Anyone considered E85?

rxmx · Postby **rxmx** » Mon Nov 08, 2010 10:42 am

caltex has started rolling out e85 and will continiue to do so over the next year, 105octane any of the FI guys considered it as there seems to be alot of benefit, can add more timing boost etc without knock depending on setup. Its cheaper but your fuel consumption will increase alot. I might make the switch next year depending on availability...

Black_Penguin · Postby **Black_Penguin** » Mon Nov 08, 2010 11:44 am

Would check that the fuel system is compatible with E85, anything up to 2005 is not compatible with E10.

rxmx · Postby **rxmx** » Mon Nov 08, 2010 12:19 pm

From what ive read you would have to upgrade your fuel system high pressure braided lines+fpr that are e85 as well as injectors and aftermarke ecu to adjust fuel/ig if u havnt already. Am i missing anything?

rxmx · Postby **rxmx** » Wed Nov 10, 2010 9:21 am

sweet, i think il slowly accumilate all the parts i need then make the switch when the availability of the fuel increases..

deviant · Postby **deviant** » Thu Nov 11, 2010 10:15 am

If this becomes the norm at more petrol stations then I will go for it. Talking to a few racers that run it they have colder engine temps and more power.

It is worth noting that you can buy this fuel in drums from motorsport fuel suppliers but it does have a limited shelf life once you crack the seal.

Sailor · Postby **Sailor** » Sun Nov 14, 2010 9:27 am

E85 has my attention!
For the Cosworth installation on my NC, E85 would be a perfect solution and negate the need to go to water/alcohol injection, and possibly save me from going to low compression pistons.
I need to get advice on the compatability issues with fuel system etc then talk to a truckload of people.

rxmx · Postby **rxmx** » Sun Nov 14, 2010 5:58 pm

group buy on big mamma e85 compatible injectors? Mt.net have a great deal on DW drop in injectors...

Sailor · Postby **Sailor** » Sun Nov 14, 2010 7:00 pm

Possibly simplest conversion is this
http://www.flexfuelkits.com.au/

rxmx · Postby **rxmx** » Thu Nov 18, 2010 8:45 am

i think a standalone ecu would be a better option. More flexibility over your tune

Sailor · Postby **Sailor** » Thu Nov 18, 2010 9:27 am

rxmx wrote:i think a standalone ecu would be a better option. More flexibility over your tune

Unfortunately there's then no flexibility in fuel choice either.
With the conversion kit apparently you can use any fuel and the system will adapt.

Of course for outright power the standalone would be the choice

rxmx · Postby **rxmx** » Thu Nov 18, 2010 11:21 am

Would there be any gains of just switching to e85 without adjusting fuel/spark though?

rxmx · Postby **rxmx** » Thu Nov 18, 2010 11:29 am

couldnt edit my post but would the gains be worthwhile with just adding e85

Sailor · Postby **Sailor** » Thu Nov 18, 2010 7:50 pm

I'd guess that the ECU will 'see' the higher octane , cooler temps and AFR and wind in advance.
I'll be using an Xede and will be using the dual map so I can switch between fuels if required.

chrisearl88 · Postby **chrisearl88** » Thu Nov 18, 2010 8:44 pm

Hey guys, im studying Mech Eng at Uni of Qld in Brisbane and my thesis was the design of a E85 fuel system for the UQ Formula SAE racing vehicle (society of Automotive Engineers).

Some things to note, E85 is less energy dense than petrol, so to compensate you need to increase flow rate by roughly 35%, so bigger injectors are on the cards. Ill assume you've got some kinda engine management as to get the benifits of E85's higher octane you will need to adjust the timing accordingly, i managed a 6 deg adv through most of the rev range from stock settings using a MOTEC ecu.

My calculations suggest around 11% power increase (130 to 145hp) can be had from employing E85 rather than 95RON on a cbr600rr bike engine, so not sure how this would translate to an mx5, but gives you an idea that good gains can be had. The engine was pretty stock other than intake mods. Yet to be put on dyno, the power figures are theoretical calculations, might be more like 10% as i dont factor in mechanical losses ect.

The big thing to address with ethanol is its corrosive nature and hydrophilic (likes water) tenancy. So you will have to make sure you fuel lines are ethanol friendly, and that your fuel pump and other components are stainless preferably.

Also if you tune for E85, you cant switch back to petty as you will ping to high heaven, unless you got a ECU that can run in two modes and you can tune for each and switch between. Oh and expect to lose about 10-15% economy, but hey if you chasing the HP pot of gold im sure the word economy is not in your vocabulary.