Pump & meth vs. E85

[turbotalon1g]

Thank you for the FEW helpful posts.
Again, I don't care about your area, you can figure it out. I also don't care about your opinions of gas stations.
Let's try and keep a tech thread going fellas.

[Kracka]

How do the E85 cars using lean-burn come off a steady cruise and into a gentle roll-on of the power? I was never happy with how my car came off lean-burn when I tried it with pump gas. The car also seemed to hesitate/stutter a bit and also seemed more prone to knock (probably from the additional heat in the combustion chamber).

[Swifty1638]

^I'd say that's more-so an issue with tuning and you size of injectors. E-85 has been great to me so far. I like that all I need to do is gas and go. How available is meth, as opposed to e-85?

[scheides]

I think its obvious, I chose pump/meth. :D The decision was very personal and I've come to learn that different setups just make sense for different people. For me, I really really wanted E85 and gave it a try, but as soon as I switched, I found out that two stations I had been planning on getting it from that were along my normal route to/from work were no longer carrying it. The only station in my hometown (Fergus Falls) is on the far end of town, the station near my house is 5 miles past it. Quickly I found getting fuel for my ride to be a PITA. I didn't care, I was happy with it. Eventually the PITA won out, I was constantly driving extra just to fill up or filling up early so I wouldn't run out of fuel, and that just made the mileage penalty worse.

I was flabberghasted by this, Jim (TalonEvo) on here makes me so jealous, he's run the stuff forever and thinks nothing of it. Well, I've come to learn that he has no less than 8 stations that carry E85 on his daily commute, so running it long term is almost a no-brainer for him, because it's 'everywhere.'

It was easy easy easy for me to try it. I had 1050cc injectors, enough fuel pump, a wideband, accurate boost measurement, etc. I could make all the changes myself and it cost me nothing. Some may argue that it cost me a headgasket but I'm not entirely sure about that to be honest.

Anyways, I LOVE the added power meth offers over straight pump, but ultimately E85 WILL MAKE MORE POWER, MORE RELIABLY. I made what I would say are ideal numbers on my setup earlier this summer, but on the street I just wasn't able to run the timing required for that last 12whp and 2° of timing that separated me from timing numbers on a comparable car. This after doubling the amount of meth/water I was spraying (950cc now) was a bit of a hard pill for me to swallow, but eventually I have come to accept it.

So, 80% of the power/torque advantage of E85 over pump gas but you get to keep the pump gas mileage. Even trade in my eyes.

Anyways, my $.02. Shane has great info on this, hopefully he can share his insight :)

[4g63tcrazy]

E85 is not only cheaper than pump gas, but if you run meth you have to pay for pump plus meth. E85 is by far MUCH cheaper and it's amazing for tuning aggressively to give you optimal performance out of your setup. Even if the blend changes it's never big enough to have to worry about. If you tune your car on E85 with lets say a 12.5 a/f at wot. With E70 it will just make you run richer. Lets just say around 12.1 or so a/f. (More safe) For closed loop cruising the ecu can just take car of that just like any factory car would do since the ethonal content in pump is not always the same. I don't think the inconsistancy of E85 is enough to think about switching back to pump. Also the loss in gas mileage IMO isnt enough to switch either. You got E85 for 1.90 (give or take) a gal. Then you got premium pump gas for 2.60 (give or take) a gal. And on top of that METH.

That's just my opinion. :)

[Swifty1638]

I will add on my post:

I was running before 111 gas. Straight up, 24/7. I had a tune back on my old scm61 for both pump at 20ish psi, and 111 for 26-28 psi. The car felt night and day different on these two gases, and fun was just too much for 111 to NOT run it all the time. Came with a price tag of 4.99/gal too. I didn't care. I drove from my house(maplegrove) out to bobby and steve's in fridley once a week to get the stuff, and put $70 of gas in my car to drive (was my only car too). Then, I re-tuned it again on 111 with the old 6776s, and drove it on that as well. Last year, I realized that 111 was now $7 and was just too much to run on a car that I considered a DD for summer. So, especially after moving to savage, 111 was much harder to get, and I switched to E-85. I've been running it since then. I have a station down here off 18, and am still working on finding more stations, but it's nice to have that corn gas at less cost then before. I also am a person who want's all the power, all the time. I don't like switching maps, and driving around with half a setup. If I put something together, then I want everything I can get outta it. when I was on 111/26-28 psi, car made 371db/509MAP. Now, on E-85, costing me LESS, and boost now able to run up to 36-40 psi, car made 533db/62xMAP. More boost, more power, less money per gallon...no brainer here! I plan on tuning with e-85 once again on the new setup next spring. Car runs cooler too!

[Kracka]

^I'd say that's more-so an issue with tuning and you size of injectors.
Not at all, same thing with stock and aftermarket injectors. Its actually very common on pump-gas Evos using lean-burn which is why so many people quit using it after trying it (and the fact it barely helps fuel mileage).

[desolate]

E85 for power

cons - tad longer cold starts, fuel tank empties faster, injector tar/gunk build up, need bigger injectors

but

For power, totally worth it. Literally almost any wot timing advance you choose. No knock when pump gas knocked at ~22psi+

[Goat Blower]

The real trick to liking E85 would be using a GM ethanol sensor and having your ECU compensate for it, basically tuning to run a given A/F ratio all the time, like pretty much any newer Tahoe out there. That would make it perfect.

[Swifty1638]

My wideband is wired into my EMS to monitor. Shane set up the tables for it, so it works just the same.