Originally Posted by Lorry

I heard the antilag they use in this thing is the same as what is in the WR cars. Aparently its safer to use as it has a throttle bypass valve that feeds air directly into the exhaust manifold, which then ignites with the fuel rich exhaust. The combustion in confined to the exhaust manifold and lowers the temperatures and pressures involved.

http://en.wikipedia.org/wiki/Anti-Lag_System

The last paragraph there explains it.