Auto vs. manual timing advance

[cordes]

How much of a difference is there between and auto and a 5 speed when it comes to timing advance? I am I wrong in thinking that the load on the motor may be greater with an auto at a given RPM, but that is worked out because the vac is less and the timing adjusted accordingly? Am I just over thinking this? I've never had to tune an auto car before.

[BadAssPerformance]

Not sure how the cal's timing differs, but thinking a locked up torque converter and a manual in gear should be about the same load, unless you're thinking longer gears?

[cordes]

Not sure how the cal's timing differs, but thinking a locked up torque converter and a manual in gear should be about the same load, unless you're thinking longer gears?

No lockup on this bad lad. I checked the 87' SL cal vs the CSX cal and there is actually quite a bit more timing in vac for part throttle with the SL cal. I'll try it out and see what the difference is between this and whatever came in the car. It will be an interesting exercise since I've never done it before and haven't taken the time to read up on it.

[ShelGame]

How much of a difference is there between and auto and a 5 speed when it comes to timing advance? I am I wrong in thinking that the load on the motor may be greater with an auto at a given RPM, but that is worked out because the vac is less and the timing adjusted accordingly? Am I just over thinking this? I've never had to tune an auto car before.

Overlay them in MP Tune and see for yourself...

From memory, the auto has a little bit more timing at idle vacuum due to the increased load of the converter.

[shadow88]

I don't remember there being a different computer for either transmission. I'm still using the same computer when I swapped to an auto a couple years ago.

[cordes]

Overlay them in MP Tune and see for yourself...

From memory, the auto has a little bit more timing at idle vacuum due to the increased load of the converter.

You're dead on. That's exactly what I saw when I compared the two.


I don't remember there being a different computer for either transmission. I'm still using the same computer when I swapped to an auto a couple years ago.

There is a difference, but the computers can be switched between transmission types in our cars with few side effects.

[turbovanman²]

Overlay them in MP Tune and see for yourself...

From memory, the auto has a little bit more timing at idle vacuum due to the increased load of the converter.

Yep, IIRC, its more of a flat line for the 5 speed, and it goes high then dips low, then levels out for the auto, kinda looks like the big dipper, :p