E85 - anyone thought about cutting over to it?

[rgvlee]

As the title says, anyone looked into running it on their gti?

Looked like someone on vwvortex has done it. Injectors, fuel pump etc etc.

We're starting to get a few suppliers of it over here now and some of the gains being talked about have piqued my interest.

[noone]

As E85 is a lower octane, you need to push a lot more of it.
From memory, bigger fuel pump, bigger injectors, custom tune, can't really swap back if you cant get E85.

[ozynigma]

As E85 is a lower octane, you need to push a lot more of it.
From memory, bigger fuel pump, bigger injectors, custom tune, can't really swap back if you cant get E85.

No, you are only half right, ethanol is higher octane but lower specific energy. So yes you have to run about 40% more fuel volume if you were running E85 uncut.

You will only get gains from an ethanol blend if your ECU is tuned to take advantage of it or is designed to be flex fuel.

I am currently in the process of getting my CX7 with the Mazda 2.3 MZR DISI motor tuned to run an E30 blend. I will be happy to share results in a few weeks. The Mazda is limited in fuel flow volume by the stock injectors with no aftermarket high flow alternatives. Therefore anything over E50 will run into injector headroom issues. The sweet spot for these motors is around E25-E30 where significant gains in hp can be made through increasing timing and boost.

[brad]

E85 is a higher octane, about 105RON (so you're less likely to have timing pull, etc) and can tune a lot more power but with a lower calorific value (it has less energy) so you need to pump a lot more through (about 30% more).

Ethanol has a lot of other advantages over petrol too. eg:
It burns cleaner;
cooler intake charge;
higher resistance to detonation as the self-ignition temp is 200 deg F higher.

There are some disadvantages - corrosive to some metals, sometimes forms a weird gum-like substance for no reason, etc

I have run E85 in my 1.8tsi and it gives it a real lift (and uses about 40% more fuel) but not knowing if the injectors are maxing out too early I just use the lower rev ranges & take advantage of the extra torque. I get a feeling that VW 02 sensors might not like ethanol too much as it takes a while for my economy to return to normal afterwards & it appears to be an 02 issue.

I think you might be able to swap the tune back if you had a multi-map style tune provider (eg: APR does multiple maps selected through the CC button or you could use a bluefin handheld unit I guess.

A mate of mine does a lot of tuning work on Subarus using E85 and gets some amazing results.

[noone]

Sorry, was a little drunk, misinformation is bad. thanks for correcting.

[brad]

HAve a few more. Info will improve or at least be more entertaining.

[rgvlee]

A new tune was part of the etc bit in my OP. I've seen guys doing the fuel lines as well.

I guess my real question for the polo guys and probably someone like Gavin is there any point doing e85 on the stock gti turbo?

[h100vw]

A new tune was part of the etc bit in my OP. I've seen guys doing the fuel lines as well.

I guess my real question for the polo guys and probably someone like Gavin is there any point doing e85 on the stock gti turbo?

Truly don't see the point, the cost of converting would be outweighed by the ease of doing a bigger turbo for me.

Gavin

[kaanage]

Por que no los dos

[rgvlee]

Bigger turbo would realistically require engine out, beef up rods etc, as opposed to injectors, fuel lines, fuel pump and tune. I'd doubt they are on the same page cost wise.