E85 on RS2: 22% more torque, 10% more power

[EspenW]

Finally got around to do some power and torque measurements of my RS2 running on E85 (E75 actually, winter mixture with more gasoline).

When I got my RS2, it had a Turbonetics E50 turbo, MTM based software by Norwegian I5 guru Jonus, Milltek 3" catback.
In order to run on E85, I installed 630cc injectors by Siemens Deka and a Bosch 044 pump fed by 14.5V (relays and fat gauge wire). Adjustable fuel pressure regulator and and Innovate LC-1 wideband to dial in AFR. Otherwise bone stock ADU engine.

As always, I used the MR Dyno for my measurements. As a baseline, a stock RS2 (that boosts 1.5bar) lays down approx. 250hp and 340Nm in 2nd gear on this testing equipment. Tuned S6 Plus (326hp stock) lays down 255hp/300Nm, chipped 1.8T lays down 159hp/251Nm at the wheels (BSR claims 196/322Nm at flywheel on this one)

My former best result in 2nd gear on 99 octane was approx 335hp and 400Nm at the wheels.
On the E85, it produced no less than 375hp and 492Nm.
Midrange kick is pretty substantial, it now pulls 0.80G peak in 2nd gear. On 99 octane, it has pulled a best of 0.66G. Stock RS2 pulls approx. 0.52G, while the tuned S6+ pulled 0.39G.
Only tuning changes that I have done so far for E85 is to adjust AFR for approx. 12:1 to redline. MBT is very similar for gasoline and E85, but E85 tolerates more timing. I need to sort out a flatspot that occurs right before the turbo starts to spool.

I also made a pull in 3rd gear and got 390hp/507Nm at the wheels. Had to let off the gas for a split sec, so there is a hole in the torque peak, so the real peak is probably approx. 520Nm. Higher gear means more power/torque due to lower inertia losses and earlier boost.

Note: all power/torque numbers are power at the wheels. Power at flywheel approx 25% higher (if assuming 20% drivetrain loss)

Graph #1 shows power on E85 vs 99 octane
Graph # 2 shows torque on E85 vs. 99 octane
Graph # 3 shows power vs standard RS2
Graph #4 shows torque vs standard RS2
Graph # 5 shows torque in 2nd gear vs. 3rd gear

[Rusty]

Much sweetness

[k.alle]

Excellent numbers, shows the power of E85

[EspenW]

Excellent numbers, shows the power of E85

No doubt, and even better: by running on biofuel, the RS2 pulls not only petrol head birds, but hot tree hugging environmentalist birds as well :mischeif:
The small solar panel battery trickle charger seals the deal

[Keeper of The Kitten]

Lol well this is interesting - do you know how much fuel is consumed for this power output?

I see a local filling station selling E85 cheaper than normal unleaded

[k.alle]

No doubt, and even better: by running on biofuel, the RS2 pulls not only petrol head birds, but hot tree hugging environmentalist birds as well :mischeif:
The small solar panel battery trickle charger seals the deal

LOL you're so right about that
I think you're on to something, get cracking

Lol well this is interesting - do you know how much fuel is consumed for this power output?

I see a local filling station selling E85 cheaper than normal unleaded

The fuel consumption is generally ~35% higher than with gasoline.

It sure does come cheaper, but you'll still have to take the price x 1.35 to make up for the higher consumption.
However, it's usually very cheap for 104octane fuel!

Approx 0.8€ per Litre here in Sweden, compared to 98 octane gasoline ~1.1-1.2€ per Litre.

[EspenW]

Octane rating for E85 is approx 104, but effective octane is 115+ due to the extreme cooling effect. E85 at 20 deg C cools as efficiently as petrol at approx -50deg C.
Right now petrol is pretty cheap, so running E85 is somewhat more expensive, due to 30-40% higher consumption, but the power gains are sort of worth it, I think

[S2central.net]

Nice data there Espen... If I understand correctly, all you have done is manually adjusted the fuelling to give good AFR on the Jonus chipset you have.

I guess that has more aggressive timing than stock which the E85 is able to withstand without concern. Are you running the same chips when doing the 99RON tests and have similar AFR on both setups ?

