The manifold you have is somewhat rare. It is from a Celica GT4 Group A Rallye/ WRC anti lag setup.
Here's a pic of the complete setup. It is not is use on the production car though. Just fitted for Homologation purposes.
http://gtfour.supras.org.nz/homologation.htm Anti-LagThe Group A was the first production car I know of with anti-lag standard, although again not operational. The system uses an ECU signal to switch two VSV's on the back of the block which provide vacuum (via a canister) to the special bypass valve fitted right beside the entrance to the IC. This heavy duty metal valve has a poppet valve which when opened directs some of the air (which usually all goes through the BOV) down four metal tubes into the exhaust manifold. A special manifold has a hole just after each exhaust port. A small heatshield sits between the manifold and the intercooler.
How do you make it work? You don't.
Anti-lag is *very* hard on turbos due to the shockwaves and high temperatures produced. Unless you have a rally team budget, forget it.
Here is some of what you need to do to activate it. My bypass valve seems to be jammed shut, maybe it has an internal spacer to stop it opening. The fittings connecting the pipes to the manifold are also not drilled though. With those aspects fixed the system will mechanically work. The VSV's are wired to the ECU, however an aftermarket ECU is needed to apply 12V to make them work. I'm guessing that (like most systems) the ECU retards the timing while continuing fuel injection. The mixture burns in the manifold, keeping the turbo spinning. This is very harsh on the system, therefore the pipes are just to supply cool air to keep temperatures down (conjecture!).