TwinTurbo.NET: Nissan 300ZX forum - You are correct...
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Subject You are correct...
     
Posted by Bigwill837 on September 15, 2015 at 7:29 AM
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In Reply To Ethanol content variation questions posted by RZturbo on September 14, 2015 at 03:44 PM
     
Message ..."E85" varies in content from station-to-station, region-to-region, and season-to-season.

That being said, you can totally run E85 without a flex-fuel input on your standalone. You will still need a flex-fuel sensor, however.

You'll need a flex fuel sensor and gauge, a way to switch fuel/timing maps, an adjustable boost controller, and a full-ethanol-range tune.

Specialty Z has a map switcher that works through the clock. They used to tune and assign different maps/boost for any given ethanol content. For example, 0% to 20% ethanol content was "Map 1," 21% to 40% ethanol content was "Map 2," 41% to 60% ethanol content was "Map 3," 61% to 80% was "Map 4," etc. (I don't recall the exact percentages, I was just giving an example). The same principle applies here.

You'll obviously need the correct tune for any given ethanol content, so it requires some extra time on the dyno for any given map/ethanol combination. But once you get it set up, all you have to do is fill the car up with fuel, look at the flex-fuel gauge in the car to see what the updated ethanol content is, and adjust the fuel/timing map and boost accordingly.

Is it a little more cumbersome than an automatic setup like Haltech? Sure. But nothing dramatic if you're diligent.

As has been said above, I don't know if Specialty Z has an "off the shelf" tune for 850cc injectors, but you would want to get the car tuned on the dyno anyway.

Finally, there is something to be said for adjusting the map and boost manually. Part of the fun of running E85 is that you get a better torque curve because of the cooling effect from the extra fuel. So you could potentially fuel the car with E85, switch to the corresponding ethanol map, but not manually increase the boost pressure. You'll get more power and a larger safety margin because you're running less boost. The same thing could be done with a Haltech, it just requires manual boost control options.

"We made a baseline pull on 91 octane fuel (green run), and switched over to E85...we made a pull on E85 without touching the boost controller or timing. We only obviously had to change the fueling. This is the difference ethanol makes just changing over on this particular Z. This is partly due to the amazing cooling effect of the fuel. 43 torque was gained at 4500 RPMs and almost 30 whp. Peak power was up 20 whp and 35 torque."

-Specialty Z's Blog

Also, update your Z Modifications profile.

Hope this helps!

     
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