Is E-85 worth it N/A? - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


ECUs and Tuning Discuss Engine Management, Tuning, & Programming

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 08-29-2015, 09:53 PM   #1
Elite Member
Thread Starter
iTrader: (5)
 
Join Date: Oct 2007
Location: Canton, Ga
Posts: 1,707
Total Cats: 19
Default Is E-85 worth it N/A?

Recently 104 octaine E85 became available less than a mile from my house, and wandering if it would be worth setting up flex fuel. All I'd need is the flex fuel sensor and a set of RX-8 420s... I could swing it for $300. My engine is around 10.5:1 with some moderate cams.. I'm thinking if I can make another 5%-10% more power it would be worth it. Is that reasonable, or am I wasting my time without a bunch more compression?
Stealth97 is offline   Reply With Quote
Old 08-29-2015, 10:13 PM   #2
Elite Member
iTrader: (15)
 
patsmx5's Avatar
 
Join Date: Aug 2007
Location: Houston, TX
Posts: 8,797
Total Cats: 248
Default

Less than 1 mile from your house? If you're ok with running the car on E85, do it. I switched mine recently. I have to drive A LOT further than 1 mile to get E85, but... I needed E85 for my setup. I'm going to buy a few more gas cans to make refueling not such a pain.

I think you'll see 5% gain minimum, possibly more. I wouldn't be surprised if you saw a 6-8% gain with your setup.
patsmx5 is offline   Reply With Quote
Old 08-29-2015, 10:24 PM   #3
Elite Member
Thread Starter
iTrader: (5)
 
Join Date: Oct 2007
Location: Canton, Ga
Posts: 1,707
Total Cats: 19
Default

Quote:
Originally Posted by patsmx5 View Post
Less than 1 mile from your house.
Yep. A real shocker too. Its a Mom&Pop place. A few months ago they got new tanks. My jaw nearly hit the floor when the pump said 104 octaine on it.

It's not consistently available at other stations around here though, so while I could just fill'er up and retune with larger injectors, I'd still need to go with flex fuel.
Stealth97 is offline   Reply With Quote
Old 08-29-2015, 10:28 PM   #4
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,187
Total Cats: 2,583
Default

I've never seen an octane rating posted on an e85 pump. That's interesting.
It's usually worth it for the power increase and safety peace of mind.
18psi is offline   Reply With Quote
Old 08-29-2015, 10:43 PM   #5
Elite Member
Thread Starter
iTrader: (5)
 
Join Date: Oct 2007
Location: Canton, Ga
Posts: 1,707
Total Cats: 19
Default

This one definitely had an octaine rating, yellow hoses too. Under $2 if paying cash!

Attached Thumbnails
Is E-85 worth it N/A?-80-p_20150823_170912_1_p_4577977e8db7772058e8e2858089fdca7af86453.jpg  
Stealth97 is offline   Reply With Quote
Old 08-29-2015, 10:54 PM   #6
Elite Member
iTrader: (15)
 
patsmx5's Avatar
 
Join Date: Aug 2007
Location: Houston, TX
Posts: 8,797
Total Cats: 248
Default

TX pump is like that too, has octane on the pump.
patsmx5 is offline   Reply With Quote
Old 08-29-2015, 11:08 PM   #7
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 17,997
Total Cats: 1,463
Default

<p>Make sure you have enough inputs for the flex fuel sensor.</p>
aidandj is offline   Reply With Quote
Old 08-29-2015, 11:31 PM   #8
Sadfab Union President
iTrader: (3)
 
Join Date: May 2014
Location: Kansas
Posts: 2,690
Total Cats: 113
Default

Flex support on the MS2 is supposedly crap, I'd run all or nothing or maybe use a table switch.

Or run with the sensor, let me know how it goes.
deezums is offline   Reply With Quote
Old 08-29-2015, 11:33 PM   #9
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 17,997
Total Cats: 1,463
Default

<p>There's no blending. Just a % fuel multiplier, and timing subtraction/addition.</p>
aidandj is offline   Reply With Quote
Old 08-30-2015, 12:20 AM   #10
Elite Member
Thread Starter
iTrader: (5)
 
Join Date: Oct 2007
Location: Canton, Ga
Posts: 1,707
Total Cats: 19
Default

Quote:
Originally Posted by aidandj View Post
<p>There's no blending. Just a % fuel multiplier, and timing subtraction/addition.</p>
Anyone have firsthand experience with Flexfuel on MS2? If isn't that great, I wont bother. Not really interested in an on/off flip a switch solution.
Stealth97 is offline   Reply With Quote
Old 08-30-2015, 01:09 AM   #11
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,187
Total Cats: 2,583
Default

Pretty neat. But it's really misleading. You actually have lower quality e85 than we do here. Be careful with that. The lower quality pumps here also say "minimum 70", which means it can be from 70-85, and it fluctuates quite a bit. The higher quality pumps say "minimum 85" and the difference on any given day between the two is quite significant. Sometimes a full 1-1.5 AFR worth. Anything between 95 octane and 115.

