within a few months of fill up I think it's a great deal. When you talk about forced induction it is an absolute bargain.

 

I already know all about injection. I started using "injection" systems on my Grand National 18 years ago then moved towards injection on my Mustang. I switched to E85 b/c the distribution was getting awful with more power.

I also had a really negative attitude towards E85 which is why I stayed with injection for so long. But the desire to make more power, and do it SAFELY, meant I had to stop looking at what I didn't like about E85 and start looking at what it gave me. In the long run I realized how much I didn't understand the benefits of how safe it was to make BIG HP with such an inexpensive fuel and the high HP game drove me to switch.

Are there disadvantages to E85? YEP!
But they don't outweigh the advantages it's giving me.

My Tundra actually gets 2MPG better gas mileage in town with E85 than with 91 octane. I could not believe it but my guess is that the timing tables are changed to make better power with E85.

ks

 

I buy E85 or E98, often by the drum here as there's a local distributor that'll drop a drum
off at my door for no extra cost. And if they're out (They're a small company) I have a station
that sells E85 at the pump about 30 minutes from me so I'll just take a drum up there and fill it myself.

Its cheaper than race gas is by far and most of the time its cheaper than 92 premium(The highest we have here).
Its 105 octane for E85, or 120 octane for E98. And I can blend it down to whatever I like.

It makes more power than 92 even without adding timing, and because of the higher octane I can add a bunch of timing.

With a cheap flex fuel sensor I can auto tune my car to any level of ethanol I want without doing anything more than just pouring it in the tank. If I can't get it, fill up with 92 and no futzing with the tune.

I built the fuel systems on the vehicles I run it in to go E85 right from the beginning, so other than the flex fuel sensor there were no additional costs. Retrofitting obviously will add some.

I used to run Sunoco GT260(100 octane unleaded) but I make more power on E85. And GT260 is up to something like $17 a gallon.... Hard to stomach when your car only gets like 10MPG on a good day

 

Just to notate. I have no problem with e85. IMO e85 will always make more power that normal gas due to its ability to cool the combustion. E85 will always allow more timing due to its greater difficulty to create predetonation from higher octane and cooling factor. When you calculate how much e85 is needed to make one pull compared to regular fuel due to the volume of e85 needed it’s costs pretty much the same as regular gas. Either way we are all here for power not to complain and cry about costs.

 

“We’re all just here looking for the spice”

 

I think you mean pre-igntion. There is no pre detonation. It detonates or doesnt.

 

I was trying to just put the word detonation but people always tell me I don’t use the word correctly so I put predetonation haha but I still couldn’t escape the mouse trap haha. Thank you for your correction.

 

I run only the finest Speedway E85 available. I use about 25% more fuel than I did 93, so no issues there, but make a ton more power safely. Holley automatically adjusts the a/f to the target, so I don't worry about the percentage.

 

How do you prevent the aluminum lines that then go from/to the body to/from the fuel from cracking?

 

Don't mount them solid near the connections. Route/bend them so they are allowed to flex over a long distance. Aluminum is very forgiving when used and mounted correctly.

Spiral wrap the tubing with rubber fuel line wherever it may rub against the frame, etc. I only have 3 clamps on the fuel line that runs approx 18ft from the tank to the regulator to the fuel rails..

ks