Hello, I am currently looking into taking my Stock Evo 8 and modding it for E85. Heres what I know....1000cc Injectors...Upgraded fuel pump(Walboro 255,400, or double pumper), ECU flash and tune, and Fuel lines. What I want to know is if I do these mods can I use E85 on the weekends and 93 durring the Week or do I need to have 2 different MAPs.....or ccan i alternate whenever. I also want to know If E85 can be mixed with 93 octane I THINK(cant recall) i heard about a Local Evo that mixed his gas 50/50 with E85 and 93. Would like to know forsure before I do this and go from 15mpg to 10mpg LOL thanks guys

 

Ok lets straighten you up some. You don't need new lines for e85, and you would use 2 different maps. You can switch on the fly with the gas pedal with tephra mods im sure. The 50/50 mix between e85 and 93 is just stupid being all gas is different and if you tune for x amount who is to say the gas will be the same every time after that. If your gonna run one run e85 primarly and then use 93 when e85 isn't available, and or to clean out the injectors once a month.

 

So your saying I can Run E85 as my main gas but If i wanted too fill up ith some 93...switch my MAP...and be good to go even if theres a small amount of E85 still in the tank? that sounds about Right...I guess ill have to get this Tephyr mod and a new laptop then

 

tephra mods*

 

Well trust me when you run e85 you will not want to run pump again hahaha. Tephra is I guess the best way to explain it is the shell of what your ecu will run. It basically is what all the tuners will use to make it easier for them, and add things that will help the tunes after they start to tune the car. It really isn't a mod its just the format they use to hack the stock ecu and to allow you to make changes. My main map is actually pump gas, but Tom was right once I started running e85 well as you can see the #s speak for themselves.

 

How do you get this Tephra software or whatever it is? I wanted to send my ECU out to either Bushur Racing or AMS to get it reflashed...is that the same thing or completely different? LOL I came from the DSM world and the thing to use then was Speed density and DSMLink....I know about EvoScan already and Plan to get it as soon as I get a laptop and more info would be greatly apprechiated

 

This all you need to know. Talk to Tom, I am sure he prob seen this thread but tell him I sent you he will do the rest. He is prob one of the best tuners on the site. He will get you all squared away.

http://www.tscomptuned.net/

 

switching once a week would be a pita to really enjoy E85

 

Thats why I said once a month to clean out the black crap it puts in the injectors.

 

Switching back to 93 once a month would be a good idea in general like cursedsm says as a precaution, but manditory if you have poor E85 or just get that goo on the injectors for whatever reason. That would be something you'll need to check once running it. So it does take a bit of watching, but well worth it! I've been running E85 100% of the time now for about 4 months and the injectors are still clean and the AFRs are still spot on. I've seen others post running a year or more and still clean. I guess it really depends on the E85 you get.

On a stock 8 you'll probably just need a pump, injectors, Tephra V7 and a tune - email Tom.

 

great info guys thanks!

 

SWitching back and forth every week; your fuel trims would be all over the place.

 

If your car was fully tuned for the 2 types of gas, your trims wouldn't matter. Your ecu doesn't go off of fuel trims it goes by afr. Trims don't mean anything.

 

Trims tell you how much your ecu make up to hit your afr. Have you tried running with ltft and stft trims 15% off or higher
You will not hit any of your 2 tunes unless you completely drain your tank every time you switch fuel.

 

I run both fuels regularly without any issues and you see the kind #'s I make. If your tuner sets up the car proprly and has your injectors scaled correctly, then doesn't matter the trims being the car will adjust reguardless. If I ran e85 for a while and switched to pump gas and my trims origionally were tuned to within 3% of dead nuts, the car will adjust to that being that is what it is tuned for. The car will have to adjust for the 33.3% of fuel that it was getting into and will run the trims in the rich side till they adjust. Once they adjust for pump gas off the tune you were given, the car will not care.