yoeddynz

DIY Fuel injection thread.

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OK- I have many questions about ecus- both standard oem ones and aftermarket items. I am still not sure what way I want to go with my new fang dangled electronically fuel infected engine and so much info out there in nerdnet land seems to be written for people who are already immersed in the subject.

Rather than me starting a new thread for each question I come up with as my project progresses I will instead just keep coming back to this thread. In fact I think the answers to the questions I ask could be quite useful to others who might be keen on going the fuel injection way. Im asking on here as there seems to be plenty who have experience with this stuff going into old cars.

First question is,

What is phased ignition? I have been looking at various ECUs and some state this being included.

example from the Gotech website on the pro x ECU......

- 4, 6 and eight Cylinder, One coil and two injector outputs with trigger per event input

- 4 Cylinder, Two coil and Two injector outputs with crank trigger (60-2, 36-1, 12-1)

- 6 Cylinder, Three coil and three injector outputs with crank trigger (60-2)

- 4 Cylinder, Full sequential Four coil and four injector output (60 -2 plus hall effect TDC)

- 6 Cylinder, Full sequential fuelling and phased ignition (60 -2 plus hall effect TDC)

And the injector outputs- what does the number of outputs refer to?

Second question is,

When you get a aftermarket ECU and it comes with a base map for starting, how easy is it to then tune the ECU without the use of a rolling road?

What I'm picturing is Hannah driving the Viva while I sit in passenger seat and 'tune' things. I realise it will take a long time but is it easy enough to do with most of the supplies softwares if you understand the basics of car tuning. I can happily set carbs, go for a drive and know whats happening and if its running lean, rich, ignition timing is out etc. This stuff I know fairly well.

What I'm hoping is that I would be able to just sit there while the car is driving, open the appropriate software window and adjust the fuelling map, ignition map to suit. Is it that easy?

Third question,

What sort of airflow meters do most ECUs support?

I realise that a hotwire maf or a map sensor will offer far less restriction than my current 'sliding dutchcap' ( well it looks like a dutch cap) VAF but I have read that the VAF is much more accurate and better for fuel economy? If I go to a map sensor or hotwire sensor then is it just a case of getting a sensor and plumbing it in place then wiring it all up to the new ECU and starting on a base map? Or is there more involved with map sensors as they use some sort of logorithmiculculas table to work out airflow based on the pressure, air temp and TPS hence need rolling road time?

Fourth question,

Would aftermarket ECUs come with an option to control a step motor or some solenoids at certain preset rev points? I fancy making a inlet manifold with variable length velocity stacks inside the plenum ala F1 so I can maximise my torque etc.

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Second question is,

When you get a aftermarket ECU and it comes with a base map for starting, how easy is it to then tune the ECU without the use of a rolling road?

What I'm picturing is Hannah driving the Viva while I sit in passenger seat and 'tune' things. I realise it will take a long time but is it easy enough to do with most of the supplies softwares if you understand the basics of car tuning. I can happily set carbs, go for a drive and know whats happening and if its running lean, rich, ignition timing is out etc. This stuff I know fairly well.

What I'm hoping is that I would be able to just sit there while the car is driving, open the appropriate software window and adjust the fuelling map, ignition map to suit. Is it that easy?

Fourth question,

Would aftermarket ECUs come with an option to control a step motor or some solenoids at certain preset rev points? I fancy making a inlet manifold with variable length velocity stacks inside the plenum ala F1 so I can maximise my torque etc.

2nd question, i found road tuning to be awesome as it allows you to tune pretty much every where quite well and it is much cheaper than using a dyno, dyno would be good to tune max horse power as you can get up in the speed very quickly on the road tuning such things. but it does take a bit of time and to do it all on a dyno if you even could would be costly. that said we didnt spend a huge amount of time tuning my car. its peice of cake with a wide band and seen as your using MAP/MAF/what ever sensors they almost auto tune them selves these days depending on what ECU you get.

4th question, yup they come with all sorts of output controls. alot have PWM for controlling stepper motors and cant think of any ECU that doesnt have relay outputs.

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Righty

1.

Injector outputs. A lot of basic ECUs batch-fire the injectors, as in multiple injectors will fire at the same time. EG on 10-5s datsun it is running two batches of 3, each batch firing 3 times per cycle (720 degrees)

You could also run 3 batches of two, often called semi-sequential, or in full sequential each injector is controlled independantly.

