I know this questin has been asked before but there have been many different responses. Some say that timing is not affected at all and others say that the map sensor voltage influences the timing in the ecu. Is there any concrete proof for either side? I saw the posts with the graphs of hondata vs afc hack timing but where did the numbers come from? I dont wanna be retarding 4 deg at the dist. for no reason. Someone help me out here...does the smc/afc hack affect timing or not?

thanks

 

In order to understand how the MAP hacks affect timing you have to understand what they do. The answer is that the hack does not affect the ECU timing maps per se, rather it effectively changes the engine load (as determined by MAP sensor voltage) at which those timing values apply. So for example say that before installing a hack you were seeing 18 degrees advance at 3000 RPM and 20 inches vacuum and 22 degrees advance at 3000 RPM and 10 inches vacuum. Now after installing the hack even though the MAP sensor is reading 10 inches of vacuum at 3000 RPM it is showing 20 inches to the ECU. So the ECU will advance the spark by 18 degrees even though the manifold vacuum is only 10 inches.

Unfortunately the net effect of this is that you will be running your max advance at or near maximum boost.

 

that sucks

 

That sums it up.

Sonny