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Need some E85 Ideas

Coreymm

Member
Oct 18, 2012
14
0
I just got finish building my car, and I wanna get three custom tunes done. The 1st one I wanna do a 93 pump gas tune. The 2nd I wanna do a E85 race tune blower only, and the 3rd I wanna do E85 what a 100 shot of NOS. now E85 is not everywhere in my City so that's why I wanna do the 93 tune.. so how do I make this happen?

Do I drive to the tuner with 93 in the tank and also bring a 5 gallon can of E85. Or do I just do those E85 tunes on different days. My tuners a busy guy so I wanna make the most out of my visit.


My fuel mods are twin GT pumps with steel braided 8in fuel lines a 40a BAP modified fpdm and 60lb injectors
My car is a Mercury marauder with a built motor, Eaton Trilogy supercharger posi ported, with a 4lb lower and 3.0 upper, Stainless works headers with no cats. and a zex 100 wet shot

any ideas or help would be great
 

blck10th

TCG Elite Member
Jan 11, 2007
17,965
24
U need to have a way to drain the 93 out as far as I know. The 93 and E85 can't be mixed. So not sure how you plan on doing that. Sounds like you would be better off running 100 when you want to go race. I doubt you would need more octane than that

I run e85 but I do not have a 93 tune. It's not practical for me to swap and drop the boost so low just to run it. I'd go back to running 100 if that was the case
 

Coreymm

Member
Oct 18, 2012
14
0
I just wanna keep it simple. so I don't wanna do a stand alone fuel system. I mean from what Ive seen and read E85 is the route to go. I just don't wanna run it all the time due to it not being available like pump gas. so I guess 100 octane looks more appealing. I just wanna maximize my horsepower
 

Zack

4 Doors 4 Life
Mar 21, 2004
6,297
20
NW Indiana
I have 2 cars committed to E85. That means they run on E85 and E85 only.
My driving distance is limited, and yours will be as well.

If you have a Trilogy, your power output will be about 520ish with E85. More so with spray obviously.

Honestly, if you have a built engine you are holding yourself back with the eaton.
What is your compression ratio?
 

massacre

Regular
May 25, 2011
161
2
You could run two fuel cells. Would be kind of a PITA to have tow run out the fuel system any time you want to switch fuels though lol.
I thought when running alcohol you had to use aluminum fittings? That could be outdated info at this point though.
I am interested in E85 because we are going to a killer motor in the drag mini bike for next year and it's gonna run E85.
 

Spoolin D Dub

"THE BOSS" But you can call me sarge!
Sep 21, 2012
201
0
Just Around da Corner
go to tuner with 93oct get tuned and drain tank and put in e85. Also a myth about e85. Someone found out last year by running out of fuel in my car (gauge broke) that it will run and drive fine with 93 in tank on e85 tune with No special sensors!!. Just can't get on it. Ask your tuner lol. I'm on a AEM stand alone. There are more stations then you think that have e85 also.
 

02BlueGT

No Fucks Have Been Given
Feb 21, 2008
9,922
18
Now apearing in Hanover Park
Lol...... A cars.pcm.will adjust the 30% fuel difference.needed by e85 because of how an o2 sensor works..... You can run a thousand mixes of e85 and 93 and a car should run. Having it perform is what requires the tune. The 3800 guys NEVER drain the tank and I have NEVER seen someone waste the time to run an alcohol sensor. Drive the car till the.tank is low, put some e85 in, repeat a few.times (dont need to do full tanks each time). Then get your tune. IF you run e85 now.(winter fuel) it is most likely e70 anyway. Also e85 is harder to start.and runs iffy till the motor.warms up in cold weather.


Sent from my phone.
 

willizm

Very Nice, Very Evil
May 13, 2009
12,829
10,148
The Woodlands, TX
I mix fuels e85 and 93 octane in my bimmers so that is a myth that you can't mix. Also I have two tunes via hptuners. If I need to switch I just run the tank really low, pull up to the pump, fill with 93 octane, flash the 93 tune file, carry on my way. 93octane contains 10% ethanol so mixing 15 gallons with maybe a half gallon in the car isn't going to cause an issue.
 

