Trigger offset (understanding)

[panel]

Can someone clarify to me a little more on the 'Trigger Offset'?

Can this be used if your Wheel/sensor combo is slightly off? Lets say that you're off a little on your TDC mark and your wheel needs to adv/retard a little but there is no adjustment how could I use the above pic to get mine bang on?

[Matt Cramer]

That's exactly what it's for. You adjust the little number using the + and - buttons until the number you see with the timing light matches the big number.

[panel]

Thanks Matt. In the pic below I had my machinist 'ovalize' the holes for me so there could be some adjustment. I have to get another one made so I'll have it with no adjustment made.('nother story) Thanks so much.

[panel]

Just want to clarify (finally getting around to doing this )

I checked my idle at the pulley and it reads 21deg. And in MT or tuner studio I want/have the idle advance at 10deg.

Do I put -11deg in this box then

[Bernard Fife]

panel,

You put the value in the trigger wizard that makes the timing gauge in the tuning software agree with the timing light. If that's -11, then use that (but we can't tell from your post because you didn't tell us what the gauge says).

So try -11 in the small box, and look at the advance gauge (large box). The physical timing will change when you change the trigger offset in the small box, so you need to recheck the actual timing with a timing light. Then if the timing light agrees with the tuning software's value for timing (in the large box), and the -11 value is right. If the advance gauge and timing light give different values, you must change the trigger wizard value until the two agree (this won't take long to hone in on). This process calibrates the tuning software timing table to match the actual timing. There's more on this here: http://www.megamanual.com/mt28.htm#o

Then you put 10 degrees in the spark advance table at the rpm(s) and kPa(s) that you idle at to get 10 degree of advance at idle.

Lance.

[panel]

Thanks for the reply/questions etc.

I tested this this morning after a trip into work(engine up to temp etc.) In the gauge at idle (big window/big #'s) it reads 10. I think I've put in 21 into the little #'s and I think I might have it. The timing light before this was at 21 and I think this might have brought it into where it's supposed to be. 10 @ idle.

I'll have to check again on the way home when up to temp to confirm.