ccarlisi

As many of you know I am trying to decide on what ecu to use for my 20b project car. One of the ecus I am looking at does not appear to allow primary and secondary injector events to occur at different angles relative to TDC. I have read and heard that this is important because the secondary injectors are further away from the intake ports than the primaries.



Does anyone have any experience running no split between them? Also what is the ideal injector angle settings for the pri and sec injectors? The E11v2 manual states that injection events should fall between 90 and 270 deg BTDC. I tried to map that out using the quicktime diagram on www.rotaryengineillustrated.com with reference to both e-shaft and rotary face rotation and it seems way too broad.

j9fd3s

ive run the e6k, e11 v2 and seen a stock ecu 20b run (doing another stock ecu 20b, in the next couple months), and the injector phasing is one thing i did get to play with.



a. we have the cosmo new model training book, and it has the injector phasing map in it, mazda doesnt phase the injectors differently (unless i'm reading it wrong), although they do seem to be harware limited.



2. i played with the injector staging in the parking lot with not load, and it made no difference, so i just used the values in the cosmo book, as i had other things to tune/worry about (such as the ecu shutting down and leaving me stuck!)



3. timing of the injectors changes (i'll try to get a sample) in 3 phases with rpm. at low rpm its a lower value (i wanna say around 90btdc, but dont quote me), and then it advances so by 3kish rpm its 200ish BTDC. cosmo book is at the animals house, but the fc book, and the rx8 book have these graphs too, so i'll try to get some kinda pic up

ccarlisi

Thanks, that would be a great!

j9fd3s

try this one http://wombat.sevarg.net/RX7/RX-7_Training_Manuals/



you want section 4 fuel and emissions, its around page 36. the rx8 has a better one, but pauls got my book, and ivans got the cosmo book

enzo250

In order to really get a benefit from injector timing you'll need to have a seq system with big injectors.

IF your trying to do it with small injectors they need to stay open alot longer in order to get the required amount of fuel you need so you cant really play with timing to much. Also this effects mostly idle and part throttle conditions. So if your worried about the timing of the secondaries your stressing out for no reason. At WOT is has little to no effect.

j9fd3s

good point, thats prolly why i didnt notice a difference. going from batch to sequential is such a big difference you can tell from across the parking lot, but the timing didnt do much, so we just set it like mazda did (stock injectors, motor, turbos, map?)

ccarlisi

J9fd3s, thanks for posting the pdf. On page 4-36 there is a diagram and a couple bullet points on fuel injection timing.



-at an engine speed of less than 3,000 rpm, fuel injection occurs at 95 deg BTDC (rotor angle: 31.7 deg).

-at an engine speed 5,000 rpm or higher, fuel injection occurs at 185 BTDC (rotor angle: 61.7).



What points in the cycle animation at http://www.rotaryengineillustrated.com/re101/cycle.php do these values correspond to? It is clearly not TDC of the compression stroke; adding 360 does not seem to work either. BBDC of the intake stroke makes some sense, but I find it hard to believe Mazda would mislabel it in the manual. What am I missing?



I have put together an Excel spread sheet and graph detailing the injector timing settings in the Haltech e11v2 1.62 2 rotor base map. Notice that the high rpm values are in excess of 360 degrees which corresponds to 12 noon on the intake stroke. The timing split range is about 10 deg between 2,000 and 8,000. That does not seem like a whole lot of rotor movement. I wonder what would be lost in terms of fuel economy and/or power by locking the split in around 10 deg.

ccarlisi

Thanks for the reply. I'm using 83lb primaries and 160lb secondaries at standard fuel pressure. Based on your response it doesn't sound like there is anything wrong with running split that is 5 deg +/- off optimum (assuming that the numbers provided by Haltech are a good reference).