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E85

57plymouth

Active member
Joined
Jul 23, 2015
Location
Blythewood, SC
How fast will E85 eat the fuel system from the inside out on a 1991 245?

Is it worth the bother to figure out what fuel map it would need and get a reflash?

Should I drink less booze this early in the day and keep feeding my rectilinear crapwagon pump swill 87 diluted with 10% corn squeezings?
 
Shouldn't eat the fuel system at all.

Don't worry about a reflash, just get injectors about 25% bigger and let the O2 sensor fine tune from there.

It could certainly use some more timing, but that's not easy to do on an LH2.4 system.

Main advantage is being able to run more boosts with less ping-ping-booms. Without running boost, it's really not worth the hassle. E85 is cheaper per gallon, but once you factor in the reduction in MPG, you're not going to save money. And it's a PITA always needing to find an E85 pump, they're not all that common even where they are common.
 
Shouldn't eat the fuel system at all.

Don't worry about a reflash, just get injectors about 25% bigger and let the O2 sensor fine tune from there.

It could certainly use some more timing, but that's not easy to do on an LH2.4 system.

Main advantage is being able to run more boosts with less ping-ping-booms. Without running boost, it's really not worth the hassle. E85 is cheaper per gallon, but once you factor in the reduction in MPG, you're not going to save money. And it's a PITA always needing to find an E85 pump, they're not all that common even where they are common.

40-45% bigger would be my choice. I actually tried on my nearly stock 940T. I went from 305cc/min to 440cc/min. LH2.4 did adapt to it without problems.
However, the engine was considerably harder to start when cold in cold weather.
And mileage gets worse by about 20-25%.
 
Sounds like it isn't worth the effort.

It is totally worth the effort, I have been running E85 for 6+ years on my car and love it.

The MPG drop is only 1-2 mpg, not that horrible. Plus depending on how it is setup I acutally gained mpg back on my new tune with the 012amm and e54 (what we get out of the pump here).

Being able to run full boost without knock is a great thing, both of my redblocks live on e54 and pretty much only get 1 gal of pump (91 oct) every few tanks to help keep things clean.

And then add in the cost being much less than pump gas. While you might lose 1-2 mpg you are also paying .60-80 cents Less per gallon. So say over 1000 miles you normally get 20mpg but 91oct fuel is 3.49/gallon. Total cost is around $175. But if your mpg drops to 18mpg on E85 but you are only paying 2.69/gallon total cost is around $150. So over that 1000 miles you not only saved $15 but you were able to run full boost and make more power while not having to worry about knock.

I ran my 15g with the stock amm on 400cc injectors without any issues @ 16psi daily. I recently went up to 65lb/hr injectors with the 012 amm and worked on a new mapping that has been good. The car has actually felt smoother and quicker with the new setup along with my mpg jumped back up 1+mpg with the new change because of the timing changes from the larger amm.
 
I'm halfway there with what Mike said. I've been running either straight E85 or a 50/50 mix for several years. Definitely runs better, might want to replace the rubber pressure hoses in the system but that would be smart anyway given the age. I've seen a little rubber buildup when pulling filters apart on another in the fleet that had hose from 91. My wagon, never saw that kind of deterioration though so YMMV.

Mileage-wise I will get around 18-19 on pump, around 15 or so on E85. Cost is around 3.99 for pump, 2.95 now for E85, dunno why the jump since it was $2.29 6 months ago.

Performance-wise, I have a hard time NOT running it. The crap we get in Cali for pump gas is kinda sad, E85 makes up for that, really does run a LOT better (part of the issue with low mileage is more right foot being used because all the bewsts). Far happier across the board. The only issue I've had has been cold starts under about 50*, might take a second try to start, but it's good after that.

I'm on #65 and 012 AMM as well, testing one of Mike's tunes, been pretty happy with it actually, running a tune built around 91* but 2.4 adapts pretty well to E85, so the same tune seems to be doing well.
 
The tune probably makes a difference, perhaps if you're running leaner on E85 you might be making up for some of the MPG drop?

My son actually did a science fair project on E85 vs. gasoline one year. Carefully measured fuel use, identical routes (peak, average speeds, elapsed time, we tossed out a couple of 'flawed' runs). O2 sensors adjusting to stochiometric on both fuels. The E85 runs used about 22% more fuel. In the turbo wagon, that was from about 21 mpg average on E85 to almost 26 on gasoline.

Of course, MPG concerns, maybe saving a few cents here or there, or spending a few more here or there, are not the reasons I'm running E85 in the wagon, it's so I can run 20 psi of boost in the heat of summer without needing meth or water injection. With the flex fuel setup I can easily swap between fuels, and running on pump 93 octane (E10 around here), I was limited to about 15 psi on a warm day before hearing some pinging that was hard to tune around by retarding spark. Put E85 in it, and it was good up to the limits of my MS setup (24 psi-ish was where my MAP sensor maxed out).
 
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