Twin Entry Turbo

[stevieturbo]

I havent read through it all, but this might cover it.
http://auto.howstuffworks.com/turbo.htm

Basically a twin entry just means 2 smaller entry paths to the turbine, in an effort to make it spool up quicker.

[wedg1e]

Ah, the venturi effect

[Apache]

kinda like a dyson

[Mr2Mike]

Multi-cylinder engines have ranges in which there is some overlap in the exhaust valve opening timing of one cylinder and its sequent cylinder. This can cause interference to the exhaust gas flow where te exhaust gases from the two cylinders join and results in exhaust energy loss in the turbocharged engine. Also, cylinders which have just finished the exhaust process are affected by the high back pressure of the exhaust initial process, so that high pressure gas remains behind more easily. This hinders smooth intake flow to the engine.

This exhaust gas interference is eliminated in the 3S-GTE engine by providing two exhaust ports, for cylinders No. 1 and No. 4, and for cylinders No. 2 and No. 3, together with two scrolls inside the turbine housing. This new design increases the engine's low-speed performance and acceleration response.

(Taken from Turbo magazine, May 1990)