[alecpicanco]

Hello!
I'm from Brazil and here we have an iconic car, Opala
It uses a inline six cylinders and those Siamese heads. Many mechanics say that the hit is only good if the injection is sequential.

I don't know if anyone has thought of using a Shift Registers (CI 74HC595) to increase the number of digital ports of the Arduino.

This CI would make it possible to implement more injectors and igniters.

[NickZ]

you CAN use 6 injectors sequentially and use wasted spark.

[alecpicanco]

you CAN use 6 injectors sequentially and use wasted spark.

How?
Replacing the ignition drive with an injection drive?

[PSIG]

...It uses a inline six cylinders and those Siamese heads. Many mechanics say that the hit is only good if the injection is sequential.

This assumption is not entirely correct. In-fact, the opposite is mostly true, that most forms of fueling are even, except un-timed single-squirt port injection. Siamese ports are unique for fuel distribution, but are generally consistent in their charge-stealing (cross-fueling). A good understanding of the odd flow dynamics is required, and there are web references for testing data. Constant-flow injection, carburetors, TBI, multi-injection semi-sequential port, and sequential can all fuel evenly when set-up properly.

For examples, paired injectors fired semi-sequentially at 2-squirts per-cycle, per-cylinder ("double-shot sequential", 3 channels) and wasted spark (3 channels) can permit equitable charge-stealing and fuel distribution in Siamese ports. Or, similar setup with TBI. So can sequential-port (6-INJ & 3-IGN) as @NickZ stated, with careful injector placement. Planning and testing would be a good idea, IMO.

[alecpicanco]

...It uses a inline six cylinders and those Siamese heads. Many mechanics say that the hit is only good if the injection is sequential.

This assumption is not entirely correct. In-fact, the opposite is mostly true, that most forms of fueling are even, except un-timed single-squirt port injection. Siamese ports are unique for fuel distribution, but are generally consistent in their charge-stealing (cross-fueling). A good understanding of the odd flow dynamics is required, and there are web references for testing data. Constant-flow injection, carburetors, TBI, multi-injection semi-sequential port, and sequential can all fuel evenly when set-up properly.

For examples, paired injectors fired semi-sequentially at 2-squirts per-cycle, per-cylinder ("double-shot sequential", 3 channels) and wasted spark (3 channels) can permit equitable charge-stealing and fuel distribution in Siamese ports. Or, similar setup with TBI. So can sequential-port (6-INJ & 3-IGN) as @NickZ stated, with careful injector placement. Planning and testing would be a good idea, IMO.

Thank you PSIG!
I want to learn as much as I can about injection and engines. I will research about the dynamic odd flow.

I'm making an Official SpeedUino (v0.4) and I'm going to use it on this car. He uses a GM 250. I intend to use this injection configuration that you mentioned. It even appears in the SpeedUino manual.

I proposed using this CI to expand the number of ports on the Mega 2560.

I know that this circuit causes a reading delay, but we could allocate sensors that would not have so much problem with this delay. As I am going to order Official SpeedUino PCBs. Some I will send to study.

[pazi88]

As said before, there is no need for shift registers to do 6-cyl sequential injection. Just use poteintially unused idle, vvt or boost outputs as injector outputs or add few more inj outputs to proto are if needed. With few minor changes to FW it will work (change how timers are used and few output changes). Up to 8x8 sequential support is already built in to speeduino FW.

There is also possibility to use teensy or stm32 processor instead of mega if you also need 6-cyl sequential ignition. The number of I/O is not limiting factor in mega, but it's number of timers.

[phsouza]

Hi Guys, I'm from Brazil too and using the oficial 0.4.3b board. But in my case I do plan to use ITB with 8 injectors and semi-sequential ignition. Can I use the ign chanels left to activate the second row of injector in semi-sequential only for high rpm while keeping the main injectors row working sequential?

Obs.: I'm using a VW 4 cyl EA-827 engine.

[theonewithin]

No.

[phsouza]

Looking at the board pins (0.4.3b) I noted that has 8 pin for injector 1/2 and 2/2, I don't understand this feature. If it support 4 injectors in sequetial mode, why those extra injectors pins?

[jonbill]

each individual pin and IDE wire is too fine to carry the potential current, so it is spread over two.