I assume it's a bridge port that has half the porting on the "bridge" side of the intake port... which must allow a better low-end and durability (since the bridge is shorter and less likely to break?).

Or maybe it's just bridge porting on only one side of each rotor housing?

...someone tell me :p

 

Its bridge porting on only the secondaries (usually) and leaving the primaries street ported.

~Mike..............

 

Your right, a bridge only on the secondary side... the primary remains non-bridge.

 

and i make 3 ... wee!

 

Yes, I agree. The purpose of a half bridge is to have more low end torque for street or rally applications. For it to work, there must be seperate throttles for each housing. It will not produce the desired decent low end torque when run with 2 barrel carbs or single throttle body injection; it needs 4 throttles to stage the primary and secondary housings.

 

The stock dynamic chamber seperates the primaries from the secondaries. Right? Why would this be different? Just curious.

 

You are right.

 

The light bulb is now lit. I understand. Speedturn, when he says "single throttle body injection" means one throttle plate. Like a Mustang throttle body. Throttling the air for all runners with ine plate.

 

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the halfie won't have much effect on the low end of a turbo car, but it'll KILL the low end in an n/a car. i don't know where people get the idea that it'll add low end. that's just crack-talk.

 

Ive had the thought of half-bridge porting a N/A for a future project.
Lets take my car for example: '89 RX7 gtu, mild street port everything else is stock.
If I 1/2BP that engine, will my low end power/torque decrease? Why?
Or will it stay the same, or increase?
From this thread, one rx7-club member said that it will increase low-end, and one said that it will decrease low-end. Which one is it? Who has actual experience/facts about this?

 

low end shouldnt be effected because the secondaires really are not moving intake charge at low throtal situations.

 

Unfortunately there is more to the dynamics than meets the eye. It still behaves like a full bridge to some degree even when the secondary throttles are closed. I've driven more than one of these so I know what I'm talking about.
Paul.