V12 injection setup

[Chop]

Hi. I am just setting up a Link G4 Xtreme on my V12 engine and have a few questions about the group fire options. I am assuming I would need to use Multi point group injection. Is it possible to set it up to group fire 2 cylinders at a time? There are enough channels for this but I cannot see an option for it. Will I need to use INJ1-4 and inject 3 cylinders? or do I set it up for sequential injection and fire 2 injectors at a time?

Any help would be appreciated.

Thanks

[Adamw]

What’s the firing order?  

[Chop]

Its 1  12  9  4  5  8  11  2  3  10  7  6

Thanks

[Adamw]

Ok, so semi-sequential is not going to be possible with that firing order.  It will have to be multipoint group.  

Set active drives 1-6 and you can wire a pair of injectors to each drive.  The injectors will be fired in two groups 180 deg apart every 360 degs.

[Chop]

Thanks for that. Just to be clear I would set it to INJ1-6 and wire drive one to 1&12, drive two 9&4, drive three 5&8 etc and inject two cylinders at a time?  It should fire in two groups 120 degrees apart every 720 degrees?

In PCLink it is stated as:

INJ1-6 - Drives 1 and 2 are used for injection, the rest (if any) are available as auxiliary outputs.

But in the PCLink G4X program it is stated as:

INJ1-6 - Drives 1 to 6 are used for injection, the rest (if any) are available as auxiliary outputs.

Is this an error or is there a difference between the earlier and later drives?

Thanks

[Adamw]

On 9/5/2020 at 9:04 PM, Chop said:

Thanks for that. Just to be clear I would set it to INJ1-6 and wire drive one to 1&12, drive two 9&4, drive three 5&8 etc and inject two cylinders at a time?  It should fire in two groups 120 degrees apart every 720 degrees?

No, as I said above, in multipoint group mode it will be in two groups 180deg apart.  All odd drives will fire together then all even drivers will fire together.  How you pair them up isnt important.

 

On 9/5/2020 at 9:04 PM, Chop said:

In PCLink it is stated as:

INJ1-6 - Drives 1 and 2 are used for injection, the rest (if any) are available as auxiliary outputs.

But in the PCLink G4X program it is stated as:

INJ1-6 - Drives 1 to 6 are used for injection, the rest (if any) are available as auxiliary outputs.

Is this an error or is there a difference between the earlier and later drives?

No it is just a typo by the looks.  G4 works the same as G4X in the multipoint group phasing.  All 6 drives are used.

[aconis]

On 8/23/2020 at 3:01 AM, Adamw said:

What’s the firing order?  

And if firing order is: 1-4-9-8-5-2-11-10-3-6-7-12 ?

[aconis]

1 hour ago, aconis said:

And if firing order is: 1-4-9-8-5-2-11-10-3-6-7-12 ?

Hope this table taken from engine manual can be helpful.

[aconis]

On 3/10/2021 at 11:36 PM, aconis said:

And if firing order is: 1-4-9-8-5-2-11-10-3-6-7-12 ?

As far as I understood there is no sense to pair injectors same as wasted spark ignition coils: 1-11, 4-10, 9-3, 8-6, 5-7, 2-12 due to we don't want to leave fuel wetting on the port walls and it is better to pair in adjacent cylinders according to firing order, i.e. 1-4, 9-8, etc.
Can anyone confirm it?

[Adamw]

Sorry for the slow reply.

The firing order wont allow semi sequential with the conventional way we do it in Link, but you can do a small fudge to make it work semi-sequential.

In the software, set the firing order to 1,2,3,4,5,6,7,8,9,10,11,12.

Wire inj drive 1 to cyl 1&4, inj drive 2 to cyl 9&8, Inj 3 to 5&2, etc...

Then you can inject fuel sequentially on cylinders with TDC's 60 deg apart.  So the first cyl of the pair will get its fuel injected 30deg later than ideal and the 2nd cyl will get its fuel 30deg earlier than ideal.  

 

[aconis]

6 minutes ago, Adamw said:

Sorry for the slow reply.

The firing order wont allow semi sequential with the conventional way we do it in Link, but you can do a small fudge to make it work semi-sequential.

In the software, set the firing order to 1,2,3,4,5,6,7,8,9,10,11,12.

Wire inj drive 1 to cyl 1&4, inj drive 2 to cyl 9&8, Inj 3 to 5&2, etc...

Then you can inject fuel sequentially on cylinders with TDC's 60 deg apart.  So the first cyl of the pair will get its fuel injected 30deg later than ideal and the 2nd cyl will get its fuel 30deg earlier than ideal.  