Just trying to understand if the gains come purely from E85 fuel or whether there are additional fuel/timing tweaks on the E85 setup which help. With your claim of such a high effective octane rating then I can see how good the fuel is alone. Mighty stuff alright...

[S2central.net]

LOL - Googling for any stations in Ireland that sell E85 I found this great article --->

http://puregreencars.com/Green-Cars-News/Ethanol/Bioethanol-E85-from-Cheesemaking-Leftovers.html

Who knew that cheese could be so useful

[EspenW]

Nice data there Espen... If I understand correctly, all you have done is manually adjusted the fuelling to give good AFR on the Jonus chipset you have.

I guess that has more aggressive timing than stock which the E85 is able to withstand without concern. Are you running the same chips when doing the 99RON tests and have similar AFR on both setups ?

Just trying to understand if the gains come purely from E85 fuel or whether there are additional fuel/timing tweaks on the E85 setup which help. With your claim of such a high effective octane rating then I can see how good the fuel is alone. Mighty stuff alright...

The Jonus chips are designed for 1.8bar boost on the Turbonetics E50. Supposed to run 5bar fuel pressure on stock RS2 injectors. However, even on petrol, I found that AFR would go to 15:1+ under boost at 5 bar, so something was off..

The 630cc injectors and 044 pump allow me to maintain 12:1 all the way to redline with 4.1bar fuel pressure, so it is very close to perfect in regards to stock fuel pressure. In theory, a global change of 30-40% fuel flow is all that is required for E85, even though some have seen that custom fuel mapping has its benefits on E85.
E85 will allow more aggressive timing, so a bespoke chip would be optimal, but I need to be able to run petrol too. I simply lower fuel pressure to 2bar to run on petrol.
Power gains come from a combination of oxygenation (the fuel carries oxygen) and extreme cooling effect (sort of like NOS). The cooling effect has the most effect at peak torque, where in chamber temps are at their peak. The fact that the Motronic don't register any knock activity no doubt helps as well, as more timing than optimal is pulled when knock is detected.
The increase in torque is simply mind blowing. I could feel it was super fast, but seeing the G values was a real eye opener.

[Rocco]

very good numbers but aniway... WTF it´s "E85"

[EspenW]

very good numbers but aniway... WTF it´s "E85"

E85 is ethanol and petrol in a 85/15 mix (15% petrol)
AKA bioethanol. Good for the environment (lower CO2 emissions) and VERY good for turbocharged engines:mischeif:

[Rocco]

E85 is ethanol and petrol in a 85/15 mix (15% petrol)
AKA bioethanol. Good for the environment (lower CO2 emissions) and VERY good for turbocharged engines:mischeif:

thank you for eplain it bioethanol 85% + 15% petrol 98 of course hehehe

and i think that E85 it´s not nothing bad or dangerous for our turbocharged engines true??

[EspenW]

thank you for eplain it bioethanol 85% + 15% petrol 98 of course hehehe

and i think that E85 it´s not nothing bad or dangerous for our turbocharged engines true??

The petrol content of E85 is 95 octane or lower, but the octane of the E85 mix is 104+. Effective octane (due to cooling) is 115+
No harm on turbo engine, the opposite is in fact true. Exhaust gas temp is lowered by approx. 100degC, exhaust volume is increased, so the turbo spools faster. Peak cylinder pressure is lower (means less stress on engine internals). (peak pressure is lower, but the burn lasts longer, so the average cylinder pressure is higher, thus the higher torque and power numbers)

[S2central.net]

Whilst I love the extra oomf that appears to come from this E85 jungle juice... Isn't kinda weird that its touted as a 'green' fuel - just cos of lower CO2 emissions I guess - havent the tree huggers noticed that MPG is reduced by ~30% ? So isn't the average car running this stuff, actually producing more CO2 as a result ?

And have the tree huggers worked out how many square miles of biomass would be needed to supply the worlds automotive fuel requirements with E85 ? The numbers just don't add up... Aint it curious that its essentially a subsided form of G-force increasing, grin inducing, upgrade for any potential turbo engine owner. Enjoy it while you can

Another question - seeing as I can't buy E85 here - could I pour a bottle of Vodka into the tank, hoik up the fuel pressure and go have some fun ?