I realize tmax don't use the map sensor . Is the timing advanced with rpm or does it advance with the tps sensor. If it's the later, in theory you could slam in close to 30 degrees advance at really low rpms. That would really suck in the detonation department if this is the case. Advance with rpm, as in a tach read would seem to make more sense. Who knows which way timing is accompished ?
Ron

 

In general timing advances as RPM increases. The reason is the piston is moving faster at higher RPMs, but the fuel burns at the same speed regardless of RPM. So you have less time to get the fuel burnt up at higher RPM which means you have to spark it earlier.

For the tmax, you'll generally see the timing decrease with increasing TPS since the tmax is doing load based on TPS (higher load = higher TPS).

 

I understand the reason for more advance with rpm, but I may need to clarify my question somewhat. Does the tmax read the engine rpm and apply timing map values to that rpm or does it use the tps position to apply timing map values? Sounds like it uses read rpm to advance and if in fact like you say it drops timing if the tps position is higher than the rpm should be for that position, that would be a good thing. Similar to the old vacume advance system of the olden days. High load it retarded the timing until vacume increased and then advanced it again. Just trying to understand how the tmax timing is controlled.
Ron

 

&nbsp\\;
It uses both. The timing tables in your map are set up for RPM and TPS. Unfortunately, since the tmax does not use MAP for timing, the timing has to be set up for the highest load situation at all RPMs.&nbsp\\;For example,&nbsp\\;at a specific RPM and TPS, the tmax has no way of&nbsp\\;differentiating if I'm going uphill (high load)&nbsp\\;or downhill (low load). Since it can't differentiate, it must set the timing for the high load situation or risk detonation.&nbsp\\;This is why if you compare a sert map's timing to a tmax map's timing, the sert map will have more advance in it.

 

ToBeFrank: That's a perfect explanation on how it works. Thanks.
Ron