Sequential and twin injectors.

This section is dedicated to discussion of DTA engine control units such as the DTA E48 EXP, P8 Pro, DTA S40, S60, S80, and S100, as well as all things ECU related.
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Sequential and twin injectors.

Post by stevieturbo »

There is no assumption.

The questions referred to what DTA does, not BMW and I have told him to find out what BMW does if he wants to copy that

But clearly you nor I tell BMW what to do.
Alex DTA
Posts: 1622
Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: Sequential and twin injectors.

Post by Alex DTA »

Offset for injectors is 0, 180, 360, 540.
This applies to both injectors on each cylinder.
Cylinder trims and injection angles are applied identically to both injectors on each cylinder.

There are 3 twin injector control strategies:

1. Simple Switch
Above X RPM and Y throttle, switch to second set of injectors.
Rarely used anymore.

2. Blend with different sized injectors
The % of first and second injector is controlled using the blend map.
If 25% is in the map, then 75% of the pulse width is assigned the primary injector, and 25% to the secondary.
If either injector runs out of duty cycle, the extra will be assigned to the other injector.

3. Use primaries until maxed out, then add secondaries.
Leave the blend map at 0.
The ECU will use the primaries until they are maxed out (not quite 100%, a bit less), then use the secondaries as required.

Use strategy 2 or 3 as required.
Borla
Posts: 51
Joined: Mon Mar 20, 2017 2:41 pm
ECU Model: S80 Pro

Re: Sequential and twin injectors.

Post by Borla »

Thanks Alex, so regardless of strategy injectors are to be configured as below?

https://flic.kr/p/SHZUqK
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Sequential and twin injectors.

Post by stevieturbo »

I'm curious as to why you're filling in the "unequal firing angle" table, when your engine is clearly not an unequal firing angle engine ?

At least the box isnt ticked.

So those numbers aint doing anything
Borla
Posts: 51
Joined: Mon Mar 20, 2017 2:41 pm
ECU Model: S80 Pro

Re: Sequential and twin injectors.

Post by Borla »

stevieturbo wrote:I'm curious as to why you're filling in the "unequal firing angle" table, when your engine is clearly not an unequal firing angle engine ?

At least the box isnt ticked.

So those numbers aint doing anything
When I started this thread I asked for advice on how to set up squential twin injectors, I posted a picture of the base map supplied to us on the new ecu. It had the unequal firing angles already filled in, but the sequential box not ticked. I filled in the angles for injectors 5, 6, 7 & 8 assuming 1, 2, 3 & 4 were correct and ticked the sequential box, are you saying this is wrong?

Problem is I live 60 miles away from where the engine is installed in the car so can't just pop out and try things.
Alex DTA
Posts: 1622
Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: Sequential and twin injectors.

Post by Alex DTA »

Unequal firing angles are not filled in. The software is simply showing that the angles are standard.
If you save that, and then open the screen again, you'll see that the values have been overwritten.

If you want sequential injection, select Sequential Active Yes. This requires a working cam sensor.

Leave Unequal Injection Angles unticked.

Now the ECU will fire both injectors at the same time, but with different opening times, depending on which of the strategies used above.
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