Gains from E85 (ethanol) on an N/A bolt on 370Z

VitViper

I got the inspiration to test E85 on the Z and see what kind of quantifiable gains can be had. Not hearsay -- but actual scientific data collection. Thank goodness for these things we call dynos!

The car has bolt ons -- Stillen intakes, G35 test pipes (modified to fit), Agency Power 2.5" dual exhaust. Our pump gas is 92 octane, and on this fuel the motor is not ignition limited -- I can roll past MBT and see no detonation, there's just zero power gains to be had at that point.

VVEL and VTC were left alone as it was already dialed in.

The car took 16.5 gallons of E85 and on the dyno it went. First and foremost I tuned fuel, and only fuel to make sure the motor was getting a proper AFR -- running 100% the identical timing map. This is to demonstrate the gains to be had from the fuel -- and because of the properties of E85 (ethanol -- cooling effect and naturally oxygenated) simply switching to the fuel and making sure the motor has a proper AFR will make power! Regardless if you're comparing it to 91 octane, 92 octane, 93 octane, 94 octane, or whatever.


As you can see, there were gains across the whole curve.

Next, we adjusted the timing map -- and the gains were super minor and the timing added to get these gains were negligible over the pump gas timing map. 4hp on the top end. Essentially the small amount of timing just told me the fuel needed to be ignited a tad sooner to get a complete burn due to the larger quantity we're not injecting.


What's it look like overall? About 12whp and 12wtq in areas.


Not bad at all for just changing fuel and minor retuning. In fact, I saw more gains with the fuel than I did with all the work and money spent on the Stillen intakes on the car. This was also done with stock injectors and a stock pump -- worked perfectly fine, holds a clean AFR all the way to fuel cut (7800 rpm). Fuel economy while cruising on the freeway at 75mph was actually the same if not 1-2mpg better than pump gas. Go figure.

So if you want to run E85 -- the gains are there -- you should see 8-12whp regardless of the octane rating of your pump gas as the properties of the ethanol alone net gains over pump gas.

lj909

Awesome. I've been contemplating this myself but since i don't really have convenient access to e85, i put it out of my mind.

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PW 07 HR350Z R.I.P. Totaled by 82yr old woman
2010 40th Anniversary 370Z

VitViper

It's actually not that hard to put together a flex fuel kit for the car, I may do it just for the ease of switching back and forth between the fuels.

370Z JT

From prior research I've seen about 10WHP gains switching to E85 from other members. Your data confirms this. I really want to do this now.

thanks for posting.

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black_sedan

I just picked up a q50 and would love to have Flex Fuel. One of the local gas stations just started carrying it @ $1.69/gal. I would be in it just for the fuel savings!

The extra HP would just be an added bonus.

JC-Nismo

And I would assume this is good for daily use over premium or is this just good to be race ready with?

BGTV8

ECUTEK used or UpRev ??

VitViper

If you have E85 available, I don't see why you couldn't daily with it? I use it on a ton of cars.

ECUTek of course. I won't touch UpRev on a 3.7L since ECUTek came out with the Phase 2 updates.

POS VETT

VipViper - this is a good news, thank you for posting this. For the longest time, I've wondered about information pieces you mentioned. I have recently acquired a GM truck (an FFV) equipped with an engine with a high compression ratio (11:1), direct injection, and variable valve timing. GM engineers managed to bump the engine output 25 hp and 33 ft-lbs just from using E85; not to mention the pleasing way the engine reacts to throttle inputs while on E85 and it even sounds different.

I thought a Z34 could benefit from using the E85 if it's so equipped (ethanol-resistant hardware first, then capacity) since the VQ37VHR runs a high enough compression ratio. Now, if you had the data, would you mind superimposing the injector duty cycle and the AFR?

ANMVQ

OK so talk to me about the injectors and pump. I have ECUTEK so I can added a map for E85 but I was under the impression that I need to change the pump and injectors?

BTW would this be safe to drive on until I get my tune updated. I only have access to Etunes and my tuner is in another state.

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14 Q50 AWD, ARK, ECUTEK (SEB), Takda,

TerribleONE

Nice to see someone try this on a NA car. Having a hard time believing your MPG improved though, mine dropped like a rock

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lj909

Get your foot out of it twin turbo man!

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PW 07 HR350Z R.I.P. Totaled by 82yr old woman
2010 40th Anniversary 370Z

njobe89

interesting

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2 plus 2 times 2 = ? ... hint, it's not 8

Stillen CBE, Stillen Gen 3, TP's, Uprev tuned - 324whp/264tq

VitViper

Yes some motors will gain more or less. We have the Ford Coyote (5.0L) engines picking up 17-18whp & 20-25wtq from E85.

The injectors are effectively maxed out -- holds a clean AFR but if you want more breathing room you can upgrade them, but you don't have to. It was the same story on the shop Coyote when we ran E85.



Lol on an F/I car you're into boost so easily that it will just suck down the fuel like a crack addict.

With the VVEL/VTC system on this motor, do yourself a favor and find a competent tuner with a reliable dyno. I've seen minor 2-3* changes to VVEL net 4-5tq through parts of the curve, or the opposite -- cause huge 40tq dips in the curve. The goal is to fatten the area under the curve, and you're going to have a hard time trying to get 4tq here and there (and the cumulative effect is nice).

Attached Images

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njobe89

so what's all needed to be able to switch from e85 to regular... there are e85 pumps around me at all times, but if you go on a trip, it's not offered at every gas station.

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2 plus 2 times 2 = ? ... hint, it's not 8

Stillen CBE, Stillen Gen 3, TP's, Uprev tuned - 324whp/264tq