Bladed-vaults

Ok up front I have skimmed the e85 megathread and done some other searches here but have not quite found my answer yet (if its here i missed it).

Im making a long haul from colorado to louisiana this weekend.
my car has an e85 tune from rogue. Ive done the search along my route and while there are e85 stations there are two stretches where its over 400 miles between them and ill have no choice but to stop and put in 93 dino gas.
how long can i get away with a partial mix? ill be dropping the boost to 10psi and being nice the whole trip to try and squeeze every mpg I can from her.

Tom M'Guinn

You'll end up running rich. The higher the gas to ethanol content, the richer you will get -- possibly rich enough that the car will not run and/or foul plugs, etc. I sure wouldn't want to find out how it works out on the open road in the winter! Can you switch over to a pump gas map for the trip? And/or set up a few maps -- one for E85, one for gas, and one for a blend? That would give you a fighting chance out on the open road anyway...

Bladed-vaults

I have a gas tune on a switch but it runs like garbage always has. the city I lived in before i got stationed in LA had abundant e85 so I never had a reason to get the gas tune looked at. In hindsight that was a mistake but it cant be helped now.

the gas tune will run no pings or smoke and the wideband never shows anything extremely rich but it has a very rough idle

Bladed-vaults

I guess I should have elaborated a bit. Im trying to get around using it if I dont have to. it has a habit if dying at stop lights because of the idle issue

Rogue_Ant

It depends on how 'partial' the mix is, and how hard you drive.
If you keep rpms low, and boost low, then the closed-loop will have the ability to correct the fueling a bit.

Wha?
I personally installed the A-Tune, then M-Tune on that car, back when Geoff owned it. Even did many dyno runs with it, all on pump-gas. It was one of the best running K26/8 cars I've seen, with a little over 300rwhp to the wheels.

What happened to it after that, I don't know - but it used to run immaculate.

Bladed-vaults

Hey Josh thanks. And yeah tge e85 tune runs fantastic. The only problem I've ever had with the car was it needing a clutch.

But the first time I ever gave the gas tune a try it just struggled to stay alive ran e85 til gas light on then filled up with premium switched over, just didn't want to idle right. Under boost and right off idle it will do just fine though.

Rogue_Ant

If switching from E85 to gas, you might need to reset the idle, and probably also adjust the FQS switch to account for the variences of the fuels...

Since you will mostly be on the highway, then I would just fill with gas (when you must) then flip to the gas mapping. Then switch back to E85 when you get to a more available location.

Bladed-vaults

Alright sweet I'll leave this at that then, seeing as you know more than anyone on here about this car.

Thanks!