That's cool, just made my day . My cold start is the last piece of the puzzle for my car. The switch to V7 went smooth, the switch to PSI Boost control went smooth, I just rescaled/redid my latencies for my injectors. In other words, the car have never performed better than now.
If I can just get the damn cold start thing to happen.....

 

I have been interested for a long time in optimum ignition timing during cruise, and I finally came across some results on another forum. A guy running E85 in an Acura that has cruise control did some controlled measurements of fuel consumption vs ignition timing showing optimum E85 ignition advance during cruise is actually a bit less than for gasoline.

http://e85vehicles.com/e85/index.php?topic=1893.0

 

That was a great thread, mrfred. I always use manifold vacuum as a sign of efficiency and correct ignition advance. The plots show the relation between IPW and mainfold pressure, so that's another data point that can be used as well.

The plot that I found most valuable there was the flame speed of ethanol compared to E85. This proves the point where we have said many times in the past that E85 needs less timing at peak torque than gasoline (unless the gasoline was knock-limited at that point). The flame speed of E85 is much faster than gasoline at those AFR levels. Very good data for E85 tuners.

 

i've been looking for e85 flame speed / combustion rate data as well. that plot in the post is very interesting, but it would be good to find its source. its likely representative of either manifold vacuum or cylinder pressure much less than what we subject our motors too. it looks suspiciously smooth too.

 

This would be a nice paper to have: http://papers.sae.org/2010-01-0620/

 

i think i can get that.

 

Here's a nice paper with some good data: http://www.psfc.mit.edu/library1/cat...ja010_full.pdf

There is a nice charts of flame speed for different fuels, similar to what was posted in your link.

 

I saw that when he first posted it awhile back. Tried that with the Evo and saw a loss in MPG, perhaps I was already at the optimium somehow with luck...

I cruise it in the 40's

It's for sure going to depend on head design as well.

I've been noticing my 4B11 isn't responding well to higher cruise timing like my 4G63 did/does.

 

Definitely agree on head design factor. I'm in the low 40s now. Once I get live mapping working, I may have a go at testing different timing values.

 

Here are a bunch of articles on ethanol fuel blends. Some good, some not so good. Sorry, no SAE stuff.

 

Mrfred, anything changed with your timing map. You've been running it a long time now so I was curious if you learned anything along the way and applied it. Thanks!

 

i've made some minor changes for new turbo, manifold, cams, etc. timing map will definitely vary with mods. tuning method is still the same - start with low boost (e.g., 15 psi) and conservative timing, set afr to 11.9-12.2:1, tune to mbt, back of timing 1-2 deg in the newly tuned cells, go to next boost level (e.g., 20 psi), tune to mbt, back off timing 1-2 deg in newly tuned cells, add more boost, etc until reaching the point of diminishing returns on power vs boost.

 

good read!

Thanks for all your info, time, and willing to share your data with us.

I just got fuel injectors and am going to start self tunning in the next few weeks.

 

bump for a awesome thread. i have been planing on switching to E85 soon and this thread has cleared up a lot of my questions towards it. i still have more but before i ask them i will continue my search a little bit longer.

 

Tons of good info here! I'm going to test some of these things on my X.