what make for a better experience e85 or 91 w/boost cooler

[58ragman]

on my 2386 turbo im torn between running 85 fuel yes i have every component including the PTFE fuel line fuel pump etc.But also during my build i decided maybe not go e85 and go 91 octane with a boost cooler and bought all the components for that set up also.Now

in the realm of 17 -20 lbs boost.

What would make for a better overall experience running 91 or e85.

I would love to hear all experiences Thanks in advance

[clonebug]

E85 has a good cooling effect due to the alcohol along with more octane. Down side is you use up to 30% more to get the same power.

It has less tendency to cause detonation and you can run higher timing because of that giving more power.
Along that you can probably run higher boost too.

I've got 91-92 pretty well figured out to 23-25 lbs.

I found the key is to keep intake temps as close to ambient as possible. I do that by running Water/Alcohol mix and a small intercooler.
In the spring and fall I can keep my intake temps below 90*F at 23 lbs. boost.

I use the IAT retard feature in MS2 to lower timing if the IAT's go over 95-100 degrees.

Running over 17-20 lbs. you want to do everything you can to keep IAT's low.....
I found 130*F IAT's are the critical point...at least for me......there is a difference of at least 7 degrees timing between those temps.
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[buguy]

The trouble i have found running E85 is you have no real idea what your temps are since you get a reading before the fuel. I haven't experienced any problems with detonation (yet) either though. I'm not sure if it even reduces intake temps since the intake charge is already there when the fuel is sprayed?? The 116 octane or whatever it is, certainly helps though!

[58ragman]

thanks for the responses keep em coming if you can if someone missed something let us know thanks in advance

[buguy]

What is your set-up? That might decide for you.

[Ohio Tom]

I'm running 93 octane with water/meth injection. (washer fluid)

It's nice because I can get fuel anywhere.

16psi (so far) no problem.

Oldschool side-draft carb with no intercooler.

Adding the water/meth was easy.
Boy did it add some power thou..

[Dauz]

C16!

I've never ran water meth or e85. But plan to.. just not sure which yet. Leaning toward water methanol in addition to a air-to-water (ice) intercooling.

Motor is at paradise.. cant' wait. New trans is underway also.

[Ohio Tom]

C16 = $16 per gallon...

NOt really street fuel...

[kangaboy]

I use a flex fuel sensor with my MegaSquirt set up, so can run one or another if necessary.

I prefer the e85 if its available though, because I can only run about 8psi on 89octane with no intercooler or water/meth system. I hit 24psi at the drag strip this year on e85. No detonation or other ill effects noted.

Like was mentioned earlier, your setup will help make your decision. If you wanna do an intercooler and/or water/meth, set up for pump gas and use any gas station around. If you wanna go e85 and have the accessability to it, go that route. A lot less piping and systems required imho.

Oh, also as mentioned above, gas mileage will suffer with e85, and you need some bigger injectors to pump all that fuel in the chambers while still having a safe (>85%) duty cycle.
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-74 Standard - "CaliBug" 2084T, MS3X w/FI and Crank Fire
-76 Westy - "Gandalf"
-18 GTI SE

[Dauz]

[buguy]

I was thinking no intercooling with drawthrough. Water meth maybe though. Injected you can do whatever you want.

[andor]

Best result is e85 and intercooler.
Some argue that it’s a downside that you use 30% more fuel with e85, I can’t see any downsides iwith that. E85 is at the same time 30% less expensive per gallon.