Any tuners try running E85

skaarlaj

.040 Over
Joined
Jul 22, 2018
Messages
58
Location
Rock Springs, Wyoming
Ride
2016 Rocket 3
I realize the lower performance motors will benefit less with high octane fuels, but these high compression kits like Carpenter, or boosted applications would probably scream if ran on E85. I would just imagine the timing advance you could get out of using it even on a stock R3 would be in the 10whp range. I'd bet a crisp 100 a carpenter bike would gain 25 if the fuel system was built to support the additional fuel needed and tuning was optimized.
 
I ran E85 in my turbo car back when it was just starting to come into the market in volume.

Since then, it’s been revealed that E85 from tank to tank can have a wildly varying ethanol content, enough to need a retune.

The only way to accurately run it using pump E85 is to have an ethanol content sensor, GM vehicles and most modern standalone systems have or can support a content sensor. The ECU then adapts to content and you can run it with no worry.

Alternatively for a race bike, just buy a 55gallon drum and tune to it.

The stock motor isn’t knock limited so there would be very little to gain using it.

One thing for sure: it’s take some quite large injectors to run a 265 kit bike on E85!! Something like 800cc should do the trick.

How much is to be gained? That is hard to say, I still run a significant amount of timing with my motor on 92, I’m not sure there’s much to be gained on timing alone. Maybe 10-15 hp, at best, but tank range would be absolutely horrid.

To maximize it, one would need to play with cam timing as well, closing up LSA and increasing dynamic compression to make more power and actually take advantage of the increased octane vs gasoline.
 
I ran E85 in my turbo car back when it was just starting to come into the market in volume.

Since then, it’s been revealed that E85 from tank to tank can have a wildly varying ethanol content, enough to need a retune.

The only way to accurately run it using pump E85 is to have an ethanol content sensor, GM vehicles and most modern standalone systems have or can support a content sensor. The ECU then adapts to content and you can run it with no worry.

Alternatively for a race bike, just buy a 55gallon drum and tune to it.

The stock motor isn’t knock limited so there would be very little to gain using it.

One thing for sure: it’s take some quite large injectors to run a 265 kit bike on E85!! Something like 800cc should do the trick.

How much is to be gained? That is hard to say, I still run a significant amount of timing with my motor on 92, I’m not sure there’s much to be gained on timing alone. Maybe 10-15 hp, at best, but tank range would be absolutely horrid.

To maximize it, one would need to play with cam timing as well, closing up LSA and increasing dynamic compression to make more power and actually take advantage of the increased octane vs gasoline.

I have a supercharged 2011 Mustang, and it runs fine with varying E content, from E65-E85, but those cars are blessed with factory wideband 02 sensors that'll take care of fueling adjustments of most Ethanol varients within reason. I run either a Gasoline tune for 91, or an E85 tune for pump E85. My Car (for example) on 10lbs, will only run about a 10.-8-10.9 on 91 octane, but will jump down to 10.5ish sometimes trapping 130 when swapping to E70 at the same boost. These Coyote 5.0's are octane / knock limited, especially on 91. I can't remember from my datalogs, but it seams like my knock sensors are less active on E70 with (4-5* more timing advance) than compared to 91 octane gasoline on the same boost with less advance. NA coyote Mustang guys get good benefits also, but this is an 11:1 motor, so Ethanol might not do much on these mild (when stock) engines.

But you're absolutely right about needing some sort of upgraded fuel flow, and less range out of your bike on a set amount of E85, compared to gasoline. My car now has an upgraded return style fuel system, and ID1000cc injectors to support the additional fueling needs.

So when increasing ignition timing on these Rockets you really don't experience much power gained, and doesn't really get into spark knock. Some motors definitely react differently to ignition timing changes. I would guess an 11:1 Carpenter bike would have great gains, and would totally benefit with ignition advance that might not be obtainable from pump gasoline?
 
Last edited:
The R3, even high comp, isn't terribly knock limited. You can advance it so far you have issues, as you can with any motor, but, reaching optimal timing isn't difficult. If you think about the missing timing, its nearly 4 full points of comp higher than stock and only a handful of degrees need be taken out. Dynamic CR stock is a little under 8:1, dynamic on my motor is right around 9:1.

I'm sure there's something be gained on a built motor, I simply don't think it'll be what force induced cars see. They have knock sensors etc that aggressively pull back timing after a single event to prevent further events, which is why they run so much better on E85, because they're heavily knock limited. On the R3 if you had a single knock event, you'd never know it, nor would the ECU, and it would just power right through dumb as a box of rocks, the nature of the stock ECU. Since it's so dumb, I've taken some measures, running the 7 range plugs, keeping it a little fat in AFRs (high 12s), and running MMT octane booster when tuning (the booster that actually works to shift full points, not fractions of a point).

To fully get the most bang out of E-85, you would need to adjust the build in the motor to need it, which would be a monster of a bike haha.

Below is a known map, that makes pretty much all the power the stock configuration has to offer:
Optimized Stock Timing.png


This is my map, which, I know doesn't knock on 92 octane and makes good smooth power:
My Timing.png
 
Gaining power on an R3 via fuels:
MR12 or Q16 from VP will get you extra power if tuned for it, a healthy amount, 4-6% or so.

Q16 is $20/gallon
MR12 is $30/gallon

They're very different fuels and both are leaded so don't go pouring it in a bike with cats :p
 
Good info Clavigar, what was the Turbo car you mentioned, and did you get pretty good gains with the Ethanol? I wasn't much of a believer until I ran it, and seen the time-slips
 
It was a fully built Neon coupe R/T with track pack (ACR) options. 2450lbs, 400whp, and cruised a 52mpg on the freeway :p

Most fun car I ever owned.
 
Back
Top