 

Thanks a lot! This is awesome answer! ;-)

[aconis]

39 minutes ago, Adamw said:

Sorry for the slow reply.

The firing order wont allow semi sequential with the conventional way we do it in Link, but you can do a small fudge to make it work semi-sequential.

In the software, set the firing order to 1,2,3,4,5,6,7,8,9,10,11,12.

Wire inj drive 1 to cyl 1&4, inj drive 2 to cyl 9&8, Inj 3 to 5&2, etc...

Then you can inject fuel sequentially on cylinders with TDC's 60 deg apart.  So the first cyl of the pair will get its fuel injected 30deg later than ideal and the 2nd cyl will get its fuel 30deg earlier than ideal.  

 

In regards to fuel timing, what would be the ideal injection time anyway? To the open intake valve or right after the exhaust valve is closed? Many people says it should be injected against closed valve.. I understand on high load when injector duty is nearly 80% it doesn't make a big difference, but on the low load and cruising it does,  i think.

[Adamw]

There is no golden rule, it is influenced by many factors, injector position, spray pattern, port temperatures etc.  But generally in modern road car engines with the injectors somewhere close to the valve the best result will be injecting all fuel before the intake valve opens.  The hot intake valve causes more vapour which is more efficient as a fuel than liquid.  End of injection somewhere around 300-400BTDC is the common ball park I see.

There are several techniques you can use to determine the best injector timing - At idle you can often find the optimum by just adjusting the timing back and forwards until you see the richest lambda for the given fuel volume.  At medium speeds & loads when the engine is making some torque then it can be determined by holding steady state on the dyno watching torque while varying inj timing.   It can possibly also be determined using experimental methods such as scatter plotting large data logs to try to find trends.    

[Chop]

Hi some good info there thanks. So it is set up semi-sequential INJ1-6?

Also could I run two e-throttles with the G4 or would I need to upgrade to the thunder.

[Adamw]

On 3/15/2021 at 9:52 AM, Adamw said:

The firing order wont allow semi sequential with the conventional way we do it in Link, but you can do a small fudge to make it work semi-sequential.

In the software, set the firing order to 1,2,3,4,5,6,7,8,9,10,11,12.

Wire inj drive 1 to cyl 1&4, inj drive 2 to cyl 9&8, Inj 3 to 5&2, etc...

Then you can inject fuel sequentially on cylinders with TDC's 60 deg apart.  So the first cyl of the pair will get its fuel injected 30deg later than ideal and the 2nd cyl will get its fuel 30deg earlier than ideal.  

 

@aconis I have just realised I made a mistake in that comment, the 1234... firing order I suggested wouldnt work.  There are a few different ways that would work fine, but I must have just been lacking concentration when I wrote that.  This one would work correctly:  1,12,2,11,3,10,4,9,5,8,6,7.  Injector wiring would be same as I originally quoted.  I tested this one on the bench to make sure I had it right this time.

 

 

12 hours ago, Chop said:

Hi some good info there thanks. So it is set up semi-sequential INJ1-6?

Also could I run two e-throttles with the G4 or would I need to upgrade to the thunder.

The old G4 can only do a single E-throttle.  G4+ thunder can do 2 E-throttles, or as I mentioned above some of the G4X series will soon be able to do two E-throttles (requires an external driver for one of them).

[Chop]

HI.

I am looking at upgrading to a Link Thunder and have a couple of questions before I commit to buying it.

We I be able to do the semi-sequential 'fudge' mentioned above. I cannot see a semi-sequential setting in PCLink G4+ but it does say "Note: This mode can also be used for semi-sequential injection" in the sequential setting.

Can I run a coil on each spark plug and run two at a time the same as wasted spark.

Will this ECU do everything that the Xtreme does.

Thanks

[Adamw]

1 hour ago, Chop said:

We I be able to do the semi-sequential 'fudge' mentioned above.

Yes.

 

1 hour ago, Chop said:

Can I run a coil on each spark plug and run two at a time the same as wasted spark.

Yes.

 

1 hour ago, Chop said:

Will this ECU do everything that the Xtreme does.

Same functionality as G4+ Xtreme yes.  Our current G4X xtreme however has seen a lot of improvements and updated strategies.

[moltenwok]

On 3/11/2021 at 10:36 AM, aconis said:

And if firing order is: 1-4-9-8-5-2-11-10-3-6-7-12 ?

Hiya mate, looking at one of these for my 1GZ-FE, do you have a contact