What I really wanted to title this is “ignorance is bliss — no WAY could ethanol possibly even a single HP over pump gas”. I was inspired to do this test by a very bold claim on a certain online forum — I’ll keep the names out of it, but it definitely gave me a chuckle.
There are so many faults with this bold claim — but the very first thing any reader should get out of it is that when someone posts something in absolutes like this you should take their statement with skepticism and simply do your own research.
Not a single hp.
Really? The one thing I’ve learned in the 12+ years of tuning ALL kinds of motors, is you simply can’t deal in absolutes. Something may make power that could be taken as “margin of error” for the type of dyno you’re on or just very negligible gains that will never be noticed in the “real world” (say like 2-3hp for example, but it really is relative to the platform, etc — this is a question best left for another discussion).
The irony here is the statement preemptively tries to attack the skills and credibility of anyone doing a pump gas to E85 (ethanol) tune. I can’t say if this is really just the ignorance of the author of the post or just a gigantic ego that blinds him to reality.
My response is simple — “Oh please”. Fortunately for us, there are a few of us that are quite capable at what we do and we have actual tools at our disposal to do quantifiable testing instead of listening to someone spew hearsay on the internet.
Now for the sake of transparency — our pump gas is 92 octane, not 93 octane. However — big deal — the gains from going to 92 octane to 93 octane on a motor that isn’t ignition limited on 92 octane will be minor or nonexistent (and ours wasn’t — I could roll past MBT on the ignition map and not get detonation, there was just no more power to be had — which is what the statement about 91 octane implies). Hey don’t take my word for it — try it yourself.
As for the argument of WHY would E85 have gains over pump gas? What the author of said post seems to miss is the properties of the fuel — it is naturally oxygenated and has much better cooling properties than pump gas (regardless if said pump gas is 91-93 octane). I’ve done hundreds upon hundreds of E85 tunes — N/A or F/I — and I have yet to see a motor that doesn’t gain SOMETHING over pump gas (see what I did there?).
OK enough with the bull shit — here’s the results and the actual FACTS.
The car is a 2015 Nissan 370Z, with bolt ons:
- Stillen Intakes
- G35 test pipes (modified to fit)
- Agency Power 2.5″ dual exhaust
VVEL and VTC had been previous tuned for this setup on pump gas, and were left alone for the E85 portion.
After the vehicle was filled up with E85 (tank took 16.5 gallons), fueling was tuned to maintain a proper air/fuel ratio without touching the timing map — the motor continued to run the same timing curve as it did on pump gas. Simply running E85 and maintaining proper fueling netted us 8whp. Wow, this is already certain more than Not A Single HP. And well above any kind of margin of error.
Next I adjusted the timing map to see if we could extract a bit more power — and 4whp was found. The amount of timing added was very negligible (could run this timing map on pump octane without seeing detonation — it however netted no gains on pump gas), and what we can gather from this is that due to the larger volume of fuel we are injecting with E85, we needed to ignite the mixture a minute amount of time sooner to get a complete burn of the mixture in the cylinder.
What does this look like overall? We picked up 12whp and as much as 12wtq through parts of the torque curve. Wow, that certainly looks like it’s a lot more than Not A Single HP. The best part about it all? This is free power — the stock fuel system supported E85 without upgrading anything — we ran stock injectors and the stock fuel pump. And to top it all off — fuel economy during freeway cruising was not impacted at all — if anything it was 1-2mpg better than what I was used to seeing on pump gas.
Really, what should be said about E85 gains on this motor is depending on the quality of your pump gas (because yes, even quality of 93 octane can vary), you may see between 2-4% gain in power with E85. You will also see it through out the whole power curve — more than can be said about the Stillen intakes I tested on this car, which had margin gains through a couple of spots of the power curve. Quite literally the dollar per HP gains from just running E85 (which is readily available at the pump by the shop) surpasses a $560 intake system.
There you have it — quantifiable results vs hearsay (or apparently I have some kind of secret to making power with E85).