dtkikols

i dont understand whats going on with the timing. shouldn't it be around 10-15? i was just crusing when i was taking this. shed some light on this for me please?

cliffyk

At those speeds and loads it's just where it should be--what makes you think it should be 10° to 15°?

dtkikols

well you hear all the time that these cars are running lets say 12* of timing or 14* of timing. im more concerned on figuring out how to read it rather then what it really is right now. i want to learn how to read it before installing the vortech to make sure im not pulling "too much" timing.

cliffyk

That's the base setting at idle with the PCM advance disabled--same as pulling and plugging the vacuum advance on a distributor. It is largely an irrelevant number on our cars (you'll never see then engine running under steady load at that number), as it's not adjustable (except with a timing adjuster like Steeda's) anyway. In fact if you have a tuner there's no reason to change it at all.

The PCM controls timing much like a conventional mechanical distributor (mostly because that's how it need to be controlled)--but better and more accurately. On a plain ol' distributor the vacuum advance would do as the name implies and advance timing at high vacuums (I.e. low loads and steady speeds, by as much as 35° to 40°) and retard timing (actually not advance) at low vacuum (I.e. WOT).

The centrifugal timing in a conventional distributor would advance timing as engine speed increased, typically by 20° to 30°, however this would/could in practice be canceled out by the vacuum advance at high loads.

The PCM does the same thing. At low loads and steady throttle position you may see timing as high as 40° to 50° BTDC, at WOT n/a you should be 25° to 27° at high mid-range rpms, dropping to 20° or so at high revs and WOT.

There needs to be a Mustang Tuning 101 document, maybe I'll write one if I get time...

vanquish

+1 That would be nice.

tws1098

+1 that would be very nice

jvog

+ another 1...looks like you have to now cliff lol