- Fast Intentions Twin Turbo Kit
- Fuel Return
- VitTuned MoTeC M150 ECU & Firmware
- 92 octane Pump Gas Fuel
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:
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).
It’s that time again — got my hands on a 2015 Nissan 370Z and the typical bolt ons we see on this platform for some tuning and parts testing! As always, I tune the car completely stock first to get a good “tuned” baseline, and then retune after every set of mods. This is a very fun platform to tune due to the very flexible VVEL system.
So what we will have on this test is:
The parts in question are the following:
So without further ado, here we go.
It was pleasant to see there was actually a fair bit of room to improve over the stock mapping on the ECU — especially with the refined ignition control available to us now. One of the nuances I was able to fix was the throttle closer on the top end and the delayed throttle opening on the low end the stock ECU exhibits — this opened up some good torque gains down low and helped smooth the power curve up top.
The VVEL system is also extremely tune-able, and I was able to net extra torque down low with adjustments to this system — however through the rest of the curve Nissan got it mostly right, not surprising since the vehicle is stock.
Not a whole lot to say about these results — clearly the exhaust modifications made power after we bolted them up to the car — but since our starting point was already a “tuned” calibration, very minor changes were necessary to extract peak gains from the parts and the fueling was still dead on since the stock intakes had been retained for this portion of the test. I expect this would not be the case if the car was still running a 100% factory tune on the ECU instead of my tuned calibration.
Depending on the intakes you chose to put on a vehicle tuned via MAF (aka AFM), you can skew the fueling dramatically — fortunately with the Stillen V3 long tube intakes I found that the mass air flow calibration was very close to the stock intakes and only required some minor adjustments to maintain proper fueling throughout the curve. However, even with perfect fueling, these intakes actually LOST power throughout the WHOLE power curve.
You might be thinking to yourself, “Whoa, what? They’re just filters on a stick….”. Indeed I was quite surprised as well.
That’s where the tuning begins — the engine required significant remapping of the VVEL system to not only return to the power the stock intakes were making, but also gain power over the stock intakes. After fully retuning the ECU, our results are some minor torque gains down low and through the mid range, and about 10-12hp on the top end.
My personal thoughts? Wow that was a lot of work for minor gains — but it does go to show how a naturally aspirated engine is a finely tuned machine with all the parts working “in harmony” with the ECU mapping to actually make power. Sometimes one small change can have drastic effects.
Well, with that out of the way, what do the gains look like over the “stock tuned” setup overall?
And what does it look like over a completely stock vehicle?