Yep drew's high pressure fuel rail blew under 2800 psi rail pressure. Ryro's car starved for fuel either because his in tank pump could not keep up or his HPFP could not handle the flow/pressure requirement in the midrange due to exceeding the torque capability of the HPFP. (he threw a low rail pressure code about 10 days after I tuned him on E-47) The car ran great when I was data logging it. It was running 22-26* of timing and running consistant 4.5 second 60-100 times.

 

Sorry for the newb question, but does lowering peak timing and generally being slightly less agressive while on the blend change the demands on the fuel system or does WOT demand the same no matter what your commanding in the tune?

 

From what Matt M said this morning, bringing in the boost slower vs having the instant spike will help with E Tunes.

So are you going to try Matt's advice and ramp the boost a bit slower to see if it helps?

 

Less timing indirectly effects the fuel demands since you'll be making a little less power. But, that is probably rather minor. An aggressive tune with high timing gives you less margin of error. Knock is very bad for an engine at WOT.

The real reason is that ethanol has a lower energy density than gasoline. This means that it takes more ethanol to produce the same amount of power as with gasoline. Because it burns cooler, compression can be raised or the timing can be bumped up to bring the power levels up. The more ethanol you use, then more you need higher fuel pressure and bigger injectors. Running lean is also very bad.

Wasn't Drewbroo running a 50-50 mix (E47)? This is another reason why I plan on staying down at the E30-E35 range. My main interest is bumping up the octane of my fuel.

 

Isn't e85 a little denser and thicker than pump gas and race gas?

I realize the rail failed below 2800psi, but that rail was built to handle 2800psi of pump gas, not 2800psi on ethanol. I would imagine that is the reason it went.

Didn't some researcher test this little lnf on e85? Wasn't there an article on that? Did they use the standard injectors or different ones?

I think without new pumps and injectors we might be sol and these problems might be an eventuality.



That is why i bring up race gas.

Sure it's expensive but why not do it?


BYT - did you ever try a TC out with 100% meth and say a 5-7gph nozzle?

How would that do in comparison?


I'm debating between the three right now lol, with 50% failure rate of this E47 stuff, even a meth kit looks like a more wise idea!

 

I have not, we ran a 75% 5gph nozzle on one car but never dyno'd it.

I ran 100 octane in my own car and then fine tuned for it, the difference was honestly VERY minimal. Nothing like adding Meth or E. Those make a much more substantial difference.

 

Okay, so ramping up the boost instead of it all hitting at once will help with the fuel system faliures we've seen. Im willing to give it a try for a bit until I get the BNR Stage 1 on the car and then Id want to see what we can do with it on 93.

Nick, I have a raised fuel pressure underlay file already from Vince that he sent when he thought I already had the bigger turbo. We can use it to tune for E but Id have to stay on the HPT side of things the whole time since the TF side is tuned for the larger turbo. I believe Vince is in Hawaii on vacation or something so theres no contacting him about it anytime soon lol

 

Did you buy a TF tune for the BNR turbo or a underlay file? With all of the underlay files, there is nothing tuned from TF. If you load that underlay file, it will change the boost and the fueling and thats it, its not a tune.

Load that, fill up the car with a 1:1 ratio and then drive it a lil to get it mixing.

 

I THINK E85 is blended with lower grade gasoline as well. Either way it will be a fun experiment since its my friends car and we can switch it back if we dont get the results we are looking for.

 

Oh, Im talking about the hybrid tune we are using now. Obviously Im confusing what an underlay file is lol Vince thought I had the BNR already so the first file he sent was with raised FP and he had modified his side of things to accomodate the larger turbo. Then we corrected that and he sent us a version with the stock FP and WG. With the TF side being GMS1 and is the file thats loaded now.

So, we CANT use the other file in which he has raised the FP? I thought I could just load that one up and then have you tune for the E blend with HPT and Id just stay on the tune the whole time and not switch to the TF side since Im still on the stock turbo.

Sorry for the thread jack

Continue with the E blend talk

 

An underlay file just has settings set then all of the tune is done with HPT.

A TF tune is obviously a tune file for whatever setup.


Either can have the dual modes and all that jazz. The difference is an underlay just has options set so we can better tune with HPT. A tune tune isn't what we can use to do the combo tune. So if you got a file originally to do a combo tune, then it's right. The BNR portion doesn't matter other then the fuel pressure is raised for it, which we want for this setup anyway.