Turbocharged400sbc

3800 & 4T80E > ALL
TCG Premium
Jun 16, 2007
32,538
15,846
hangover park IL
people will tell you that a pcm will adjust + to neg 22% fuel trims. this is untrue, the pcm (at least for gm's) will go to 44% either way if it needs too.

for the most part we can change base afr with the iat tables so that could be used to dial in your tune based on what you figure your e85/93 mix ratio is when you fillup.
xsized tank of e85, add 93 figure % and turn an iat potentiometer to the right spot.

you dont really need to do that. if your just going for drivability, set yourself up with a tune on a 50/50 tank, that way as you approach 100% of either fuel the pcm will learn to +/- 15%. just reset fuel trims when you fillup and give it a bit to relearn.

if your using e85 as more of a racing fuel then youd be better to tune for e85 and let the pcm pull ~30% fuel whenever you run gas on the street. dep on how often you go into power enrichment it should learn how to run it after 50miles or so. but it will be pig rich anytime you go into PE and the pcm stops closed loop mixture feedback.

everything is a compromise...either do two seperate tunes and change the pcm or reflash it. or deal with the other headaches...or just stick with one fuel.
 

boogeyman

T-BURD
Sep 25, 2012
486
0
demotte in
my timing tables have 11 degrees differance bewteen 93octane and e-85 the fuel sensor just dictates what timing and fuel table it runs off of so no matter if i have pure 93 or run the car empty and fill with e-85 or any mix in between it sure beats adjusting the iat sensor output voltage with a pot to get it to run right especially when a boosted car needs a true iat reading to keep it safe.
id have to agree that just sticking with 93 and 110 would be much easier since the availability of e-85 is poor in your area.
 

Turbocharged400sbc

3800 & 4T80E > ALL
TCG Premium
Jun 16, 2007
32,538
15,846
hangover park IL
my timing tables have 11 degrees differance bewteen 93octane and e-85 the fuel sensor just dictates what timing and fuel table it runs off of so no matter if i have pure 93 or run the car empty and fill with e-85 or any mix in between it sure beats adjusting the iat sensor output voltage with a pot to get it to run right especially when a boosted car needs a true iat reading to keep it safe.
id have to agree that just sticking with 93 and 110 would be much easier since the availability of e-85 is poor in your area.

you do know that the density change of air over a typical...lets say 32*f and 100*f ambient air temp would change the afr at most .25 afr
from near freezing to the hotest air your actual afr would read .25 richer.

aside from this fact is that by design a maf senses air MASS, which means it senses ambient air temp as well as the current flow through thermister/s to maintain a slightly higher temp to figure on the air density.

so right there your maf sensor is automatically negating the air density afr change.

now look at what the IAT is actually used for. it is a rationality test for ECT at cold startup, it also has primary function of changing timing and often trans pressure/shift parameters for those who buy a car and want it to feel perfect all the time...where a real gearhead knows not to beaton a car till its up to temp the manufacturers know that people are stupid so the pcm is tasked with making everything as smooth as possible to keep a customer from bringing in their car with complaints.

go with a mod'd trans or one with non adjustable mainline pressure and you just killed half the function of the iat.

like i said everything is a compromise....and it depends on what the car owner is comfortable with...whether its keeping two 5 gal cans in the trunk for e85 or some quick math with a calc at the pump and turn a knob.
alternatly just using an AFC on the maf would allow for fairly quick fuel ratio tuning as well though this will affect load calcs/shifts/etc.

we do have BARO correction on our pcm's that affects base afr so it could be possible to make changes that way as long as its a dual sensor high altitude car. otherwise baro is only sensed at just before startup or certain wot conditions (na engines). a high altitude vehicle references a seperate baro sensor all the time.

edit: our iat has relation to timing as well as afr tables so the iat makes a bit more sense from my point of view since baro correction influences fuel tables only
 
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