Singleport batch fire or sequential firing

[Billyisgr8]

So what would work best for a turbo singleport with this manifold, sequential, or batch firing?

Kevin

[miniman82]

MS2 with Extra 3.0.3 alpha code with sequential siamese or any version of MS (or any ECU) with a TBI are your only options.

[MarioVelotta]

Why wouldn't batch work?

[miniman82]

Charge robbing. I suspect CIS would work though, that could be another option.

[Billyisgr8]

My friend thinks sequential would work with both injectors in the side of the manifold. Now I'm really confused. Wouldn't anything work better than my dellorto draw through set up?

Kevin

[mschilling]

You should be able to try them both and see for yourself.

[jonas_linder]

Ofcourse it would work better then a draw-through setup.

I now some members here swear by using a certain setup to get better idle but basically it all boils down to getting a "small enough" squirt down the drain!

There is information about how to set it up in the ms manual.

If you do not use any cam trigger so you know where you are on the revolution batch or sequential doesn't really matter.

I agree with your friend!

ps. I like what you have done with your car/engine ds.

[fastback]

i would also advice simultanous squirt, maybe 2 or 4 squirts pr engine cycle , but this also depends on the injector sizing and how low PW u can run at idle.

[Piledriver]

The main advantage of using the sequential-siamese is it was more or less specifically designed for this sort of setup.

To work best, you would want relatively huge injectors to keep the duty cycle to a minimum, modern 1000cc injectors and MS2 can apparently still idle OK.

I would provide a more consistent (and tunable) mixture on a per-cylinder basis.

On a boosted motor... It could be a lifesaver.

CIS wouldn't help... Unless you put the injectors just under the TB.

The lag in the manifold somewhat averages out the mixture, but it would be only marginally better than the draw through except for ease of tuning.

CIS doesn't like a lot of overlap either... A too-small plenum makes it much worse.

[Billyisgr8]

Sequential siamese, and after googling it I understand it, very differrent aproach for teh siamesed port.

I was thinking if I was to do sequential to have the injectors fairly low to the head, pointing directly at the back side of the valve so the injectors would be in a X pattern. The injector on the #4 side is pointing at the #3 valve, and injector on #3 side pointing at # 4 valve. This is the only picture I have of the head port. You can sort of see what I am getting at.

Kevin

[panel]

If you go this route I can't wait to see the MS build. Start one if you do!

[MarioVelotta]

As far as idle goes this is a race car, idle isn't the most important thing Im sure. It will be an added benefit. Also I don't think you need to have the injectors in an X pattern. That may help low speed but you are going to be more top end. I would put some bungs in the top of your plenum's and just fire them straight down. It will make your fuel rails much easier to fabricate also. Or one LARGE injector on each side fired batch would work IMO.

[miniman82]

one LARGE injector on each side fired batch would work IMO.

So what's going to happen during the 4/3 or 1/2 intake stroke, and the injector has only fired one time?

And if your solution is 'fire it more than one time', what guarantee does the engine have that those pulses will be accurately timed to the intake valve without the siamese code? This is shared intake ports, it's not like ITB where the injected fuel simply waits in it's respective port to be taken in by one dedicated cylinder- here, it could go into either.

Like I said, charge robbing in siamese ported engines is a big deal. The only way FI has been accomplished in the A-Series 5-port Mini engine was the application of the sequential siamese code written for MS, and the factory's own horrendously complicated injection system (which is also full sequential). That's why I say that for the average person, TBI is gonna be the easy thing to do. But then, you still have the same issues the stock T1 center carb had with dropout, manifold heat, ect.

[Turbo_Manx_Maniac]

Just an idea and not fully thought out, but what about wiring the injectors so the 1/2 cylinder gets the 1/3 injectors? Seems this way there would be a shot 90° apart to combat the fuel robbing.

I'm with ya mini, the first cylinder would rob most of the fuel and the second would run leaner if they just fired linearly, sequential would do it.

[miniman82]

Just an idea and not fully thought out, but what about wiring the injectors so the 1/2 cylinder gets the 1/3 injectors? Seems this way there would be a shot 90° apart to combat the fuel robbing.

You're halfway there: the only other thing I can think of that *might* work is having 4 small injectors, one pair in each head. You wire each pair to be on both injector channels, then set MS to fire alternately (eg, 4 squirts/alternating). This way you'd get a semi constant stream of fuel, but there's still no guarantee that charge robbing would not occur. I suspect it still would, and the sequential siamese code will be the only sure solution.