Can you on a MS1 V3.0 trim between front and rear rotors as the rear rotor generally runs leaner than the fron i have found on EGT sensors

is there any way to trim as on other ECU's or will i be just finding a happy medium in AFR's and EGT on both rotors ?

 

One signal from the MS runs both the primary injectors. One more signal runs both secondary injectors.

 

yes i get this but can i not make a screw type trimming pot to more accuratley control each primary and cecondary injector ?

because i know one rotor will run lean or rich out of the two a WB sensor only picks up whats coming off both rotors where as my EGT can read individual b4 the turbo which shows a lean condition on the rear rotor and a normal tune afr's off the O2 sensor LC-1 front rotor egt's are good

where with microtech you can trim each injector i think one model of ecu does this

so my idea would be to construct a sepereate box for the injector bank wires to go to first with 4 x Pot screw driver type

1 x Front prime
1 x Front secondary
1 x Rear Prime
1 x Rear Secondary

with a trim of +/- 10% of Signal

If this is possiable what pot ranges would i need and resistors this would be a mechanical trimming device instead of a digital ecu controlled device

this is a critical area in rotarys as rear rotor lean out condition can happen with good afr's as you only reading the overall afr not on a individual basis

compression on particula engine in question is the same on all rotor faces front and rear, all injectors are brand new and flow tested (750cc prime 1600 second) ports are port matched laser cut so are identical

 

You would need 4 injector channels to do that,and there is only 2 on the current MS's (with injector staging you are stuck with the primaries on one channel and the secondaries on the other).Since there are only 2 signals I can't see how you can change 4 injectors individually. The add-on sequencer they are bringing out would be able to do that since it's designed for seq. injection(more fuel/ign. drivers controlled via CAN).Plan on at least doubling your MS expense with that product. Injector trimming on a Turbo rotary is a very appealing option though.Have the injectors flow tested and put the highest flowing in the leanest rotor and call it a day(for now at least).

 

hrmmm i know it is frustrating though lol

what is this device you metioned info links etc

i think injector trimming is a vital aide for turbo rotarys more so for high boost applications because rear rotor lean is to common and most people dont see it via wide band the only way to know is via egt

 

You could run a little bigger of injector in the rear. If you could get your injector flow tested and see if the some of them flow more than other and install them in the rear. Or get custom sized injectors.

 

Quick serch of the Megasquirt site,check there for more info.

http://www.megamanual.com/seq/index.htm

http://www.msefi.com/viewtopic.php?f=92&t=28604

They are also apparently bringing out a daughterboard version where the expensive ampseal connectors will be replaced with header pins.That should be a noticable cost decrease.Here's the link on this years MS plans/outlook by the developers.

http://www.msefi.com/viewtopic.php?f=92&t=31305

The hardware side may be out soon but someone still needs to write code for it to work with staged injection,etc. so it may not be useable real soon.

 

We're also starting dev on the ms3. I've actually already started designing the ignition code for that.

Check out ms3efi.com for updates.

ms3 will definitely support per rotor/cylinder trims, even when staging.

Ken

 

hi muay is this gonna be a cpu change or a whole new unit to build ?

 

also is there no way i can make a trimming boxt on the individual injector voltage ie run a trim pot on the 12v of each injector and use that to decrease voltage to lean it on the front rotor to brin it in par with the rear and then map from there into a acceptable afr ?

so scenario i trim the input voltage on inj front prim to 11volt and run the rear inj prim at 12v wil that 1v or what ever voltage it may be .5v etc you get the idea

will that in turn lean the front injector enought to bring it on par with the rear so it can be mapped up

i mean i could put the highest flowing in the rear and call it a day but im a diy efi guy so if i can have atleast a wee bit of control over it i would love it ?

i might test it on and old injector and see how much it flows at 12v and then at 1 v increments what type of pot would i need for this muay that is controlable with out fluctuatuion ?

 

First of all, I wouldn't wait for it, it'll probably be Christmas before it's ready.

Second, it's going to be a completely new unit, but not to build, it's going to be all SMT most likely. It'll also probably be considerably more expensive than the current MS options (will support 8 fuel, 8 spark, 7 high-current outputs, 8 low-current outputs, several 0-5v ADC inputs, several on-off inputs, VSS, etc...).

Ken

 

That assumes that the amount of trim you want per-rotor is always the same no matter what load, RPM, etc... you want. Most likely this is not the case.

Ken

 

Hey ken, this is just a thought... For staged injection on the new stuff you guys are working on. I think that it would be a good idea (I don't know how feasable) to add injector open timing for secondary injectors as well as primary. More precision to add when they stage making it smoother. Just a suggestion and I don't even have a clue as to how hard this would be. I figured I would throw it out there. Its not something I have seen but I know it would help with high rpm tuning for turbo aplications where much larger secondaries are often used.


dpf22

 

IIRC that is a feature added in ms2-extra 2.0,maybe someone can comfirm that though.

 

If it is in the ms2 already then sorry for mentioning it. Sadly enough I haven't had enough time as of late to look into the 2 very much. However, it stands as a "good idea" anyways

dpf22

 

Correct

 

hey what is the other signal on the injector i know one is 12 v but what is the ecu signal is it a variable current ?

 

The ECU grounds the injector to open it. Current is controlled by PWM when in the "hold" state.

 

Injectors do not work the way you seem to think they work.

They are either open, or closed. If you reduce the voltage to the injector, you will not reduce its flow, until the point where the injector isn't opening. At that point the flow will be unpredictable.

The way injectors are controlled is by opening them for a calculated *length of time*. That is not something you can adjust with a resistor, it is something you adjust with software. Which is why you would need a separate injector driver for each injector, because each injector's opening time would have to be individually changed.

The easiest way to do it with currently available bits is to not use a Megasquirt.

 

Yep, as the others have said, ms2/extra has this feature.

Ken

 

yay my ? is answered thanks guys i will flow test my injectors and put the largest in the rear

 

RX3, I think a lot of people would really appreciate it if you'd get rid of those huge pictures in your sig. Seeing them once was plenty.

Thanks,