Ah, well then, off they come, cause i'm with Makenzie on this one, no cats, no actuators...

 

Try doing the electrical method.

 

Because it wouldn't be any better, in fact I doubt it would meet any of mazda's design specs, reliability, economy, driveability.

6-port motors do have much longer duration and the same opening time as turbo 4-ports, this is very benefitial to a turbo motor... no more overlap than the 4-port but longer time to fill the combustion chamber.

It's just werid that every person i've seen talking about how their turbo 6-port's behave and drive it always seems very positive.

WonkoTheSane: You could always remove your sleeves even just temporarily to see if you like it or not, they're not that difficult to take in and out at all.

 

1987 - Eh, I think i'll try it out per White FC's idea, and see how i like it... but that's a good idea...

White FC - you have a very valid point... and probably the most practical, since both sides seem pretty entrenched in their opinions

 

i have a streetported s4, with rb header and 2.5 single exhaust. My exhaust doesnt have enough backpressure to open the aux ports. If I wire them open, driveability is dramatically reduced below 3000rpms, but a heavy increase in top end is noticed. I have a spare manifold I ported and removed the aux ports + actuation all together but decided it would be great for racing but impractivcal for street. If your streetporting your motor, you will not like your ports removed. Maybe you would compromise for the hp, but in the end you would want something fast and driveable.

 

Joao - how did you compromise? if you didn't have the back pressure to open them, did you switch to the elctronic method?

 

My ECU stopped giving the activation voltage to my aux port's solenoid, so the solenoid now recieves power from one of the on/off buttons on my shift ****. I can have them open when I know I'll be doing hard driving, or shut them down for better drivability. I have noticed no serious detriment on low end, but my idle is most certainly choppier when I have them left open.

 

No it doesn't. When the secondaries come on line, there is no sudden increase in fuel flow, because the injector pulsewidth is halved so that all four inject the same amount as the primaries were before.

You can't just turn on extra injectors without changing what the other ones are doing. This would result is a rich condition and the engine would bog.

Engine demand is what drives fuel consumption, not the number of injectors firing.

 

So what prevents a car from running on just two injectors? Could just two be wired to run the engine at all times?

 

Nothing..
There are many engine out there that do..
the first gen 13b 6-port did..
theres some engines that run with only ONE injector..

The only problem is the fuel flow vs clean atomisation (sp?). If you only have one or two injectors feeding an engine it would be ok if they were corectly sized to the engine to start with and the engine didn't have a huge dynamic range, ie, didn't rev high, didn't make much power. The reason you can't just slap in two huge injectors to get around the problem of not making good power on two small ones is that big injectors do NOT atomise the fuel very well at low pulse widths, ie, at idle. So your emission/fuel economy/smoothness with all go to ****.
Solution? have lots of small injectors! either in a staged arrangement, or a sequential arrangement, either way you end up with lots of small injectors.. much better way of doing things than just one or two huge ones.

 

gotcha