Megasquirt ECU

[James Bowen]

Thanks,......but I was thinking of "Track'n'road Powerformance" in Rainham, Essex. They are the Rolling road operaters that set up the ignition management.

Professional, and their road gives repeatable, consistant results, without pandering to customers wish to see big HP rather than the truth.

Personally I wouldn't recommend KMS. It works fine on my car. But aftersales wasn't brilliant. QEP on the other hand, I would recommend. Mark the owner isn't someone who does bodges, and the firm started out as a precision machinists. Mark developing the engine side as that is what interests him.

Regards James

[Walezy]

Hello Guy,
You have asked about an info from someone who has running and tuned Megasquirt. Well, I am running my car on this ECU and it works good.
I am using 2.0 l Fiat 132 engine with 16v head from Lancia thema. The intake manifold is modified Fiat 2.0 16v turbo with 4 x 44mm slide plate throttle body. Camshafts are standard Lancia thema non-turbo. Pistons are cast taken from Fiat Tipo 1,8L(it has a little dome). Conrods are lightened standard ones(690g), Flywheel is lightened(quite a lot but i have not checked the weight). Exhaust manifold is 4-2-1 with primary pipes 38mm and secondary 42mm.
Head has been ported by me but I am not able to check it on the flowbench.
I am using standard valves and valve seats are not modified.
Right now I am using standard wet sump oil pump with accusump(previously I used dry sump with Titan oil pump)
I am using Fiat Coupe turbo fuel injectors and fuel rail.
I have tuned the engine on MAHA LPS 3000 dyno. I have made it by setting the rev limit(on dyno) by 500rpm from 2000 to 7000rpm and I was using different load(light throttle to fully open throttle) on each rpm limit.
I have used speed density mapping with MAP connected to all 4 intakes with little fuel filter before the ECU to damp the pressure jumps on idle. I am thinking of Alpha-N right now but i will wait until I get somewhere good cams for this engine.
The engine has most torque at Lambda 0.86.
I was able to tune the ECU to have smooth running engine and after i used mapped ignition(not on the dyno plot) the engine got a lot more torque than it was on standard bosch distributor but i have not checked it on dyno(I am thinking of at least 10Nm in almost whole power band as the ignition was way too early on distrirutor)
I am using 2 fuel maps(road/stage) and launch control. Everything works perfectly, engine idles smoothly at 700rpm, i has good throttle response and it never failed. I have done all the build and tune up with my friend(co-driver) and we never used any assist of any kind of professionals.

[Guy Croft]

Tomasz, I'm pleased and impressed, well done.

I was really hoping there would be someone who understands MS and has fitted it and got good results. I would certainly like to know more.

Please would post this in the Competition Engines section under Megasquirt fuel injection. I have opened a new thread for you. Please edit the graphs using some dotted lines as the colours and thickness are not clear enough. The subject will be retained as an announcement to keep it at top level and you can add to it when you wish.

Thank you for taking time to write,

GC

[Piero]

Hi,
I read with interest, and wonder if any one has any comments on the Weber Alpha system that Guy spoke of.
how does this system compare.

[berkut]

This is my first post over here, so Hello Guys !

A few words of introduction to my Megasquirt instalation.

The car i owned at that time was a Ford Escort RS Turbo, the stock engine runs on a KE-Jetronic mechanical fuel injection system. After some upgrades to the engine (some head porting, forged internals, a hotter cam, an Ahmed Bayoo ignition computer chip) the injection system itself, regarding engine power wasnt bad, the biggest drawback was the high flow resistance the vane type flowmeter produced and the engine behaviour, to put it short the car could be driven either really slowly, like when youre driving for your grocery store or hard, with the boost almost all the time at the max.



I get really attached to my cars, so was the case with my RS Turbo, the decision was made to buy the Megasquirt 2.2 and a V3 pcb.

A few things i need to add over here. Many peapole think they only need to buy the engine ECU and the costs end here. In order to sucesfully install any new engine management you need tools to monitor the engine, that's why i bought a Innovatec AFR widemand meter and a EGT temp probe. The megasquirt unit comes pre calibrated for GM type sensors, thats why I bought them too, calibrating the MS unit for different sensors may be difficult at times. As a finishing touch the complete wirering harness was ordered too.

I never intended to controll the ignition with MS (the chipped stock ignition system off the KE-Jetronic engine management has a knock sensor and was mapped good enough for a proper job) so i didnt buy anything for it. Normally i would buy a Ford EDIS unit.

Wirering and installing the system is a snatch, it took me half a day to complete the entire harness, hack it in to the Fords wirering and do some beta tests. The megasquirt harness has labels on each wire, your really cannot miss it. Beacause the stock manifold on my Ford was for the CIS type injectors i had to change the inlet manifold to a EFI one, the injectors were VW G60 short nose green top bosh injectors. The sensors were bolt on with the Ford threads and everthing fitted perfectly. The idle air valve i choosed was a stock ford type soleneoid controlled via PWM, the lambda sensor was off a Fiat Seicento.

The hardest part: tuning the megasqirt unit.

At the time when i was installing MS in my car i had good knowlege of how EFI injection works, know a lot about engines, tuning them, still i was lacking experience, this was my first time ever to do such stuff alone.

