Important! : The ultimate guide for megasquirting your saxo/106

[saxosuper1600]

Hello everyone,

Im writing from Chile, South america i recently finished the engine on my citroen saxo vts turbo with a megasquirt EFI and i would like to share the knowledge of this very useful and cheap engine management system with you and make once and for all a thread with all the information to get you up and running with a system from stock.... (im not going to explain what it does or all the features in it just search for it on google) SO HERE IT GOES.

1) Buy your megasquirt from www.diyautotune.com, search in products, complete assembled kits and choose Megasquirt II or III v3.57 (if you have skills on electronics better to choose V3) and you are done.

2) Next you need to modify your ecu to match your saxo/106, i sent my megasquirt to some guy who did the electronics for me maybe someone in the forum knows what is needed or maybe you can match the pictures with some wiring diagrams in the megamanual page or ms2extra page













3)Wire your car exactly as this wiring

(mods resize if it dont fit please!)

ALSO AND THIS IS VERY IMPORTANT!! ALL DECODER WHEELS (SAXOS AND 106 USE 60-2 TOOTHED WHEELS) THAT USE 60-2 OR 36-2 ETC... YOU NEED TO SOLDER A 10KOHM TO 20KOHM (WHATEVER YOU FIND IN BETWEEN WORKS ALSO) IN THE SIGNAL CABLE OF THE CRANKSHAFT POSITION SENSOR OR THE ENGINE WILL NOT REV MORE THAN 2500 RPM!!!!!!!! (MEGASQUIRT LOSES SYNC WITH THE WHEELED TOOTH IF YOU DONT HAVE THAT RESISTOR WELDED THERE).

Here is mine:



4) Once you have all the wiring done you need to start with the basic settings to get you up and running, use the following as your BASE MAP to start your car and then MODIFY to your need.... I DO NOT TAKE ANY RESPONSABILITY ON YOUR ENGINE DAMAGED WHATSOEVER!!!! (THIS SETTINGS WORKED ON MY SAXO 8V)





Now that you have all this information you need to start your car and set up the megasquirt EFI to suit all your needs and start playing with your car, i hope everything shown here will speed up your process of megasquirting your car for me it took almost two months to do everything that is written here.

Thanks a lot and lets hope this will be your one and only Megasquirt procedure manual for all saxos and 106 around the world.

Tomas Preece

[Rossp]

Thanks Tomas! This looks like it might be useful to those wanting to follow this route who are adventurous enough to try it😄

[saxosuper1600]

Thanks, decided to make this tutorial for all the people out there who are in the same situation as me 2 months ago, and internet don't help in this kind of scenario for the PSA community.

This is my toy, T25 turbo with megasquirt EFI.

[luthor1]

You've got a PWM Idle valve wired in there which the 106/saxo doesn't have. Also only 1 spark output (saxo/106 is wasted spark) also, you have not got the 2nd relay in the relay section; on 106 this relay controls power to the vehicle speed sensor which operates the dashboard. Also, you have a HALL effect sensor in there, which the Saxo/106 doesn't have? There is no mention of the throttly body heater or the EVAP canister solenoid either? you have no MAP sensor on there, I assume you're using the one onboard the MS? You should note that it shares +5v with the TPS for completeness......

Hmm, maybe it's time I gave out my diagrams and workings to make sure people don't go down a route which may lead to problems

[saxosuper1600]

Hi, i dont have an IAC valve working so i dont use the PWM valve cable, the megasquirt was wired up on the first pictures to use the wasted spark system so i have spark A and spark B, also i use a tablet with 3g and gps to get my speed in a ddigitl dashboard (its only for reference because i will use this car as a trackday car so i dont need a very accurate speedo), also the megasquirt was modified to use a VR CKP, the trottle body heater also was removed so i dont need a cable to operate it, same with EVAP and yes im using the onboard MAP on the megasquirt i will only boost 1.2BAR so it should be ok but if you want to add more info please share with us.

Bye

[luthor1]

I think this should be a progress thread on a private project rather than a recommendation for others to use as a template

[luthor1]

Also please note: The ignition map in the picture shows 27 degrees of timing advance at 4000rpm / 200kPA, which is 1bar or 14.5PSI of positive boost.

This will wreck your engine. That's the kind of advance you would have on a throttle bodies car a wide open throttle 4000rpm, not a turbo.

[axsaxoman]

possibly not allowed for offset on crank pick-up?
but yes anybody that uses that or any other map without confirming everything as gospel is asking for trouble

[saxosuper1600]

What kind of advance do you recommend for a turbo setup then at 4000 with 200kpa??

[luthor1]

That's hard to say without knowing compression, AFR, and so on, but I'd guess somewhere in the low to mid 'teens for a turbo, more advance for a supercharger because it's not as hot on the intake side. Also I notice that you're using 117 as your crank angle, I think 114 is correct for rising edge. Also your required fuel is off the reservation at 22. You want it to be somewhere between 5 - 15 for proper scaling.

Idle fuelling should be around 50-65 which gives sufficient resolution to make mild changes. Assuming you're using Speed density and multiply-map even with huge power you should not be going that high on the Fuel table

[saxosuper1600]

My compression is on the 8:1, the AFR tables you have them there... for now im using only stock injectors for max of 0.6 bar because my 440cc injectors died, on the crank angle i saw people talking about 114 and 120... so i dont know which one to choose, so you think on high RPM and high load i should lower the value of the advance?.

the table was done with that values of KPA because thats the max i want to reach when everything is working properly.

[luthor1]

Your AFR table only goes up to 100kPA, which is atmospheric pressure (wide open throttle on a NA) and you are targetting 10.x:1 which is MEGA RICH! you should be targetting 13.2 at 100kPA, and smoothly transitioning down to around 11.8-12.1 at 200kPA so you need to attend to that

[saxosuper1600]

Ok but what about the ignition timing??

Everything you post here will help other people building their proyects and will be here saved for future references

Thanks a lot for your time

[saxosuper1600]

Didnt notice i made the scale up to 100kpa it was meant to be at 200kpa like the VE table i will change that.

[luthor1]

I mean for the ignition you should be looking at a normal N/A type curve on the 100kPA line, so around 10 degrees from 500-1200rpm, then pretty much a straight line up to 23 degrees or so around 3000rpm then sweep up to 28degrees at 7000rpm.
then at 200kPA should be aiming around 10-14degrees max advance and blend through the kPA up to that, but also it's key to have the AFR correct, so 13.2 across the 100kPA line and then blending down to 11.8-12.2 on the 200kPA line, and then go back and check for detonation

[saxosuper1600]

Luthor1:

I corrected my tables with your values please check them if they are closer to what you told me in your last post.

The idea is to have the basic numbers on the tables so everyone can make their own based on this thread.

[luthor1]

that looks a LOT safer to me.
on the 25kpa line you want to be idling at 12-14 degrees, and then bring the cruise and low kPA up to around 35 degrees, you can go quite heavy here, will help economy a lot!

Possibl a bit rich from 160kpa to 218, anything richer than 11.8 points to either *extreme* boost or problems elsewhere in the build if it has to be that high to supress detonation

[saxosuper1600]

Luthor1:

Again did the corrections you pointed out and this is the table (also i left on the screen also the old tables for you to compare on the same picture.

Maybe you have to correct me on the cruise and low kpa advance... maybe i did it steeper than is meant to be because it jumps from 5 on 5 dregrees to reach out 35 dregrees of advance on such short RPM range.

[barabimbarabum]

Anyone have pics from this thread, would love to get those injection / ignition maps.