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[Aus Capri]

I installed 560cc evo injectors with risistors last weekend, I had been told it wouldn't work but I wanted to see how bad it was and if there was any wizardry I could perform to make them work. I can make it idle ok but as soon as it's driven and throttle applied it bogged out and spluttered and had a ridiculously rich afr no matter how much I tweaked the air flow meter. The injectors I had in there were 360cc bpt injectors so 560cc is a big step up. Really not wanting to mess around swapping injector plugs to the round style to put the bpt injectors back in, Ifigured I would try it on e85 as the injectors are around 35% bigger than what I was running and e85 needs around 35% more fuel to run properly. I drained as much petrol as I could and put 40Lof e85 in it and straight away it became drivable! It's a bit richer than it was on 360cc injectors on petrol, though not ridiculously rich. With the afrs being different for e85 and petrol I was unsure what afr I wanted to see on the gauge but after doing some reading I found the sensors measure lamba values and express them as afr values on the gauge  and the lamda values for petrol and e85 are very similar so  I still tune for petrol afrs on my gauge  example (14.7 on guage is really 9.7 afr when running e85) but still tune for petrol afrs and it's where it needs to be. A bit confusing and I did a crap job of explaining it sorry!

I have only given it a quick second gear pull and wasn't able to look at afrs but it felt very promising! Seemed to spool faster and I have all the advantages of e85, heat absorbsion, 107 octane rating can probably give it heaps more spark advancement, more boost if I have more fuel up top, I haven't sussed it out yet but I guess it will have lover afrs than before.

I'll keep you all posted, I'm doing this at the moment because I have no money and probably won't have any spare for a while for a standalone the evo injectors were 7 bucks each and in my budget

[EShepherd]

Can the factory ecm tell that there are bigger injectors, or compensate for them? Or are you spraying the same amount of fuel, at a much lower duty cycle? Also, how can you use E85 without a flex fuel sensor? Is that safe?

[greywolf27030]

Wow.....that's crazy!

[Aus Capri]

The ecu dosent compensate not when its in open loop. At idle in closed loop it does. It is spraying the same amount as stock with same duty cycle, it's rich across the whole rpm range untill heaps of boost is paired with it, no flex fuel sensor the ecu thinks its all stock injectors on petrol. I can't go full throttle at low rpm with out the afrs dropping to 10/1 so I modulate the throttle till at higher rpm then plant my foot. As for safety I'm not sure, bore wash is my main concern. Though before my rebuild I had ran 10/1 afr and the 30 year old bores still looked OK.

[Aus Capri]

Sorry when I said it's spraying as much as stock at the same duty cycle, I ment to say it's got a chipped stock ecu, (not a rocket chip it says fueltronic on the chip) I dono how this compares to the rocket chip)  so I guess it has more duty cycle than a stock ecu and the same fuel pressure as a stock car. The only reason it runs on the 560cc injectors is because e85 needs way more fuel around 35%  and coincidentally the injectors I got are 35% bigger. In theory it should run similar to how it ran on 360cc injectors on 98 petrol. 98 is our premium here our octane ratings are different to the USA, just to extra complicate what I'm trying to explain 😂

[Aus Capri]

By the way guys this is me experimenting, no one has told me to do this or that it will be ok. I take responsibility for any damage that may occur to my motor and I'm not recommending any one to try this, I'm just letting you all know what I've been up to. Take from it what you will and any comments or advice are appreciated.

Dave Robbo

[EShepherd]

I mean if you are running super rich, now sounds like the correct time for a big shot of nitrous, no? Gotta add some oxygen somehow.... 

[Aus Capri]

Ha I wish I had the cash for it! I really need to get a standalone and a tune.

Rocketman, is there any way you could remove duty from the injectors below 5000rpm and up it for me after 5500 + take the rev I limiter up a bit while we are at it? How much would you charge? If it's possible that is. Would you need the whole ecu or just the chip?

[Aus Capri]

Hey guys could you have a look at this ecu for me and tell me what you think? Would it be suitable and easy enough to install? Also what coils would you recommend I use? I'm not very confident in installing it though with your help hopefully I can make it work! It's what I need for the car, I should stop messing around trying to tweak the stock setup

[Aus Capri]

https://www.ebay.com.au/itm/Megasquirt-2-ECU-with-knock-control-/294030925994?_trksid=p2349624.m46890.l49286

[Rocketman]

What are you going to do for crank trigger? Miata CAS? That diagram shows it is setup for a VR sensor, the miata CAS is optical I think, the MS needs setup different for that.

I'm not sure what coils the B6/ BP guys use, I think they usually use Toyota COPs with a custom mount plate

You'll need to talk to the MS builder to get the finer details on what crank trigger, coils, sensors etc are needed for the way he builds that unit

The price seems very reasonable for that unit though

[Aus Capri]

Custom megasquirt 2. For 4 (5,6,8) cylinder engine. Fully operable. VR sensor input (NCV1124) or hall sensor.

Is a hall sensor what the CAS from a miata use?
I just mailed he guy and asked a few questions too, I'll ost up here so you guys can see when he replies.

Thanks for he help

[Aus Capri]

Is the crank trigger the CAS or do I need a crank trigger sensor as well? . Thanks for the help, I'm way better with the mechanical side of things than the electrical!

[Aus Capri]

This is what I asked.
Hi I would like to run this ecu on my mazda b6t motor, can you advise me if I use a cam angle sensor from a 1.6 L miata will it work? And could you be able to advise me on what coil set up to use for it. The car is a Ford Capri with a Mazda B6t engine it rus a distributor from the factroy, though the 1.6 miata CAS fits in its place. Thank you for any help you can provide me. Regards David

Reply
Hello. Yes it will work. But you have to disassemble the distributor and see how many holes there are on the trigger disk. If there are 4 holes then you will have to use the factory coil. To use a dual coil, you need to install a pulley trigger and a crankshaft sensor.
Regards, Andrew.

It's still over my head rocket can you give this to me in super layman's terms.

[Rocketman]

The single VR sensor input is for something like a 36-1 trigger wheel. It has 36 teeth, with one missing. The ecu sees a pulse every 10° and when it sees the 20° gap it knows it is at TDC, so it starts a new cycle.

Let's ignore our stock distributor, there's literally no reason to keep it, let's assume you use the Miata CAS (cam angle sensor) It bolts right in place of the stock distributor.

It has a 4/2 trigger wheel. A two tooth wheel gives a signal at TDC, starting the cycle (I believe one pulse is longer than the other). The 4 tooth wheel gives pulses every 90° aligning with each cylinder's firing.
It's much lower resolution but for running batch fire it's fine, you may be able to do sequential injection/ignition with it.
These signals are called CMP and CMK and require two separate input lines into the MS unit instead of one. It has to be configured for the two inputs at the circuit level.

You can tell your ECU builder that you will use the 4G63/miata CAS as the trigger.

This stuff is the heart of the ECU, I would recommend a pile of reading on how the Megasquirt works and relies on the sensors. There is a plethora of documentation, specifically for the 1.6L Miata that will be helpful. Here's a start:https://www.diyautotune.com/support/tech/install/mazda/megasquirt-your-miata/
You can use the stock Miata coils but the COPs would be a little better, read the warnings on the page about the stock miata coils.
The settings/configurations on that page are necessary, you will probably have to configure it yourself when you get it