I believe mine had similiar discoloration as well - prior to running E50. I'll look when I get a chance.

It is already available and has been for some time. They are fighting a losing battle.

I also have similar cap discoloration, and never used an ethanol blend.

When I had issues with leaking injectors it was always from the smaller seal at the top end where it seats on the rail, not the larger one close to the nozzle. Not to say you wont have issues, just some feedback. Brettus, perhaps you could do a test by leaving a spare seal soaking in some E85 for a few weeks and see if it comes out weaker.

The first photo is of two relatively new injectors that saw E50 for a couple months. The rest of the photos are old injectors that never saw more than E10.


https://cimg7.ibsrv.net/gimg/www.rx8...5a250eca7d.jpg

https://cimg8.ibsrv.net/gimg/www.rx8...ff7e493b5e.jpg

https://cimg9.ibsrv.net/gimg/www.rx8...a345920fd5.jpg

https://cimg0.ibsrv.net/gimg/www.rx8...463b8ea6b3.jpg

So do you guys just not have the fuel system capacity to run e85 or what's the deal here?

Straight E85? Even if you could tune for it no way I don't think without significant fuel system upgrades. My 335i will need port injection to handle full E85 and high boost.

For me it's more about the size of the tank and how far I can get on it . E50 seems to be a good compromise between ultimate knock resistance/power and range .I feel that I would have to go to another round of mods to run E85 at my power level as well .

Just retuned on E50 after fitting larger injectors and everything seems ok on the stock system (with uprated pump and injectors) to 16psi/400+whp ...................... so far.

Brettus, what injectors did you go for?

Blues in p1 then 4x uncapped yellows.Seems to work well . Took about an hour ;)

This may be a dumb question but I have plenty of them.... Since carbon is a common problem with the 8 and ethanol runs cooler than 93 octane, do you guys run into any carbon build up issues going with the e25/e50? I'm assuming the frequent redline helps prevent carbon build up like usual.

I doubt the amount of cooling is enough to make any difference but theoretically ,as ethanol burns without deposits, there should be less carbon deposits the higher in ethanol % you go.

Makes sense. I've been doing a ton of forum reading the past few weeks. I'm getting ready for a turbo swap in my newly acquired shinka. It's been molested by the previous owner (87 octane pure gas, dumb old lady). The thought of e85 turbo pleased me but it seems the fuel delivery isn't enough really worth the effort. The e50 has my interest though.

You will be struggling with E50 on the stock system as well .

This was the conclusion I came to as well... :icon_tup:

I'm with brett and Slash on e50. you get the important benefits of e85 for a street car. I think going full e85 would be more beneficial on a track car as going full e85 adds more combustion cooling benefits

Do you think the seals will hold the high amounts of boost that ethanol can provide, like 18+, or will detonation occur before we reach these levels?

@9k How much boost are you running if you don't mind me asking?

I know 9k isn't much of an Atkins fan but with the E50 is there any need for cryo treated parts?

Of course ...that is mostly the point of using it .

I am running 10-13psi at the moment.

what octane rating do you guys get on E50 and E25 blends respectively?

Have a read thru this attachment.

TL;DR:


https://cimg3.ibsrv.net/gimg/www.rx8...4f9b6d4aef.jpg

It's not really fair the put E85 on the traditional "anti knock index" that gasoline is graded on here in the US.

The evaporative cooling properties and cooler combustion temperatures of "alcohol" fuels is a big part of its knock resistance. Good E85 can hold its own even against 105+ octane race gas.

I'm no expert, just sharing what I found. They do discuss cooling effect in the paper, IIRC. What I can tell you from my own personal experience is that I ran E50 up to 12.5 AFR at 15psi or so with no perceptible knock. So for a street car I was happy with the benefits of E50 without taking quite the MPG hit of E85 :)

So I've agonised over this a lot and finally came to the conclusion that E30 with oem seals is the way to go for a high power Renesis for these reasons:


*good octane boost taking 93 octane E10 to 96 octane (101 octane for us in NZ)
*good charge cooling eliminating the need for W/M.
*Engine and intake should stay clean and carbon free.
*reasonable mpg .My research suggests 20-30% is the best ethanol level for mpg. Some piston engines are getting same mpg as straight petrol.
*Easy to work out at the pump , 1 part E85 to 3 parts E10 gives E29. Should also mean I can easily carry extra E85 should I want to travel far from a pump.
*Good wear characteristics for a long engine life with the oem seals . Octane and charge cooling effects should minimise the possibility of apex breaking detonation events . (I had excessive wear with E50 and an aftermarket seal combo.)

I'll also be running an AEM failsafe guage to minimise the possibility of a leanout event killing the engine.

Curious - if E10 requires a lower air:fuel ratio at stoichiometric than real petrol, how does the ECM know this and adjust? Is it the O2 sensor that corrects - preventing a lean burn situation or loss of power?

O2 sensor reads Lambda.....so it doesn't care what Stoich is..... O2 sensor allows for fuel to be added or subtracted up to ECU limit of trims to get it right.