Same deal with spark. Ya can run one ignition trigger like on a dizzy setup, a wasted spark setup with 1 coil per 2 cylinders or full sequential with a coil per cylinder. I guess that's what they're calling phased ignition

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3.

It mostly depends on the ECU. Most aftermarket units will let you run whatever you want, but the most common is to simply plug a MAP sensor into the manifold and do away with the AFM all together. Factory ECUs are limited to what they had stock, and will generally not accept anything else.

Often the factory AFMs will also house an intake air temperature sensor too, which you may need to rig up separate if you do omit the factory intake.

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In addition to the previous answers;

First Question:

Your ECU will have a preset number of injector drivers or ignition outputs. You can configure them in a few different ways depending on what engine type you have and what sort of system you want to use. For example;

The ECU on my Legacy has 8 injector and 8 ignition ouputs. I use 6 of each to drive 6 injectors and 6 coil packs individually. This means i can adjust timing and fueling on any cylinder completely independantly. The 4 spare outputs i use to driver other stuff like radiator fans.

If i wanted to have even more outputs spare, i could switch to wasted spark. Then i only need 3 ignition outputs as i can pair up the coil packs running 2 from one output and each coil will fire twice as often. I could also switch to group injection so that multiple injectors are triggered at the same time and therefore use less outputs. Doing this would however remove my ability to tune individual cylinders. If you had a straight 6 with a nasty intake and the rear cylinders were running a bit richer - you could tune that out.

My ECU also has built in knock control and i run one knock sensor per bank. Using knock windowing and the balance between the 2 sensors, it can detect which cylinder is knocking and dial the ignition curve back on that one cylinder at that one load point - so you dont really notice a performance change. With wasted spark, it would only be able to adjust a pair of cylinders. Usually after a hard drive, my ignition trim maps will show that cylinder 3 and 4 had a few degrees of timing pulled so there must be some airflow or cooling differences which its accounting for.

They say that sequential injection and direct ignition gives a much crisper throttle feel but really i dont think i would notice the difference.

Second question:

Yes you can tune it yourself pretty well. Ive used the auto-tune function on my Link a bit. You basically just attach a wideband oxygen sensor, then the ECU gives you a throttle setting and speed to hold. You hold them for 3 seconds and the ECU adjusts its own fueling. Very simple, brakes do get a bit hot tho if youve got some power.

I would rather spend $500 on a dyno and know everything is A-OK than try to roadtune an entire map. Especially on a turbo car. Dyno tuning allows you to take your time and concentrate a lot more. Trying to listen for knock while attempting to use a laptop AND drive a car just results in crashes....and trying to get a partner to do the driving bit results in fights. Those are my experiences.

Third Question:

Link support quite a few air flow meters. I would happily have used one if my car had one from the factory. Most people will just switch to using a MAP sensor anyways.

Fourth Question:

Yes you can program them to all sorts of shit. An acquaintance has his Link ECU configured to also run the center differential in his AWD Subaru. It uses inputs from the thottle, steering angle and G sensors plotted into a 4D graph to control the amount of power sent to the rear wheels. It drives the solenoid using a PWM output and also runs intercooler water spray and heaps of stuff like that set off temperature and RPM dependant triggers.

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wow- cool. some bloody good info there. Cheers!

What other signals does an ecu need when using a map sensor to work out airflow? temperature you said. Tps?

To do the link type auto tune on a V engine would I need to have two widebands? My current wideband gauge, a inovate mtx, has a spare digital output plug. I presume that this is what I would plug my ECU into?

Are there many other ecu brands that offer a similar auto tune feature like link? Hopefully at a cheaper price...

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Just MAP and TPS. The intake temp is good to have as it will adjust the fuel to compensate for changes in ambient air temperature, and you can also have an external MAP sensor hooked up for barometric correction.

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If you like cheap DIY style stuff you could take a stab at the Megasquirt ECUs. Tis what Mark and I have been playing around with and they are pretty sweet if you're on a budget. The MS3X would be a bit of fun to play with.

http://www.diyautotune.com/catalog/megasquirt-iii-c-76.html?osCsid=538a825043336e170002c4a8092ff0d8

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Just as a note, if you want to run semi-sequential or full sequential, you'll need the proper cam/crank position sensors so the ECU knows where the engine is. A missing tooth trigger wheel on the crank will allow you to run semi-sequential injection and wastes spark ignition, but for full sequential you'll need a cam trigger as well. Often the factory dizzy / cam sensor can be used on aftermarket ecus with little or no modification required.

