Injector firing order
Guys I think I just had a revelation.When I wired up my MSII,I followed Peter Florances L-Jet - MS wiring diagram.This groups injectors 1-3 on one output and 4-6 on another.Given that the firing order of our engines is 1-4-2-5-3-6 wouldn't it make more sense to group the injectors (1,4,2) & (5,3,6) particularly if using "alternating" injection banks on the MS.It seems to me that you'd want to squirt as close to the cylinder intake stroke as possible.
1986-GTV6
1989-75 Twinspark very sadly sold-remarkable sedan !
2014 Audi Q5 3.0l TDI - torque MONSTER
1989-75 Twinspark very sadly sold-remarkable sedan !
2014 Audi Q5 3.0l TDI - torque MONSTER
Murray,The dynamics of what happens to the fuel and air in the intake port during operation are such that you will have remrants of mixture in the port all the time,it does not all go into the combustion chamber all the time..
I find that I prefer firing all 6 injectors at the same time as in multipiont firing mode..By going batch firing as you want to,idling is not as smooth,your injector open time is larger..As you accelerate this means nothing though..For me its a smoother idle..
Ive run my car on true sequential and found that after a LOT of playing I could get it as smooth as a std 164 multi valve motor at idle..Its not that easy to do..performance was on par with the other setups,but if I had to choose,Id go multipiont(all firing at once)Its the easiest in the long run..
I now try and set up most engines I do in the phase sequential mode,this is when the injectors follow the firing of the pairs of coils.
1,5,3.4,2.6. On the newer ecu`s this is very good..This is what you have now,I believe..(Haltech,Dicktator,Gotec etc..)
What you need to do is play..Go with one ,evaluate ,then try the next..Youll pick up the differences soon enough...
Happy playing and welcome to a new dimension of fun..
I find that I prefer firing all 6 injectors at the same time as in multipiont firing mode..By going batch firing as you want to,idling is not as smooth,your injector open time is larger..As you accelerate this means nothing though..For me its a smoother idle..
Ive run my car on true sequential and found that after a LOT of playing I could get it as smooth as a std 164 multi valve motor at idle..Its not that easy to do..performance was on par with the other setups,but if I had to choose,Id go multipiont(all firing at once)Its the easiest in the long run..
I now try and set up most engines I do in the phase sequential mode,this is when the injectors follow the firing of the pairs of coils.
1,5,3.4,2.6. On the newer ecu`s this is very good..This is what you have now,I believe..(Haltech,Dicktator,Gotec etc..)
What you need to do is play..Go with one ,evaluate ,then try the next..Youll pick up the differences soon enough...
Happy playing and welcome to a new dimension of fun..
Thanks Barry - So basically it's not worth splitting hairs on this issue.I will continue to fire alternating banks as the MS tuning instructions suggest that doing so smooths out the rail fuel pressure drops as compared to shooting them all off at once.Seems to make sense and my idle is very smooth using this method.Probably my "S" cams are a little bit more conservative than what you're sticking in there. 
1986-GTV6
1989-75 Twinspark very sadly sold-remarkable sedan !
2014 Audi Q5 3.0l TDI - torque MONSTER
1989-75 Twinspark very sadly sold-remarkable sedan !
2014 Audi Q5 3.0l TDI - torque MONSTER
Murray,dont let fuel rail pulsing be of concern...This only becomes an issue on our motors when you start sticking in 600 cc and up sized injectors.And then not too bad either..Can you batch fire all the injectors??
You will find you will be using smaller idle open times and its probably worth playing with,even if its only to see the other side..
Remember that the average injector needs about 1ms in response time..So if youre already sitting at below 2ms for idling,I would not go batch as the open time will drop further..
Ive just done a 30l 12v using the original low impedance 2.5 injectors and find with batch my idle open time is about 2.6ms..this I mention for reference only..
You will find you will be using smaller idle open times and its probably worth playing with,even if its only to see the other side..
Remember that the average injector needs about 1ms in response time..So if youre already sitting at below 2ms for idling,I would not go batch as the open time will drop further..
Ive just done a 30l 12v using the original low impedance 2.5 injectors and find with batch my idle open time is about 2.6ms..this I mention for reference only..
Barry - yes MS gives me the option to batch fire my injectors and I will give a try.
I'm using stock spec. low impedance injectors.Much of the MS setup manual is derived from people working with NA V8's with gigantic injectors so what your saying makes perfect sense.Currently I'm sitting at about 4ms pulse width at idle using "alternating"which includes the 1ms.opening time.Would I be correct in understanding that I should be batch firing my injectors once per 720 deg.?
I'm using stock spec. low impedance injectors.Much of the MS setup manual is derived from people working with NA V8's with gigantic injectors so what your saying makes perfect sense.Currently I'm sitting at about 4ms pulse width at idle using "alternating"which includes the 1ms.opening time.Would I be correct in understanding that I should be batch firing my injectors once per 720 deg.?
1986-GTV6
1989-75 Twinspark very sadly sold-remarkable sedan !
2014 Audi Q5 3.0l TDI - torque MONSTER
1989-75 Twinspark very sadly sold-remarkable sedan !
2014 Audi Q5 3.0l TDI - torque MONSTER
Murray,I would fire my injectors once per 720 deg..Id use a devide by 3 on a 6 cyl.
If you fired every carnk rev,you should end up with about 2ms..at idle..
I suspect it might improve idle and response for you..It does mean remapping again..But save the original so you can go back if you want to..
This is fun,huh??
*Toyota are fond of using large injectors and firing them every second crank rev up to about 3500rpm,it the fires them every crank rev for additional fuel*
If you fired every carnk rev,you should end up with about 2ms..at idle..
I suspect it might improve idle and response for you..It does mean remapping again..But save the original so you can go back if you want to..
This is fun,huh??
*Toyota are fond of using large injectors and firing them every second crank rev up to about 3500rpm,it the fires them every crank rev for additional fuel*