MicroSquirt.com read only forum (Jan.15,2018)

DJ Kill wrote:
Why is maximum advance for further timing calculations (for boosted or NA engines) is assumed to be reached at 3000 rpm and not at higher rpm?

same question :why 3000 rmp? on a suzuki swift i have set the redline to 8300 rpm and i dont understend why a flat map from 3000 rpm to 8300 rpm

And i tried the XLS spreadsheet "just for the fun of it" and thought the advance figures at low rpms, especially around idle became VERY weird...

The idle advance figure ended up at the 100kpa bin, now that can´t be right ?

if i put in 8 degrees idle advance i get 29degrees advance at 30kpa/800rpm , that´s a bit rough on a standard engine i think

Although it follows the general "guideline" of advancing the timing at lower loads i don´t think that way of doing it would work to well every time, you need to scale it up so the lower left corner on the "MT" screen becomes low for the idle to work nicely. On most cars anyhow.

What about lumpy cams (i have rally cam) and what table i must use to run correctly ?

woh wrote:...Have a look at this ignition map. It comes from the Jeff Hartman book, Fuel Injection installation, performance tuning, modifications. I modeled this map for my car...

Werner, the statement at the bottom of the pic says the greatest advance at highest load, but unless I'm reading it wrong (lowest pressure and rpm 'idle' at top left and highest pressure about 100kpa at bottom center), it shows the greatest advance at light load where cruise would be. The map in general appears okay but the statement appears wrong - no?
David

Yes, I can see how you might see it that way.

What he is trying to point out is that at maximum load (front of graph at 1024millibar) the maximum advance is at the maximum torque range.

Either that or the comment is wrong.

OpenOffice.org

can open excell sheets and is free for download.

snillet wrote:And i tried the XLS spreadsheet "just for the fun of it" and thought the advance figures at low rpms, especially around idle became VERY weird...

The idle advance figure ended up at the 100kpa bin, now that can´t be right ?

if i put in 8 degrees idle advance i get 29degrees advance at 30kpa/800rpm , that´s a bit rough on a standard engine i think

Although it follows the general "guideline" of advancing the timing at lower loads i don´t think that way of doing it would work to well every time, you need to scale it up so the lower left corner on the "MT" screen becomes low for the idle to work nicely. On most cars anyhow.

Can anyone comment on this, I couldn't agree more with what's said above. I'd really like to use this generated map as it is very close to what a friend tuned his car to (at no small expense) on a rolling road (within 1 degree at nearly all points!). Except around idle.

The best approach I can see to this is to create a flat little island in the map where the engine idles, say a 4x4 grid with an advance of 10,10,10,10 and all around it, the timing will leap back up to the generated values...

Cheers
Dave

do you all think this map will work on my 3TC?

CHB wrote:do you all think this map will work on my 3TC?

That looks like a ton of spark advance under boost - does this motor make boost? I really hope not!

Excellent guidelines for setting up a starting point ignition map Lance!

After uppgrading to headers and dual 2,5" exhaust and goint to squirt'n spark extra, I really wanted to use the "standard" ignition timing for my car, but that was sort of lost as i locked up the distributor and threq the vacuum unit away..

I had some of the key figures for thew stock setting, but didn't quite know how to turn that in to an ignition map "emulating" the stock distributor advance.

Figure it wouild make sense to tune fuel first using a known working ignition timing, and start tweaking once the fuleing was sorted!