I've already done a search and it didnt provide anything useful. I'd just like some input from you guys, especially those of you with bridgeports. Just how streetable are they, life expectancy, and what kind of powercan a 13 b-port make? Thanks.

 

There is quite a few different types of bridge ports.

The normal bridge (not j-bridge) is ok,it will be streetable.Idling at about 1200,and making good power.
It wont be as driveable as a streetport,but make lots more hp.

The 13B`s are more driveable than the 12A`s..seeing that they have more low down torque,and that helps allot in pulling away from intersections at low revs.

http://www.mazdarotary.net/porting.htm < this will answer most of your questions

 

Some people like half bridgeports, where only the secondaries are bridged. Others say that it sucks and you should only fully bridgeport, or just a big extended streetport with lots of overlap.

I'll do a half bridgeport and see how it runs and drives.

 

One thing I don't understand is the different definitions of a J-bridgeport. Go look at Mazdatrix pic of a j-bridge, that's what I have and the templates that I bought. Now look at the port on the above sight for j-bridge. I thought a j-bridge is just when you start to cut into the rotor housing to allow a bigger bridge port. The one on the site mentioned would have to be devconed to seal up the water jacket. Seems like a big difference to have the same name. I believe that one is a monster port.
By the way, just got my j-bridge running, no tuning to the Holley yet and I don't feel it's all that bad as far as driveability. And don't have a problem with letting the exhaust get a little louder.

 

I've setup a few half-bridgeported Turbo II's and they worked out real well. They made alot more torque (a whole lot more) and generally higher horsepower for less boost (about 25%). I was pretty impressed with the results.

However, I haven't tried a full bridge for the street yet. I'm nearly tempted to try it on my next rebuild I do for my street car, but not sure yet. So, I'm not certain just how streetable it is. The half-BP is perfectly driveable on the street, nets you some of the advantages of the BP (more torque, better HP w/ less boost, use of a larger turbocharger, and that nice idle sound) without all the disadvantages (loss of all low-end torque, peaky torque range, etc.).

B

 

and he built a motor for a daily driver that kicked down an 11:74! (the bosssssturd!!!)