I am considering converting to Flex Fuel and I am wondering if you need to increase the size of your fuel injectors. If so what size? I don't even know what size the stock are.
I have a basically stock 08, LS3, A6, Z06 exhaust, dyno tuned.
Also looking for recomendations on conversion kits. I understand DSX tuning is popular. Thoughts?

 

If your stock on the motor, stock injectors will fine. The e85 full will take about 30% more fuel through the ejectors than petrol, but will not increase the duty cycle on the ejectors higher than they can produce to start with.

So currently on petrol, fuel ejectors are running about 85% duty cycle at max, and E85 will only push that duty cycle up to about 90% instead.

As for on stock motor, really not worth it, since your going to be burning 30% more fuel even when cruising, and you do have all the head ache of the water in the E-85 fuel as well. Bottom line, Ls3 only needs a octane rating of 91 to run it best, and although E85 does have a Octane rating of about 120, it's a waste on a stock motor that does not need that high of a octane rating instead. Also, at most with a very, very aggressive tune in the Flex fuel tables, may gain a few HP (less than 10HP), but very few gas station pumps have true E85 rated fuel to begin with. So as the E level in the fuel is lower, this means more water in the E fuel that is going to cause more problems as well.

 

Unless you have a very specific reason for changing, why would you? I'm not trying to be a jerk, just asking. I'm curious.

 

im willing to bet somebody has told him some BS and he wants every ounce of power he can squeeze out of his car like most of us lol anyway I have heard like most of you its is NOT worth the cost on a basically stock LS anything even a FBO does NOT see enough of a gain to go E85 but there is always that one car that sees a decent improvement I saw this happen on a 5th gen that gained 35rwhp from the E85 and is just FBO the Tuner said it was a freak of Nature and still not sure why lol

 

Some guys have done it with their tuned Zr1 or Z06 but a stock ls3 will give you no gains

 

Funny this post came up today. The dude on "Gearz" this morning, was pitching an E85 conversion kit. Buyer beware!! Smoke 'em if you got 'em! Just not E85!

 

E85 conversion makes senses on a motor that needs higher octane levels to being with. As stated, stock LS3 only needs 91 octane to make all the power is can, so octane rated fuel at 120 will not make a differance on stock tune. Granted that with re-tune, may be able to get say 10hp at most, but that is with True E-85, and not the E70'ish that you going to get at most standard pumps isntead.

Then as stated, your going to be burning 30% more fuel, even with cruising with E-85, so just not worth it on a stock motor.

On the other hand, say you have a LS7 that you bumped compression and needs a octane of say close to 100, or pushing the boost pressure on a LS9 that now needs an octane rating of over 100, then now you need the higher octane rating of the pump E-85 to get the most power out of these motors isntead.

 

Thank for the info. I was under the impression it would give a stock LS3 a notable increase in horsepower. But it doesn't sound like it. I also did not know there is a problem with water but would like to know more about this if you care to elaborate.

 

Just an FYI. I ran E-85 for a while in my Pantera with 13.5;1 comp. loved it but hard to get if I traveled far from local area. Had custom dual tanks made (40 gallons) total and lined them to protect from moisture. dropped compression to 11;1 and went back to gas. Lost about 100 hp. Moral of this story is, if you don't have real high compression. You will not benefit from E-85. Its ok im still in the 11s @ 125 spinning my street tires thru second. Not bad for a car designed to turn corners.

 

Not to hi jack your thread..... I have a 2010 c6 base with a vaaaram cold air intake and I am going to be adding headers with cat deletes and I want to add e85 to avoid the smell.... I was looking at the dms kit, and I am just trying to confirm something...

if I run long tube headers, cold air intake and e85 conversion (with stock injectors and fuel pump) would I be good... I am not a weekend racer, I would like to wake it up a little and make some noise in the process. I only drive mine to meets and maybe once a month to work, it usually

sits in my garage so the lower fuel economy isn't a big deal to me. Also the dms kit says you basically install the kit and the fuel maps just unlock? Although Once everything is installed I will be taking it to a local tuner to get whatever horsepower I can pull out of it.

so again, I would do it to avoid the smell not to give me a massive increase in horsepower, although the long tube headers, cat delete and e85 would probably net me 35 extra horses give or take... any advice before I drop some $$ would be awesome, thanks

 

Tuner will need to turn on the Flex fuel table in the tune, then tune in the tables since they are already part of the ECM tables (just turned off now).

As for stink, High flow cats will rob you of about 3HP total to solve the unburnt fuel smell problem, and would money better spent over converting to E85 for the lower LS3 motor that is not really going to pick up any HP to speak of on the E85.

As for your list of upgrades, will pick up about 25hp with the long tube headers, the Cold air intake will not pick up any power, but just preserve hp instead of the engine drawing in hot air (lose HP as the motor has to retard spark for the hotter air).
As for tune, will pick up about another 15hp over that of the long tube headers. So between re-tune and long tuber headers, will pick up about 40hp, and the total 3HP you are going to lose via high flow cats to keep the car from stinking up the cabin every stop light (as well as the car behind you/down wind.

Again, E85 and it 30% more burn rate over petro, only makes sense when you bump the motor compression to the point than that motor needs the much higher octane rating to run correctly. Truth is, even a blower motor, still prefer to run a meth kit, instead of the conversion to E85.

The first reason, you are only going to use the meth mix when you get on the motor, so even a gallon of mix tends to last weeks without a reduction in fuel mile. The second reason, if all your running is E85, it really a crap shot if you are getting full e-85 or something lower. Again, flex fuel table will deal with the timing retard when the mix is less than e-85 so the motor runs correctly (although reduced power, since motor is pulling timing running on the less then E85 fuel, and would have less power out of the motor then if it was running 91 octane petro).

 

Hey Dano523
couldn't have said better. well done!

 

It is worth the smell alone if you are running straight exhaust.

 

If you don't mind, and since you really seem to your know S**t, how does e85 get to 120 octane?

 

Sunoco E85-R is only rated for 104 octane. I was wondering about the 120 myself. Maybe there are some moonshine stills pumping out some super ethanol

 

One very important thing to remember with making power. YOU NEED COMPESSION !!!. You will only receive the benefits of E-85 with high compression. upwards of 15;1.with out it, it is not worth the effort. Ethanol burns cool and slow so you receive both benefits. Adding more fuel to get the Air / Fuel ratio correct can be offset to some degree by producing more power. however you need Compression to receive this benefit. then timing, fuel pump and injectors ect.. ask yourself..would you run race fuel in your lawn mower? .Um??

 

Weights and measures, e85 octane rating is around 104... so I could see E90 or Sunoco E98 going upwards of the 110-115 octane? but really who cares?

I run the dms kit and alky meth sprayer with my supercharger, also the Fore triple pump with rails and ID1300 injectors... the smell of fresh started E in the morning is worth it alone... I do run no cats as well, so i'm happy for that benefit.

The meth does last, but if you drive, spirited, you are going to go through it... Anytime I hit 4PSI or more of boost, my meth sprays, even on E... so on pump, that would be draining my reservoir. I go through a gallon of meth in a week or two between fill ups.

E85 from sheetz here in western PA is about 75% ethanol rating (i have the innovate ECB-1 Gauge)...it's around $2.50 a gallon, i can get E90 at a pump, but it's almost $4 a gallon and I've been told that basically any ethanol over 50% is 'enough' for the benefits of ethanol and the additional Ethanol (or octane) is not worth it, however i cringe when i have to mix pump gas and see that E % drop.

Just my experience with it.