2 stroke outboard fuel injection

[YamahaV4]

well howdy; so i plan on using a link ecu to run my custom fuel injection setup on my 1993 V4 yamaha 2 stroke outboard. right now im in the process of figuring out what sensors im going to need and am looking for feedback. this is a full custom race build so any ideas may be good ideas. im looking to use alphaN tuning as loopcharged 2 strokes dont work well with MAP or MAP sensors, and installing said sensors would be quite difficult given the intake design. right now my sensors are as follows

crank position sensor- for fuel injection timing                                                                                                                crank position sensor 2- for ignition timing                                                                                                                       intake air temperature                                                                                                                                                         Engine coolant temperature                                                                                                                                               throttle position sensor                                                                                                                                                       dual lambda O2 sensors- one for each cylinder bank

my question is im wondering if i should also run a fuel pressure sensor as well; and/or control the fuel pump from the ecm...also will these sensors be sufficient for what im trying to do here? I understand alphaN is somewhat limited compred to other methods but i think it would work considering in a marine applicaton engine load is fairly proportional to throttle input. 

thanks, chris

                                                                                                                                                                                                                           

 

 

[Adamw]

Yes, that will be fine.  A single crank sensor is all it needs provided you can use a missing tooth pattern such as 36-1.  Alpha N is fine.  The injection event needs to be timed with the transfer event so you need injectors that are big enough to get all your fuel in in ~<180deg.  Better still, injectors firing into the transfer ports if they are accessible.

Fuel pressure sensor is nice to have, but not essential.  TPS, IAT, ECT and lambda is all you need.  I wouldnt bother with ecu speed control for the fuel pump, this is typically only done to reduce noise.  Just use a reputable brand of regulator.  

[YamahaV4]

hey Adam that's what i wanted to hear. i didnt know if id be able to run both ignition and injection off the same sensor. il probably scratch the fuel pressure sensor then; regardless the injectors are the v-max injectors from a vmax V6 150hp. the injectors are the same type as what comes in a honda B16 civic motor so if they cant keep up im thinking of either running the pressure higher or just simply get bigger injectors. estimated power output is gonna be around 200~220hp good info about timing for the transfer port, ill probably be running batchfire like yamaha used in the vmax because ive heard timing sequential injection in a crankcase scavenged 2 stroke can be quite tricky