Hi,

Just wondering if anyone has used E85 in their 996 Turbo using a box converter e.g. www.change2e85.com without changing fuel lines/pumps/injectors etc. I'm already running one on my Volvo but am a bit nervous about hooking one up to my Porsche.

 

Interesting! How does it work on your Volvo?

 

Works ok on my Volvo although you have to out up with a few turns of the engine to get it started in the cold (as I'm in the UK). There is also an adjustment pot inside the box to fine tune it. I have covered around 1500 mile so far without a problem.

 

Why not get an E85 tune?

 

I think he was more worried about the fuel pump, lines, filter, etc. Which I would be too. Could the stock pump even handle E85 (lph?). It looks to me it uses injector harnesses to increase (I would imagine) injector pulse length to compensate for the extra fueling and a E85 air/fuel sensor to monitor? Might be risky at WOT though.

 

You NEED a full E85 fueling set up... 6an lines, wallbro E85 pump etc, proper injectors yada yada

 

You'll need to increase fuel flow to run E85 properly. Despite having a higher octane rating, E85 has a lower overall energy density than pure pump fuel. Pure gasoline contains approximately 125,000 BTUs per gallon, while E85 contains approximately 84,000. This means that a greater volume of E85 must be utilized to realize the same energy content.

 

By far one of the best and most technical posts I've seen on this forum. lol

+Reputation points to you my friend

 

E85 seems to have THE most opposing opinions of any subject I've researched. There are many that say don't entertain it as it will eat your car and others that say it's the greatest and, that they have been using it on stock fuel lines etc. for years.

I myself have hoooked up a converter box to my 2004 Volvo V70 and have done 1500 miles. Some of my colleagues have run it on their stock fuel lines/pumps etc. for tens of thousands of miles without a problem. Although, I think it's still too scary just throw it in a Porsche.

 

What is the goal from running E85?

BTW, DSCOFF didn't go far enough. Not only is there less energy in a given amount of E85 than just straight up gasoline the stoichiometric mixture of ethanol is less than that of gasoline.

For air:gasoline it is 14.7:1 (by mass) and the gasoline represents about 6.8% the mixture by mass. For air:ethanol it is 9.1:1 (by mass) and the ethanol represents about 11% of the mixture by mass.

IOWs, not only does the engine have to burn more E85 than gasoline to generate the same heat energy the mixture it burns will have to contain more ethanol by mass to reach a stoichiometric mixture, so combustion is at its optimum.

In short, then running E85 requires loads more fuel and the fuel system must be capable of delivering that under all RPM/load conditions. At full chat a Turbo engine gulps the gasoline. Replace that gasoline with E85 and gulping doesn't begin to describe how fast fuel will be consumed.

Proper fueling is crucial to state the obvious. There is also convenience, which to me means the distance I can travel on a tank of fuel. On the highway being good but running maybe 75mph my Turbo can deliver around 26mpg (it could possibly do better but I'm not that "good") which gives me a cruising range of around 250 to 280 miles (with some reserve) before I have to fill up. Running E85 about all you can do is circle the gas station a few times.

There is the question of how well the converters will work with the engine burning E85 even if it is burning a stoichiometric mixture.

Last but not least turbo charged engines experience more blow by. This means the oil will get contaminated with whatever fuel you burn. The engine is designed, the oil selected, with at best just a 10% blend of ethanol with gasoline in mind. (And my info is refineries have not even been blending E10 to the 10% level, but stopping at around 7% to 8% ethanol.) What effect then does the running 85% ethanol have on the oil you choose to run? How well the oil can do its job carrying a load of ethanol? The change interval? How will this higher concentration of ethanol on the oil affect the seals?

Sure, there are E85 vehicles out there and as far as I know these issues have been resolved, but these vehicles were designed/manufactured with running E85 from the outset. This was not just a spur of the moment idea.

 

I am getting 14 mpg with E85

 

What are you running it in? Have you upgraded your fuel system?

 

I ran E85 on my 700HP Evolution 8 for thousands of miles with no ill effect. But due to be blow by effect of turbo cars a considerable amount of ethanol would mix with my oil thus "thinning it out" and reducing the viscosity of the oil; causing more frequent oil changes. I could actually smell the ethanol in the oil in addition to seeing a significant change in oil fluidity during oil changes. I never had an issue with my engine/turbo seals but a "pro" of using Ethanol was, that is cleaned out the majority or carbon deposit buildup on the engine internals.

Mario

 

Yes I have a fully upgraded fuel system on a 996 Turbo S

1. Injector Dyn ID1000s
2. 6an return lines
3. Wallbro 400 intank fuel pump (E85)
4. Eurodyne protune for E85 by Tim941NYC

I drove it this week in temps as low as 20F, starts and idles within a minute to perfection. I did go back to 93 octane for 2 fills then back to E85 as some people suggested here. Both my 93 and E85 tune work perfectly and take all of 3 minutes to switch over.

Also running mafless, 1 step colder plugs, 997 coils etc, AWE GT2 race exhaust and ETS Intercoolers.

Car pulls like a freight train even on stock K24s... much more power and I thrash my car so mpg is way down going from around 22 mpg on E20 to 14 mpg on E85.

You MUST have a tune for E85 as you will be pumping in 40% more E85 than 93 octane.. your tuner will adjust cold idle, warm idle, TIMING ad infinitum.

Note on 93 octane my IDC% does not get above 40%, but on E85 it is at 100% using the ID1000s, so when I upgrade turbos next year I will go to ID2000s.

On 997.1 cars I understand some guys have just added an EPL or COBB tune on the stock fuel system (it has 2 pumps)... as per prodigymb

 

I should add the cooling effect of the E85 on the 2 days I did 150 mph multiple pulls in ( mild heat)was very noticeable. I was doing consistent, one after the other (no cool down) 60-130 mph in 4th gear = 6.76-6.86 secs. IATs rose only 2-3* C