Toddiesel

I just traded my 2016 stingray for a 2016 Z06 and the first thing I want to do is a flexfuel conversion. Heard a lot about how much more power you can squeeze out of a boosted car running E85. I've been doing research and I'm coming across some info saying you need bigger injectors and a beefier fuel pump due to the fact that you have to use a lot more ethanol than gas to get the same efficiency. Having said that, I've also seen info where things like the DSX bolt on flexfuel conversion kit will allow the ECM to adjust as needed and makes it sound like no additional upgrades (aside from a tune) is required. I've looked around the forum (and the googles) and haven't found any definitive answers, especially as it applies to the C7 Z06, and am wondering if anyone has done the flexfuel conversion and if you had to do any other mods (aside from tune)? If not, how much extra power do you get with just a tune? I'm planning on adding a CAI and probably a lower pulley as well, but I'm more focused on what the flexfuel conversion can do and what it requires right now. Any info would be appreciated!

TOPSPOT

Subscribed. I am wondering the same thing for just an E85 conversion. I am under the assumption that if you don't do secondary port injection, you will need a low side fuel pump, and a cam with 32%-38% fuel lobe, and you can run full E85 with stock injectors. Also under the assumption that you can run a Meth setup to get E85 as well?

Aftermarket injectors are mad expensive.

0Billy@MTI

You need a meth kit

TOPSPOT

What are the ways that you can do full e85 without Meth?

Toddiesel

Can you elaborate on that a little? What entails a meth kit and what does it accomplish? Were you directing that at me, or TOPSPOT?

Toddiesel

Billy really raised more questions than he answered, but according to the website, you don't need a meth kit to run full E85 (though E85 is only roughly 85% ethanol, so I'm not sure if you meant E85 or straight ethanol when you use the term "full") using the flexfuel conversion kit from DSX. It just doesn't tell you any of the stuff I asked in my original post. https://dsxtuning.com/collections/fl...7-corvette-z06

musclesbmf

Let me try to help clear up some questions...
On the LS motors, adding larger injectors would take care of your fuel needs on a basic modded car. Obviously on high HP builds, larger fuel pump and better fuel system may be required. On the LT platform, injectors at this point really aren't an option cause I'm only aware of one upgrade that is very costly and only provides an additional 10% more fuel (I think). Also on the LT platform there are 2 fuel pumps. An in tank and one that is up under the intake that is driven by the camshaft (I'm sure many other people can share a lot more details than I can). Many guys replace the cam with one that has a larger fuel lobe and I think get about 38% more fuel. Again that is a costly upgrade but yo also get the benefit of more power from the cam. So how do guys get the additional fuel needed so they can run full E85? Methanol Injection. E85 burns 30% more fuel than gas. So in order to suply the extra fuel demands guys use meth injection. I think many guys have had success running between 30% and 50% E85 mixed with gas without using meth. All the small particulars come down to your tuner and how safe they make the tune as to not over tax the fuel system and potentially damage the motor.

Hope that helps,
Mark

Toddiesel

Thanks Mark! OK, so what I'm taking from your statement is that you DO need more than just the flexfuel kit. You either need larger injectors/beefier fuel pumps (which sounds like is not an option), a costly cam upgrade, or to include methanol in your fuel supply. Now, I'm not a chemist, but if I recall from basic chemistry class (and an episode of House MD with LL Cool J guest starring), I'm given to understand that methanol and ethanol neutralize each other. Is that correct? I'm still a little unclear as far as what the best way to make a flexfuel conversion work and still have no idea what kind of gains I'd be getting. It seems like a pretty complicated subject :-(

TOPSPOT

So I get what he is saying and that is basically the assumptions I have had all along. The fuel pump upgrades are definitely possible. Supposedly with the low side, it is permanent? But to get full E85, you have to supplement the additional fuel required so that you don't over tax the fuel system as stated.

The DSX Flex Fuel will not allow you to run full E85 by itself.