So this will work fine. Don't change anything, and fill up with a 1:1 mix of E and 93. Then drive for 20-30mins watching the logger. The LT's will start to drift positive, when they hit +15, start a new log and do the usual method I sent minus any WOT pulls. Should have it pretty set by the end of the night if you can go do a couple logs quick

 

Yes, that is correct. Still, E85 averages around 105 octane.

 

Talked with BYT and got the details. Call/txt me.

 

Yea, we're straight now and Stamina knows what's up now too!

 

You have to keep in mind that that is the motor octane. The research octane is much higher due to alcohol fuels being rated in a different way. Now of course E30 wont have as big of a difference between motor octane and research octane because there is less E content but it will still be a little higher. Like I said it will be a fun experiment since he doesnt want to blend at the pump

 

LOL Okay

FYI none of this can happen until after work which is seven tonight my time.

 

Actually thinking about it I think the E is still based off R+M/2 so its motor rating is lower than the octane it is advertised at so batboy you may be right. The cooling benefits and change in stoich should help though. I appologize, as I am multitasking at work and quickly typing all this lol

 

That's fine. I'll be out flying this evening anyway, so I can just meet you after that.

 

That's fine with me too. It will take a bit of driving around to get it blended and registering right. Just keep the logger running and wait for +15% or until it plateau's just before that, if thats the case.

We had Tglems' E blend tune pretty dialed in by 2 flashed lol. Comes along quick. So as long as you can keep going out driving tonight, Ill keep updating

 

Sounds good. Thats totally doable. Never thought I'd be THIS excited about using cornjuice in my engine

 

When you see what 13* vs 23+ * feels like, you will see this was the right choice for your car!

 

According to wikipedia:

E85 has an octane rating higher than that of regular gasoline's typical rating of 87, or premium gasoline's 91-93. This allows it to be used in higher compression engines which tend to produce more power per unit of displacement than their gasoline counterparts. The Renewable Fuels Foundation states in its Changes in Gasoline IV manual, "There is no requirement to post octane on an E85 dispenser. If a retailer chooses to post octane, they should be aware that the often cited 105 octane is incorrect. This number was derived by using ethanol’s blending octane value in gasoline. This is not the proper way to calculate the octane of E85. Ethanol’s true octane value should be used to calculate E85’s octane value. This results in an octane range of 94-96 (R+M)/2.

This is was their source:

http://ethanolrfa.3cdn.net/dd9e74ce1..._rbm6bdgh3.pdf

Looks like I have some reading to do.

 

The more I research about ethanol octane, the more confused I get. Apparently the 105-109 octane numbers that are usually quoted are RON numbers. Motor octane ratings are usually a lot lower. What you see at the pump (road octane rating) is an average of RON and motor (R+M/2).

Answers.com:

Pure (200 proof) Ethanol (non-denatured) will typically have a RON value of between 109 and 112 Octane. It will also have a typical MON value of between 89 and 92 Octane. Using the Road Octane Number (R+M)/2 and the average RON and MON ratings this equates to a value of around (110.5+90.5)/2 = 100.5 for what would be published at the pump on the yellow sticker provided that you could actually buy 200 proof at the pump. However you cannot do this.

Since Fuel Grade Ethanol is denatured, and the source of the denaturant varies from natural gasoline (pentanes, hexanes, and heptanes) to commercial grade gasoline, this is even slightly more variability in the Octane Value of "denatured ethanol). Although the aforementioned 100.5 value should be a reasonable target answer.

The source for these measurements are test measurements run in accordance with ASTM D2699 and D2700 (RON and MOn respectively).

The actual "Octane Number" boost you will get by adding ethanol to a fuel will vary substantially depending on what the base fuel was made of. High concentrations of parrafins such as iso-octane (2,2,4 tri-methyl pentane) will dramatically increase the boost effect.

Some literature points out that Ethanol may actually have an even higher added "combustion enhancing" effect due to the latent heat of vaporization differences when you consider ethanol.

 

You have to look at more than octane. E85 burns at around 12,000BTU while gasoline is around 20,000BTU. It also takes more fuel to run E85 (9.7 stoich compared to gasolines 14.7) so between those 2 factors it drops cylinder temps drastically and allows for a lot more timing and reliable power. Sure race gas may be 116 octane but I know which fuel I would rather run

 

Right, even if the octane was perfectly equal, ethanol burns at cooler temps would definitely allow more timing (or higher compression or more boost).