What exactly do engine managment systems such as hondata do? Why does this help when boosting?

 

I'm positive this has been covered before... but

Boost on a car not designed for it will die very quickly without some sort of fuel increasing device.
And since the stock ECU does not have any special fuel/ignition maps to run while under boost, Hondata/Uberdata/Chrome create such maps to handle everything correctly.

http://www.hondata.com/aboutus.html

 

Basically, a Hondata, or any engine management system, gives you the ability to change the stock ECU settings to further benefit the modifications you have done to your motor already. Its basically like getting your ECU chipped, only the changes aren't static, you can modify them based on power gains or losses, fuel economy and etc.. if you have a built motor, its definatly a good investment.

Hondata however, is still a "piggyback" system. It uses your stock ECU so you get a good idle, and modifies it.