MicroSquirt.com read only forum (Jan.15,2018)

Dudes:

check out this datalog. i think i nailed it with 0.4ms opening time, and i adjusted down the voltage correction pari passu.

AFR, RPM, & MAP are all pretty much rock solid through the transition. i unplugged cam sync, let motor run for some moments then plugged in. you can see the pulsewidths move from 1.8ms to 3.2ms.

very buttery.

i'll start working a bit on the accel enrichments, but i'd like to settle on injection timing first so i don't have to redo accels. playing around a bit with injection timing did not change AFR, but i would think during accel the rules change.

i'm seeing a bit of noise on the TPS signal now, but prob from my nesty wiring. i think i'm going to wire this thing in a permanent fashion. i think the sequencer is the one.

Bruce- you share some great information, thanks.

I'm really interested to see how you go about tuning injection timing. Even though I've written the sequential injection code for MS2/extra, the tuning part is still somewhat obscure to me.

Jean

racingmini_mtl wrote:I'm really interested to see how you go about tuning injection timing. Even though I've written the sequential injection code for MS2/extra, the tuning part is still somewhat obscure to me.

Jean

Jean-

i'm not sure it will be too meaningful what I end up doing on injection timing. first crack at this is not showing super noticeable differences with injection timing, although i will try 5 or so spots around the cycle and record them to see if any difference can be noticed. i won't be using any multi-gas meters. i suppose i will end up timing my injection cycle based on some of the SAE stuff that Bruce is sharing, and some other research. if i find anything interesting i will be sharing it.

Scott.

What Bruce has been saying and what we experienced long ago in my car is that there isn't generally much noticeable difference between batch and sequential, but sequential will allow you to really screw things up if you purposely inject during exhaust open on each cylinder. That is bad from every standpoint - performance, emissions and economy. With batch it is impossible to do this, but it is also impossible to tune so all cylinders get optimal emissions (by squirting on the hot intake). That is the main reason oems went to sequential Also, with an 8 cylinder it becomes very hard to tell what is going on, because in batch only 1 out of 8 is probably getting bad injection timing at any given instant. It might be more apparent when people with 4 cylinder engines try it.

But another advantage with sequential is individual cylinder trim. It will be interesting to see how this helps people with distribution problems and people with turbos.

Sorry to change the subject but I assume that another nice thing that sequential can provide is a softer fuel cut rev limiter. If you cut only some injectors in an alternating (or round-robin) way you'd get a much smoother, and still safe, rev limiting. I don't know if this is implemented or even on the road map but that would be a good feature to have.

Jean

Yes we had soft rev lim in there too and that can easily be resurrected.

In trying to follow this thread and learn some good stuff, I find that I cannot figure out how to read the .msl datalogs. What application is needed to read these files?

Brian

I cannot figure out how to read the .msl datalogs. What application is needed to read these files?

It's tabular data. A text editor will work, as will MSexcel or other spreadsheet program.

cmonref wrote:In trying to follow this thread and learn some good stuff, I find that I cannot figure out how to read the .msl datalogs. What application is needed to read these files?

Brian

Brian-

Excel should open it right up, or use MegaLogViewer http://www.ideasandsolutions.biz/MegaLogViewer/

Scott.

A slight change in topic...

I have the seq. fueling and sparking the engine - but needed to really crank the Req Fuel by over 3:1 to get the VE, WUE, ASE with in range. Even then the VE table at idle had to move from VE = ~15 to VE =~ 40 to get a good idle. This is with the seq. running in wasted mode.

The Req fuel is a comparison to the MS2 which is decently tuned. << running 6 injectors, 6 cylinders, 6 squirts alternating.