Just a heads up.
18psi is offline   Reply With Quote
Old 08-30-2015, 07:20 PM   #12
Junior Member
 
Join Date: May 2014
Location: North St Paul, MN
Posts: 397
Total Cats: 23
Default

We have one gas station chain locally that sells E85 that tests in the E85 and E90 range. However, a bunch of local gas stations sell E85 and usually they test as E70 or lower. As well, the state of MN just passed a law for the stickers. Ours now say that the E85 has to be E50 or better. I don't know how they get away with the crap. So we just tell everyone to only use the brand that we have found to be the most consistent.
ofspunk7 is offline   Reply With Quote
Old 08-30-2015, 07:25 PM   #13
Elite Member
iTrader: (15)
 
patsmx5's Avatar
 
Join Date: Aug 2007
Location: Houston, TX
Posts: 8,797
Total Cats: 248
Default

Quote:
Originally Posted by ofspunk7 View Post
We have one gas station chain locally that sells E85 that tests in the E85 and E90 range. However, a bunch of local gas stations sell E85 and usually they test as E70 or lower. As well, the state of MN just passed a law for the stickers. Ours now say that the E85 has to be E50 or better. I don't know how they get away with the crap. So we just tell everyone to only use the brand that we have found to be the most consistent.
The ones I saw in TX said E85, E70 minimum. Sucks that if varies, but that problem should go away with a flex fuel sensor and tuning it. But I have not installed any flex fuel hardware yet, someone here was attempting it and I was waiting on him to figure it out so I could copy!
patsmx5 is offline   Reply With Quote
Old 08-30-2015, 07:34 PM   #14
Sadfab Union President
iTrader: (3)
 
Join Date: May 2014
Location: Kansas
Posts: 2,690
Total Cats: 113
Default

You've got me reading up on this again.

MS2 can only do a simple global scaling based on a flex sensor. You literally have 4 inputs, timing to add and fuel % at low alcohol, and the same at high ethanol blends. If you have decent injectors (rx8's aren't those) I bet it would be possible to use the simple scaling to get something pretty damn close. If you find you need 30% more at 5500, but only 20% more at idle you are seriously screwed.

I believe you'd probably want to leave timing on the table for safety, what with MS2 not doing knock, unless maybe you only buy one station's crap. That's where all the goodness comes from. I think you'd be leaving a lot on the table, probably not worth the expense.
deezums is offline   Reply With Quote
Old 08-30-2015, 08:11 PM   #15
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 17,997
Total Cats: 1,463
Default

<p>
Quote:
Originally Posted by patsmx5 View Post
The ones I saw in TX said E85, E70 minimum. Sucks that if varies, but that problem should go away with a flex fuel sensor and tuning it. But I have not installed any flex fuel hardware yet, someone here was attempting it and I was waiting on him to figure it out so I could copy!
</p><p>yank&nbsp;has it wired up, im going to try and play with it this week. but everything looks good so far.</p>
aidandj is offline   Reply With Quote
Old 08-30-2015, 09:02 PM   #16
Elite Member
Thread Starter
iTrader: (5)
 
Join Date: Oct 2007
Location: Canton, Ga
Posts: 1,707
Total Cats: 19
Default

Quote:
Originally Posted by deezums View Post
You've got me reading up on this again.

MS2 can only do a simple global scaling based on a flex sensor. You literally have 4 inputs, timing to add and fuel % at low alcohol, and the same at high ethanol blends. If you have decent injectors (rx8's aren't those) I bet it would be possible to use the simple scaling to get something pretty damn close. If you find you need 30% more at 5500, but only 20% more at idle you are seriously screwed.

I believe you'd probably want to leave timing on the table for safety, what with MS2 not doing knock, unless maybe you only buy one station's crap. That's where all the goodness comes from. I think you'd be leaving a lot on the table, probably not worth the expense.
What's wrong with RX8s?
Stealth97 is offline   Reply With Quote
Old 08-30-2015, 09:04 PM   #17
Elite Member
iTrader: (17)
 
Join Date: Aug 2007
Location: Fort Myers, FL
Posts: 2,791
Total Cats: 130
Default

On a 10.5 compression motor I think it'd be worth playing with, and you could do that with some $100 RX8 injectors. Virtualdyno.net can tell you exactly what kind of power you gain with a couple datalogs and if you're not happy with the gains it's easy to go back.

I've never bothered with the flex sensor. I use MSDroid on my phone a lot, when I started using E85 (about a year ago) I always kept a 93 octane map so I could switch over. Lately I haven't even bothered, I just run E85 all the time and haven't had a problem yet. If I do ever get caught without it it's easy enough to pull timing and fuel so I can make it home on 93.
pdexta is offline   Reply With Quote
Old 08-30-2015, 09:12 PM   #18
Sadfab Union President
iTrader: (3)
 
Join Date: May 2014
Location: Kansas
Posts: 2,690
Total Cats: 113
Default

Quote:
Originally Posted by Stealth97 View Post
What's wrong with RX8s?
They are older tech, they won't be as linear which would be helpful if you are multiplying the fuel table.

I wonder, is it possible to run flex sensor comps on a switched table? Then you could have a 93/91 table, and a dedicated E85 table you could apply flex calculations to.

I'd use MSdroid to disable the flex sensor when I went on a long trip away from E85, maybe just load a 93/91 table through the phone.
deezums is offline   Reply With Quote
Old 08-30-2015, 09:13 PM   #19
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 17,997
Total Cats: 1,463
Default

<p>*cough* buy an ms3 *cough*</p>
aidandj is offline   Reply With Quote
Old 08-30-2015, 09:19 PM   #20
Sadfab Union President
iTrader: (3)
 
Join Date: May 2014
Location: Kansas
Posts: 2,690
Total Cats: 113
Default

True story
deezums is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
1.6 ACT ZM1-XTSS clutch was $320 NOW $200 btabor Miata parts for sale/trade 14 10-05-2015 03:04 PM
Megasquirt 2 or 3 ? TheNomad Engine Performance 3 09-21-2015 11:20 PM
DIYPNP Won't Stay Running huesmann MEGAsquirt 19 09-16-2015 08:11 PM
Noob from Fort Worth, Texas checking in. Miatabro Meet and Greet 7 09-11-2015 01:13 PM
Anything To Gain from Using Piggyback on N/A car? 2000SE ECUs and Tuning 5 09-08-2015 12:30 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 10:45 PM.