Setting up the unit with the tutorials on the Megasquirt.info site is a breeze, took me about 1 hour to understand and set everything before startup, turn the ignition key and after 10 min of trying the engine idled properly on a generated map. A few more minutes playing with the fuel enrichment for throttle response, some adjustments to the map the engine was finally warm and i could try to drive out of my garage. After a few stalls i a lot of experiments with startup values i managed to get out of it and start setting up the fuel map.

To be honest - this is about as easy as it might get. I have a 3 mile long strech, set the boost to 0.1 bar (lowest possible), a laptop on my knees, the wideband in my hand, my Father behind the steering wheel and the megasquirt 3d display of the fuel map.

The procedure is simple: 1000rpm, WOT, I watch the AFR display, pick up a fuel map point and set it richer or leaner untill the desired effect all the way to 6500rpm. Up the boost, do everything again.

A few things you will imidietly notice is how easy it is to set WOT maps and how much better the car runs. The boost came 1000rpm earlyer than on the KE Jetronic (2200-2500rpm vs 3200).

Setting part throttle is simple too, just observe the MAP pressure and try to keep it constant with the throttle for the entire rev range. Done. The fuel maps are basicly set.


Unfourtenetly first problems start here.

Setting the crancking PWM signal for the injectors is a guess and try game. You can not simply copy the values from a knother engine beacause you will either end up lean (thats when youre lucky) or flood the engine. There are 2 parameters you set, one is for -40F and the second one is for 170F. It really takes time to set everything properly for the engine to start without a hassle at -20C temps as well as when its 80C.

I had no knowlege on how much do i need to enrichen the mixture for the engine during cold startup. Its really a matter of guess and try before setting it up, and it can take a while, it took me a week before everything worked flawlessly and the mix was spot on.

The EGO is simple to set up, just a matter of a few experiments and some gentle driving through the city.

The hardest part and the biggest drawback:

The enrichment table is really hard to set on a turbocharged car. To put it simple - its too small. You can set it for TPS and MAP and later decide wich to use more (you can pick wich map you want to use more, in %). I have found the best way to tune the engine is to record logs and set the pulse times according to them, save the settings and take her for a short spin.

When set for normal daily driving the car will perform correctly as long as we drive normally, change gears taking our time. To put it simple - when boost is vented to the atmosphere before the throttle is pressed again everything's ok. As soon as we start to rapidly change gears the pressure rise inside the manifold is too high and the engine leans out and loses power.

If the acceleration enrichment tables are set for hardcore driving the engine will flood everythime we press the accelerator during calm driving.

Maybe i am not skilled enough, or it was a matter of the configuration but i never managed to make the engine smooth enough in all driving conditions. I just couldnt set it right. 3 or 4 set points are missing.

When i set the engine for n/a operation it took me 15min to set it to a super smooth and perfect state in all conditions.

I think its a problem related only to turbo / super charging and speed density setting, i belive that there wouldnt be any problems when set to Alpha N or hybrid, but in that case the use of a turbo/super charger isnt possible.

The second problem. MAP reading. Digital interpolation is poor. It just makes your signal change too slow. If we connect the map sensor directly to the manifold and set it for the highest sensitivity it will read every pulse in the inlet manifold.

One needs to find a orifice and expansion chamber in such a configuration where the pulses are minimized and a high signal fall / rise rate is archieved. To make things more complicated - the orientation of the MAP pickup point is crucial for a proper signal.



Final words. The car gained a few hp, the boost came 1000rpm earlyer, the engine sounded better and the charge air was a few degrees cooler due to higher turbocharger efficiency. If it wasnt for the enrichement table i think it would be perfect.

I still havent loosed hope for MS. Right now i am building a 400 bhp Toyota 1UZFE non vvti engine wich i plan to use with megasquirt engine management and EDIS 8. Im perfectly sure it will run A-ok. The first results should be within a month or two.

I think thats enough for now, I need to go to have a life ;)

[Guy Croft]

Very impressive post Tomas, well done.

I read every word with great interest and particularly liked the 'readable' style with which you wrote the feature. Superb grasp of English too.

Some photos of the components would add useful detail, but if you don't have any - don't worry.
GC

[berkut]

Guy - i cannot find any pictures of my Ford instalation, i only have pictures of my current build.


The injectors are wired for A and B channel (megasquirt offers 2 channels for injection controll, in my case it means 2 banks of 4 injectors running in batch mode) wich are wired in an ABABABAB fashion related to ignition events, if i ever consider running on 4 cylinders insead of all 8 it will be a snatch, only requirering some small changes to one of the fuel maps and some clever lambda sensor positioning or exaust manifold fabrication. If i had wired the injectors one for each bank the engine would run really bad and shake violently.


The stock manifold will be used only for the begening when finetuning of the suspension and initial tests of the drivetrain and chassis. Later i plan switching to slide type throttle bodies and a totally different manifold and i will have a few questions to you Guy, but that belongs to a different section.


***edit***

It seems i have made a few mistakes, regarding posting rules, i hope i have corrected myself now.

I added my megasquirt settings with comments.