Anyone considered E85?

[NitroDann]

Im running E85 in newcastle right now. anyone who wants to have a look see can text me on 0401387968 and come have a look at the car and my old maps compared to my new maps.

Its worth 11ish percent based on the decrease in calorific capacity and increase in fuel pumped in due to air fuel ratio changes. But that doesnt account for the fact you can run heaps more boost and timing.

In other words, it outputs less energy per kilo burned than 98ron, but you actually pump in 42% more (by weight, 30% by volume cos its heavier) and because you pump in more you make more power. Nitromethane has less energy per kilo than 98ron but you pump in 5 times more for it to run.

You pump in more because every revolution you suck in a fixed amount of air (atr the same volumetric efficiency). Lets assume 1600cc for a 1.6L, and you need to get the right amount of fuel in so that all this oxygen is used, but during combustion E85 releases much more oxygen on its own, requiring more fuel... hence making more power.

Because its 105-110 octane you get not only 11% more from the fuel energy output, you also get the gains from running 40 degrees of timing in a naturally aspirated application, or stock rather than reduced timing with lots more boost, and this advantage gives you more power again on top of that 11%.

Cheers,
Dann

[NitroDann]

also i run 550cc injectors and stock everything else in a 90 model NA6. The fuel parts are all totally safe with ethanol in all mx5's.

Dann

[zossy1]

The fuel parts are all totally safe with ethanol in all mx5's.

Dann

Meaning that basically, if remap and retune the car to run on e85, my fuel lines, rail, injectors etc will all stand up?

Only reason I am considering e85 is to get the car through the engineering emissions test...

[NitroDann]

absolutely so long as you have enough injector and if you havent run ethanol blends before (including e10) expect to have to replace your newly blocked fuel filter soon due to the crap it cleans from your tank.

cheers,
Dann

[Sean]

Excellent posts by chrisearl88 and NitroDann.

Only thing, Dan are you saying you didn't change the fuel hoses? I've seen hoses turn to jelly in early MX5s with certain fuels, I'd definately be spending the few dollars to upgrade them all - simple and inexpensive job.

[NitroDann]

Didnt change them, thousands of clicks and months on and they are fine inside and out, yeah Ive checked.

Engines been in and out its fair share of times maybe it doesnt have original hoses, having said that No-one on miataturbo is having issues with early e85 powered stock NA's.

Dann

[Sean]

Ah, ok that's good news.
I've seen jelly lines and they worried me! Sounds like maybe the cars I'd seen may have had non standard hoses of a lower grade.

[madjak]

Dann, you reckon it's worth doing on a high powered N/A engine? Since I have to run larger injectors anyway, I was thinking of moving to E85 as well. I currently have the 265cc NB8B injectors running at 60PSI and I'm close to maxing them atm. So I figure I should be running at least 400cc injectors and really need to double them for E85 (plus I might supercharge later)

I would also run the Haltech / GM flex sensor and run a dual tune.

[Magpie]

madjak my build is running ID725 injectors and I will soon know if these are the correct size. My calcs for E85 and 220 hp equates to 725cc injectors.

[madjak]

Yeah well there is very little cost to do it really. If I don't have to upgrade fuel lines as Dann says, and since I have to put in new injectors and get an updated tune anyway, all I have to add is a GM flex sensors for $100. I figure the 725cc injectors should be about right too.

Later if I supercharge this engine I'd probably need bigger injectors again... maybe I should shoot straight for 1000cc injectors. Sounds a bit excessive to me though.

[NitroDann]

Do it. Genuine ID1k's are so responsive at low rpm etc that there is literally no downside.

Pats na6 is at 11.2:1 and we just crammed in 24pai and made 349.6rwhp.

Do it you wont regret it

[madjak]

Ok I'm sold! Any suggestions on where to purchase the flex sensors from? Are the eBay $100 gm ones fine?

[Magpie]

Consider the Haltech kit that includes the flex sensor and IO Box (Part No. HT-059906). The reason is that the PS1000 has only limited inputs (4 x 5 volt, 4 x digital pulse inputs) and if you add more sensors like oil temp, oil pressure, speed, fuel level, brake pressures and others you will quickly crowd out the inputs. The IO box gives 12 more (4 x 5 volt, 4 x digital pulse inputs and 4 x digital pulsed output).

Discussion here http://www.sau.com.au/forums/topic/445930-haltech-flex-sensor-vs-gm-flex-sensor/

[davekmoore]

Mine has Haltech PS1000, ID1000s, Haltech Flex Sensor, and everything else needed (as well as heaps I've since learned was not strictly needed) to support E85.

It runs pretty well off idle but several months and countless trips back to the tuner and it still doesn't idle or set off on part throttle consistently or reliably. It behaves differently on each fuel, and differently depending on air temp, under-bonnet temp, humidity, whether the a/c is on, etc etc. Warm start-ups see it rev to 2500, or not, depending on what mood it's in. All of this is at best inconvenient and at worse dangerous.

It goes to a different tuner in a month.

I'll immediately report back in this thread to confirm whether the issue(s) was/were hardware, software or tuner.

[madjak]

My car is 99% a track car now. I could run canned e85 and not even bother with the flex sensor but I figure its worth doing for safety in case I get a bad batch of fuel. I think I have a spare input so for now I'll just connect directly to the Haltech.

My car doesn't have air IAC so it requires someone in the car to keep it idling till it's warm anyway and even then idle is lumpy and almost shakes the car apart due to big cams. Also no air con.

I'll probably order the parts required after the next race.