e85 and my s2

[denniselbows]

hi all i have seen some of you on here have posted about e85 and the gains you have had. I have just seen today that some of my local morrisons petrol stations are listed as having it. Can i use it in my s2 or is it only for heavily tuned cars. As i only have rs2 air box rs2 maf wagner reverse im with the intercooler kit miltek down pipe back exhaust mrc high boost chips with a 2.5 bar map sensor. Your thoughts please

[Error404]

I think you'd need a switchable map at the minimum for it as it requires a much higher volume of fuel thatn petrol as far as I understand it, you might need bigger injectors too?

[speeding-g60]

30% more fuel is standard....

[GazzaG60]

not an expert but believe the gas law id slightly different. targets are like 9:1 instead (sure ill be corrected)

[Jamo]

Yeah Stoich is 15% richer around 9.7:1

[EspenW]

You need bigger injectors and possibly a bigger fuel pump.
Adjustable fuel pressure reglator and wideband lambda lets you tune in the correct AFR.
E85 has the effective octane (RON) of approx 116octane race gas, but the MON rating is lower. Thus, it is advised to run colder plugs. I currently run Bosch F3CS plugs gapped to 0.5.
Significant gains at the same boost pressure due to extreme colling effect. Exhaust gas runs approx 100 degrees colder and the sky high octane allows boost to be raised without detonation. Bigger exhaust volume makes the turbo spool 300-500rpm earlier.

[quattro84]

Yeah Stoich is 15% richer around 9.7:1

yup, 9,855:1 to be precise.

@EspenW: did you change to the colder plugs after seeing bad/worn sparkplugs?
i've never tried because i didn't notice any changes on the plugs.

[EspenW]

yup, 9,855:1 to be precise.

@EspenW: did you change to the colder plugs after seeing bad/worn sparkplugs?
i've never tried because i didn't notice any changes on the plugs.

No, changed to colder plugs after reading that it is recommended due to the "low" MON rating of E85.
Due to the clean burn of Ethanol, colder plugs won't foul up like they can on petrol.
Working on the gapping these days. Stock 0.6mm gap increases misfires around torque peak compared to 0.5mm gap, but I'm working on mixing in a little bit of petrol, since the alcohol content is very high now. I need to crank the fuel pressure way up compared to on winter blend. I ran 3.7 bar pressure on winter blend (E75) and everything was fine, but now on summer blend, even 5bar+ pressure can't get AFR under 13 at high rpm, and it gets too much fuel in the midrange, causing misfires around torque peak. I reach the same torque level, but then starts to misfire, so torque drops.
I will mix in some petro to make E75 and lower fuel pressure to around 4bar. Then the 0.6gap should work fine.

[caterpillar]

esbenW@ have you tryed som other coil/ ign?? it seems the fuel are wery rich, then you may need some power in to the spark??

[EspenW]

No, stock ADU ignition. Something like 034 high output coils would probably help, but I don't like the way they clutter up an otherwise close to stock looking RS2 engine compartment.
I will lower the fuel pressure and do some more power logs. Misfires are very easy to spot on the power/torque/G graphs.
Everything was super on E75, but I would like to avoid the hassle of mixing in an inferior fuel (petrol). A leaner AFR on E85 will probably still burn cooler than a richer AFR on E75. Not like extended periods of constant boost is common on the miserable roads in our country either..., so I'm not very worried about some elevated AFRs at high rpm on E85. In fact, it is a trend among the more experienced E85 fiddlers (EVO guys, etc) to tune for low 13's on E85 now.