Toddiesel

Not trying to be difficult, and maybe they're lying, but straight from the site:
"Use these kits to add the ability to run anywhere from straight gasoline to straight ethanol as well as reveal the true power potential of your setup."

Straight ethanol would be E100, so according to that, you should be able to run E85 no problem. This is part of the confusion for me. Seems to be a lot of opposing ideas out there. I don't know if it exists, but I'm looking for a concrete, clearly defined guideline on what you need to run on E85 (not pure ethanol as I will always get my fuel from a filling station).

For example (and I'm straight making this up just for demonstration):

In order to take full advantage of E85, in addition to a flexfuel kit, you will need XYZ cam, Hp tuners tune, and ABC methanol kit which includes DEF parts, in order to be able to get in the area of XX hp on YY lbs of boost.

From what I can tell, you can run on E85 with the flexfuel conversion alone, but it won't do anything as far as performance gains without a minimum of a tune, but I'm trying to find out what additionally is needed to see real gains and what combinations there are. Maybe I can get ~40hp on just the kit and a tune, but I can get ~75hp on the kit, a tune, and a cam and maybe ~150hp on the kit, a tune, a cam, and a meth kit. I have no better understanding now than when I first posed the question (well, maybe SLIGHTLY better after Mark's response, but I'm still foggy).

Higgs Boson

this is all information that is posted but I will summarize.

a flex fuel sensor (kit) allows a non-flex fuel enabled vehicle to sense and take advantage of ethanol with a proper tune. this is completely separate from having a robust enough fuel system to keep from running out of capacity to support the level of airflow going through the engine.

on a stock Z06 the fuel system will support E85. the more you modify/increase airflow levels the less ethanol you will be able to run in the mixture. by the time you have pullies and intakes and headers, etc you will only be able to run E30-E40 before your fuel system taps out and you need to upgrade it.

Toddiesel

Ok, that's far more helpful! HB you're always on point with your posts! So let's say all I do is the flexfuel and a tune. Would I be fine with E85? If so, ROUGHLY (not holding any feet to the fire) what kind of gains are we looking at? Bonus question, if I'd still be fine with that setup, could I get away with a CAI?

Higgs Boson

you're better off doing an intake, flex sensor, tune and running E40.

E40 will give you 95% of the gains of E85 and not push your fuel system to its limits.

i never quote hp gains for mods though.

Toddiesel

Fair enough. Only problem is I have no idea where to get E40 (unless i buy a CD from the early 90s! ). But seriously, do I just try to do half a tank of E85 and half a tank of gasoline?

Higgs Boson

basically. it doesn't have to be exact. the flex fuel sensor and tune will take care of the calculations needed for anything from E0 to E100 but the tune is typically set up for E10 to E85. So if you get E30 or E50 it will be fine. Then you run it low and fill up on E10 for the week and it adjusts fuel and spark automatically.

Toddiesel

Well that works for me. I'm getting it dynoed in the morning for a baseline, so I'll go ahead and order a flexfuel hit and CAI and then do a dyno tune and post the results so people know the difference.

Pacembellum

But could you do this on a spare ECU and swap back to stock? asking for a friend that wants to keep his powertrain warranty.

Toddiesel

You can just save a stock tune and flash back to the stock tune before you take it to the dealership. I did that on my mustang.

Warp Factor

No, you can't. The C7 ECM keeps a record of every time a change or flash is made.

Higgs, when you put some gasoline in, and then some E-85 (or the reverse order), how long does it take the two to mix evenly? Presumably, whatever goes in first will go into the driver side tank (where the engine supply fuel pump is) until that side is full, and then the rest goes into the passenger side tank. The "jet pump" in the passenger side tank, which is always pushing fuel to the driver side tank will eventually mix the two pretty evenly, but how long does this take, and might the proportions be pretty far off right after a fillup?

Toddiesel

Seriously??? Wow that sucks!!




Wait... are you saying there are 2 fuel tanks? Are we driving big rigs here?? Naw, but seriously, that's a thing??? How does that even work?