ignition timing.
09-06-02, 07:16 PM
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ignition timing.
'85 GSL-SE 13b RE-EGI
Hrm. So, There are two markings for timing, one for leading and one for trailing, now if I were to advance, how do I know how far I'm going? .... ?
with only 2 markings it's a little iffy
And, advancing timing leads to gains where, low-end, mid-range, or top-end?
Hrm. So, There are two markings for timing, one for leading and one for trailing, now if I were to advance, how do I know how far I'm going? .... ?
with only 2 markings it's a little iffyAnd, advancing timing leads to gains where, low-end, mid-range, or top-end?
09-06-02, 07:36 PM
#2
advance gains low and mid but mainly mid. you also have to watch advancing too much since your vacuum will advance it as you hit the throttle. that is of course unless you killed the vacuum advance. as for marking the pulley, there is a website on that. can't remember were though.
09-07-02, 12:09 AM
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Stock timing is for pussies. 
The pulley is really easy to mark as the circumference is 360mm... so 1mm = 1* obviously. On mine I have it marked in 5* increments from 10* BTDC to 30* BTDC.
When setting the timing for total advance you have to disconnect the vacuum advance and rev the engine up to 4000rpm. It's actually better to leave the vacuum advance disconnected for good as it allows you to run high total advance without the possibility of going too high while under both vacuum and mechanical advance. Most stock to street-ported engines like about 25* leading and 15* trailing give or take a bit.
The pulley is really easy to mark as the circumference is 360mm... so 1mm = 1* obviously. On mine I have it marked in 5* increments from 10* BTDC to 30* BTDC.
When setting the timing for total advance you have to disconnect the vacuum advance and rev the engine up to 4000rpm. It's actually better to leave the vacuum advance disconnected for good as it allows you to run high total advance without the possibility of going too high while under both vacuum and mechanical advance. Most stock to street-ported engines like about 25* leading and 15* trailing give or take a bit.
09-07-02, 04:12 AM
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The vacuum advance is there mainly for emissions reasons and has no effect on performance as there's no manifold vacuum at WOT... so most people get rid of it.
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01-06-03, 06:59 PM
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I know this is a late addition to the thread but Racingbeat recommends the following for stock GSL-SE 13b EFI
Leading : 2.5 BTC
Trailing: 12.5 BTC
Adjust in 2 degree increments, leading first, then trailing.
You won't get much power gains from adjusting the trailing.
F.
Leading : 2.5 BTC
Trailing: 12.5 BTC
Adjust in 2 degree increments, leading first, then trailing.
You won't get much power gains from adjusting the trailing.
F.
08-19-06, 06:05 PM
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Ok yeah, I'm a newbie here but for some reason when I try to set the timing at 4k rpm, The trailing seems to be ahead of the leading, regardless of where I move the vac advance. I made a mark 24 deg after (clockwise) the leading (yellow mark) which I think is correct, set the leading to that mark with the vac advance unhooked and carb plugged, then tightened the dist and hooked vac adv back up, switched timing light to trailing side and i'll be damned if I can't get it behind the 24 deg mark, even with the vac advance pushed all the way in. Any help or comments would be much appreciated, thanks.
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