I'm looking into buying a GSR which is converted to run on e85. The car has stock internals and is N/A. Car has been tuned on e85.
It has Aem fuel rail, Aem fuel pressure regulator and upgraded injectors.

My question is: How difficult would it be to get it back on regular unleaded, and would i mess up the engine/tune by doing so?

 

i can't think of a single reason why someone would convert to e85 on a stock car. i suspect the car has been turbo at some point.

but to answer your question, you could put a chip that has been flashed with a stock map if you put stock injectors back in. fuel pressure put back to stock pressures, if changed.

or you can get it tuned for whatever injectors are in the car.

 

I don't think it was ever boosted.
stock internals with the upgraded injectors and regulator. Car is properly tuned for e85 currently.

 

Yes but that makes no sense what's so ever to do that. Must be a newbie. It's like driving a stock car on race gas. Where's the purpose expect to spend more money. No gains out of that

 

Thanks guys.
This helps

 

Sure there are, there's always gains when using E85. No it's not going to be large gains, but over pump gas there are cooling properties, oxygenated properties, etc. That car probably picked up a lot of mid range, and I can imagine the timing is set to be as aggressive as possible.

 

Running E85 on a stock engine wont have much of an impact unless its tuned to optimize the fuel. Even still, a stock GSR really wont benefit from e85 compared to a solid tune on 92-93oct. When you consider the costs to upgrade the fuel system for e85, its certainly not a worthwhile upgrade on a stock b series. The previous owner would have been better off with a set of cams and tune on pump gas, but who knows what the rest of the setup was...could have been boosted, who knows