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edit;

would I need both the cam and crank angle sensor to go sequential you say? The engine has a cam mounted dizzy. I found a fella who made neat unit with an enclosed hall sensor in its place used for his ignition...

http://www.mx6.com/forums/2g-mx6-forced-induction/217582-my-home-made-m90-manifold-6.html

is that the sort of sensor you mean or is a cam angle sensor more accurate?

Apart from the fella selling MS on trademe is there any other importers for the kits? Did you build them your selves- that appeals to me being even cheaper.

Is MS as easy to tune as it sounds like link is? does it come with some sort of auto tune feature.

I had asked in a previous thread about sequential injection and what it was. If i'm to look at an aftermarket ecu then I would like to at least have the capability to go sequential. I think the MS3 or MS plus an extra add on box? can offer this?

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Yep the MS3 with the expansion card will give you 8 ignition and 8 injection outputs. I think without the add on card ya get 1 ignition and 2 injection, but with some hardware mods you can bring that up to 4 of each. It gets a bit messy though

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There's a guy in Tauranga who deals with them, dunno if he's the same guy on Trademe though. It's probably cheaper to get from overseas.

I didn't assemble mine from scratch, but I did significantly alter it and have built a fair bit of new hardware for it. New injection / coil driver boards, high power outputs and such.

Tuning is basically the same as any. The Tunerstudio software is pretty good and does have an autotune feature, but ya have to pay for that. It's disabled in the free version. I think it's only $20 or so though.

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Only one wideband needed for a V engine. You could run one per bank but thats just getting over the top.

Cant comment on megasquirts since the last time i looked at them it was 4 years ago. I have however heard bad things about the ones you can buy ready built on trademe.

I went with Link since they were the first ECU to support the triggering on my engine and worked out to be the cheapest once tuned. (excepting stuff like MS). At about $1600 for the Atom and $1800 for the Storm, its not a bad price for what you can do with them. I bought the Extreme at $2100 to get the extra outputs and internal knock control.

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+1 for not dealing with the trademe guy. if its still the same guy from a year or so back anyway. he managed to solder the 12v+ and ground together on the loom that a mate got off him.

can buy megasquirt prebuilt from diy autotune, if you wanted to go that way.

the triggers on them aren't very flexible. one of their big downfalls imo, either have to go with a knowen setup, or be prepared for alot of messing around to get a clean rpm signal

tuning software is ok.

they have a crappy loom plug

im talking ms1,ms2 and ms3 here.

i would spend the extra and go with a link if you can. they just work, no hassles and software is better. maybe find a 2nd hand g3 if you want something cheaper. although they seem to hold there value

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haven't seen those before. software looks pretty yuck going by those screen caps. personally i wouldn't touch something like that. good thing about the more common ecu's esp link. is pretty much every decent tuner in nz will know them, makes tuning faster and cheaper. if you decided tuning yourself was not going to happen.

g3's. haven't been up with what they sell for lately. but were still going for around 1k awhile back. sub 1k is probably worth buying. the firmware on them can be upgraded to g4 spec. for around $200. you end up with an ecu that sits somewhere between a atom and a storm. but if you dont need any of the features and aren't worried about using the older software, not worth the upgrade. pretty sure the latest g3 software had autotune. cant comment on how good it is as never use autotune.

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Really in New Zealand, the biggest downfall with any ECU other than Link/Vipec/microtec and maybe Haltech is the support side of things. Everyone knows Link and the PCLink software is freakin sweet to use. They have support for heaps of vehicles and the online forums or phone support is excellent! They frequently write requested features into future firmware updates which is nice.

The biggest decider for picking an ECU is the triggering support. If the ECU you use doesnt explicitly support your engines triggering configuration - you have to fuck about adding external trigger wheels or fuck about even more with writing code or adding the support you need. For my engine - i just clicked a drop down menu, selected Subaru EZ30/EZ36 and immediately everything was ready to run.

You might pay between 1000-1500 for a G3 wire-in. Considering a brand new Storm isnt too much more, i wouldnt buy a second hand one. Certain G3's can be flashed to run G4 firmware too so are as good as a new one - hence the high resale value.

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