Injection End Angle

[Ryan.g]

The End angle is not just a 0-360 value its a 0-720 value so 0 is at TDC Firing.

Its set this way in nearly all Engine management system

[Hugh]

Thanks for confirming Ryan.

Thanks alaso to steiveturbo, RICE RACING and earlier contributers.

Will get on with some testing now

[Hugh]

Ryan,

Been continuing to read up on this subject. Looking at the following two links, it appears that other ECU manufacturers consider Injector end opening angle to be degrees before TDC on the compression stroke. Whereas Syvecs declare on the injector end angle to be degrees after TDC on the compression stroke.

https://forum.efilive.com/attachment.ph ... 1391928956

http://www.motec.com.au/forum/viewtopic ... mbda#p3583

Clearly not all engine management systems treat this subject in the same way.

Thanks

Hugh

[RICE RACING]

Not that you need to reference what other inferior ECU makers do or say, but in the one you linked " A value of 0 is the same as a value of 720 i.e. both are Top Dead Centre" and you can set it as EOI or SOI, whatever you prefer, simple.

You have the answer from Ryan "nearly all", now go do the tests
FYI, I use Injection End Angle and typically its from idle to full rpm 360ATDC to 280ATDC respectively. Works well on 4 stroke engines with right sized fuel injectors.

p.s.Keep in mind this simple differentiating fact. Life Racing (parent) are sister companies to racing engine manufacturer AER (Advanced Engine Research), they know more about the end application first hand , they are cutting edge world sports car championship winners and not some cut n paste feature set copiers like the rest out there and this is the reason for the ultimate existence of these companies LR/Syvecs. What others do or conventions they use are largely irrelevant.

[Hugh]

RICE RACER,

Many thanks for the excellent response again.

Following on from Ryans clear statement on how injection end angle works, the links I provided show that Ryans comment "Its set this way in nearly all Engine management system" suggets that one can reference the way that other companies treat the ECU set-up parameters and know how it will be within Syvecs, is not safe.

I am not looking for an argument, but this is an important subject that has not as far as I can tell been covered before and highlights how the lack of Syvecs ECU documentataion makes life extremely hard for the novice user.

Thanks

Hugh

[pat]

Hugh,

Ryan's comment about other management systems was perhaps more hindrance than help, please just ignore it to save confusion. Of course it is entirely irrelevant what others do, when you need to know how it is done in Syvecs And the answer I believe has been provided... 0 degrees is TDC compression.

That said, let me explain why this is and why it is the most sensible option. The most used "angles" in calibrating an ECU are ignition angles. You always talk about ignition timing, and it is relative to TDC. When you're advanced you're BTDC, when you're retarded you're ATDC. But the datum is TDC compression. Given the use of this datum, why would you then elect to use a different datum for something like cam timing, or injection angle ? Why have more than one datum ? That just gets confusing!

There is of course a second good reason. All Syvecs ECUs run a hardware angle clock. When we decide that we want to fire a spark at 32 degrees BTDC (688 ATDC), that is what the control register is set to... not "100 microseconds after the previously seen tooth". This clock, like all good clocks needs to have a fixed datum, a bit like midnight is on the clocks you to keep track of the day. Everything that is going to happen in the course of a cycle (or a day) can be defined in terms of when (in our case, at which angle) it will happen. Lunch happens at 12:30.... intake valve opens at 350 degrees etc etc. Hopefully this makes sense. There is one datum, and everything is relative to that.

Of course the "one true datum" is #1 TDC, which means that the angles for all other cylinders will be rotated relative to that datum. Clearly we don't talk about firing a spark in cylinder #3 at 150 degrees ATDC #1, we talk about 30 degrees BTDC #3 - the register would be set to 150, but that's just because the cylinder TDC offset is applied (done automagically if the engine is symmetric, but you can define your own cylinder offsets if it is not).

Hope this helps,

Pat.

[Slowie]

Ryans comment "Its set this way in nearly all Engine management system" suggets that one can reference the way that other companies treat the ECU set-up parameters and know how it will be within Syvecs

It does?

[stevieturbo]

As Pat says, no sense assuming because another ecu "might" do something, that Syvecs is doing the same.

The way Syvecs does it does make perfect sense in terms of the bigger picture.