I was wondering if its possible on MS3X? I'm building a Semi-PP engine and was looking to run injectors with the new ports. Would save me from having rather large secondary injectors (~2500cc). If it is doable how would one go about wiring it/setting up the software? Thanks guys

If its not possible I'll just relocate the secondary rail to the pp's runners.

 

There are two ways to accomplish this. If you want staged control as follows, it will require another output per injector from the MS3X
0-3000: Primaries only
3000-6000: Primary & Secondary
6000+: Primary, Secondary & Tertiary injectors

I don't see a reason for needing tri-staged injection like this though. Proper tuning can have your car run properly just on the two primaries and the intended four secondaries.

The other way is a trick that C.Ludwig showed me for use on a Haltech, it should work fine on a MegaSquirt as well. It involves setting the ECU up for High Impedance injectors and then run two Low Impedance injectors in parallel on each of the secondary injector channels. Both injectors will operate at the same time, acting like a really big, high flow one. As long as the ECU sees the same or greater impedance than the injectors have, it will be happy as a clam to deliver the goods.

 

Parallel the injectors with an appropriate resistor.

Use an injector driver board to split the injector channel. Just tie the inputs for two channels on the board to one output channel on the MegaSquirt. One such board is this:
Peak&Hold Injector Driver Board for Megasquirt

But they are available from several vendors.

 

I would use the primaries on the ms3x and the 4 sec. 0n the v3 injector output.

 

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Hello, i´m using 8 injectors on my setup with MS3.

They are high impedance 14 ohm, 4 in parallel for primary, and more 4 in parallel for secondary, each one have about 200cc, because they
are from a 2005 CBR600RR.

I have try staging at 3500, 4000 and 2000rpm, no problem at all, and very smooth the transition.


Depending on the size of your injectors, you can use 2 for primary, see if they can handle till 3000rpm on every load, than use the other 4 injectors
for the secondary, if they are low impedance, use the resistors as already advised here.


Hope you find the better way to make it work.


Regards

.

 

I don't think I want to run a Tri-staged injection either, as it probably won't be necessary. Thanks for the other info though.
Like both you and Aaron said I might go down the route with two injectors on one channel. Although I was hoping to run all high impedance injectors, we'll see.

Hmm I haven't though about that. Would you setup the MS3 to be on a tbi setting for the other 4 injectors or?

This seems like more of what I wanted to do. Do you have all the injectors on the MS3X outputs? If you're even running MS3X it that is.
Would I be able to see what kind of ecu settings you're running?


Thanks everyone I'll have to play around with these and see what works best in my setup.

 

the 2 primaries on stock location(ms3x)and the 4 secondary (v3 board)on a modified lower intake manifold or tbi your choices.

 

This seems like more of what I wanted to do. Do you have all the injectors on the MS3X outputs? If you're even running MS3X it that is.
Would I be able to see what kind of ecu settings you're running?


-----------------------



I have build as Aaron setup, all as it was only 4 injectors, the only
difference was that instead of 2 in parallel, for prim and sec, i
use 4 in parallel for each one.

They are all connected to the Ms3 outputs, but all are high impedance.

Here you can see on the last page

https://www.rx7club.com/megasquirt-f...-835786/page3/


Do you want my MSQ file ?

Regards



-

 

I don't have a car running with this setup yet. but its a option especially if you have hi and low ohms injectors and don't want to use resistor or a peak and hold board the way you have your injectors wire should work without a problem.