moving to E85

LR6GSR · Post by **LR6GSR** » Tue Sep 30, 2008 4:03 pm

Interesting results i remember when it first came out at Morrisons Dave at Emerlad did a back to back dyno test.
I think he found 10% or so gain with no remap just the fuel swap on his 944 turbo
One thing he mentioned to me was how it could potentially eat away the fuel system internals. He said the tank looked like it had been acid stripped when the emptied it.
I guess depends on each car as to how the lines and pump would cope long term.

Liam

duncan · Post by **duncan** » Tue Sep 30, 2008 4:19 pm

Guys in the states having been running pure E85 (if that isnt a contradiction of terms in itself) on subarus since 2004 and I am yet to hear of one having an issue. I think there was a global change around 2000 in composition of materials to allow for ethanol content.

LR6GSR · Post by **LR6GSR** » Tue Sep 30, 2008 4:49 pm

Dunc it figures after a certain date cars are a better spec Dave's 944 is no spring chicken if you now what i mean.

I note you use more fuel what do you think the MPG are as a comparison?

Liam

duncan · Post by **duncan** » Tue Sep 30, 2008 4:54 pm

mpg...

:whistle:

No idea in fairness - less though :thumb:

duncan · Post by **duncan** » Tue Sep 30, 2008 7:11 pm

Code: Select all

Fuel                      AFRst     FARst     Equivalence   Lambda 
----                      -----     -----       Ratio       ----- 
=======================--==================================== 

Gasoline   stoich          14.7    0.068       1           1 
Gasoline Max power rich    12.5    0.08        1.176       0.8503 
Gasoline Max power lean    13.23   0.0755      1.111       0.900 

=======================--==================================== 

E85 stoich                 9.765    0.10235    1          1 
E85 Max power rich         6.975    0.1434     1.40       0.7143 
E85 Max power lean         8.4687   0.118      1.153      0.8673

For reference

duncan · Post by **duncan** » Sat Nov 08, 2008 3:03 pm

The 20% E85 mix gave the following results on Zen's dyno a couple of weeks ago:

It seemed that the 490 bhp map was a little octane limited at the top end and the extra provided by the E85 meant it would keep more timing in. I doubt whether the E85 provided 55bhp power advantage on its own.

Having had a chance to look at MPG on the 20% mix it has not altered much to be fair, still getting on average 23 mpg with a mixture of driving and 26-70 on mostly motorway.

Now moving to a slightly stronger mix 8)

ScoobieWRX · Post by **ScoobieWRX** » Sat Nov 08, 2008 4:37 pm

Duncan,
Were you running mid 12's AFR at high load on just 99RON and no additives? If so what AFR's at load are you running on a 5% and 10% mix.

Curious to know as i will be visiting my local E85 stockist in Wellingborough next week for 20ltrs of their finest to start looking at the possibilities of permanently running 5% or 10% mix. Any ideas what the Octane rating will be at those % mixes?

I know in the USA you can buy pre-mixed 93 Octane (98RON) pump gas with varying % mix of E85. Shame they didn't do that here.

duncan · Post by **duncan** » Sat Nov 08, 2008 5:38 pm

Francis - I dont run in the 12's AFR wise apart from part throttle. Peak torque I am at about 0.78 lambda.

Ignore the octane - the burn characteristics are different - you will be surprised how different.

I didnt bother with a 5% or 10% mix on the E85 in the end - just went straight to a 20% but I would think that a 10% mix would net some noticeable improvements if you took it to a dyno.

10% mix is easy though - 5litres bio 45 litres Vpower.

ScoobieWRX · Post by **ScoobieWRX** » Sat Nov 08, 2008 6:24 pm

I have a 60ltr tank so 6ltrs for me. Don't think i'm ready to run 20% but 10% in daily use would be good i think and as you've said, should net some reasonable results.

So you're running c.11.46 AFR at peak torque on 99RON only. I'm not too far off that myself

Looking forward to doing some logging. :thumb:

duncan · Post by **duncan** » Sat Nov 08, 2008 6:38 pm

5 litre can (+ 45 litres vpower) is best bet as you wont want to fill it up from absolutely empty each time :thumb: