projekteg

i get a lot of pm's and see people posting asking the difference between step retard and linear retard, i make this little write up on uberdata forum and figured i'd post it here also since not all of you go over there. hope this helps a few people out


linear retard is when you retard a certain set amount of timing per every psi. say you go under the 'boost' tab in uberdata and set 'ign. retard' at 1° (in real life this is a lot, but it's an easy number to use for an example), when you hit 'apply', the program is going to take away 1° for every pound of boost. this is how much timing you'll be pulling out at every psi.

1psi = -1°
2psi = -2°
3psi = -3°
4psi = -4°
5psi = -5°
etc., etc.

now this is very safe, but, you don't need as much retard in lower psi as you do in higher psi, so although you may need 1° per psi if you're boosting over 10-12 psi, you definitely don't need that much if any retard in lower psi. by retarding the lower psi that much, you're actually robbing power and slowing spool time.

with a step retard, you actually retard a certain amount per psi. i usually do mine like this

1-2 psi = no retard
3-4 psi = -.25° per psi
5-7 psi = -.50° per psi
8-10 psi = -.75° per psi
11-13 and up = -1.0° per psi

by doing this, you're getting a much smoother transition in to boost and making a lot more power in the lower psi's, since we all know timing makes power. so essentially with the above chart as a reference, your timing maps will look like this for a step retard.

1psi = 0 retard
2psi = 0 retard
3psi = -.75°
4psi = -1.0°
5psi = -2.5°
6psi = -3.0°
7psi = -3.5°
8psi = -6.0°
9psi = -6.75°
10 psi = -7.50°
etc., etc.

now, you're timing maps won't 'look' like this, but this will be the total timing pulled at each psi once you multiply the amount you're taking out, by the actual psi it's at (common sense). hope that helps explain a little better.

willahlborn

good explanation, best one i've seen in EM for a while, sticky that sheeeit.

Terrabomb

mind if I use this elsewhere eg?

projekteg

i don't care dude, just give me a dollar for every time you copy and paste it 'eg' is for 'teg', not 'eg', even though i drive an em, don't ask :P.
projekteg = projek-teg

MikeJ-2009

Kevin, you're my hero.

Integral

it always reads integra but who knew it was an eg

tranceminister

Very good write up Kevin. I understand the whole concept and how to figure the retard per degree, but how do you normally apply that in the ignition map? I beleive you started a post about you figuring it out before, but my slow *** hasn't quite fingered it out yet Is it a simple means of copy and paste or just add/subtract the values into the map manually? Thanks for the help.
Steve

projekteg

set ign. retard to 0 in the boost tab, which will leave stock timing all the way in boost. then go in and manually add/subtract the columns. there is a new step retard script, but you have to set it per the psi range it's set up for. you can dl it on uberdat under 'script' forum.

Chris Harris

Can you copy/paste into Uberdata's grid?

You could easily make up an excel ------ sheet to do this for you. All you would have to do is change the column headings to reflect those of your particular BIN file.

If you can copy/paste...let me know, I'll whip up a quick ------sheet.

projekteg

the script is actually incorporated in ud now, it works great, but i've just been doing it my own way for so long, that i continue to still do it that way. i think you're a lot more proficient with excel than i am chris :P however, even if you use the script, you still have to understand what a step retard is and how much to set per psi range.