[PSIG]

30hp for 3º must be some serious street engine, like in the 300 - 500hp range, because I don't see that happening in a old NA engine with a leaking VSS.

Yep, 434hp on pump gas, which is no big deal for street these days, and typical for US V6 & V8 NA or better. The point is that it is no longer only the realm of high-end racing teams or wealthy hot rodders, and now within the grasp of home garage tuners on shoestring budgets, from an open-source program on an Arduino. Very cool. There is also a much greater cylinder-to-cylinder variation in non-race-prepped engines, so the relative effects are larger than what the racing teams see.

Before the new offset blower they used to drop the comp of individual cyls in TF Nitro if they keep blowing.

Yep, as cylinder trim is not an option for TF, which is also too rich for my blood.

David

[androidcho]

What about simple per-cyl trim in DEG BTDC to add or take from the base Advance map. It'll be much, much easier to do.

[PSIG]

What about simple per-cyl trim in DEG BTDC to add or take from the base Advance map. It'll be much, much easier to do.

You are suggesting simple single-digit full-time offset (Cyl2, -3°, all MAP, all RPM)? That's better than nothing sometimes, and if the Mega's brain won't take it then so be it; but with simple offset you are also crippling the same cylinder during operation that does not need the offset. Easier, but also less effective at improving average torque. Peak TQ and HP do not win races or make max mileage, but average TQ and average HP across the operating range do. Making 1hp, 3hp, 2hp and 1.5hp on each of 4 cylinders at redline isn't much to scream about, but gaining that improvement all the way across the operating range is. I'll take what I can get, but if we're going to do it . . .

David

[Old Grey]

If it feasible, even if just individual channel offset and still years away, it would be good to know now.

I'm thinking about dumping my 323 4 channel IGN and going with a simpler 2 channel waste spark setup.
With 2ch I only need to find 1 pin on the DENSO, make 2 igniters, and find 4 COPs - dumb COP is only $11ea -.
Where as with 4ch I will need to find 3 pins on the DENSO plug, make 4 igniters, and run the same 4 COP. And to what advantage over 2ch, probably none.

That being said, if I can find more driveability with sequential at low rpm for my economy fuel map, and the a button to switch to batch full power, I would still find this more useful.

[apollard]

There are quite a few engines where individual cylinder timing would be useful. Chevy Big Blocks typically detonate on #7 first, so a few degrees less there would be useful. Part, but not all of the problem can be addresses with individual cylinder fueling though.

I can see that it would be a large programming project, however.

[PSIG]

There are quite a few engines where individual cylinder timing would be useful. Chevy Big Blocks typically detonate on #7 first, so a few degrees less there would be useful. Part, but not all of the problem can be addresses with individual cylinder fueling though.

Not only useful, but only when needed. Sure, you can use a band-aid for a workaround, as done with the Honda earlier. But, it hurts torque everywhere to richen more than proper timing would, and even more when not at the needed point—so the gains are less. We are not looking for split-hair improvements here; but basic tuning to get the majority of the engine's capability onto the crankshaft flange. Most stock and hobby engines have greater gains due to not being nearly as "right" before trims are applied (greater cyl-to-cyl variation). You can't compare racing team results on cutting-edge engines to the magnified flaws in our beaters. We have more to gain.

That being said, if I can find more driveability with sequential at low rpm for my economy fuel map, and the a button to switch to batch full power, I would still find this more useful.

Speeduino has sequential with trims almost ready now, and if you value that, why wouldn't you want the same benefits for your ignition? BTW - no need for a "batch button", as sequential effectively becomes batch at higher rpm anyway as the duration extends, and many seq systems switched to batch only because they couldn't think fast enough and/or it doesn't matter as the timing is pooched anyway. Not sure I see the benefits you're thinking of.

David

[Old Grey]

With seq you only get 1 squirt every 2 revs, so you need a bigger INJ because of high rpm. Batch you get 1 squirt per rev, so you can use std INJs. With my std INJs, which I'm not going to change, it will probably run out of fuel without the 2 squirts at high rpm. But then again I don't know if the std Mazda is 2 squirts per rev, so maybe it's fine.

[noisymime]

With seq you only get 1 squirt every 2 revs, so you need a bigger INJ because of high rpm. Batch you get 1 squirt per rev, so you can use std INJs. With my std INJs, which I'm not going to change, it will probably run out of fuel without the 2 squirts at high rpm. But then again I don't know if the std Mazda is 2 squirts per rev, so maybe it's fine.

Not sure I understand your logic here... With sequential (1 squirt per cycle) you can use smaller injectors because you only have 1x dead time rather 2x. The overall pulsewidth time over 720 degrees is shorter than with 2 squirts.

[Old Grey]

I guess I need to do some more reading because I thought seq only squirts for a limited time only during inlet valve open, ie once per 2 rev.

Do you think individual cyl timing will ever be added?

[cygnus x-1]

I guess I need to do some more reading because I thought seq only squirts for a limited time only during inlet valve open, ie once per 2 rev.

Do you think individual cyl timing will ever be added?

With sequential there is only one injection per 720 crank degrees but it will be however long it needs to be to get the correct amount of fuel. If it takes 700 crank degrees to get enough fuel, the injector will be open for 700 crank degrees (that includes opening time). The thing about sequential is that you get to choose where in the engine cycle the injection starts or ends (either one or the other but not both).


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