Hello I want to run e85 on my 09 cobalt ss. Does anyone know what I would need to get to do it. And how much extra power I would gain

 

A tune is required. Power gains vary but around 20-40whp depending on how aggressive the tune is and what other mods you have.

I see you're in California, not 100% sure if you'll pass CARB if you tune the ECU

 

Do you have any mods currently?
if your stock you can pretty much just tune for it. But if you have gone bigger turbo you may need some fuel support mods.

 

I was under the impression you'd need a larger fuel lobe to run higher fuel pressure? Only reason I've stayed away is cause of that lol.

 

It really depends on how far you want to push the stock turbo if the larger lobe is needed. You can run lower boost and e85, but if you want to run 22-24psi and you're near sea level you need the extra fuel from the lobe. I was a fan of running e47, but it does require a little math and at least something to follow fuel trims to be sure your mix is close.

 

Ecaulk pretty much nailed it.
e47 would be a great option for best of both worlds and not needing the cam