Hi everyone
so I got the flex fuel kit for my 2017 C7 GS. Haven’t installed it yet. So out here where I am, I can buy the E85 ethanol in bulk or in pales. Where I am. Nobody sells it at the pumps, but I have heard that apparently if you run that you need bigger injectors, and you need to change your fuel pump? Just wondering if that’s true or not? Also, has anybody run VP racing gas versus E85 ethanol and if so, which do you prefer? I was told the VP racing isn’t harsh on the engine as E85?

Now my car isn’t stock. It’s got ported intake port throttle body cold air induction, long tube headers off-road racing pipe with HP tune.

 

I'd call GM and see what they think of burning E85.

 

Boosted engines see the most benefits from running E. A stock engine can run E safely though.
Don't store your car long term with E in it. Run a tank of 93 now and then. That's pretty much what I do and never had an issue.
You will need a new tune.

 

I buy mine buy the drum to keep in the garage since there are no stations within 30 miles of me that sell it at the pump. Also nice knowing it's always consistent. It gets a little expensive this way though and you have to deal with storing and getting rid of the old drums. My car doesn't sit for too long at a time but if it is going to i'lll store it with a mostly 93 mix. I run One ethanol R.

 

I would assume that you know that you are going to need a tune to run full E85. I would consult your tuner to see if he thinks that this is achievable on the stock fuel pumps and injectors. I think that you may be okay to run full E85 at least on a stock lt1, but I am not sure. Add in your existing mods and I really couldn't tell you. Consult the tuner, they will have better information about this. Also, as was already mentioned, E will give much more gain to posted cars vs NA cars. I am in the process of doing a full E85 conversion and I now have SPI which gives me 16 injectors to supply all the fuel I need. You won't need close to this, but I am trying to push the power envelope. I also think that ethanol is relatively safe, but I would just not store it in the car for long periods of time without driving the car. So to answer your question, you may or may not need bigger injectors or a larger high side fuel pump/cam or bigger low side fuel pump. You can definitely run a mix of E and pump gas no matter what, but this begins to be a pain after a while.