E85 ratio

[Noz]

Hi guys I've searched but can't find much.

What ratio do you guys put in the fuel tank please?

I cant find much in Google either to be fair.

What kind of blend are you looking for ideally.

[Mike2JZ]

Depends. 

From ethanol pumps in Europe I've seen a blend of about 70-80%, even though it's advertised as e85. I have seen similar ratio's from VP & Renegade e85 fuels. It probably is closer to 85% in the real world, but very hard to have a completely drained tank with no petrol content before you add your E85 to the mix. If e85 isn't enough then you can purchase E98/E100 blends from race fuel companies, or just use pure ethanol but be wary of the lack of lubrication as this can destroy fuel systems. 

That said, typically by the time you at E60-E70 you are getting the vast majority of gains from ethanol (det resistance, cooling effect etc). You will continue to increase these with more ethanol % but the gains are smaller compared to the first 70%, so unless you are running something pretty extreme it's not always needed to run more than E70 from what I've seen. On pump E85, running more than E70 doesn't always mean that you will make more power. 

So a target of E60/E70 will cover you for most applications whilst getting the most benefits from the fuel. 

Another deciding factor of how much % you can run is the fuel system.

As E% increases the required fuel to be injected increases quite dramatically, so you will need to factor in things like bigger injectors, multiple high flow pumps, bigger fuel lines etc depending on what you are trying to achieve with your setup. 

I've had to limit the amount of boost a Supra can run on a few occasions whilst using E85 due to the fuel system not being up to the task. So owners in that situation need to be careful on what sort of blend they are running as its very easy to lean out if you are using a blend that the fuel system cannot support. 

This is just a rough guide, so take with a pinch of salt, but I've found that:

Mixtures up to E10, require little to no modification of fuel system/map. You get some added det resistance and cooler running, but not advisable to run the engine any more aggressively that normal petrol map. 

Mixtures E10-20 require changes to fuel mapping but you can probably get away with on a "normal" pump fuel system assuming you aren't already running it on the limit. More cooling and det resistance, so you can squeeze 1-2more psi and maybe 1-2 degrees more timing than normal fairly safely. 

Mixtures E30 and beyond will require large changes to fuel system and a dedicated ethanol/flex tune. Depending on how much % you are running, then you can keep increasing timing/boost. If you have enough E%, then you can keep tuning until you find MBT, even under high boost with not much danger of det. 

On a supra with 1000cc injectors with a 450 walbro pump. I've seen fuel systems max out at around 600whp using a blend of around E30-E50. 

Also worth noting that a lot of racing e85 fuels will contain a mix of race fuel that is oxygenated in the 15% that isn't ethanol, hence why you can normally make more power using a race e85 fuel compared to pump e85. 

Finally. It really pays off to have a flex E85 capable ecu and fuel system. Rather than worrying about ratio's too much, just stick whatever you have in there and let the ECU decide how much power to give you that has been deemed safe & acceptable whilst it was tuned. 

 

[Noz]

Great reply Mike, thanks for taking the time to go over it.

I'm shocked at the 1000cc 600whp. Bet the dyno curve looks great though. Also surprised the 450 wax maxed.

I suppose knowing ratio's I'm putting in the tank just means I'm consistent.

Have you ever used a water/meth setup with E85 as well?

Does E85 ever impact the o rings around the injectors at all. As never seen anyone say they aren't usually upto the job.

[Mike2JZ]

22 minutes ago, Noz said:

Great reply Mike, thanks for taking the time to go over it.

I'm shocked at the 1000cc 600whp. Bet the dyno curve looks great though. Also surprised the 450 wax maxed.

I suppose knowing ratio's I'm putting in the tank just means I'm consistent.

Have you ever used a water/meth setup with E85 as well?

Does E85 ever impact the o rings around the injectors at all. As never seen anyone say they aren't usually upto the job.

There are ways to make 1000cc injector do a bit more than 600whp, but its never as good as just uprating the fuel system. But yes the power delivery and curve is far superior to 600whp on pump fuel, cleaner power with more area under the curve, just quoting the peak power doesn't do it justice. 

Take results with a slight pinch of salt, but I've found this calculator accurate within 100hp. HP Calculator (fuelinjectorclinic.com)

I done a bit of tuning on my own car with water meth whilst doing e85 and didn't really notice anything worthwhile. Using just ethanol I was already able to max out my power output safely, so spraying meth on top didn't really achieve anything other than it being yet another variable that needed adjusting and integrating into the map (aka ballache). I'm sure there will be a setup out there where having both e85 and meth is useful, but I couldn't find it on my setup. 

I went from having a fairly large nozzle pre TB to now using the smallest one possible. In addition I T'd a new line that runs to pre turbo and uses a very small jet that sprays a fine mist of meth straight onto compressor. Using this setup I no longer am injecting enough water/meth to require any changes to my fuel map, but it's enough meth that it reduces turbo compressor outlet temperatures by 10-20C, and drop IAT's pre TB by 5-10C. So I went from using meth as a power adder, to now just using it as an aid to help bring temperatures down so I can keep beating the shit out of car for a bit longer. 

They make E85 specific o-rings for injectors that you can purchase. We normally install them if car runs primarily on E85 , if you use E85 once in a blue moon then normal rubber o-rings are fine. 9/10 times they aren't an issue. 

 

 

Edited January 16, 2021 by Mike2JZ (see edit history)

[Luxluc]

The E85 I get from the pump is generally between 75-82 % ethanol

 

In winter, it is less than 70%

Edited January 16, 2021 by Luxluc (see edit history)

[Samurai 20V]

Hi Mike,

 

In these percentages mix of petrol to ethanol, what octane is the petrol? 95 or 98?

With lower octane, I guess more eth to meet the tuning guide you listed above?

 

Thanks.

 

 

[Mike2JZ]

Yo. 

Personally I'd always try to run the highest octane fuel available in the mix.  I haven't done any testing myself between 95 vs 98 mixed with ethanol, so can't comment to what degree the change in petrol octane would have on how much extra E% you would need to retain a higher octane level. It might not make any difference. From my experience running E85 direct from the pumps that has an unknown blend of petrol in it, I would assume that the octane rating of the petrol is not significant. 

I'd assume E85 from the pumps will be mixed with cheap petrol, it won't be high octane as goal of said fuel isn't all performance on modified cars, it's a cheaper/greener fuel alternative, used quite a bit for agricultural vehicles.

Cheers

[Samurai 20V]

Thanks Mike

[Luxluc]

E85 from the pump is generally ethanol + 95 octan