I understand it removes the MAF from the equation and thats about it. How does it compare to a standard tune? Is it better? Is it worse? Better for certain apps?

Someone enlighten me

 

What my knowledge is on them, is that yes, no MAF tunned, but also elevation is factored in. Say you SD at 3000' sea level...if you go to 0' sea level, your tune will be off, and should require a new one for that elevation. I would check over at the Tunning section of the forum...they know their stuff. But when big power is the goal, SD is the way from what I have seen.

 

SD is big in boosted applications as well...

 

an sd tune is based on MAP and O2 sensor readings. It uses those two sensors as the major factors in controling the a/f ratio. This tune is very popular in FI because you can use a 3 bar MAP sensor for those running a lot of boost.